5027 lines
186 KiB
HTML
5027 lines
186 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<title>
|
|
FFmpeg Codecs Documentation
|
|
</title>
|
|
<meta name="viewport" content="width=device-width,initial-scale=1.0">
|
|
<link rel="stylesheet" type="text/css" href="bootstrap.min.css">
|
|
<link rel="stylesheet" type="text/css" href="style.min.css">
|
|
</head>
|
|
<body>
|
|
<div class="container">
|
|
<h1>
|
|
FFmpeg Codecs Documentation
|
|
</h1>
|
|
<div align="center">
|
|
</div>
|
|
|
|
|
|
<a name="SEC_Top"></a>
|
|
|
|
<a name="SEC_Contents"></a>
|
|
<h2 class="contents-heading">Table of Contents</h2>
|
|
|
|
<div class="contents">
|
|
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Description" href="#Description">1 Description</a></li>
|
|
<li><a name="toc-Codec-Options" href="#Codec-Options">2 Codec Options</a></li>
|
|
<li><a name="toc-Decoders" href="#Decoders">3 Decoders</a></li>
|
|
<li><a name="toc-Video-Decoders" href="#Video-Decoders">4 Video Decoders</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-hevc" href="#hevc">4.1 hevc</a></li>
|
|
<li><a name="toc-rawvideo" href="#rawvideo">4.2 rawvideo</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options" href="#Options">4.2.1 Options</a></li>
|
|
</ul></li>
|
|
</ul></li>
|
|
<li><a name="toc-Audio-Decoders" href="#Audio-Decoders">5 Audio Decoders</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-ac3" href="#ac3">5.1 ac3</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-AC_002d3-Decoder-Options" href="#AC_002d3-Decoder-Options">5.1.1 AC-3 Decoder Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-flac-1" href="#flac-1">5.2 flac</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-FLAC-Decoder-options" href="#FLAC-Decoder-options">5.2.1 FLAC Decoder options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-ffwavesynth" href="#ffwavesynth">5.3 ffwavesynth</a></li>
|
|
<li><a name="toc-libcelt" href="#libcelt">5.4 libcelt</a></li>
|
|
<li><a name="toc-libgsm" href="#libgsm">5.5 libgsm</a></li>
|
|
<li><a name="toc-libilbc" href="#libilbc">5.6 libilbc</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-1" href="#Options-1">5.6.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libopencore_002damrnb" href="#libopencore_002damrnb">5.7 libopencore-amrnb</a></li>
|
|
<li><a name="toc-libopencore_002damrwb" href="#libopencore_002damrwb">5.8 libopencore-amrwb</a></li>
|
|
<li><a name="toc-libopus" href="#libopus">5.9 libopus</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Subtitles-Decoders" href="#Subtitles-Decoders">6 Subtitles Decoders</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-dvbsub" href="#dvbsub">6.1 dvbsub</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-2" href="#Options-2">6.1.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-dvdsub" href="#dvdsub">6.2 dvdsub</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-3" href="#Options-3">6.2.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libzvbi_002dteletext" href="#libzvbi_002dteletext">6.3 libzvbi-teletext</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-4" href="#Options-4">6.3.1 Options</a></li>
|
|
</ul></li>
|
|
</ul></li>
|
|
<li><a name="toc-Encoders" href="#Encoders">7 Encoders</a></li>
|
|
<li><a name="toc-Audio-Encoders" href="#Audio-Encoders">8 Audio Encoders</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-aac" href="#aac">8.1 aac</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-5" href="#Options-5">8.1.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-ac3-and-ac3_005ffixed" href="#ac3-and-ac3_005ffixed">8.2 ac3 and ac3_fixed</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-AC_002d3-Metadata" href="#AC_002d3-Metadata">8.2.1 AC-3 Metadata</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Metadata-Control-Options" href="#Metadata-Control-Options">8.2.1.1 Metadata Control Options</a></li>
|
|
<li><a name="toc-Downmix-Levels" href="#Downmix-Levels">8.2.1.2 Downmix Levels</a></li>
|
|
<li><a name="toc-Audio-Production-Information" href="#Audio-Production-Information">8.2.1.3 Audio Production Information</a></li>
|
|
<li><a name="toc-Other-Metadata-Options" href="#Other-Metadata-Options">8.2.1.4 Other Metadata Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Extended-Bitstream-Information" href="#Extended-Bitstream-Information">8.2.2 Extended Bitstream Information</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Extended-Bitstream-Information-_002d-Part-1" href="#Extended-Bitstream-Information-_002d-Part-1">8.2.2.1 Extended Bitstream Information - Part 1</a></li>
|
|
<li><a name="toc-Extended-Bitstream-Information-_002d-Part-2" href="#Extended-Bitstream-Information-_002d-Part-2">8.2.2.2 Extended Bitstream Information - Part 2</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-Other-AC_002d3-Encoding-Options" href="#Other-AC_002d3-Encoding-Options">8.2.3 Other AC-3 Encoding Options</a></li>
|
|
<li><a name="toc-Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options" href="#Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options">8.2.4 Floating-Point-Only AC-3 Encoding Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-flac-2" href="#flac-2">8.3 flac</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-6" href="#Options-6">8.3.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libfdk_005faac" href="#libfdk_005faac">8.4 libfdk_aac</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-7" href="#Options-7">8.4.1 Options</a></li>
|
|
<li><a name="toc-Examples" href="#Examples">8.4.2 Examples</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libmp3lame-1" href="#libmp3lame-1">8.5 libmp3lame</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-8" href="#Options-8">8.5.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libopencore_002damrnb-1" href="#libopencore_002damrnb-1">8.6 libopencore-amrnb</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-9" href="#Options-9">8.6.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libshine-1" href="#libshine-1">8.7 libshine</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-10" href="#Options-10">8.7.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libtwolame" href="#libtwolame">8.8 libtwolame</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-11" href="#Options-11">8.8.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libvo_002damrwbenc" href="#libvo_002damrwbenc">8.9 libvo-amrwbenc</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-12" href="#Options-12">8.9.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libopus-1" href="#libopus-1">8.10 libopus</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Option-Mapping" href="#Option-Mapping">8.10.1 Option Mapping</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libvorbis" href="#libvorbis">8.11 libvorbis</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-13" href="#Options-13">8.11.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libwavpack-1" href="#libwavpack-1">8.12 libwavpack</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-14" href="#Options-14">8.12.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-wavpack" href="#wavpack">8.13 wavpack</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-15" href="#Options-15">8.13.1 Options</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Shared-options" href="#Shared-options">8.13.1.1 Shared options</a></li>
|
|
<li><a name="toc-Private-options" href="#Private-options">8.13.1.2 Private options</a></li>
|
|
</ul></li>
|
|
</ul></li>
|
|
</ul></li>
|
|
<li><a name="toc-Video-Encoders" href="#Video-Encoders">9 Video Encoders</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-libopenh264" href="#libopenh264">9.1 libopenh264</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-16" href="#Options-16">9.1.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-jpeg2000" href="#jpeg2000">9.2 jpeg2000</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-17" href="#Options-17">9.2.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-snow" href="#snow">9.3 snow</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-18" href="#Options-18">9.3.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libtheora" href="#libtheora">9.4 libtheora</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-19" href="#Options-19">9.4.1 Options</a></li>
|
|
<li><a name="toc-Examples-1" href="#Examples-1">9.4.2 Examples</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libvpx" href="#libvpx">9.5 libvpx</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-20" href="#Options-20">9.5.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libwebp" href="#libwebp">9.6 libwebp</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Pixel-Format" href="#Pixel-Format">9.6.1 Pixel Format</a></li>
|
|
<li><a name="toc-Options-21" href="#Options-21">9.6.2 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libx264_002c-libx264rgb" href="#libx264_002c-libx264rgb">9.7 libx264, libx264rgb</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Supported-Pixel-Formats" href="#Supported-Pixel-Formats">9.7.1 Supported Pixel Formats</a></li>
|
|
<li><a name="toc-Options-22" href="#Options-22">9.7.2 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libx265" href="#libx265">9.8 libx265</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-23" href="#Options-23">9.8.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libxvid" href="#libxvid">9.9 libxvid</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-24" href="#Options-24">9.9.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-mpeg2" href="#mpeg2">9.10 mpeg2</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-25" href="#Options-25">9.10.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-png" href="#png">9.11 png</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Private-options-1" href="#Private-options-1">9.11.1 Private options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-ProRes" href="#ProRes">9.12 ProRes</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Private-Options-for-prores_002dks" href="#Private-Options-for-prores_002dks">9.12.1 Private Options for prores-ks</a></li>
|
|
<li><a name="toc-Speed-considerations" href="#Speed-considerations">9.12.2 Speed considerations</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-libkvazaar" href="#libkvazaar">9.13 libkvazaar</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-26" href="#Options-26">9.13.1 Options</a></li>
|
|
</ul></li>
|
|
<li><a name="toc-QSV-encoders" href="#QSV-encoders">9.14 QSV encoders</a></li>
|
|
<li><a name="toc-vc2" href="#vc2">9.15 vc2</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-27" href="#Options-27">9.15.1 Options</a></li>
|
|
</ul></li>
|
|
</ul></li>
|
|
<li><a name="toc-Subtitles-Encoders" href="#Subtitles-Encoders">10 Subtitles Encoders</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-dvdsub-1" href="#dvdsub-1">10.1 dvdsub</a>
|
|
<ul class="no-bullet">
|
|
<li><a name="toc-Options-28" href="#Options-28">10.1.1 Options</a></li>
|
|
</ul></li>
|
|
</ul></li>
|
|
<li><a name="toc-See-Also" href="#See-Also">11 See Also</a></li>
|
|
<li><a name="toc-Authors" href="#Authors">12 Authors</a></li>
|
|
</ul>
|
|
</div>
|
|
|
|
|
|
<a name="Description"></a>
|
|
<h2 class="chapter">1 Description<span class="pull-right"><a class="anchor hidden-xs" href="#Description" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Description" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>This document describes the codecs (decoders and encoders) provided by
|
|
the libavcodec library.
|
|
</p>
|
|
|
|
<a name="codec_002doptions"></a><a name="Codec-Options"></a>
|
|
<h2 class="chapter">2 Codec Options<span class="pull-right"><a class="anchor hidden-xs" href="#Codec-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Codec-Options" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>libavcodec provides some generic global options, which can be set on
|
|
all the encoders and decoders. In addition each codec may support
|
|
so-called private options, which are specific for a given codec.
|
|
</p>
|
|
<p>Sometimes, a global option may only affect a specific kind of codec,
|
|
and may be nonsensical or ignored by another, so you need to be aware
|
|
of the meaning of the specified options. Also some options are
|
|
meant only for decoding or encoding.
|
|
</p>
|
|
<p>Options may be set by specifying -<var>option</var> <var>value</var> in the
|
|
FFmpeg tools, or by setting the value explicitly in the
|
|
<code>AVCodecContext</code> options or using the <samp>libavutil/opt.h</samp> API
|
|
for programmatic use.
|
|
</p>
|
|
<p>The list of supported options follow:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Set bitrate in bits/s. Default value is 200K.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ab <var>integer</var> (<em>encoding,audio</em>)</samp></dt>
|
|
<dd><p>Set audio bitrate (in bits/s). Default value is 128K.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bt <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
|
|
tolerance specifies how far ratecontrol is willing to deviate from the
|
|
target average bitrate value. This is not related to min/max
|
|
bitrate. Lowering tolerance too much has an adverse effect on quality.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>flags <var>flags</var> (<em>decoding/encoding,audio,video,subtitles</em>)</samp></dt>
|
|
<dd><p>Set generic flags.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>mv4</samp>’</dt>
|
|
<dd><p>Use four motion vector by macroblock (mpeg4).
|
|
</p></dd>
|
|
<dt>‘<samp>qpel</samp>’</dt>
|
|
<dd><p>Use 1/4 pel motion compensation.
|
|
</p></dd>
|
|
<dt>‘<samp>loop</samp>’</dt>
|
|
<dd><p>Use loop filter.
|
|
</p></dd>
|
|
<dt>‘<samp>qscale</samp>’</dt>
|
|
<dd><p>Use fixed qscale.
|
|
</p></dd>
|
|
<dt>‘<samp>gmc</samp>’</dt>
|
|
<dd><p>Use gmc.
|
|
</p></dd>
|
|
<dt>‘<samp>mv0</samp>’</dt>
|
|
<dd><p>Always try a mb with mv=<0,0>.
|
|
</p></dd>
|
|
<dt>‘<samp>input_preserved</samp>’</dt>
|
|
<dt>‘<samp>pass1</samp>’</dt>
|
|
<dd><p>Use internal 2pass ratecontrol in first pass mode.
|
|
</p></dd>
|
|
<dt>‘<samp>pass2</samp>’</dt>
|
|
<dd><p>Use internal 2pass ratecontrol in second pass mode.
|
|
</p></dd>
|
|
<dt>‘<samp>gray</samp>’</dt>
|
|
<dd><p>Only decode/encode grayscale.
|
|
</p></dd>
|
|
<dt>‘<samp>emu_edge</samp>’</dt>
|
|
<dd><p>Do not draw edges.
|
|
</p></dd>
|
|
<dt>‘<samp>psnr</samp>’</dt>
|
|
<dd><p>Set error[?] variables during encoding.
|
|
</p></dd>
|
|
<dt>‘<samp>truncated</samp>’</dt>
|
|
<dt>‘<samp>naq</samp>’</dt>
|
|
<dd><p>Normalize adaptive quantization.
|
|
</p></dd>
|
|
<dt>‘<samp>ildct</samp>’</dt>
|
|
<dd><p>Use interlaced DCT.
|
|
</p></dd>
|
|
<dt>‘<samp>low_delay</samp>’</dt>
|
|
<dd><p>Force low delay.
|
|
</p></dd>
|
|
<dt>‘<samp>global_header</samp>’</dt>
|
|
<dd><p>Place global headers in extradata instead of every keyframe.
|
|
</p></dd>
|
|
<dt>‘<samp>bitexact</samp>’</dt>
|
|
<dd><p>Only write platform-, build- and time-independent data. (except (I)DCT).
|
|
This ensures that file and data checksums are reproducible and match between
|
|
platforms. Its primary use is for regression testing.
|
|
</p></dd>
|
|
<dt>‘<samp>aic</samp>’</dt>
|
|
<dd><p>Apply H263 advanced intra coding / mpeg4 ac prediction.
|
|
</p></dd>
|
|
<dt>‘<samp>cbp</samp>’</dt>
|
|
<dd><p>Deprecated, use mpegvideo private options instead.
|
|
</p></dd>
|
|
<dt>‘<samp>qprd</samp>’</dt>
|
|
<dd><p>Deprecated, use mpegvideo private options instead.
|
|
</p></dd>
|
|
<dt>‘<samp>ilme</samp>’</dt>
|
|
<dd><p>Apply interlaced motion estimation.
|
|
</p></dd>
|
|
<dt>‘<samp>cgop</samp>’</dt>
|
|
<dd><p>Use closed gop.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>me_method <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set motion estimation method.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>zero motion estimation (fastest)
|
|
</p></dd>
|
|
<dt>‘<samp>full</samp>’</dt>
|
|
<dd><p>full motion estimation (slowest)
|
|
</p></dd>
|
|
<dt>‘<samp>epzs</samp>’</dt>
|
|
<dd><p>EPZS motion estimation (default)
|
|
</p></dd>
|
|
<dt>‘<samp>esa</samp>’</dt>
|
|
<dd><p>esa motion estimation (alias for full)
|
|
</p></dd>
|
|
<dt>‘<samp>tesa</samp>’</dt>
|
|
<dd><p>tesa motion estimation
|
|
</p></dd>
|
|
<dt>‘<samp>dia</samp>’</dt>
|
|
<dd><p>dia motion estimation (alias for epzs)
|
|
</p></dd>
|
|
<dt>‘<samp>log</samp>’</dt>
|
|
<dd><p>log motion estimation
|
|
</p></dd>
|
|
<dt>‘<samp>phods</samp>’</dt>
|
|
<dd><p>phods motion estimation
|
|
</p></dd>
|
|
<dt>‘<samp>x1</samp>’</dt>
|
|
<dd><p>X1 motion estimation
|
|
</p></dd>
|
|
<dt>‘<samp>hex</samp>’</dt>
|
|
<dd><p>hex motion estimation
|
|
</p></dd>
|
|
<dt>‘<samp>umh</samp>’</dt>
|
|
<dd><p>umh motion estimation
|
|
</p></dd>
|
|
<dt>‘<samp>iter</samp>’</dt>
|
|
<dd><p>iter motion estimation
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>extradata_size <var>integer</var></samp></dt>
|
|
<dd><p>Set extradata size.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>time_base <var>rational number</var></samp></dt>
|
|
<dd><p>Set codec time base.
|
|
</p>
|
|
<p>It is the fundamental unit of time (in seconds) in terms of which
|
|
frame timestamps are represented. For fixed-fps content, timebase
|
|
should be <code>1 / frame_rate</code> and timestamp increments should be
|
|
identically 1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>g <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set the group of picture (GOP) size. Default value is 12.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ar <var>integer</var> (<em>decoding/encoding,audio</em>)</samp></dt>
|
|
<dd><p>Set audio sampling rate (in Hz).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ac <var>integer</var> (<em>decoding/encoding,audio</em>)</samp></dt>
|
|
<dd><p>Set number of audio channels.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>cutoff <var>integer</var> (<em>encoding,audio</em>)</samp></dt>
|
|
<dd><p>Set cutoff bandwidth.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>frame_size <var>integer</var> (<em>encoding,audio</em>)</samp></dt>
|
|
<dd><p>Set audio frame size.
|
|
</p>
|
|
<p>Each submitted frame except the last must contain exactly frame_size
|
|
samples per channel. May be 0 when the codec has
|
|
CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
|
|
restricted. It is set by some decoders to indicate constant frame
|
|
size.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>frame_number <var>integer</var></samp></dt>
|
|
<dd><p>Set the frame number.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>delay <var>integer</var></samp></dt>
|
|
<dt><samp>qcomp <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set video quantizer scale compression (VBR). It is used as a constant
|
|
in the ratecontrol equation. Recommended range for default rc_eq:
|
|
0.0-1.0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qblur <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set video quantizer scale blur (VBR).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qmin <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set min video quantizer scale (VBR). Must be included between -1 and
|
|
69, default value is 2.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qmax <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set max video quantizer scale (VBR). Must be included between -1 and
|
|
1024, default value is 31.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qdiff <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set max difference between the quantizer scale (VBR).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bf <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set max number of B frames between non-B-frames.
|
|
</p>
|
|
<p>Must be an integer between -1 and 16. 0 means that B-frames are
|
|
disabled. If a value of -1 is used, it will choose an automatic value
|
|
depending on the encoder.
|
|
</p>
|
|
<p>Default value is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>b_qfactor <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set qp factor between P and B frames.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_strategy <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set ratecontrol method.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>b_strategy <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set strategy to choose between I/P/B-frames.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ps <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set RTP payload size in bytes.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mv_bits <var>integer</var></samp></dt>
|
|
<dt><samp>header_bits <var>integer</var></samp></dt>
|
|
<dt><samp>i_tex_bits <var>integer</var></samp></dt>
|
|
<dt><samp>p_tex_bits <var>integer</var></samp></dt>
|
|
<dt><samp>i_count <var>integer</var></samp></dt>
|
|
<dt><samp>p_count <var>integer</var></samp></dt>
|
|
<dt><samp>skip_count <var>integer</var></samp></dt>
|
|
<dt><samp>misc_bits <var>integer</var></samp></dt>
|
|
<dt><samp>frame_bits <var>integer</var></samp></dt>
|
|
<dt><samp>codec_tag <var>integer</var></samp></dt>
|
|
<dt><samp>bug <var>flags</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dd><p>Workaround not auto detected encoder bugs.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>autodetect</samp>’</dt>
|
|
<dt>‘<samp>old_msmpeg4</samp>’</dt>
|
|
<dd><p>some old lavc generated msmpeg4v3 files (no autodetection)
|
|
</p></dd>
|
|
<dt>‘<samp>xvid_ilace</samp>’</dt>
|
|
<dd><p>Xvid interlacing bug (autodetected if fourcc==XVIX)
|
|
</p></dd>
|
|
<dt>‘<samp>ump4</samp>’</dt>
|
|
<dd><p>(autodetected if fourcc==UMP4)
|
|
</p></dd>
|
|
<dt>‘<samp>no_padding</samp>’</dt>
|
|
<dd><p>padding bug (autodetected)
|
|
</p></dd>
|
|
<dt>‘<samp>amv</samp>’</dt>
|
|
<dt>‘<samp>ac_vlc</samp>’</dt>
|
|
<dd><p>illegal vlc bug (autodetected per fourcc)
|
|
</p></dd>
|
|
<dt>‘<samp>qpel_chroma</samp>’</dt>
|
|
<dt>‘<samp>std_qpel</samp>’</dt>
|
|
<dd><p>old standard qpel (autodetected per fourcc/version)
|
|
</p></dd>
|
|
<dt>‘<samp>qpel_chroma2</samp>’</dt>
|
|
<dt>‘<samp>direct_blocksize</samp>’</dt>
|
|
<dd><p>direct-qpel-blocksize bug (autodetected per fourcc/version)
|
|
</p></dd>
|
|
<dt>‘<samp>edge</samp>’</dt>
|
|
<dd><p>edge padding bug (autodetected per fourcc/version)
|
|
</p></dd>
|
|
<dt>‘<samp>hpel_chroma</samp>’</dt>
|
|
<dt>‘<samp>dc_clip</samp>’</dt>
|
|
<dt>‘<samp>ms</samp>’</dt>
|
|
<dd><p>Workaround various bugs in microsoft broken decoders.
|
|
</p></dd>
|
|
<dt>‘<samp>trunc</samp>’</dt>
|
|
<dd><p>trancated frames
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>lelim <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set single coefficient elimination threshold for luminance (negative
|
|
values also consider DC coefficient).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>celim <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set single coefficient elimination threshold for chrominance (negative
|
|
values also consider dc coefficient)
|
|
</p>
|
|
</dd>
|
|
<dt><samp>strict <var>integer</var> (<em>decoding/encoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Specify how strictly to follow the standards.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>very</samp>’</dt>
|
|
<dd><p>strictly conform to an older more strict version of the spec or reference software
|
|
</p></dd>
|
|
<dt>‘<samp>strict</samp>’</dt>
|
|
<dd><p>strictly conform to all the things in the spec no matter what consequences
|
|
</p></dd>
|
|
<dt>‘<samp>normal</samp>’</dt>
|
|
<dt>‘<samp>unofficial</samp>’</dt>
|
|
<dd><p>allow unofficial extensions
|
|
</p></dd>
|
|
<dt>‘<samp>experimental</samp>’</dt>
|
|
<dd><p>allow non standardized experimental things, experimental
|
|
(unfinished/work in progress/not well tested) decoders and encoders.
|
|
Note: experimental decoders can pose a security risk, do not use this for
|
|
decoding untrusted input.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>b_qoffset <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set QP offset between P and B frames.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>err_detect <var>flags</var> (<em>decoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Set error detection flags.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>crccheck</samp>’</dt>
|
|
<dd><p>verify embedded CRCs
|
|
</p></dd>
|
|
<dt>‘<samp>bitstream</samp>’</dt>
|
|
<dd><p>detect bitstream specification deviations
|
|
</p></dd>
|
|
<dt>‘<samp>buffer</samp>’</dt>
|
|
<dd><p>detect improper bitstream length
|
|
</p></dd>
|
|
<dt>‘<samp>explode</samp>’</dt>
|
|
<dd><p>abort decoding on minor error detection
|
|
</p></dd>
|
|
<dt>‘<samp>ignore_err</samp>’</dt>
|
|
<dd><p>ignore decoding errors, and continue decoding.
|
|
This is useful if you want to analyze the content of a video and thus want
|
|
everything to be decoded no matter what. This option will not result in a video
|
|
that is pleasing to watch in case of errors.
|
|
</p></dd>
|
|
<dt>‘<samp>careful</samp>’</dt>
|
|
<dd><p>consider things that violate the spec and have not been seen in the wild as errors
|
|
</p></dd>
|
|
<dt>‘<samp>compliant</samp>’</dt>
|
|
<dd><p>consider all spec non compliancies as errors
|
|
</p></dd>
|
|
<dt>‘<samp>aggressive</samp>’</dt>
|
|
<dd><p>consider things that a sane encoder should not do as an error
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>has_b_frames <var>integer</var></samp></dt>
|
|
<dt><samp>block_align <var>integer</var></samp></dt>
|
|
<dt><samp>mpeg_quant <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Use MPEG quantizers instead of H.263.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qsquish <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>How to keep quantizer between qmin and qmax (0 = clip, 1 = use
|
|
differentiable function).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_qmod_amp <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set experimental quantizer modulation.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_qmod_freq <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set experimental quantizer modulation.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_override_count <var>integer</var></samp></dt>
|
|
<dt><samp>rc_eq <var>string</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set rate control equation. When computing the expression, besides the
|
|
standard functions defined in the section ’Expression Evaluation’, the
|
|
following functions are available: bits2qp(bits), qp2bits(qp). Also
|
|
the following constants are available: iTex pTex tex mv fCode iCount
|
|
mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
|
|
avgTex.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>maxrate <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>minrate <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
|
|
encode. It is of little use elsewise.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bufsize <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Set ratecontrol buffer size (in bits).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_buf_aggressivity <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Currently useless.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>i_qfactor <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set QP factor between P and I frames.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>i_qoffset <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set QP offset between P and I frames.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_init_cplx <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set initial complexity for 1-pass encoding.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>dct <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set DCT algorithm.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>auto</samp>’</dt>
|
|
<dd><p>autoselect a good one (default)
|
|
</p></dd>
|
|
<dt>‘<samp>fastint</samp>’</dt>
|
|
<dd><p>fast integer
|
|
</p></dd>
|
|
<dt>‘<samp>int</samp>’</dt>
|
|
<dd><p>accurate integer
|
|
</p></dd>
|
|
<dt>‘<samp>mmx</samp>’</dt>
|
|
<dt>‘<samp>altivec</samp>’</dt>
|
|
<dt>‘<samp>faan</samp>’</dt>
|
|
<dd><p>floating point AAN DCT
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>lumi_mask <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Compress bright areas stronger than medium ones.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>tcplx_mask <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set temporal complexity masking.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>scplx_mask <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set spatial complexity masking.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>p_mask <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set inter masking.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>dark_mask <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Compress dark areas stronger than medium ones.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>idct <var>integer</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dd><p>Select IDCT implementation.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>auto</samp>’</dt>
|
|
<dt>‘<samp>int</samp>’</dt>
|
|
<dt>‘<samp>simple</samp>’</dt>
|
|
<dt>‘<samp>simplemmx</samp>’</dt>
|
|
<dt>‘<samp>simpleauto</samp>’</dt>
|
|
<dd><p>Automatically pick a IDCT compatible with the simple one
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>arm</samp>’</dt>
|
|
<dt>‘<samp>altivec</samp>’</dt>
|
|
<dt>‘<samp>sh4</samp>’</dt>
|
|
<dt>‘<samp>simplearm</samp>’</dt>
|
|
<dt>‘<samp>simplearmv5te</samp>’</dt>
|
|
<dt>‘<samp>simplearmv6</samp>’</dt>
|
|
<dt>‘<samp>simpleneon</samp>’</dt>
|
|
<dt>‘<samp>simplealpha</samp>’</dt>
|
|
<dt>‘<samp>ipp</samp>’</dt>
|
|
<dt>‘<samp>xvidmmx</samp>’</dt>
|
|
<dt>‘<samp>faani</samp>’</dt>
|
|
<dd><p>floating point AAN IDCT
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>slice_count <var>integer</var></samp></dt>
|
|
<dt><samp>ec <var>flags</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dd><p>Set error concealment strategy.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>guess_mvs</samp>’</dt>
|
|
<dd><p>iterative motion vector (MV) search (slow)
|
|
</p></dd>
|
|
<dt>‘<samp>deblock</samp>’</dt>
|
|
<dd><p>use strong deblock filter for damaged MBs
|
|
</p></dd>
|
|
<dt>‘<samp>favor_inter</samp>’</dt>
|
|
<dd><p>favor predicting from the previous frame instead of the current
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>bits_per_coded_sample <var>integer</var></samp></dt>
|
|
<dt><samp>pred <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set prediction method.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>left</samp>’</dt>
|
|
<dt>‘<samp>plane</samp>’</dt>
|
|
<dt>‘<samp>median</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>aspect <var>rational number</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set sample aspect ratio.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>sar <var>rational number</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set sample aspect ratio. Alias to <var>aspect</var>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>debug <var>flags</var> (<em>decoding/encoding,audio,video,subtitles</em>)</samp></dt>
|
|
<dd><p>Print specific debug info.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>pict</samp>’</dt>
|
|
<dd><p>picture info
|
|
</p></dd>
|
|
<dt>‘<samp>rc</samp>’</dt>
|
|
<dd><p>rate control
|
|
</p></dd>
|
|
<dt>‘<samp>bitstream</samp>’</dt>
|
|
<dt>‘<samp>mb_type</samp>’</dt>
|
|
<dd><p>macroblock (MB) type
|
|
</p></dd>
|
|
<dt>‘<samp>qp</samp>’</dt>
|
|
<dd><p>per-block quantization parameter (QP)
|
|
</p></dd>
|
|
<dt>‘<samp>mv</samp>’</dt>
|
|
<dd><p>motion vector
|
|
</p></dd>
|
|
<dt>‘<samp>dct_coeff</samp>’</dt>
|
|
<dt>‘<samp>green_metadata</samp>’</dt>
|
|
<dd><p>display complexity metadata for the upcoming frame, GoP or for a given duration.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>skip</samp>’</dt>
|
|
<dt>‘<samp>startcode</samp>’</dt>
|
|
<dt>‘<samp>pts</samp>’</dt>
|
|
<dt>‘<samp>er</samp>’</dt>
|
|
<dd><p>error recognition
|
|
</p></dd>
|
|
<dt>‘<samp>mmco</samp>’</dt>
|
|
<dd><p>memory management control operations (H.264)
|
|
</p></dd>
|
|
<dt>‘<samp>bugs</samp>’</dt>
|
|
<dt>‘<samp>vis_qp</samp>’</dt>
|
|
<dd><p>visualize quantization parameter (QP), lower QP are tinted greener
|
|
</p></dd>
|
|
<dt>‘<samp>vis_mb_type</samp>’</dt>
|
|
<dd><p>visualize block types
|
|
</p></dd>
|
|
<dt>‘<samp>buffers</samp>’</dt>
|
|
<dd><p>picture buffer allocations
|
|
</p></dd>
|
|
<dt>‘<samp>thread_ops</samp>’</dt>
|
|
<dd><p>threading operations
|
|
</p></dd>
|
|
<dt>‘<samp>nomc</samp>’</dt>
|
|
<dd><p>skip motion compensation
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>vismv <var>integer</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dd><p>Visualize motion vectors (MVs).
|
|
</p>
|
|
<p>This option is deprecated, see the codecview filter instead.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>pf</samp>’</dt>
|
|
<dd><p>forward predicted MVs of P-frames
|
|
</p></dd>
|
|
<dt>‘<samp>bf</samp>’</dt>
|
|
<dd><p>forward predicted MVs of B-frames
|
|
</p></dd>
|
|
<dt>‘<samp>bb</samp>’</dt>
|
|
<dd><p>backward predicted MVs of B-frames
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>cmp <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set full pel me compare function.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>sad</samp>’</dt>
|
|
<dd><p>sum of absolute differences, fast (default)
|
|
</p></dd>
|
|
<dt>‘<samp>sse</samp>’</dt>
|
|
<dd><p>sum of squared errors
|
|
</p></dd>
|
|
<dt>‘<samp>satd</samp>’</dt>
|
|
<dd><p>sum of absolute Hadamard transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>dct</samp>’</dt>
|
|
<dd><p>sum of absolute DCT transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>psnr</samp>’</dt>
|
|
<dd><p>sum of squared quantization errors (avoid, low quality)
|
|
</p></dd>
|
|
<dt>‘<samp>bit</samp>’</dt>
|
|
<dd><p>number of bits needed for the block
|
|
</p></dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>rate distortion optimal, slow
|
|
</p></dd>
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>0
|
|
</p></dd>
|
|
<dt>‘<samp>vsad</samp>’</dt>
|
|
<dd><p>sum of absolute vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>vsse</samp>’</dt>
|
|
<dd><p>sum of squared vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>nsse</samp>’</dt>
|
|
<dd><p>noise preserving sum of squared differences
|
|
</p></dd>
|
|
<dt>‘<samp>w53</samp>’</dt>
|
|
<dd><p>5/3 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>w97</samp>’</dt>
|
|
<dd><p>9/7 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>dctmax</samp>’</dt>
|
|
<dt>‘<samp>chroma</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>subcmp <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set sub pel me compare function.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>sad</samp>’</dt>
|
|
<dd><p>sum of absolute differences, fast (default)
|
|
</p></dd>
|
|
<dt>‘<samp>sse</samp>’</dt>
|
|
<dd><p>sum of squared errors
|
|
</p></dd>
|
|
<dt>‘<samp>satd</samp>’</dt>
|
|
<dd><p>sum of absolute Hadamard transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>dct</samp>’</dt>
|
|
<dd><p>sum of absolute DCT transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>psnr</samp>’</dt>
|
|
<dd><p>sum of squared quantization errors (avoid, low quality)
|
|
</p></dd>
|
|
<dt>‘<samp>bit</samp>’</dt>
|
|
<dd><p>number of bits needed for the block
|
|
</p></dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>rate distortion optimal, slow
|
|
</p></dd>
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>0
|
|
</p></dd>
|
|
<dt>‘<samp>vsad</samp>’</dt>
|
|
<dd><p>sum of absolute vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>vsse</samp>’</dt>
|
|
<dd><p>sum of squared vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>nsse</samp>’</dt>
|
|
<dd><p>noise preserving sum of squared differences
|
|
</p></dd>
|
|
<dt>‘<samp>w53</samp>’</dt>
|
|
<dd><p>5/3 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>w97</samp>’</dt>
|
|
<dd><p>9/7 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>dctmax</samp>’</dt>
|
|
<dt>‘<samp>chroma</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>mbcmp <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set macroblock compare function.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>sad</samp>’</dt>
|
|
<dd><p>sum of absolute differences, fast (default)
|
|
</p></dd>
|
|
<dt>‘<samp>sse</samp>’</dt>
|
|
<dd><p>sum of squared errors
|
|
</p></dd>
|
|
<dt>‘<samp>satd</samp>’</dt>
|
|
<dd><p>sum of absolute Hadamard transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>dct</samp>’</dt>
|
|
<dd><p>sum of absolute DCT transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>psnr</samp>’</dt>
|
|
<dd><p>sum of squared quantization errors (avoid, low quality)
|
|
</p></dd>
|
|
<dt>‘<samp>bit</samp>’</dt>
|
|
<dd><p>number of bits needed for the block
|
|
</p></dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>rate distortion optimal, slow
|
|
</p></dd>
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>0
|
|
</p></dd>
|
|
<dt>‘<samp>vsad</samp>’</dt>
|
|
<dd><p>sum of absolute vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>vsse</samp>’</dt>
|
|
<dd><p>sum of squared vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>nsse</samp>’</dt>
|
|
<dd><p>noise preserving sum of squared differences
|
|
</p></dd>
|
|
<dt>‘<samp>w53</samp>’</dt>
|
|
<dd><p>5/3 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>w97</samp>’</dt>
|
|
<dd><p>9/7 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>dctmax</samp>’</dt>
|
|
<dt>‘<samp>chroma</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>ildctcmp <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set interlaced dct compare function.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>sad</samp>’</dt>
|
|
<dd><p>sum of absolute differences, fast (default)
|
|
</p></dd>
|
|
<dt>‘<samp>sse</samp>’</dt>
|
|
<dd><p>sum of squared errors
|
|
</p></dd>
|
|
<dt>‘<samp>satd</samp>’</dt>
|
|
<dd><p>sum of absolute Hadamard transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>dct</samp>’</dt>
|
|
<dd><p>sum of absolute DCT transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>psnr</samp>’</dt>
|
|
<dd><p>sum of squared quantization errors (avoid, low quality)
|
|
</p></dd>
|
|
<dt>‘<samp>bit</samp>’</dt>
|
|
<dd><p>number of bits needed for the block
|
|
</p></dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>rate distortion optimal, slow
|
|
</p></dd>
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>0
|
|
</p></dd>
|
|
<dt>‘<samp>vsad</samp>’</dt>
|
|
<dd><p>sum of absolute vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>vsse</samp>’</dt>
|
|
<dd><p>sum of squared vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>nsse</samp>’</dt>
|
|
<dd><p>noise preserving sum of squared differences
|
|
</p></dd>
|
|
<dt>‘<samp>w53</samp>’</dt>
|
|
<dd><p>5/3 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>w97</samp>’</dt>
|
|
<dd><p>9/7 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>dctmax</samp>’</dt>
|
|
<dt>‘<samp>chroma</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>dia_size <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set diamond type & size for motion estimation.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>last_pred <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set amount of motion predictors from the previous frame.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>preme <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set pre motion estimation.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>precmp <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set pre motion estimation compare function.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>sad</samp>’</dt>
|
|
<dd><p>sum of absolute differences, fast (default)
|
|
</p></dd>
|
|
<dt>‘<samp>sse</samp>’</dt>
|
|
<dd><p>sum of squared errors
|
|
</p></dd>
|
|
<dt>‘<samp>satd</samp>’</dt>
|
|
<dd><p>sum of absolute Hadamard transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>dct</samp>’</dt>
|
|
<dd><p>sum of absolute DCT transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>psnr</samp>’</dt>
|
|
<dd><p>sum of squared quantization errors (avoid, low quality)
|
|
</p></dd>
|
|
<dt>‘<samp>bit</samp>’</dt>
|
|
<dd><p>number of bits needed for the block
|
|
</p></dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>rate distortion optimal, slow
|
|
</p></dd>
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>0
|
|
</p></dd>
|
|
<dt>‘<samp>vsad</samp>’</dt>
|
|
<dd><p>sum of absolute vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>vsse</samp>’</dt>
|
|
<dd><p>sum of squared vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>nsse</samp>’</dt>
|
|
<dd><p>noise preserving sum of squared differences
|
|
</p></dd>
|
|
<dt>‘<samp>w53</samp>’</dt>
|
|
<dd><p>5/3 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>w97</samp>’</dt>
|
|
<dd><p>9/7 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>dctmax</samp>’</dt>
|
|
<dt>‘<samp>chroma</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>pre_dia_size <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set diamond type & size for motion estimation pre-pass.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>subq <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set sub pel motion estimation quality.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>dtg_active_format <var>integer</var></samp></dt>
|
|
<dt><samp>me_range <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set limit motion vectors range (1023 for DivX player).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ibias <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set intra quant bias.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>pbias <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set inter quant bias.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>color_table_id <var>integer</var></samp></dt>
|
|
<dt><samp>global_quality <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dt><samp>coder <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>vlc</samp>’</dt>
|
|
<dd><p>variable length coder / huffman coder
|
|
</p></dd>
|
|
<dt>‘<samp>ac</samp>’</dt>
|
|
<dd><p>arithmetic coder
|
|
</p></dd>
|
|
<dt>‘<samp>raw</samp>’</dt>
|
|
<dd><p>raw (no encoding)
|
|
</p></dd>
|
|
<dt>‘<samp>rle</samp>’</dt>
|
|
<dd><p>run-length coder
|
|
</p></dd>
|
|
<dt>‘<samp>deflate</samp>’</dt>
|
|
<dd><p>deflate-based coder
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>context <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set context model.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>slice_flags <var>integer</var></samp></dt>
|
|
<dt><samp>xvmc_acceleration <var>integer</var></samp></dt>
|
|
<dt><samp>mbd <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set macroblock decision algorithm (high quality mode).
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>simple</samp>’</dt>
|
|
<dd><p>use mbcmp (default)
|
|
</p></dd>
|
|
<dt>‘<samp>bits</samp>’</dt>
|
|
<dd><p>use fewest bits
|
|
</p></dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>use best rate distortion
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>stream_codec_tag <var>integer</var></samp></dt>
|
|
<dt><samp>sc_threshold <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set scene change threshold.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>lmin <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set min lagrange factor (VBR).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>lmax <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set max lagrange factor (VBR).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>nr <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set noise reduction.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_init_occupancy <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set number of bits which should be loaded into the rc buffer before
|
|
decoding starts.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>flags2 <var>flags</var> (<em>decoding/encoding,audio,video</em>)</samp></dt>
|
|
<dd>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>fast</samp>’</dt>
|
|
<dd><p>Allow non spec compliant speedup tricks.
|
|
</p></dd>
|
|
<dt>‘<samp>sgop</samp>’</dt>
|
|
<dd><p>Deprecated, use mpegvideo private options instead.
|
|
</p></dd>
|
|
<dt>‘<samp>noout</samp>’</dt>
|
|
<dd><p>Skip bitstream encoding.
|
|
</p></dd>
|
|
<dt>‘<samp>ignorecrop</samp>’</dt>
|
|
<dd><p>Ignore cropping information from sps.
|
|
</p></dd>
|
|
<dt>‘<samp>local_header</samp>’</dt>
|
|
<dd><p>Place global headers at every keyframe instead of in extradata.
|
|
</p></dd>
|
|
<dt>‘<samp>chunks</samp>’</dt>
|
|
<dd><p>Frame data might be split into multiple chunks.
|
|
</p></dd>
|
|
<dt>‘<samp>showall</samp>’</dt>
|
|
<dd><p>Show all frames before the first keyframe.
|
|
</p></dd>
|
|
<dt>‘<samp>skiprd</samp>’</dt>
|
|
<dd><p>Deprecated, use mpegvideo private options instead.
|
|
</p></dd>
|
|
<dt>‘<samp>export_mvs</samp>’</dt>
|
|
<dd><p>Export motion vectors into frame side-data (see <code>AV_FRAME_DATA_MOTION_VECTORS</code>)
|
|
for codecs that support it. See also <samp>doc/examples/export_mvs.c</samp>.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>error <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dt><samp>qns <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Deprecated, use mpegvideo private options instead.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>threads <var>integer</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dd><p>Set the number of threads to be used, in case the selected codec
|
|
implementation supports multi-threading.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>auto, 0</samp>’</dt>
|
|
<dd><p>automatically select the number of threads to set
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is ‘<samp>auto</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>me_threshold <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set motion estimation threshold.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mb_threshold <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set macroblock threshold.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>dc <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set intra_dc_precision.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>nssew <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set nsse weight.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skip_top <var>integer</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dd><p>Set number of macroblock rows at the top which are skipped.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skip_bottom <var>integer</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dd><p>Set number of macroblock rows at the bottom which are skipped.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>profile <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dd>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>unknown</samp>’</dt>
|
|
<dt>‘<samp>aac_main</samp>’</dt>
|
|
<dt>‘<samp>aac_low</samp>’</dt>
|
|
<dt>‘<samp>aac_ssr</samp>’</dt>
|
|
<dt>‘<samp>aac_ltp</samp>’</dt>
|
|
<dt>‘<samp>aac_he</samp>’</dt>
|
|
<dt>‘<samp>aac_he_v2</samp>’</dt>
|
|
<dt>‘<samp>aac_ld</samp>’</dt>
|
|
<dt>‘<samp>aac_eld</samp>’</dt>
|
|
<dt>‘<samp>mpeg2_aac_low</samp>’</dt>
|
|
<dt>‘<samp>mpeg2_aac_he</samp>’</dt>
|
|
<dt>‘<samp>mpeg4_sp</samp>’</dt>
|
|
<dt>‘<samp>mpeg4_core</samp>’</dt>
|
|
<dt>‘<samp>mpeg4_main</samp>’</dt>
|
|
<dt>‘<samp>mpeg4_asp</samp>’</dt>
|
|
<dt>‘<samp>dts</samp>’</dt>
|
|
<dt>‘<samp>dts_es</samp>’</dt>
|
|
<dt>‘<samp>dts_96_24</samp>’</dt>
|
|
<dt>‘<samp>dts_hd_hra</samp>’</dt>
|
|
<dt>‘<samp>dts_hd_ma</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>level <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dd>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>unknown</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>lowres <var>integer</var> (<em>decoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skip_threshold <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set frame skip threshold.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skip_factor <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set frame skip factor.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skip_exp <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set frame skip exponent.
|
|
Negative values behave identical to the corresponding positive ones, except
|
|
that the score is normalized.
|
|
Positive values exist primarily for compatibility reasons and are not so useful.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skipcmp <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set frame skip compare function.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>sad</samp>’</dt>
|
|
<dd><p>sum of absolute differences, fast (default)
|
|
</p></dd>
|
|
<dt>‘<samp>sse</samp>’</dt>
|
|
<dd><p>sum of squared errors
|
|
</p></dd>
|
|
<dt>‘<samp>satd</samp>’</dt>
|
|
<dd><p>sum of absolute Hadamard transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>dct</samp>’</dt>
|
|
<dd><p>sum of absolute DCT transformed differences
|
|
</p></dd>
|
|
<dt>‘<samp>psnr</samp>’</dt>
|
|
<dd><p>sum of squared quantization errors (avoid, low quality)
|
|
</p></dd>
|
|
<dt>‘<samp>bit</samp>’</dt>
|
|
<dd><p>number of bits needed for the block
|
|
</p></dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>rate distortion optimal, slow
|
|
</p></dd>
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>0
|
|
</p></dd>
|
|
<dt>‘<samp>vsad</samp>’</dt>
|
|
<dd><p>sum of absolute vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>vsse</samp>’</dt>
|
|
<dd><p>sum of squared vertical differences
|
|
</p></dd>
|
|
<dt>‘<samp>nsse</samp>’</dt>
|
|
<dd><p>noise preserving sum of squared differences
|
|
</p></dd>
|
|
<dt>‘<samp>w53</samp>’</dt>
|
|
<dd><p>5/3 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>w97</samp>’</dt>
|
|
<dd><p>9/7 wavelet, only used in snow
|
|
</p></dd>
|
|
<dt>‘<samp>dctmax</samp>’</dt>
|
|
<dt>‘<samp>chroma</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>border_mask <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Increase the quantizer for macroblocks close to borders.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mblmin <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set min macroblock lagrange factor (VBR).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mblmax <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set max macroblock lagrange factor (VBR).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mepc <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set motion estimation bitrate penalty compensation (1.0 = 256).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skip_loop_filter <var>integer</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dt><samp>skip_idct <var>integer</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dt><samp>skip_frame <var>integer</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dd>
|
|
<p>Make decoder discard processing depending on the frame type selected
|
|
by the option value.
|
|
</p>
|
|
<p><samp>skip_loop_filter</samp> skips frame loop filtering, <samp>skip_idct</samp>
|
|
skips frame IDCT/dequantization, <samp>skip_frame</samp> skips decoding.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>none</samp>’</dt>
|
|
<dd><p>Discard no frame.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>default</samp>’</dt>
|
|
<dd><p>Discard useless frames like 0-sized frames.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>noref</samp>’</dt>
|
|
<dd><p>Discard all non-reference frames.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>bidir</samp>’</dt>
|
|
<dd><p>Discard all bidirectional frames.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>nokey</samp>’</dt>
|
|
<dd><p>Discard all frames excepts keyframes.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>all</samp>’</dt>
|
|
<dd><p>Discard all frames.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is ‘<samp>default</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bidir_refine <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Refine the two motion vectors used in bidirectional macroblocks.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>brd_scale <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Downscale frames for dynamic B-frame decision.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>keyint_min <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set minimum interval between IDR-frames.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>refs <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set reference frames to consider for motion compensation.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>chromaoffset <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set chroma qp offset from luma.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>trellis <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dd><p>Set rate-distortion optimal quantization.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>sc_factor <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set value multiplied by qscale for each frame and added to
|
|
scene_change_score.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mv0_threshold <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dt><samp>b_sensitivity <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Adjust sensitivity of b_frame_strategy 1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>compression_level <var>integer</var> (<em>encoding,audio,video</em>)</samp></dt>
|
|
<dt><samp>min_prediction_order <var>integer</var> (<em>encoding,audio</em>)</samp></dt>
|
|
<dt><samp>max_prediction_order <var>integer</var> (<em>encoding,audio</em>)</samp></dt>
|
|
<dt><samp>timecode_frame_start <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Set GOP timecode frame start number, in non drop frame format.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>request_channels <var>integer</var> (<em>decoding,audio</em>)</samp></dt>
|
|
<dd><p>Set desired number of audio channels.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bits_per_raw_sample <var>integer</var></samp></dt>
|
|
<dt><samp>channel_layout <var>integer</var> (<em>decoding/encoding,audio</em>)</samp></dt>
|
|
<dd>
|
|
<p>Possible values:
|
|
</p></dd>
|
|
<dt><samp>request_channel_layout <var>integer</var> (<em>decoding,audio</em>)</samp></dt>
|
|
<dd>
|
|
<p>Possible values:
|
|
</p></dd>
|
|
<dt><samp>rc_max_vbv_use <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dt><samp>rc_min_vbv_use <var>float</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dt><samp>ticks_per_frame <var>integer</var> (<em>decoding/encoding,audio,video</em>)</samp></dt>
|
|
<dt><samp>color_primaries <var>integer</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dd><p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>bt709</samp>’</dt>
|
|
<dd><p>BT.709
|
|
</p></dd>
|
|
<dt>‘<samp>bt470m</samp>’</dt>
|
|
<dd><p>BT.470 M
|
|
</p></dd>
|
|
<dt>‘<samp>bt470bg</samp>’</dt>
|
|
<dd><p>BT.470 BG
|
|
</p></dd>
|
|
<dt>‘<samp>smpte170m</samp>’</dt>
|
|
<dd><p>SMPTE 170 M
|
|
</p></dd>
|
|
<dt>‘<samp>smpte240m</samp>’</dt>
|
|
<dd><p>SMPTE 240 M
|
|
</p></dd>
|
|
<dt>‘<samp>film</samp>’</dt>
|
|
<dd><p>Film
|
|
</p></dd>
|
|
<dt>‘<samp>bt2020</samp>’</dt>
|
|
<dd><p>BT.2020
|
|
</p></dd>
|
|
<dt>‘<samp>smpte428_1</samp>’</dt>
|
|
<dd><p>SMPTE ST 428-1
|
|
</p></dd>
|
|
<dt>‘<samp>smpte431</samp>’</dt>
|
|
<dd><p>SMPTE 431-2
|
|
</p></dd>
|
|
<dt>‘<samp>smpte432</samp>’</dt>
|
|
<dd><p>SMPTE 432-1
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>color_trc <var>integer</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dd><p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>bt709</samp>’</dt>
|
|
<dd><p>BT.709
|
|
</p></dd>
|
|
<dt>‘<samp>gamma22</samp>’</dt>
|
|
<dd><p>BT.470 M
|
|
</p></dd>
|
|
<dt>‘<samp>gamma28</samp>’</dt>
|
|
<dd><p>BT.470 BG
|
|
</p></dd>
|
|
<dt>‘<samp>smpte170m</samp>’</dt>
|
|
<dd><p>SMPTE 170 M
|
|
</p></dd>
|
|
<dt>‘<samp>smpte240m</samp>’</dt>
|
|
<dd><p>SMPTE 240 M
|
|
</p></dd>
|
|
<dt>‘<samp>linear</samp>’</dt>
|
|
<dd><p>Linear
|
|
</p></dd>
|
|
<dt>‘<samp>log</samp>’</dt>
|
|
<dd><p>Log
|
|
</p></dd>
|
|
<dt>‘<samp>log_sqrt</samp>’</dt>
|
|
<dd><p>Log square root
|
|
</p></dd>
|
|
<dt>‘<samp>iec61966_2_4</samp>’</dt>
|
|
<dd><p>IEC 61966-2-4
|
|
</p></dd>
|
|
<dt>‘<samp>bt1361</samp>’</dt>
|
|
<dd><p>BT.1361
|
|
</p></dd>
|
|
<dt>‘<samp>iec61966_2_1</samp>’</dt>
|
|
<dd><p>IEC 61966-2-1
|
|
</p></dd>
|
|
<dt>‘<samp>bt2020_10bit</samp>’</dt>
|
|
<dd><p>BT.2020 - 10 bit
|
|
</p></dd>
|
|
<dt>‘<samp>bt2020_12bit</samp>’</dt>
|
|
<dd><p>BT.2020 - 12 bit
|
|
</p></dd>
|
|
<dt>‘<samp>smpte2084</samp>’</dt>
|
|
<dd><p>SMPTE ST 2084
|
|
</p></dd>
|
|
<dt>‘<samp>smpte428_1</samp>’</dt>
|
|
<dd><p>SMPTE ST 428-1
|
|
</p></dd>
|
|
<dt>‘<samp>arib-std-b67</samp>’</dt>
|
|
<dd><p>ARIB STD-B67
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>colorspace <var>integer</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dd><p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>rgb</samp>’</dt>
|
|
<dd><p>RGB
|
|
</p></dd>
|
|
<dt>‘<samp>bt709</samp>’</dt>
|
|
<dd><p>BT.709
|
|
</p></dd>
|
|
<dt>‘<samp>fcc</samp>’</dt>
|
|
<dd><p>FCC
|
|
</p></dd>
|
|
<dt>‘<samp>bt470bg</samp>’</dt>
|
|
<dd><p>BT.470 BG
|
|
</p></dd>
|
|
<dt>‘<samp>smpte170m</samp>’</dt>
|
|
<dd><p>SMPTE 170 M
|
|
</p></dd>
|
|
<dt>‘<samp>smpte240m</samp>’</dt>
|
|
<dd><p>SMPTE 240 M
|
|
</p></dd>
|
|
<dt>‘<samp>ycocg</samp>’</dt>
|
|
<dd><p>YCOCG
|
|
</p></dd>
|
|
<dt>‘<samp>bt2020_ncl</samp>’</dt>
|
|
<dd><p>BT.2020 NCL
|
|
</p></dd>
|
|
<dt>‘<samp>bt2020_cl</samp>’</dt>
|
|
<dd><p>BT.2020 CL
|
|
</p></dd>
|
|
<dt>‘<samp>smpte2085</samp>’</dt>
|
|
<dd><p>SMPTE 2085
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>color_range <var>integer</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dd><p>If used as input parameter, it serves as a hint to the decoder, which
|
|
color_range the input has.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>chroma_sample_location <var>integer</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dt><samp>log_level_offset <var>integer</var></samp></dt>
|
|
<dd><p>Set the log level offset.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>slices <var>integer</var> (<em>encoding,video</em>)</samp></dt>
|
|
<dd><p>Number of slices, used in parallelized encoding.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>thread_type <var>flags</var> (<em>decoding/encoding,video</em>)</samp></dt>
|
|
<dd><p>Select which multithreading methods to use.
|
|
</p>
|
|
<p>Use of ‘<samp>frame</samp>’ will increase decoding delay by one frame per
|
|
thread, so clients which cannot provide future frames should not use
|
|
it.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>slice</samp>’</dt>
|
|
<dd><p>Decode more than one part of a single frame at once.
|
|
</p>
|
|
<p>Multithreading using slices works only when the video was encoded with
|
|
slices.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>frame</samp>’</dt>
|
|
<dd><p>Decode more than one frame at once.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is ‘<samp>slice+frame</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>audio_service_type <var>integer</var> (<em>encoding,audio</em>)</samp></dt>
|
|
<dd><p>Set audio service type.
|
|
</p>
|
|
<p>Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>ma</samp>’</dt>
|
|
<dd><p>Main Audio Service
|
|
</p></dd>
|
|
<dt>‘<samp>ef</samp>’</dt>
|
|
<dd><p>Effects
|
|
</p></dd>
|
|
<dt>‘<samp>vi</samp>’</dt>
|
|
<dd><p>Visually Impaired
|
|
</p></dd>
|
|
<dt>‘<samp>hi</samp>’</dt>
|
|
<dd><p>Hearing Impaired
|
|
</p></dd>
|
|
<dt>‘<samp>di</samp>’</dt>
|
|
<dd><p>Dialogue
|
|
</p></dd>
|
|
<dt>‘<samp>co</samp>’</dt>
|
|
<dd><p>Commentary
|
|
</p></dd>
|
|
<dt>‘<samp>em</samp>’</dt>
|
|
<dd><p>Emergency
|
|
</p></dd>
|
|
<dt>‘<samp>vo</samp>’</dt>
|
|
<dd><p>Voice Over
|
|
</p></dd>
|
|
<dt>‘<samp>ka</samp>’</dt>
|
|
<dd><p>Karaoke
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>request_sample_fmt <var>sample_fmt</var> (<em>decoding,audio</em>)</samp></dt>
|
|
<dd><p>Set sample format audio decoders should prefer. Default value is
|
|
<code>none</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>pkt_timebase <var>rational number</var></samp></dt>
|
|
<dt><samp>sub_charenc <var>encoding</var> (<em>decoding,subtitles</em>)</samp></dt>
|
|
<dd><p>Set the input subtitles character encoding.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>field_order <var>field_order</var> (<em>video</em>)</samp></dt>
|
|
<dd><p>Set/override the field order of the video.
|
|
Possible values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>progressive</samp>’</dt>
|
|
<dd><p>Progressive video
|
|
</p></dd>
|
|
<dt>‘<samp>tt</samp>’</dt>
|
|
<dd><p>Interlaced video, top field coded and displayed first
|
|
</p></dd>
|
|
<dt>‘<samp>bb</samp>’</dt>
|
|
<dd><p>Interlaced video, bottom field coded and displayed first
|
|
</p></dd>
|
|
<dt>‘<samp>tb</samp>’</dt>
|
|
<dd><p>Interlaced video, top coded first, bottom displayed first
|
|
</p></dd>
|
|
<dt>‘<samp>bt</samp>’</dt>
|
|
<dd><p>Interlaced video, bottom coded first, top displayed first
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>skip_alpha <var>integer</var> (<em>decoding,video</em>)</samp></dt>
|
|
<dd><p>Set to 1 to disable processing alpha (transparency). This works like the
|
|
‘<samp>gray</samp>’ flag in the <samp>flags</samp> option which skips chroma information
|
|
instead of alpha. Default is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>codec_whitelist <var>list</var> (<em>input</em>)</samp></dt>
|
|
<dd><p>"," separated list of allowed decoders. By default all are allowed.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>dump_separator <var>string</var> (<em>input</em>)</samp></dt>
|
|
<dd><p>Separator used to separate the fields printed on the command line about the
|
|
Stream parameters.
|
|
For example to separate the fields with newlines and indention:
|
|
</p><div class="example">
|
|
<pre class="example">ffprobe -dump_separator "
|
|
" -i ~/videos/matrixbench_mpeg2.mpg
|
|
</pre></div>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
|
|
<a name="Decoders"></a>
|
|
<h2 class="chapter">3 Decoders<span class="pull-right"><a class="anchor hidden-xs" href="#Decoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Decoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>Decoders are configured elements in FFmpeg which allow the decoding of
|
|
multimedia streams.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported native decoders
|
|
are enabled by default. Decoders requiring an external library must be enabled
|
|
manually via the corresponding <code>--enable-lib</code> option. You can list all
|
|
available decoders using the configure option <code>--list-decoders</code>.
|
|
</p>
|
|
<p>You can disable all the decoders with the configure option
|
|
<code>--disable-decoders</code> and selectively enable / disable single decoders
|
|
with the options <code>--enable-decoder=<var>DECODER</var></code> /
|
|
<code>--disable-decoder=<var>DECODER</var></code>.
|
|
</p>
|
|
<p>The option <code>-decoders</code> of the ff* tools will display the list of
|
|
enabled decoders.
|
|
</p>
|
|
|
|
<a name="Video-Decoders"></a>
|
|
<h2 class="chapter">4 Video Decoders<span class="pull-right"><a class="anchor hidden-xs" href="#Video-Decoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-Decoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>A description of some of the currently available video decoders
|
|
follows.
|
|
</p>
|
|
<a name="hevc"></a>
|
|
<h3 class="section">4.1 hevc<span class="pull-right"><a class="anchor hidden-xs" href="#hevc" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-hevc" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>HEVC / H.265 decoder.
|
|
</p>
|
|
<p>Note: the <samp>skip_loop_filter</samp> option has effect only at level
|
|
<code>all</code>.
|
|
</p>
|
|
<a name="rawvideo"></a>
|
|
<h3 class="section">4.2 rawvideo<span class="pull-right"><a class="anchor hidden-xs" href="#rawvideo" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-rawvideo" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Raw video decoder.
|
|
</p>
|
|
<p>This decoder decodes rawvideo streams.
|
|
</p>
|
|
<a name="Options"></a>
|
|
<h4 class="subsection">4.2.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>top <var>top_field_first</var></samp></dt>
|
|
<dd><p>Specify the assumed field type of the input video.
|
|
</p><dl compact="compact">
|
|
<dt><samp>-1</samp></dt>
|
|
<dd><p>the video is assumed to be progressive (default)
|
|
</p></dd>
|
|
<dt><samp>0</samp></dt>
|
|
<dd><p>bottom-field-first is assumed
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dd><p>top-field-first is assumed
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
|
|
<a name="Audio-Decoders"></a>
|
|
<h2 class="chapter">5 Audio Decoders<span class="pull-right"><a class="anchor hidden-xs" href="#Audio-Decoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Audio-Decoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>A description of some of the currently available audio decoders
|
|
follows.
|
|
</p>
|
|
<a name="ac3"></a>
|
|
<h3 class="section">5.1 ac3<span class="pull-right"><a class="anchor hidden-xs" href="#ac3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ac3" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>AC-3 audio decoder.
|
|
</p>
|
|
<p>This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
|
|
the undocumented RealAudio 3 (a.k.a. dnet).
|
|
</p>
|
|
<a name="AC_002d3-Decoder-Options"></a>
|
|
<h4 class="subsection">5.1.1 AC-3 Decoder Options<span class="pull-right"><a class="anchor hidden-xs" href="#AC_002d3-Decoder-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-AC_002d3-Decoder-Options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-drc_scale <var>value</var></samp></dt>
|
|
<dd><p>Dynamic Range Scale Factor. The factor to apply to dynamic range values
|
|
from the AC-3 stream. This factor is applied exponentially.
|
|
There are 3 notable scale factor ranges:
|
|
</p><dl compact="compact">
|
|
<dt><samp>drc_scale == 0</samp></dt>
|
|
<dd><p>DRC disabled. Produces full range audio.
|
|
</p></dd>
|
|
<dt><samp>0 < drc_scale <= 1</samp></dt>
|
|
<dd><p>DRC enabled. Applies a fraction of the stream DRC value.
|
|
Audio reproduction is between full range and full compression.
|
|
</p></dd>
|
|
<dt><samp>drc_scale > 1</samp></dt>
|
|
<dd><p>DRC enabled. Applies drc_scale asymmetrically.
|
|
Loud sounds are fully compressed. Soft sounds are enhanced.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="flac-1"></a>
|
|
<h3 class="section">5.2 flac<span class="pull-right"><a class="anchor hidden-xs" href="#flac-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-flac-1" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>FLAC audio decoder.
|
|
</p>
|
|
<p>This decoder aims to implement the complete FLAC specification from Xiph.
|
|
</p>
|
|
<a name="FLAC-Decoder-options"></a>
|
|
<h4 class="subsection">5.2.1 FLAC Decoder options<span class="pull-right"><a class="anchor hidden-xs" href="#FLAC-Decoder-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-FLAC-Decoder-options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-use_buggy_lpc</samp></dt>
|
|
<dd><p>The lavc FLAC encoder used to produce buggy streams with high lpc values
|
|
(like the default value). This option makes it possible to decode such streams
|
|
correctly by using lavc’s old buggy lpc logic for decoding.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="ffwavesynth"></a>
|
|
<h3 class="section">5.3 ffwavesynth<span class="pull-right"><a class="anchor hidden-xs" href="#ffwavesynth" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ffwavesynth" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Internal wave synthetizer.
|
|
</p>
|
|
<p>This decoder generates wave patterns according to predefined sequences. Its
|
|
use is purely internal and the format of the data it accepts is not publicly
|
|
documented.
|
|
</p>
|
|
<a name="libcelt"></a>
|
|
<h3 class="section">5.4 libcelt<span class="pull-right"><a class="anchor hidden-xs" href="#libcelt" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libcelt" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libcelt decoder wrapper.
|
|
</p>
|
|
<p>libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
|
|
Requires the presence of the libcelt headers and library during configuration.
|
|
You need to explicitly configure the build with <code>--enable-libcelt</code>.
|
|
</p>
|
|
<a name="libgsm"></a>
|
|
<h3 class="section">5.5 libgsm<span class="pull-right"><a class="anchor hidden-xs" href="#libgsm" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libgsm" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libgsm decoder wrapper.
|
|
</p>
|
|
<p>libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
|
|
the presence of the libgsm headers and library during configuration. You need
|
|
to explicitly configure the build with <code>--enable-libgsm</code>.
|
|
</p>
|
|
<p>This decoder supports both the ordinary GSM and the Microsoft variant.
|
|
</p>
|
|
<a name="libilbc"></a>
|
|
<h3 class="section">5.6 libilbc<span class="pull-right"><a class="anchor hidden-xs" href="#libilbc" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libilbc" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libilbc decoder wrapper.
|
|
</p>
|
|
<p>libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
|
|
audio codec. Requires the presence of the libilbc headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libilbc</code>.
|
|
</p>
|
|
<a name="Options-1"></a>
|
|
<h4 class="subsection">5.6.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-1" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following option is supported by the libilbc wrapper.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>enhance</samp></dt>
|
|
<dd>
|
|
<p>Enable the enhancement of the decoded audio when set to 1. The default
|
|
value is 0 (disabled).
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libopencore_002damrnb"></a>
|
|
<h3 class="section">5.7 libopencore-amrnb<span class="pull-right"><a class="anchor hidden-xs" href="#libopencore_002damrnb" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libopencore_002damrnb" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libopencore-amrnb decoder wrapper.
|
|
</p>
|
|
<p>libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
|
|
Narrowband audio codec. Using it requires the presence of the
|
|
libopencore-amrnb headers and library during configuration. You need to
|
|
explicitly configure the build with <code>--enable-libopencore-amrnb</code>.
|
|
</p>
|
|
<p>An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
|
|
without this library.
|
|
</p>
|
|
<a name="libopencore_002damrwb"></a>
|
|
<h3 class="section">5.8 libopencore-amrwb<span class="pull-right"><a class="anchor hidden-xs" href="#libopencore_002damrwb" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libopencore_002damrwb" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libopencore-amrwb decoder wrapper.
|
|
</p>
|
|
<p>libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
|
|
Wideband audio codec. Using it requires the presence of the
|
|
libopencore-amrwb headers and library during configuration. You need to
|
|
explicitly configure the build with <code>--enable-libopencore-amrwb</code>.
|
|
</p>
|
|
<p>An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
|
|
without this library.
|
|
</p>
|
|
<a name="libopus"></a>
|
|
<h3 class="section">5.9 libopus<span class="pull-right"><a class="anchor hidden-xs" href="#libopus" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libopus" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libopus decoder wrapper.
|
|
</p>
|
|
<p>libopus allows libavcodec to decode the Opus Interactive Audio Codec.
|
|
Requires the presence of the libopus headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libopus</code>.
|
|
</p>
|
|
<p>An FFmpeg native decoder for Opus exists, so users can decode Opus
|
|
without this library.
|
|
</p>
|
|
|
|
<a name="Subtitles-Decoders"></a>
|
|
<h2 class="chapter">6 Subtitles Decoders<span class="pull-right"><a class="anchor hidden-xs" href="#Subtitles-Decoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Subtitles-Decoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<a name="dvbsub"></a>
|
|
<h3 class="section">6.1 dvbsub<span class="pull-right"><a class="anchor hidden-xs" href="#dvbsub" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dvbsub" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<a name="Options-2"></a>
|
|
<h4 class="subsection">6.1.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-2" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>compute_clut</samp></dt>
|
|
<dd><dl compact="compact">
|
|
<dt><samp>-1</samp></dt>
|
|
<dd><p>Compute clut if no matching CLUT is in the stream.
|
|
</p></dd>
|
|
<dt><samp>0</samp></dt>
|
|
<dd><p>Never compute CLUT
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dd><p>Always compute CLUT and override the one provided in the stream.
|
|
</p></dd>
|
|
</dl>
|
|
</dd>
|
|
<dt><samp>dvb_substream</samp></dt>
|
|
<dd><p>Selects the dvb substream, or all substreams if -1 which is default.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="dvdsub"></a>
|
|
<h3 class="section">6.2 dvdsub<span class="pull-right"><a class="anchor hidden-xs" href="#dvdsub" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dvdsub" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
|
|
also be found in VobSub file pairs and in some Matroska files.
|
|
</p>
|
|
<a name="Options-3"></a>
|
|
<h4 class="subsection">6.2.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-3" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>palette</samp></dt>
|
|
<dd><p>Specify the global palette used by the bitmaps. When stored in VobSub, the
|
|
palette is normally specified in the index file; in Matroska, the palette is
|
|
stored in the codec extra-data in the same format as in VobSub. In DVDs, the
|
|
palette is stored in the IFO file, and therefore not available when reading
|
|
from dumped VOB files.
|
|
</p>
|
|
<p>The format for this option is a string containing 16 24-bits hexadecimal
|
|
numbers (without 0x prefix) separated by comas, for example <code>0d00ee,
|
|
ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
|
|
7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ifo_palette</samp></dt>
|
|
<dd><p>Specify the IFO file from which the global palette is obtained.
|
|
(experimental)
|
|
</p>
|
|
</dd>
|
|
<dt><samp>forced_subs_only</samp></dt>
|
|
<dd><p>Only decode subtitle entries marked as forced. Some titles have forced
|
|
and non-forced subtitles in the same track. Setting this flag to <code>1</code>
|
|
will only keep the forced subtitles. Default value is <code>0</code>.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="libzvbi_002dteletext"></a>
|
|
<h3 class="section">6.3 libzvbi-teletext<span class="pull-right"><a class="anchor hidden-xs" href="#libzvbi_002dteletext" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libzvbi_002dteletext" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
|
|
subtitles. Requires the presence of the libzvbi headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libzvbi</code>.
|
|
</p>
|
|
<a name="Options-4"></a>
|
|
<h4 class="subsection">6.3.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-4" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-4" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>txt_page</samp></dt>
|
|
<dd><p>List of teletext page numbers to decode. You may use the special * string to
|
|
match all pages. Pages that do not match the specified list are dropped.
|
|
Default value is *.
|
|
</p></dd>
|
|
<dt><samp>txt_chop_top</samp></dt>
|
|
<dd><p>Discards the top teletext line. Default value is 1.
|
|
</p></dd>
|
|
<dt><samp>txt_format</samp></dt>
|
|
<dd><p>Specifies the format of the decoded subtitles. The teletext decoder is capable
|
|
of decoding the teletext pages to bitmaps or to simple text, you should use
|
|
"bitmap" for teletext pages, because certain graphics and colors cannot be
|
|
expressed in simple text. You might use "text" for teletext based subtitles if
|
|
your application can handle simple text based subtitles. Default value is
|
|
bitmap.
|
|
</p></dd>
|
|
<dt><samp>txt_left</samp></dt>
|
|
<dd><p>X offset of generated bitmaps, default is 0.
|
|
</p></dd>
|
|
<dt><samp>txt_top</samp></dt>
|
|
<dd><p>Y offset of generated bitmaps, default is 0.
|
|
</p></dd>
|
|
<dt><samp>txt_chop_spaces</samp></dt>
|
|
<dd><p>Chops leading and trailing spaces and removes empty lines from the generated
|
|
text. This option is useful for teletext based subtitles where empty spaces may
|
|
be present at the start or at the end of the lines or empty lines may be
|
|
present between the subtitle lines because of double-sized teletext charactes.
|
|
Default value is 1.
|
|
</p></dd>
|
|
<dt><samp>txt_duration</samp></dt>
|
|
<dd><p>Sets the display duration of the decoded teletext pages or subtitles in
|
|
milliseconds. Default value is 30000 which is 30 seconds.
|
|
</p></dd>
|
|
<dt><samp>txt_transparent</samp></dt>
|
|
<dd><p>Force transparent background of the generated teletext bitmaps. Default value
|
|
is 0 which means an opaque background.
|
|
</p></dd>
|
|
<dt><samp>txt_opacity</samp></dt>
|
|
<dd><p>Sets the opacity (0-255) of the teletext background. If
|
|
<samp>txt_transparent</samp> is not set, it only affects characters between a start
|
|
box and an end box, typically subtitles. Default value is 0 if
|
|
<samp>txt_transparent</samp> is set, 255 otherwise.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Encoders"></a>
|
|
<h2 class="chapter">7 Encoders<span class="pull-right"><a class="anchor hidden-xs" href="#Encoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Encoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>Encoders are configured elements in FFmpeg which allow the encoding of
|
|
multimedia streams.
|
|
</p>
|
|
<p>When you configure your FFmpeg build, all the supported native encoders
|
|
are enabled by default. Encoders requiring an external library must be enabled
|
|
manually via the corresponding <code>--enable-lib</code> option. You can list all
|
|
available encoders using the configure option <code>--list-encoders</code>.
|
|
</p>
|
|
<p>You can disable all the encoders with the configure option
|
|
<code>--disable-encoders</code> and selectively enable / disable single encoders
|
|
with the options <code>--enable-encoder=<var>ENCODER</var></code> /
|
|
<code>--disable-encoder=<var>ENCODER</var></code>.
|
|
</p>
|
|
<p>The option <code>-encoders</code> of the ff* tools will display the list of
|
|
enabled encoders.
|
|
</p>
|
|
|
|
<a name="Audio-Encoders"></a>
|
|
<h2 class="chapter">8 Audio Encoders<span class="pull-right"><a class="anchor hidden-xs" href="#Audio-Encoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Audio-Encoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>A description of some of the currently available audio encoders
|
|
follows.
|
|
</p>
|
|
<a name="aacenc"></a><a name="aac"></a>
|
|
<h3 class="section">8.1 aac<span class="pull-right"><a class="anchor hidden-xs" href="#aac" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-aac" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Advanced Audio Coding (AAC) encoder.
|
|
</p>
|
|
<p>This encoder is the default AAC encoder, natively implemented into FFmpeg. Its
|
|
quality is on par or better than libfdk_aac at the default bitrate of 128kbps.
|
|
This encoder also implements more options, profiles and samplerates than
|
|
other encoders (with only the AAC-HE profile pending to be implemented) so this
|
|
encoder has become the default and is the recommended choice.
|
|
</p>
|
|
<a name="Options-5"></a>
|
|
<h4 class="subsection">8.1.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-5" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-5" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Set bit rate in bits/s. Setting this automatically activates constant bit rate
|
|
(CBR) mode. If this option is unspecified it is set to 128kbps.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>q</samp></dt>
|
|
<dd><p>Set quality for variable bit rate (VBR) mode. This option is valid only using
|
|
the <code>ffmpeg</code> command-line tool. For library interface users, use
|
|
<samp>global_quality</samp>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>cutoff</samp></dt>
|
|
<dd><p>Set cutoff frequency. If unspecified will allow the encoder to dynamically
|
|
adjust the cutoff to improve clarity on low bitrates.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aac_coder</samp></dt>
|
|
<dd><p>Set AAC encoder coding method. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>twoloop</samp>’</dt>
|
|
<dd><p>Two loop searching (TLS) method.
|
|
</p>
|
|
<p>This method first sets quantizers depending on band thresholds and then tries
|
|
to find an optimal combination by adding or subtracting a specific value from
|
|
all quantizers and adjusting some individual quantizer a little. Will tune
|
|
itself based on whether <samp>aac_is</samp>, <samp>aac_ms</samp> and <samp>aac_pns</samp>
|
|
are enabled.
|
|
This is the default choice for a coder.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>anmr</samp>’</dt>
|
|
<dd><p>Average noise to mask ratio (ANMR) trellis-based solution.
|
|
</p>
|
|
<p>This is an experimental coder which currently produces a lower quality, is more
|
|
unstable and is slower than the default twoloop coder but has potential.
|
|
Currently has no support for the <samp>aac_is</samp> or <samp>aac_pns</samp> options.
|
|
Not currently recommended.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>fast</samp>’</dt>
|
|
<dd><p>Constant quantizer method.
|
|
</p>
|
|
<p>This method sets a constant quantizer for all bands. This is the fastest of all
|
|
the methods and has no rate control or support for <samp>aac_is</samp> or
|
|
<samp>aac_pns</samp>.
|
|
Not recommended.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>aac_ms</samp></dt>
|
|
<dd><p>Sets mid/side coding mode. The default value of "auto" will automatically use
|
|
M/S with bands which will benefit from such coding. Can be forced for all bands
|
|
using the value "enable", which is mainly useful for debugging or disabled using
|
|
"disable".
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aac_is</samp></dt>
|
|
<dd><p>Sets intensity stereo coding tool usage. By default, it’s enabled and will
|
|
automatically toggle IS for similar pairs of stereo bands if it’s benefitial.
|
|
Can be disabled for debugging by setting the value to "disable".
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aac_pns</samp></dt>
|
|
<dd><p>Uses perceptual noise substitution to replace low entropy high frequency bands
|
|
with imperceivable white noise during the decoding process. By default, it’s
|
|
enabled, but can be disabled for debugging purposes by using "disable".
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aac_tns</samp></dt>
|
|
<dd><p>Enables the use of a multitap FIR filter which spans through the high frequency
|
|
bands to hide quantization noise during the encoding process and is reverted
|
|
by the decoder. As well as decreasing unpleasant artifacts in the high range
|
|
this also reduces the entropy in the high bands and allows for more bits to
|
|
be used by the mid-low bands. By default it’s enabled but can be disabled for
|
|
debugging by setting the option to "disable".
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aac_ltp</samp></dt>
|
|
<dd><p>Enables the use of the long term prediction extension which increases coding
|
|
efficiency in very low bandwidth situations such as encoding of voice or
|
|
solo piano music by extending constant harmonic peaks in bands throughout
|
|
frames. This option is implied by profile:a aac_low and is incompatible with
|
|
aac_pred. Use in conjunction with <samp>-ar</samp> to decrease the samplerate.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aac_pred</samp></dt>
|
|
<dd><p>Enables the use of a more traditional style of prediction where the spectral
|
|
coefficients transmitted are replaced by the difference of the current
|
|
coefficients minus the previous "predicted" coefficients. In theory and sometimes
|
|
in practice this can improve quality for low to mid bitrate audio.
|
|
This option implies the aac_main profile and is incompatible with aac_ltp.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>profile</samp></dt>
|
|
<dd><p>Sets the encoding profile, possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>aac_low</samp>’</dt>
|
|
<dd><p>The default, AAC "Low-complexity" profile. Is the most compatible and produces
|
|
decent quality.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>mpeg2_aac_low</samp>’</dt>
|
|
<dd><p>Equivalent to <code>-profile:a aac_low -aac_pns 0</code>. PNS was introduced with the
|
|
MPEG4 specifications.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>aac_ltp</samp>’</dt>
|
|
<dd><p>Long term prediction profile, is enabled by and will enable the <samp>aac_ltp</samp>
|
|
option. Introduced in MPEG4.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>aac_main</samp>’</dt>
|
|
<dd><p>Main-type prediction profile, is enabled by and will enable the <samp>aac_pred</samp>
|
|
option. Introduced in MPEG2.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
<p>If this option is unspecified it is set to ‘<samp>aac_low</samp>’.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="ac3-and-ac3_005ffixed"></a>
|
|
<h3 class="section">8.2 ac3 and ac3_fixed<span class="pull-right"><a class="anchor hidden-xs" href="#ac3-and-ac3_005ffixed" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ac3-and-ac3_005ffixed" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>AC-3 audio encoders.
|
|
</p>
|
|
<p>These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
|
|
the undocumented RealAudio 3 (a.k.a. dnet).
|
|
</p>
|
|
<p>The <var>ac3</var> encoder uses floating-point math, while the <var>ac3_fixed</var>
|
|
encoder only uses fixed-point integer math. This does not mean that one is
|
|
always faster, just that one or the other may be better suited to a
|
|
particular system. The floating-point encoder will generally produce better
|
|
quality audio for a given bitrate. The <var>ac3_fixed</var> encoder is not the
|
|
default codec for any of the output formats, so it must be specified explicitly
|
|
using the option <code>-acodec ac3_fixed</code> in order to use it.
|
|
</p>
|
|
<a name="AC_002d3-Metadata"></a>
|
|
<h4 class="subsection">8.2.1 AC-3 Metadata<span class="pull-right"><a class="anchor hidden-xs" href="#AC_002d3-Metadata" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-AC_002d3-Metadata" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The AC-3 metadata options are used to set parameters that describe the audio,
|
|
but in most cases do not affect the audio encoding itself. Some of the options
|
|
do directly affect or influence the decoding and playback of the resulting
|
|
bitstream, while others are just for informational purposes. A few of the
|
|
options will add bits to the output stream that could otherwise be used for
|
|
audio data, and will thus affect the quality of the output. Those will be
|
|
indicated accordingly with a note in the option list below.
|
|
</p>
|
|
<p>These parameters are described in detail in several publicly-available
|
|
documents.
|
|
</p><ul>
|
|
<li> <a href="http://www.atsc.org/cms/standards/a_52-2010.pdf">A/52:2010 - Digital Audio Compression (AC-3) (E-AC-3) Standard</a>
|
|
</li><li> <a href="http://www.atsc.org/cms/standards/a_54a_with_corr_1.pdf">A/54 - Guide to the Use of the ATSC Digital Television Standard</a>
|
|
</li><li> <a href="http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf">Dolby Metadata Guide</a>
|
|
</li><li> <a href="http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf">Dolby Digital Professional Encoding Guidelines</a>
|
|
</li></ul>
|
|
|
|
<a name="Metadata-Control-Options"></a>
|
|
<h4 class="subsubsection">8.2.1.1 Metadata Control Options<span class="pull-right"><a class="anchor hidden-xs" href="#Metadata-Control-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Metadata-Control-Options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-per_frame_metadata <var>boolean</var></samp></dt>
|
|
<dd><p>Allow Per-Frame Metadata. Specifies if the encoder should check for changing
|
|
metadata for each frame.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dd><p>The metadata values set at initialization will be used for every frame in the
|
|
stream. (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dd><p>Metadata values can be changed before encoding each frame.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Downmix-Levels"></a>
|
|
<h4 class="subsubsection">8.2.1.2 Downmix Levels<span class="pull-right"><a class="anchor hidden-xs" href="#Downmix-Levels" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Downmix-Levels" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-center_mixlev <var>level</var></samp></dt>
|
|
<dd><p>Center Mix Level. The amount of gain the decoder should apply to the center
|
|
channel when downmixing to stereo. This field will only be written to the
|
|
bitstream if a center channel is present. The value is specified as a scale
|
|
factor. There are 3 valid values:
|
|
</p><dl compact="compact">
|
|
<dt><samp>0.707</samp></dt>
|
|
<dd><p>Apply -3dB gain
|
|
</p></dd>
|
|
<dt><samp>0.595</samp></dt>
|
|
<dd><p>Apply -4.5dB gain (default)
|
|
</p></dd>
|
|
<dt><samp>0.500</samp></dt>
|
|
<dd><p>Apply -6dB gain
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-surround_mixlev <var>level</var></samp></dt>
|
|
<dd><p>Surround Mix Level. The amount of gain the decoder should apply to the surround
|
|
channel(s) when downmixing to stereo. This field will only be written to the
|
|
bitstream if one or more surround channels are present. The value is specified
|
|
as a scale factor. There are 3 valid values:
|
|
</p><dl compact="compact">
|
|
<dt><samp>0.707</samp></dt>
|
|
<dd><p>Apply -3dB gain
|
|
</p></dd>
|
|
<dt><samp>0.500</samp></dt>
|
|
<dd><p>Apply -6dB gain (default)
|
|
</p></dd>
|
|
<dt><samp>0.000</samp></dt>
|
|
<dd><p>Silence Surround Channel(s)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Audio-Production-Information"></a>
|
|
<h4 class="subsubsection">8.2.1.3 Audio Production Information<span class="pull-right"><a class="anchor hidden-xs" href="#Audio-Production-Information" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Audio-Production-Information" aria-hidden="true">TOC</a></span></h4>
|
|
<p>Audio Production Information is optional information describing the mixing
|
|
environment. Either none or both of the fields are written to the bitstream.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>-mixing_level <var>number</var></samp></dt>
|
|
<dd><p>Mixing Level. Specifies peak sound pressure level (SPL) in the production
|
|
environment when the mix was mastered. Valid values are 80 to 111, or -1 for
|
|
unknown or not indicated. The default value is -1, but that value cannot be
|
|
used if the Audio Production Information is written to the bitstream. Therefore,
|
|
if the <code>room_type</code> option is not the default value, the <code>mixing_level</code>
|
|
option must not be -1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>-room_type <var>type</var></samp></dt>
|
|
<dd><p>Room Type. Describes the equalization used during the final mixing session at
|
|
the studio or on the dubbing stage. A large room is a dubbing stage with the
|
|
industry standard X-curve equalization; a small room has flat equalization.
|
|
This field will not be written to the bitstream if both the <code>mixing_level</code>
|
|
option and the <code>room_type</code> option have the default values.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>notindicated</samp></dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>large</samp></dt>
|
|
<dd><p>Large Room
|
|
</p></dd>
|
|
<dt><samp>2</samp></dt>
|
|
<dt><samp>small</samp></dt>
|
|
<dd><p>Small Room
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Other-Metadata-Options"></a>
|
|
<h4 class="subsubsection">8.2.1.4 Other Metadata Options<span class="pull-right"><a class="anchor hidden-xs" href="#Other-Metadata-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Other-Metadata-Options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-copyright <var>boolean</var></samp></dt>
|
|
<dd><p>Copyright Indicator. Specifies whether a copyright exists for this audio.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>off</samp></dt>
|
|
<dd><p>No Copyright Exists (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>on</samp></dt>
|
|
<dd><p>Copyright Exists
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-dialnorm <var>value</var></samp></dt>
|
|
<dd><p>Dialogue Normalization. Indicates how far the average dialogue level of the
|
|
program is below digital 100% full scale (0 dBFS). This parameter determines a
|
|
level shift during audio reproduction that sets the average volume of the
|
|
dialogue to a preset level. The goal is to match volume level between program
|
|
sources. A value of -31dB will result in no volume level change, relative to
|
|
the source volume, during audio reproduction. Valid values are whole numbers in
|
|
the range -31 to -1, with -31 being the default.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>-dsur_mode <var>mode</var></samp></dt>
|
|
<dd><p>Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
|
|
(Pro Logic). This field will only be written to the bitstream if the audio
|
|
stream is stereo. Using this option does <b>NOT</b> mean the encoder will actually
|
|
apply Dolby Surround processing.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>notindicated</samp></dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>off</samp></dt>
|
|
<dd><p>Not Dolby Surround Encoded
|
|
</p></dd>
|
|
<dt><samp>2</samp></dt>
|
|
<dt><samp>on</samp></dt>
|
|
<dd><p>Dolby Surround Encoded
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-original <var>boolean</var></samp></dt>
|
|
<dd><p>Original Bit Stream Indicator. Specifies whether this audio is from the
|
|
original source and not a copy.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>off</samp></dt>
|
|
<dd><p>Not Original Source
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>on</samp></dt>
|
|
<dd><p>Original Source (default)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Extended-Bitstream-Information"></a>
|
|
<h4 class="subsection">8.2.2 Extended Bitstream Information<span class="pull-right"><a class="anchor hidden-xs" href="#Extended-Bitstream-Information" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Extended-Bitstream-Information" aria-hidden="true">TOC</a></span></h4>
|
|
<p>The extended bitstream options are part of the Alternate Bit Stream Syntax as
|
|
specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
|
|
If any one parameter in a group is specified, all values in that group will be
|
|
written to the bitstream. Default values are used for those that are written
|
|
but have not been specified. If the mixing levels are written, the decoder
|
|
will use these values instead of the ones specified in the <code>center_mixlev</code>
|
|
and <code>surround_mixlev</code> options if it supports the Alternate Bit Stream
|
|
Syntax.
|
|
</p>
|
|
<a name="Extended-Bitstream-Information-_002d-Part-1"></a>
|
|
<h4 class="subsubsection">8.2.2.1 Extended Bitstream Information - Part 1<span class="pull-right"><a class="anchor hidden-xs" href="#Extended-Bitstream-Information-_002d-Part-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Extended-Bitstream-Information-_002d-Part-1" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-dmix_mode <var>mode</var></samp></dt>
|
|
<dd><p>Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
|
|
(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>notindicated</samp></dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>ltrt</samp></dt>
|
|
<dd><p>Lt/Rt Downmix Preferred
|
|
</p></dd>
|
|
<dt><samp>2</samp></dt>
|
|
<dt><samp>loro</samp></dt>
|
|
<dd><p>Lo/Ro Downmix Preferred
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-ltrt_cmixlev <var>level</var></samp></dt>
|
|
<dd><p>Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
|
|
center channel when downmixing to stereo in Lt/Rt mode.
|
|
</p><dl compact="compact">
|
|
<dt><samp>1.414</samp></dt>
|
|
<dd><p>Apply +3dB gain
|
|
</p></dd>
|
|
<dt><samp>1.189</samp></dt>
|
|
<dd><p>Apply +1.5dB gain
|
|
</p></dd>
|
|
<dt><samp>1.000</samp></dt>
|
|
<dd><p>Apply 0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.841</samp></dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt><samp>0.707</samp></dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.595</samp></dt>
|
|
<dd><p>Apply -4.5dB gain (default)
|
|
</p></dd>
|
|
<dt><samp>0.500</samp></dt>
|
|
<dd><p>Apply -6.0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.000</samp></dt>
|
|
<dd><p>Silence Center Channel
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-ltrt_surmixlev <var>level</var></samp></dt>
|
|
<dd><p>Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
|
|
surround channel(s) when downmixing to stereo in Lt/Rt mode.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0.841</samp></dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt><samp>0.707</samp></dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.595</samp></dt>
|
|
<dd><p>Apply -4.5dB gain
|
|
</p></dd>
|
|
<dt><samp>0.500</samp></dt>
|
|
<dd><p>Apply -6.0dB gain (default)
|
|
</p></dd>
|
|
<dt><samp>0.000</samp></dt>
|
|
<dd><p>Silence Surround Channel(s)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-loro_cmixlev <var>level</var></samp></dt>
|
|
<dd><p>Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
|
|
center channel when downmixing to stereo in Lo/Ro mode.
|
|
</p><dl compact="compact">
|
|
<dt><samp>1.414</samp></dt>
|
|
<dd><p>Apply +3dB gain
|
|
</p></dd>
|
|
<dt><samp>1.189</samp></dt>
|
|
<dd><p>Apply +1.5dB gain
|
|
</p></dd>
|
|
<dt><samp>1.000</samp></dt>
|
|
<dd><p>Apply 0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.841</samp></dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt><samp>0.707</samp></dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.595</samp></dt>
|
|
<dd><p>Apply -4.5dB gain (default)
|
|
</p></dd>
|
|
<dt><samp>0.500</samp></dt>
|
|
<dd><p>Apply -6.0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.000</samp></dt>
|
|
<dd><p>Silence Center Channel
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-loro_surmixlev <var>level</var></samp></dt>
|
|
<dd><p>Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
|
|
surround channel(s) when downmixing to stereo in Lo/Ro mode.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0.841</samp></dt>
|
|
<dd><p>Apply -1.5dB gain
|
|
</p></dd>
|
|
<dt><samp>0.707</samp></dt>
|
|
<dd><p>Apply -3.0dB gain
|
|
</p></dd>
|
|
<dt><samp>0.595</samp></dt>
|
|
<dd><p>Apply -4.5dB gain
|
|
</p></dd>
|
|
<dt><samp>0.500</samp></dt>
|
|
<dd><p>Apply -6.0dB gain (default)
|
|
</p></dd>
|
|
<dt><samp>0.000</samp></dt>
|
|
<dd><p>Silence Surround Channel(s)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Extended-Bitstream-Information-_002d-Part-2"></a>
|
|
<h4 class="subsubsection">8.2.2.2 Extended Bitstream Information - Part 2<span class="pull-right"><a class="anchor hidden-xs" href="#Extended-Bitstream-Information-_002d-Part-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Extended-Bitstream-Information-_002d-Part-2" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-dsurex_mode <var>mode</var></samp></dt>
|
|
<dd><p>Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
|
|
(7.1 matrixed to 5.1). Using this option does <b>NOT</b> mean the encoder will actually
|
|
apply Dolby Surround EX processing.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>notindicated</samp></dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>on</samp></dt>
|
|
<dd><p>Dolby Surround EX Off
|
|
</p></dd>
|
|
<dt><samp>2</samp></dt>
|
|
<dt><samp>off</samp></dt>
|
|
<dd><p>Dolby Surround EX On
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-dheadphone_mode <var>mode</var></samp></dt>
|
|
<dd><p>Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
|
|
encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
|
|
option does <b>NOT</b> mean the encoder will actually apply Dolby Headphone
|
|
processing.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>notindicated</samp></dt>
|
|
<dd><p>Not Indicated (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>on</samp></dt>
|
|
<dd><p>Dolby Headphone Off
|
|
</p></dd>
|
|
<dt><samp>2</samp></dt>
|
|
<dt><samp>off</samp></dt>
|
|
<dd><p>Dolby Headphone On
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-ad_conv_type <var>type</var></samp></dt>
|
|
<dd><p>A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
|
|
conversion.
|
|
</p><dl compact="compact">
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>standard</samp></dt>
|
|
<dd><p>Standard A/D Converter (default)
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>hdcd</samp></dt>
|
|
<dd><p>HDCD A/D Converter
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Other-AC_002d3-Encoding-Options"></a>
|
|
<h4 class="subsection">8.2.3 Other AC-3 Encoding Options<span class="pull-right"><a class="anchor hidden-xs" href="#Other-AC_002d3-Encoding-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Other-AC_002d3-Encoding-Options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-stereo_rematrixing <var>boolean</var></samp></dt>
|
|
<dd><p>Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
|
|
is an optional AC-3 feature that increases quality by selectively encoding
|
|
the left/right channels as mid/side. This option is enabled by default, and it
|
|
is highly recommended that it be left as enabled except for testing purposes.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options"></a>
|
|
<h4 class="subsection">8.2.4 Floating-Point-Only AC-3 Encoding Options<span class="pull-right"><a class="anchor hidden-xs" href="#Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Floating_002dPoint_002dOnly-AC_002d3-Encoding-Options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>These options are only valid for the floating-point encoder and do not exist
|
|
for the fixed-point encoder due to the corresponding features not being
|
|
implemented in fixed-point.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>-channel_coupling <var>boolean</var></samp></dt>
|
|
<dd><p>Enables/Disables use of channel coupling, which is an optional AC-3 feature
|
|
that increases quality by combining high frequency information from multiple
|
|
channels into a single channel. The per-channel high frequency information is
|
|
sent with less accuracy in both the frequency and time domains. This allows
|
|
more bits to be used for lower frequencies while preserving enough information
|
|
to reconstruct the high frequencies. This option is enabled by default for the
|
|
floating-point encoder and should generally be left as enabled except for
|
|
testing purposes or to increase encoding speed.
|
|
</p><dl compact="compact">
|
|
<dt><samp>-1</samp></dt>
|
|
<dt><samp>auto</samp></dt>
|
|
<dd><p>Selected by Encoder (default)
|
|
</p></dd>
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>off</samp></dt>
|
|
<dd><p>Disable Channel Coupling
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>on</samp></dt>
|
|
<dd><p>Enable Channel Coupling
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>-cpl_start_band <var>number</var></samp></dt>
|
|
<dd><p>Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
|
|
value higher than the bandwidth is used, it will be reduced to 1 less than the
|
|
coupling end band. If <var>auto</var> is used, the start band will be determined by
|
|
the encoder based on the bit rate, sample rate, and channel layout. This option
|
|
has no effect if channel coupling is disabled.
|
|
</p><dl compact="compact">
|
|
<dt><samp>-1</samp></dt>
|
|
<dt><samp>auto</samp></dt>
|
|
<dd><p>Selected by Encoder (default)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="flac"></a><a name="flac-2"></a>
|
|
<h3 class="section">8.3 flac<span class="pull-right"><a class="anchor hidden-xs" href="#flac-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-flac-2" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>FLAC (Free Lossless Audio Codec) Encoder
|
|
</p>
|
|
<a name="Options-6"></a>
|
|
<h4 class="subsection">8.3.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-6" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-6" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by FFmpeg’s flac encoder.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>compression_level</samp></dt>
|
|
<dd><p>Sets the compression level, which chooses defaults for many other options
|
|
if they are not set explicitly.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>frame_size</samp></dt>
|
|
<dd><p>Sets the size of the frames in samples per channel.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>lpc_coeff_precision</samp></dt>
|
|
<dd><p>Sets the LPC coefficient precision, valid values are from 1 to 15, 15 is the
|
|
default.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>lpc_type</samp></dt>
|
|
<dd><p>Sets the first stage LPC algorithm
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>none</samp>’</dt>
|
|
<dd><p>LPC is not used
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>fixed</samp>’</dt>
|
|
<dd><p>fixed LPC coefficients
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>levinson</samp>’</dt>
|
|
<dt>‘<samp>cholesky</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>lpc_passes</samp></dt>
|
|
<dd><p>Number of passes to use for Cholesky factorization during LPC analysis
|
|
</p>
|
|
</dd>
|
|
<dt><samp>min_partition_order</samp></dt>
|
|
<dd><p>The minimum partition order
|
|
</p>
|
|
</dd>
|
|
<dt><samp>max_partition_order</samp></dt>
|
|
<dd><p>The maximum partition order
|
|
</p>
|
|
</dd>
|
|
<dt><samp>prediction_order_method</samp></dt>
|
|
<dd><dl compact="compact">
|
|
<dt>‘<samp>estimation</samp>’</dt>
|
|
<dt>‘<samp>2level</samp>’</dt>
|
|
<dt>‘<samp>4level</samp>’</dt>
|
|
<dt>‘<samp>8level</samp>’</dt>
|
|
<dt>‘<samp>search</samp>’</dt>
|
|
<dd><p>Bruteforce search
|
|
</p></dd>
|
|
<dt>‘<samp>log</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>ch_mode</samp></dt>
|
|
<dd><p>Channel mode
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>auto</samp>’</dt>
|
|
<dd><p>The mode is chosen automatically for each frame
|
|
</p></dd>
|
|
<dt>‘<samp>indep</samp>’</dt>
|
|
<dd><p>Chanels are independently coded
|
|
</p></dd>
|
|
<dt>‘<samp>left_side</samp>’</dt>
|
|
<dt>‘<samp>right_side</samp>’</dt>
|
|
<dt>‘<samp>mid_side</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>exact_rice_parameters</samp></dt>
|
|
<dd><p>Chooses if rice parameters are calculated exactly or approximately.
|
|
if set to 1 then they are chosen exactly, which slows the code down slightly and
|
|
improves compression slightly.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>multi_dim_quant</samp></dt>
|
|
<dd><p>Multi Dimensional Quantization. If set to 1 then a 2nd stage LPC algorithm is
|
|
applied after the first stage to finetune the coefficients. This is quite slow
|
|
and slightly improves compression.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libfdk_002daac_002denc"></a><a name="libfdk_005faac"></a>
|
|
<h3 class="section">8.4 libfdk_aac<span class="pull-right"><a class="anchor hidden-xs" href="#libfdk_005faac" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libfdk_005faac" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
|
|
</p>
|
|
<p>The libfdk-aac library is based on the Fraunhofer FDK AAC code from
|
|
the Android project.
|
|
</p>
|
|
<p>Requires the presence of the libfdk-aac headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libfdk-aac</code>. The library is also incompatible with GPL,
|
|
so if you allow the use of GPL, you should configure with
|
|
<code>--enable-gpl --enable-nonfree --enable-libfdk-aac</code>.
|
|
</p>
|
|
<p>This encoder is considered to produce output on par or worse at 128kbps to the
|
|
<a href="#aacenc">the native FFmpeg AAC encoder</a> but can often produce better
|
|
sounding audio at identical or lower bitrates and has support for the
|
|
AAC-HE profiles.
|
|
</p>
|
|
<p>VBR encoding, enabled through the <samp>vbr</samp> or <samp>flags
|
|
+qscale</samp> options, is experimental and only works with some
|
|
combinations of parameters.
|
|
</p>
|
|
<p>Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
|
|
higher.
|
|
</p>
|
|
<p>For more information see the fdk-aac project at
|
|
<a href="http://sourceforge.net/p/opencore-amr/fdk-aac/">http://sourceforge.net/p/opencore-amr/fdk-aac/</a>.
|
|
</p>
|
|
<a name="Options-7"></a>
|
|
<h4 class="subsection">8.4.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-7" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-7" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are mapped on the shared FFmpeg codec options.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Set bit rate in bits/s. If the bitrate is not explicitly specified, it
|
|
is automatically set to a suitable value depending on the selected
|
|
profile.
|
|
</p>
|
|
<p>In case VBR mode is enabled the option is ignored.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ar</samp></dt>
|
|
<dd><p>Set audio sampling rate (in Hz).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>channels</samp></dt>
|
|
<dd><p>Set the number of audio channels.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>flags +qscale</samp></dt>
|
|
<dd><p>Enable fixed quality, VBR (Variable Bit Rate) mode.
|
|
Note that VBR is implicitly enabled when the <samp>vbr</samp> value is
|
|
positive.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>cutoff</samp></dt>
|
|
<dd><p>Set cutoff frequency. If not specified (or explicitly set to 0) it
|
|
will use a value automatically computed by the library. Default value
|
|
is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>profile</samp></dt>
|
|
<dd><p>Set audio profile.
|
|
</p>
|
|
<p>The following profiles are recognized:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>aac_low</samp>’</dt>
|
|
<dd><p>Low Complexity AAC (LC)
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>aac_he</samp>’</dt>
|
|
<dd><p>High Efficiency AAC (HE-AAC)
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>aac_he_v2</samp>’</dt>
|
|
<dd><p>High Efficiency AAC version 2 (HE-AACv2)
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>aac_ld</samp>’</dt>
|
|
<dd><p>Low Delay AAC (LD)
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>aac_eld</samp>’</dt>
|
|
<dd><p>Enhanced Low Delay AAC (ELD)
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>If not specified it is set to ‘<samp>aac_low</samp>’.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The following are private options of the libfdk_aac encoder.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>afterburner</samp></dt>
|
|
<dd><p>Enable afterburner feature if set to 1, disabled if set to 0. This
|
|
improves the quality but also the required processing power.
|
|
</p>
|
|
<p>Default value is 1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>eld_sbr</samp></dt>
|
|
<dd><p>Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
|
|
if set to 0.
|
|
</p>
|
|
<p>Default value is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>signaling</samp></dt>
|
|
<dd><p>Set SBR/PS signaling style.
|
|
</p>
|
|
<p>It can assume one of the following values:
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>default</samp>’</dt>
|
|
<dd><p>choose signaling implicitly (explicit hierarchical by default,
|
|
implicit if global header is disabled)
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>implicit</samp>’</dt>
|
|
<dd><p>implicit backwards compatible signaling
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>explicit_sbr</samp>’</dt>
|
|
<dd><p>explicit SBR, implicit PS signaling
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>explicit_hierarchical</samp>’</dt>
|
|
<dd><p>explicit hierarchical signaling
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is ‘<samp>default</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>latm</samp></dt>
|
|
<dd><p>Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
|
|
</p>
|
|
<p>Default value is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>header_period</samp></dt>
|
|
<dd><p>Set StreamMuxConfig and PCE repetition period (in frames) for sending
|
|
in-band configuration buffers within LATM/LOAS transport layer.
|
|
</p>
|
|
<p>Must be a 16-bits non-negative integer.
|
|
</p>
|
|
<p>Default value is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>vbr</samp></dt>
|
|
<dd><p>Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
|
|
good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
|
|
(Constant Bit Rate) is enabled.
|
|
</p>
|
|
<p>Currently only the ‘<samp>aac_low</samp>’ profile supports VBR encoding.
|
|
</p>
|
|
<p>VBR modes 1-5 correspond to roughly the following average bit rates:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>1</samp>’</dt>
|
|
<dd><p>32 kbps/channel
|
|
</p></dd>
|
|
<dt>‘<samp>2</samp>’</dt>
|
|
<dd><p>40 kbps/channel
|
|
</p></dd>
|
|
<dt>‘<samp>3</samp>’</dt>
|
|
<dd><p>48-56 kbps/channel
|
|
</p></dd>
|
|
<dt>‘<samp>4</samp>’</dt>
|
|
<dd><p>64 kbps/channel
|
|
</p></dd>
|
|
<dt>‘<samp>5</samp>’</dt>
|
|
<dd><p>about 80-96 kbps/channel
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is 0.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Examples"></a>
|
|
<h4 class="subsection">8.4.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<ul>
|
|
<li> Use <code>ffmpeg</code> to convert an audio file to VBR AAC in an M4A (MP4)
|
|
container:
|
|
<div class="example">
|
|
<pre class="example">ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
|
|
</pre></div>
|
|
|
|
</li><li> Use <code>ffmpeg</code> to convert an audio file to CBR 64k kbps AAC, using the
|
|
High-Efficiency AAC profile:
|
|
<div class="example">
|
|
<pre class="example">ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
|
|
</pre></div>
|
|
</li></ul>
|
|
|
|
<a name="libmp3lame"></a><a name="libmp3lame-1"></a>
|
|
<h3 class="section">8.5 libmp3lame<span class="pull-right"><a class="anchor hidden-xs" href="#libmp3lame-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libmp3lame-1" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>LAME (Lame Ain’t an MP3 Encoder) MP3 encoder wrapper.
|
|
</p>
|
|
<p>Requires the presence of the libmp3lame headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libmp3lame</code>.
|
|
</p>
|
|
<p>See <a href="#libshine">libshine</a> for a fixed-point MP3 encoder, although with a
|
|
lower quality.
|
|
</p>
|
|
<a name="Options-8"></a>
|
|
<h4 class="subsection">8.5.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-8" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-8" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by the libmp3lame wrapper. The
|
|
<code>lame</code>-equivalent of the options are listed in parentheses.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b (<em>-b</em>)</samp></dt>
|
|
<dd><p>Set bitrate expressed in bits/s for CBR or ABR. LAME <code>bitrate</code> is
|
|
expressed in kilobits/s.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>q (<em>-V</em>)</samp></dt>
|
|
<dd><p>Set constant quality setting for VBR. This option is valid only
|
|
using the <code>ffmpeg</code> command-line tool. For library interface
|
|
users, use <samp>global_quality</samp>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>compression_level (<em>-q</em>)</samp></dt>
|
|
<dd><p>Set algorithm quality. Valid arguments are integers in the 0-9 range,
|
|
with 0 meaning highest quality but slowest, and 9 meaning fastest
|
|
while producing the worst quality.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>reservoir</samp></dt>
|
|
<dd><p>Enable use of bit reservoir when set to 1. Default value is 1. LAME
|
|
has this enabled by default, but can be overridden by use
|
|
<samp>--nores</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>joint_stereo (<em>-m j</em>)</samp></dt>
|
|
<dd><p>Enable the encoder to use (on a frame by frame basis) either L/R
|
|
stereo or mid/side stereo. Default value is 1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>abr (<em>--abr</em>)</samp></dt>
|
|
<dd><p>Enable the encoder to use ABR when set to 1. The <code>lame</code>
|
|
<samp>--abr</samp> sets the target bitrate, while this options only
|
|
tells FFmpeg to use ABR still relies on <samp>b</samp> to set bitrate.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libopencore_002damrnb-1"></a>
|
|
<h3 class="section">8.6 libopencore-amrnb<span class="pull-right"><a class="anchor hidden-xs" href="#libopencore_002damrnb-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libopencore_002damrnb-1" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>OpenCORE Adaptive Multi-Rate Narrowband encoder.
|
|
</p>
|
|
<p>Requires the presence of the libopencore-amrnb headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libopencore-amrnb --enable-version3</code>.
|
|
</p>
|
|
<p>This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
|
|
but you can override it by setting <samp>strict</samp> to ‘<samp>unofficial</samp>’ or
|
|
lower.
|
|
</p>
|
|
<a name="Options-9"></a>
|
|
<h4 class="subsection">8.6.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-9" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-9" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Set bitrate in bits per second. Only the following bitrates are supported,
|
|
otherwise libavcodec will round to the nearest valid bitrate.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>4750</samp></dt>
|
|
<dt><samp>5150</samp></dt>
|
|
<dt><samp>5900</samp></dt>
|
|
<dt><samp>6700</samp></dt>
|
|
<dt><samp>7400</samp></dt>
|
|
<dt><samp>7950</samp></dt>
|
|
<dt><samp>10200</samp></dt>
|
|
<dt><samp>12200</samp></dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>dtx</samp></dt>
|
|
<dd><p>Allow discontinuous transmission (generate comfort noise) when set to 1. The
|
|
default value is 0 (disabled).
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libshine"></a><a name="libshine-1"></a>
|
|
<h3 class="section">8.7 libshine<span class="pull-right"><a class="anchor hidden-xs" href="#libshine-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libshine-1" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Shine Fixed-Point MP3 encoder wrapper.
|
|
</p>
|
|
<p>Shine is a fixed-point MP3 encoder. It has a far better performance on
|
|
platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
|
|
However, as it is more targeted on performance than quality, it is not on par
|
|
with LAME and other production-grade encoders quality-wise. Also, according to
|
|
the project’s homepage, this encoder may not be free of bugs as the code was
|
|
written a long time ago and the project was dead for at least 5 years.
|
|
</p>
|
|
<p>This encoder only supports stereo and mono input. This is also CBR-only.
|
|
</p>
|
|
<p>The original project (last updated in early 2007) is at
|
|
<a href="http://sourceforge.net/projects/libshine-fxp/">http://sourceforge.net/projects/libshine-fxp/</a>. We only support the
|
|
updated fork by the Savonet/Liquidsoap project at <a href="https://github.com/savonet/shine">https://github.com/savonet/shine</a>.
|
|
</p>
|
|
<p>Requires the presence of the libshine headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libshine</code>.
|
|
</p>
|
|
<p>See also <a href="#libmp3lame">libmp3lame</a>.
|
|
</p>
|
|
<a name="Options-10"></a>
|
|
<h4 class="subsection">8.7.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-10" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-10" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by the libshine wrapper. The
|
|
<code>shineenc</code>-equivalent of the options are listed in parentheses.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b (<em>-b</em>)</samp></dt>
|
|
<dd><p>Set bitrate expressed in bits/s for CBR. <code>shineenc</code> <samp>-b</samp> option
|
|
is expressed in kilobits/s.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libtwolame"></a>
|
|
<h3 class="section">8.8 libtwolame<span class="pull-right"><a class="anchor hidden-xs" href="#libtwolame" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libtwolame" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>TwoLAME MP2 encoder wrapper.
|
|
</p>
|
|
<p>Requires the presence of the libtwolame headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libtwolame</code>.
|
|
</p>
|
|
<a name="Options-11"></a>
|
|
<h4 class="subsection">8.8.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-11" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-11" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by the libtwolame wrapper. The
|
|
<code>twolame</code>-equivalent options follow the FFmpeg ones and are in
|
|
parentheses.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b (<em>-b</em>)</samp></dt>
|
|
<dd><p>Set bitrate expressed in bits/s for CBR. <code>twolame</code> <samp>b</samp>
|
|
option is expressed in kilobits/s. Default value is 128k.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>q (<em>-V</em>)</samp></dt>
|
|
<dd><p>Set quality for experimental VBR support. Maximum value range is
|
|
from -50 to 50, useful range is from -10 to 10. The higher the
|
|
value, the better the quality. This option is valid only using the
|
|
<code>ffmpeg</code> command-line tool. For library interface users,
|
|
use <samp>global_quality</samp>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mode (<em>--mode</em>)</samp></dt>
|
|
<dd><p>Set the mode of the resulting audio. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>auto</samp>’</dt>
|
|
<dd><p>Choose mode automatically based on the input. This is the default.
|
|
</p></dd>
|
|
<dt>‘<samp>stereo</samp>’</dt>
|
|
<dd><p>Stereo
|
|
</p></dd>
|
|
<dt>‘<samp>joint_stereo</samp>’</dt>
|
|
<dd><p>Joint stereo
|
|
</p></dd>
|
|
<dt>‘<samp>dual_channel</samp>’</dt>
|
|
<dd><p>Dual channel
|
|
</p></dd>
|
|
<dt>‘<samp>mono</samp>’</dt>
|
|
<dd><p>Mono
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>psymodel (<em>--psyc-mode</em>)</samp></dt>
|
|
<dd><p>Set psychoacoustic model to use in encoding. The argument must be
|
|
an integer between -1 and 4, inclusive. The higher the value, the
|
|
better the quality. The default value is 3.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>energy_levels (<em>--energy</em>)</samp></dt>
|
|
<dd><p>Enable energy levels extensions when set to 1. The default value is
|
|
0 (disabled).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>error_protection (<em>--protect</em>)</samp></dt>
|
|
<dd><p>Enable CRC error protection when set to 1. The default value is 0
|
|
(disabled).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>copyright (<em>--copyright</em>)</samp></dt>
|
|
<dd><p>Set MPEG audio copyright flag when set to 1. The default value is 0
|
|
(disabled).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>original (<em>--original</em>)</samp></dt>
|
|
<dd><p>Set MPEG audio original flag when set to 1. The default value is 0
|
|
(disabled).
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libvo_002damrwbenc"></a>
|
|
<h3 class="section">8.9 libvo-amrwbenc<span class="pull-right"><a class="anchor hidden-xs" href="#libvo_002damrwbenc" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libvo_002damrwbenc" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>VisualOn Adaptive Multi-Rate Wideband encoder.
|
|
</p>
|
|
<p>Requires the presence of the libvo-amrwbenc headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libvo-amrwbenc --enable-version3</code>.
|
|
</p>
|
|
<p>This is a mono-only encoder. Officially it only supports 16000Hz sample
|
|
rate, but you can override it by setting <samp>strict</samp> to
|
|
‘<samp>unofficial</samp>’ or lower.
|
|
</p>
|
|
<a name="Options-12"></a>
|
|
<h4 class="subsection">8.9.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-12" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-12" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Set bitrate in bits/s. Only the following bitrates are supported, otherwise
|
|
libavcodec will round to the nearest valid bitrate.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>6600</samp>’</dt>
|
|
<dt>‘<samp>8850</samp>’</dt>
|
|
<dt>‘<samp>12650</samp>’</dt>
|
|
<dt>‘<samp>14250</samp>’</dt>
|
|
<dt>‘<samp>15850</samp>’</dt>
|
|
<dt>‘<samp>18250</samp>’</dt>
|
|
<dt>‘<samp>19850</samp>’</dt>
|
|
<dt>‘<samp>23050</samp>’</dt>
|
|
<dt>‘<samp>23850</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>dtx</samp></dt>
|
|
<dd><p>Allow discontinuous transmission (generate comfort noise) when set to 1. The
|
|
default value is 0 (disabled).
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libopus-1"></a>
|
|
<h3 class="section">8.10 libopus<span class="pull-right"><a class="anchor hidden-xs" href="#libopus-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libopus-1" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libopus Opus Interactive Audio Codec encoder wrapper.
|
|
</p>
|
|
<p>Requires the presence of the libopus headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libopus</code>.
|
|
</p>
|
|
<a name="Option-Mapping"></a>
|
|
<h4 class="subsection">8.10.1 Option Mapping<span class="pull-right"><a class="anchor hidden-xs" href="#Option-Mapping" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Option-Mapping" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>Most libopus options are modelled after the <code>opusenc</code> utility from
|
|
opus-tools. The following is an option mapping chart describing options
|
|
supported by the libopus wrapper, and their <code>opusenc</code>-equivalent
|
|
in parentheses.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b (<em>bitrate</em>)</samp></dt>
|
|
<dd><p>Set the bit rate in bits/s. FFmpeg’s <samp>b</samp> option is
|
|
expressed in bits/s, while <code>opusenc</code>’s <samp>bitrate</samp> in
|
|
kilobits/s.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>vbr (<em>vbr</em>, <em>hard-cbr</em>, and <em>cvbr</em>)</samp></dt>
|
|
<dd><p>Set VBR mode. The FFmpeg <samp>vbr</samp> option has the following
|
|
valid arguments, with the <code>opusenc</code> equivalent options
|
|
in parentheses:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>off (<em>hard-cbr</em>)</samp>’</dt>
|
|
<dd><p>Use constant bit rate encoding.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>on (<em>vbr</em>)</samp>’</dt>
|
|
<dd><p>Use variable bit rate encoding (the default).
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>constrained (<em>cvbr</em>)</samp>’</dt>
|
|
<dd><p>Use constrained variable bit rate encoding.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>compression_level (<em>comp</em>)</samp></dt>
|
|
<dd><p>Set encoding algorithm complexity. Valid options are integers in
|
|
the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
|
|
gives the highest quality but slowest encoding. The default is 10.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>frame_duration (<em>framesize</em>)</samp></dt>
|
|
<dd><p>Set maximum frame size, or duration of a frame in milliseconds. The
|
|
argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
|
|
frame sizes achieve lower latency but less quality at a given bitrate.
|
|
Sizes greater than 20ms are only interesting at fairly low bitrates.
|
|
The default is 20ms.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>packet_loss (<em>expect-loss</em>)</samp></dt>
|
|
<dd><p>Set expected packet loss percentage. The default is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>application (N.A.)</samp></dt>
|
|
<dd><p>Set intended application type. Valid options are listed below:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>voip</samp>’</dt>
|
|
<dd><p>Favor improved speech intelligibility.
|
|
</p></dd>
|
|
<dt>‘<samp>audio</samp>’</dt>
|
|
<dd><p>Favor faithfulness to the input (the default).
|
|
</p></dd>
|
|
<dt>‘<samp>lowdelay</samp>’</dt>
|
|
<dd><p>Restrict to only the lowest delay modes.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>cutoff (N.A.)</samp></dt>
|
|
<dd><p>Set cutoff bandwidth in Hz. The argument must be exactly one of the
|
|
following: 4000, 6000, 8000, 12000, or 20000, corresponding to
|
|
narrowband, mediumband, wideband, super wideband, and fullband
|
|
respectively. The default is 0 (cutoff disabled).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mapping_family (<em>mapping_family</em>)</samp></dt>
|
|
<dd><p>Set channel mapping family to be used by the encoder. The default value of -1
|
|
uses mapping family 0 for mono and stereo inputs, and mapping family 1
|
|
otherwise. The default also disables the surround masking and LFE bandwidth
|
|
optimzations in libopus, and requires that the input contains 8 channels or
|
|
fewer.
|
|
</p>
|
|
<p>Other values include 0 for mono and stereo, 1 for surround sound with masking
|
|
and LFE bandwidth optimizations, and 255 for independent streams with an
|
|
unspecified channel layout.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libvorbis"></a>
|
|
<h3 class="section">8.11 libvorbis<span class="pull-right"><a class="anchor hidden-xs" href="#libvorbis" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libvorbis" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libvorbis encoder wrapper.
|
|
</p>
|
|
<p>Requires the presence of the libvorbisenc headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libvorbis</code>.
|
|
</p>
|
|
<a name="Options-13"></a>
|
|
<h4 class="subsection">8.11.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-13" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-13" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by the libvorbis wrapper. The
|
|
<code>oggenc</code>-equivalent of the options are listed in parentheses.
|
|
</p>
|
|
<p>To get a more accurate and extensive documentation of the libvorbis
|
|
options, consult the libvorbisenc’s and <code>oggenc</code>’s documentations.
|
|
See <a href="http://xiph.org/vorbis/">http://xiph.org/vorbis/</a>,
|
|
<a href="http://wiki.xiph.org/Vorbis-tools">http://wiki.xiph.org/Vorbis-tools</a>, and oggenc(1).
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b (<em>-b</em>)</samp></dt>
|
|
<dd><p>Set bitrate expressed in bits/s for ABR. <code>oggenc</code> <samp>-b</samp> is
|
|
expressed in kilobits/s.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>q (<em>-q</em>)</samp></dt>
|
|
<dd><p>Set constant quality setting for VBR. The value should be a float
|
|
number in the range of -1.0 to 10.0. The higher the value, the better
|
|
the quality. The default value is ‘<samp>3.0</samp>’.
|
|
</p>
|
|
<p>This option is valid only using the <code>ffmpeg</code> command-line tool.
|
|
For library interface users, use <samp>global_quality</samp>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>cutoff (<em>--advanced-encode-option lowpass_frequency=N</em>)</samp></dt>
|
|
<dd><p>Set cutoff bandwidth in Hz, a value of 0 disables cutoff. <code>oggenc</code>’s
|
|
related option is expressed in kHz. The default value is ‘<samp>0</samp>’ (cutoff
|
|
disabled).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>minrate (<em>-m</em>)</samp></dt>
|
|
<dd><p>Set minimum bitrate expressed in bits/s. <code>oggenc</code> <samp>-m</samp> is
|
|
expressed in kilobits/s.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>maxrate (<em>-M</em>)</samp></dt>
|
|
<dd><p>Set maximum bitrate expressed in bits/s. <code>oggenc</code> <samp>-M</samp> is
|
|
expressed in kilobits/s. This only has effect on ABR mode.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>iblock (<em>--advanced-encode-option impulse_noisetune=N</em>)</samp></dt>
|
|
<dd><p>Set noise floor bias for impulse blocks. The value is a float number from
|
|
-15.0 to 0.0. A negative bias instructs the encoder to pay special attention
|
|
to the crispness of transients in the encoded audio. The tradeoff for better
|
|
transient response is a higher bitrate.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libwavpack"></a><a name="libwavpack-1"></a>
|
|
<h3 class="section">8.12 libwavpack<span class="pull-right"><a class="anchor hidden-xs" href="#libwavpack-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libwavpack-1" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>A wrapper providing WavPack encoding through libwavpack.
|
|
</p>
|
|
<p>Only lossless mode using 32-bit integer samples is supported currently.
|
|
</p>
|
|
<p>Requires the presence of the libwavpack headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libwavpack</code>.
|
|
</p>
|
|
<p>Note that a libavcodec-native encoder for the WavPack codec exists so users can
|
|
encode audios with this codec without using this encoder. See <a href="#wavpackenc">wavpackenc</a>.
|
|
</p>
|
|
<a name="Options-14"></a>
|
|
<h4 class="subsection">8.12.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-14" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-14" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p><code>wavpack</code> command line utility’s corresponding options are listed in
|
|
parentheses, if any.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>frame_size (<em>--blocksize</em>)</samp></dt>
|
|
<dd><p>Default is 32768.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>compression_level</samp></dt>
|
|
<dd><p>Set speed vs. compression tradeoff. Acceptable arguments are listed below:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>0 (<em>-f</em>)</samp>’</dt>
|
|
<dd><p>Fast mode.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>1</samp>’</dt>
|
|
<dd><p>Normal (default) settings.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>2 (<em>-h</em>)</samp>’</dt>
|
|
<dd><p>High quality.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>3 (<em>-hh</em>)</samp>’</dt>
|
|
<dd><p>Very high quality.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>4-8 (<em>-hh -x</em><var>EXTRAPROC</var>)</samp>’</dt>
|
|
<dd><p>Same as ‘<samp>3</samp>’, but with extra processing enabled.
|
|
</p>
|
|
<p>‘<samp>4</samp>’ is the same as <samp>-x2</samp> and ‘<samp>8</samp>’ is the same as <samp>-x6</samp>.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="wavpackenc"></a><a name="wavpack"></a>
|
|
<h3 class="section">8.13 wavpack<span class="pull-right"><a class="anchor hidden-xs" href="#wavpack" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-wavpack" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>WavPack lossless audio encoder.
|
|
</p>
|
|
<p>This is a libavcodec-native WavPack encoder. There is also an encoder based on
|
|
libwavpack, but there is virtually no reason to use that encoder.
|
|
</p>
|
|
<p>See also <a href="#libwavpack">libwavpack</a>.
|
|
</p>
|
|
<a name="Options-15"></a>
|
|
<h4 class="subsection">8.13.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-15" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-15" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The equivalent options for <code>wavpack</code> command line utility are listed in
|
|
parentheses.
|
|
</p>
|
|
<a name="Shared-options"></a>
|
|
<h4 class="subsubsection">8.13.1.1 Shared options<span class="pull-right"><a class="anchor hidden-xs" href="#Shared-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Shared-options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following shared options are effective for this encoder. Only special notes
|
|
about this particular encoder will be documented here. For the general meaning
|
|
of the options, see <a href="#codec_002doptions">the Codec Options chapter</a>.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>frame_size (<em>--blocksize</em>)</samp></dt>
|
|
<dd><p>For this encoder, the range for this option is between 128 and 131072. Default
|
|
is automatically decided based on sample rate and number of channel.
|
|
</p>
|
|
<p>For the complete formula of calculating default, see
|
|
<samp>libavcodec/wavpackenc.c</samp>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>compression_level (<em>-f</em>, <em>-h</em>, <em>-hh</em>, and <em>-x</em>)</samp></dt>
|
|
<dd><p>This option’s syntax is consistent with <a href="#libwavpack">libwavpack</a>’s.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Private-options"></a>
|
|
<h4 class="subsubsection">8.13.1.2 Private options<span class="pull-right"><a class="anchor hidden-xs" href="#Private-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Private-options" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>joint_stereo (<em>-j</em>)</samp></dt>
|
|
<dd><p>Set whether to enable joint stereo. Valid values are:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>on (<em>1</em>)</samp>’</dt>
|
|
<dd><p>Force mid/side audio encoding.
|
|
</p></dd>
|
|
<dt>‘<samp>off (<em>0</em>)</samp>’</dt>
|
|
<dd><p>Force left/right audio encoding.
|
|
</p></dd>
|
|
<dt>‘<samp>auto</samp>’</dt>
|
|
<dd><p>Let the encoder decide automatically.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>optimize_mono</samp></dt>
|
|
<dd><p>Set whether to enable optimization for mono. This option is only effective for
|
|
non-mono streams. Available values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>on</samp>’</dt>
|
|
<dd><p>enabled
|
|
</p></dd>
|
|
<dt>‘<samp>off</samp>’</dt>
|
|
<dd><p>disabled
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
|
|
<a name="Video-Encoders"></a>
|
|
<h2 class="chapter">9 Video Encoders<span class="pull-right"><a class="anchor hidden-xs" href="#Video-Encoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-Encoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>A description of some of the currently available video encoders
|
|
follows.
|
|
</p>
|
|
<a name="libopenh264"></a>
|
|
<h3 class="section">9.1 libopenh264<span class="pull-right"><a class="anchor hidden-xs" href="#libopenh264" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libopenh264" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper.
|
|
</p>
|
|
<p>This encoder requires the presence of the libopenh264 headers and
|
|
library during configuration. You need to explicitly configure the
|
|
build with <code>--enable-libopenh264</code>. The library is detected using
|
|
<code>pkg-config</code>.
|
|
</p>
|
|
<p>For more information about the library see
|
|
<a href="http://www.openh264.org">http://www.openh264.org</a>.
|
|
</p>
|
|
<a name="Options-16"></a>
|
|
<h4 class="subsection">9.1.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-16" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-16" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following FFmpeg global options affect the configurations of the
|
|
libopenh264 encoder.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Set the bitrate (as a number of bits per second).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>g</samp></dt>
|
|
<dd><p>Set the GOP size.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>maxrate</samp></dt>
|
|
<dd><p>Set the max bitrate (as a number of bits per second).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>flags +global_header</samp></dt>
|
|
<dd><p>Set global header in the bitstream.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>slices</samp></dt>
|
|
<dd><p>Set the number of slices, used in parallelized encoding. Default value
|
|
is 0. This is only used when <samp>slice_mode</samp> is set to
|
|
‘<samp>fixed</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>slice_mode</samp></dt>
|
|
<dd><p>Set slice mode. Can assume one of the following possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>fixed</samp>’</dt>
|
|
<dd><p>a fixed number of slices
|
|
</p></dd>
|
|
<dt>‘<samp>rowmb</samp>’</dt>
|
|
<dd><p>one slice per row of macroblocks
|
|
</p></dd>
|
|
<dt>‘<samp>auto</samp>’</dt>
|
|
<dd><p>automatic number of slices according to number of threads
|
|
</p></dd>
|
|
<dt>‘<samp>dyn</samp>’</dt>
|
|
<dd><p>dynamic slicing
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is ‘<samp>auto</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>loopfilter</samp></dt>
|
|
<dd><p>Enable loop filter, if set to 1 (automatically enabled). To disable
|
|
set a value of 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>profile</samp></dt>
|
|
<dd><p>Set profile restrictions. If set to the value of ‘<samp>main</samp>’ enable
|
|
CABAC (set the <code>SEncParamExt.iEntropyCodingModeFlag</code> flag to 1).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>max_nal_size</samp></dt>
|
|
<dd><p>Set maximum NAL size in bytes.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>allow_skip_frames</samp></dt>
|
|
<dd><p>Allow skipping frames to hit the target bitrate if set to 1.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="jpeg2000"></a>
|
|
<h3 class="section">9.2 jpeg2000<span class="pull-right"><a class="anchor hidden-xs" href="#jpeg2000" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-jpeg2000" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>The native jpeg 2000 encoder is lossy by default, the <code>-q:v</code>
|
|
option can be used to set the encoding quality. Lossless encoding
|
|
can be selected with <code>-pred 1</code>.
|
|
</p>
|
|
<a name="Options-17"></a>
|
|
<h4 class="subsection">9.2.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-17" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-17" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>format</samp></dt>
|
|
<dd><p>Can be set to either <code>j2k</code> or <code>jp2</code> (the default) that
|
|
makes it possible to store non-rgb pix_fmts.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="snow"></a>
|
|
<h3 class="section">9.3 snow<span class="pull-right"><a class="anchor hidden-xs" href="#snow" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-snow" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<a name="Options-18"></a>
|
|
<h4 class="subsection">9.3.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-18" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-18" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>iterative_dia_size</samp></dt>
|
|
<dd><p>dia size for the iterative motion estimation
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="libtheora"></a>
|
|
<h3 class="section">9.4 libtheora<span class="pull-right"><a class="anchor hidden-xs" href="#libtheora" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libtheora" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libtheora Theora encoder wrapper.
|
|
</p>
|
|
<p>Requires the presence of the libtheora headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<code>--enable-libtheora</code>.
|
|
</p>
|
|
<p>For more information about the libtheora project see
|
|
<a href="http://www.theora.org/">http://www.theora.org/</a>.
|
|
</p>
|
|
<a name="Options-19"></a>
|
|
<h4 class="subsection">9.4.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-19" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-19" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following global options are mapped to internal libtheora options
|
|
which affect the quality and the bitrate of the encoded stream.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
|
|
case VBR (Variable Bit Rate) mode is enabled this option is ignored.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>flags</samp></dt>
|
|
<dd><p>Used to enable constant quality mode (VBR) encoding through the
|
|
<samp>qscale</samp> flag, and to enable the <code>pass1</code> and <code>pass2</code>
|
|
modes.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>g</samp></dt>
|
|
<dd><p>Set the GOP size.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>global_quality</samp></dt>
|
|
<dd><p>Set the global quality as an integer in lambda units.
|
|
</p>
|
|
<p>Only relevant when VBR mode is enabled with <code>flags +qscale</code>. The
|
|
value is converted to QP units by dividing it by <code>FF_QP2LAMBDA</code>,
|
|
clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
|
|
value in the native libtheora range [0-63]. A higher value corresponds
|
|
to a higher quality.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>q</samp></dt>
|
|
<dd><p>Enable VBR mode when set to a non-negative value, and set constant
|
|
quality value as a double floating point value in QP units.
|
|
</p>
|
|
<p>The value is clipped in the [0-10] range, and then multiplied by 6.3
|
|
to get a value in the native libtheora range [0-63].
|
|
</p>
|
|
<p>This option is valid only using the <code>ffmpeg</code> command-line
|
|
tool. For library interface users, use <samp>global_quality</samp>.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="Examples-1"></a>
|
|
<h4 class="subsection">9.4.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-1" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<ul>
|
|
<li> Set maximum constant quality (VBR) encoding with <code>ffmpeg</code>:
|
|
<div class="example">
|
|
<pre class="example">ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
|
|
</pre></div>
|
|
|
|
</li><li> Use <code>ffmpeg</code> to convert a CBR 1000 kbps Theora video stream:
|
|
<div class="example">
|
|
<pre class="example">ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
|
|
</pre></div>
|
|
</li></ul>
|
|
|
|
<a name="libvpx"></a>
|
|
<h3 class="section">9.5 libvpx<span class="pull-right"><a class="anchor hidden-xs" href="#libvpx" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libvpx" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>VP8/VP9 format supported through libvpx.
|
|
</p>
|
|
<p>Requires the presence of the libvpx headers and library during configuration.
|
|
You need to explicitly configure the build with <code>--enable-libvpx</code>.
|
|
</p>
|
|
<a name="Options-20"></a>
|
|
<h4 class="subsection">9.5.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-20" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-20" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by the libvpx wrapper. The
|
|
<code>vpxenc</code>-equivalent options or values are listed in parentheses
|
|
for easy migration.
|
|
</p>
|
|
<p>To reduce the duplication of documentation, only the private options
|
|
and some others requiring special attention are documented here. For
|
|
the documentation of the undocumented generic options, see
|
|
<a href="#codec_002doptions">the Codec Options chapter</a>.
|
|
</p>
|
|
<p>To get more documentation of the libvpx options, invoke the command
|
|
<code>ffmpeg -h encoder=libvpx</code>, <code>ffmpeg -h encoder=libvpx-vp9</code> or
|
|
<code>vpxenc --help</code>. Further information is available in the libvpx API
|
|
documentation.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b (<em>target-bitrate</em>)</samp></dt>
|
|
<dd><p>Set bitrate in bits/s. Note that FFmpeg’s <samp>b</samp> option is
|
|
expressed in bits/s, while <code>vpxenc</code>’s <samp>target-bitrate</samp> is in
|
|
kilobits/s.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>g (<em>kf-max-dist</em>)</samp></dt>
|
|
<dt><samp>keyint_min (<em>kf-min-dist</em>)</samp></dt>
|
|
<dt><samp>qmin (<em>min-q</em>)</samp></dt>
|
|
<dt><samp>qmax (<em>max-q</em>)</samp></dt>
|
|
<dt><samp>bufsize (<em>buf-sz</em>, <em>buf-optimal-sz</em>)</samp></dt>
|
|
<dd><p>Set ratecontrol buffer size (in bits). Note <code>vpxenc</code>’s options are
|
|
specified in milliseconds, the libvpx wrapper converts this value as follows:
|
|
<code>buf-sz = bufsize * 1000 / bitrate</code>,
|
|
<code>buf-optimal-sz = bufsize * 1000 / bitrate * 5 / 6</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_init_occupancy (<em>buf-initial-sz</em>)</samp></dt>
|
|
<dd><p>Set number of bits which should be loaded into the rc buffer before decoding
|
|
starts. Note <code>vpxenc</code>’s option is specified in milliseconds, the libvpx
|
|
wrapper converts this value as follows:
|
|
<code>rc_init_occupancy * 1000 / bitrate</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>undershoot-pct</samp></dt>
|
|
<dd><p>Set datarate undershoot (min) percentage of the target bitrate.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>overshoot-pct</samp></dt>
|
|
<dd><p>Set datarate overshoot (max) percentage of the target bitrate.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>skip_threshold (<em>drop-frame</em>)</samp></dt>
|
|
<dt><samp>qcomp (<em>bias-pct</em>)</samp></dt>
|
|
<dt><samp>maxrate (<em>maxsection-pct</em>)</samp></dt>
|
|
<dd><p>Set GOP max bitrate in bits/s. Note <code>vpxenc</code>’s option is specified as a
|
|
percentage of the target bitrate, the libvpx wrapper converts this value as
|
|
follows: <code>(maxrate * 100 / bitrate)</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>minrate (<em>minsection-pct</em>)</samp></dt>
|
|
<dd><p>Set GOP min bitrate in bits/s. Note <code>vpxenc</code>’s option is specified as a
|
|
percentage of the target bitrate, the libvpx wrapper converts this value as
|
|
follows: <code>(minrate * 100 / bitrate)</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>minrate, maxrate, b <em>end-usage=cbr</em></samp></dt>
|
|
<dd><p><code>(minrate == maxrate == bitrate)</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>crf (<em>end-usage=cq</em>, <em>cq-level</em>)</samp></dt>
|
|
<dt><samp>tune (<em>tune</em>)</samp></dt>
|
|
<dd><dl compact="compact">
|
|
<dt>‘<samp>psnr (<em>psnr</em>)</samp>’</dt>
|
|
<dt>‘<samp>ssim (<em>ssim</em>)</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>quality, deadline (<em>deadline</em>)</samp></dt>
|
|
<dd><dl compact="compact">
|
|
<dt>‘<samp>best</samp>’</dt>
|
|
<dd><p>Use best quality deadline. Poorly named and quite slow, this option should be
|
|
avoided as it may give worse quality output than good.
|
|
</p></dd>
|
|
<dt>‘<samp>good</samp>’</dt>
|
|
<dd><p>Use good quality deadline. This is a good trade-off between speed and quality
|
|
when used with the <samp>cpu-used</samp> option.
|
|
</p></dd>
|
|
<dt>‘<samp>realtime</samp>’</dt>
|
|
<dd><p>Use realtime quality deadline.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>speed, cpu-used (<em>cpu-used</em>)</samp></dt>
|
|
<dd><p>Set quality/speed ratio modifier. Higher values speed up the encode at the cost
|
|
of quality.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>nr (<em>noise-sensitivity</em>)</samp></dt>
|
|
<dt><samp>static-thresh</samp></dt>
|
|
<dd><p>Set a change threshold on blocks below which they will be skipped by the
|
|
encoder.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>slices (<em>token-parts</em>)</samp></dt>
|
|
<dd><p>Note that FFmpeg’s <samp>slices</samp> option gives the total number of partitions,
|
|
while <code>vpxenc</code>’s <samp>token-parts</samp> is given as
|
|
<code>log2(partitions)</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>max-intra-rate</samp></dt>
|
|
<dd><p>Set maximum I-frame bitrate as a percentage of the target bitrate. A value of 0
|
|
means unlimited.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>force_key_frames</samp></dt>
|
|
<dd><p><code>VPX_EFLAG_FORCE_KF</code>
|
|
</p>
|
|
</dd>
|
|
<dt><samp>Alternate reference frame related</samp></dt>
|
|
<dd><dl compact="compact">
|
|
<dt><samp>auto-alt-ref</samp></dt>
|
|
<dd><p>Enable use of alternate reference frames (2-pass only).
|
|
</p></dd>
|
|
<dt><samp>arnr-max-frames</samp></dt>
|
|
<dd><p>Set altref noise reduction max frame count.
|
|
</p></dd>
|
|
<dt><samp>arnr-type</samp></dt>
|
|
<dd><p>Set altref noise reduction filter type: backward, forward, centered.
|
|
</p></dd>
|
|
<dt><samp>arnr-strength</samp></dt>
|
|
<dd><p>Set altref noise reduction filter strength.
|
|
</p></dd>
|
|
<dt><samp>rc-lookahead, lag-in-frames (<em>lag-in-frames</em>)</samp></dt>
|
|
<dd><p>Set number of frames to look ahead for frametype and ratecontrol.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>error-resilient</samp></dt>
|
|
<dd><p>Enable error resiliency features.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>VP9-specific options</samp></dt>
|
|
<dd><dl compact="compact">
|
|
<dt><samp>lossless</samp></dt>
|
|
<dd><p>Enable lossless mode.
|
|
</p></dd>
|
|
<dt><samp>tile-columns</samp></dt>
|
|
<dd><p>Set number of tile columns to use. Note this is given as
|
|
<code>log2(tile_columns)</code>. For example, 8 tile columns would be requested by
|
|
setting the <samp>tile-columns</samp> option to 3.
|
|
</p></dd>
|
|
<dt><samp>tile-rows</samp></dt>
|
|
<dd><p>Set number of tile rows to use. Note this is given as <code>log2(tile_rows)</code>.
|
|
For example, 4 tile rows would be requested by setting the <samp>tile-rows</samp>
|
|
option to 2.
|
|
</p></dd>
|
|
<dt><samp>frame-parallel</samp></dt>
|
|
<dd><p>Enable frame parallel decodability features.
|
|
</p></dd>
|
|
<dt><samp>aq-mode</samp></dt>
|
|
<dd><p>Set adaptive quantization mode (0: off (default), 1: variance 2: complexity, 3:
|
|
cyclic refresh).
|
|
</p></dd>
|
|
<dt><samp>colorspace <em>color-space</em></samp></dt>
|
|
<dd><p>Set input color space. The VP9 bitstream supports signaling the following
|
|
colorspaces:
|
|
</p><dl compact="compact">
|
|
<dt><samp>‘<samp>rgb</samp>’ <em>sRGB</em></samp></dt>
|
|
<dt><samp>‘<samp>bt709</samp>’ <em>bt709</em></samp></dt>
|
|
<dt><samp>‘<samp>unspecified</samp>’ <em>unknown</em></samp></dt>
|
|
<dt><samp>‘<samp>bt470bg</samp>’ <em>bt601</em></samp></dt>
|
|
<dt><samp>‘<samp>smpte170m</samp>’ <em>smpte170</em></samp></dt>
|
|
<dt><samp>‘<samp>smpte240m</samp>’ <em>smpte240</em></samp></dt>
|
|
<dt><samp>‘<samp>bt2020_ncl</samp>’ <em>bt2020</em></samp></dt>
|
|
</dl>
|
|
</dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>For more information about libvpx see:
|
|
<a href="http://www.webmproject.org/">http://www.webmproject.org/</a>
|
|
</p>
|
|
|
|
<a name="libwebp"></a>
|
|
<h3 class="section">9.6 libwebp<span class="pull-right"><a class="anchor hidden-xs" href="#libwebp" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libwebp" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>libwebp WebP Image encoder wrapper
|
|
</p>
|
|
<p>libwebp is Google’s official encoder for WebP images. It can encode in either
|
|
lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
|
|
frame. Lossless images are a separate codec developed by Google.
|
|
</p>
|
|
<a name="Pixel-Format"></a>
|
|
<h4 class="subsection">9.6.1 Pixel Format<span class="pull-right"><a class="anchor hidden-xs" href="#Pixel-Format" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Pixel-Format" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
|
|
to limitations of the format and libwebp. Alpha is supported for either mode.
|
|
Because of API limitations, if RGB is passed in when encoding lossy or YUV is
|
|
passed in for encoding lossless, the pixel format will automatically be
|
|
converted using functions from libwebp. This is not ideal and is done only for
|
|
convenience.
|
|
</p>
|
|
<a name="Options-21"></a>
|
|
<h4 class="subsection">9.6.2 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-21" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-21" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>-lossless <var>boolean</var></samp></dt>
|
|
<dd><p>Enables/Disables use of lossless mode. Default is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>-compression_level <var>integer</var></samp></dt>
|
|
<dd><p>For lossy, this is a quality/speed tradeoff. Higher values give better quality
|
|
for a given size at the cost of increased encoding time. For lossless, this is
|
|
a size/speed tradeoff. Higher values give smaller size at the cost of increased
|
|
encoding time. More specifically, it controls the number of extra algorithms
|
|
and compression tools used, and varies the combination of these tools. This
|
|
maps to the <var>method</var> option in libwebp. The valid range is 0 to 6.
|
|
Default is 4.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>-qscale <var>float</var></samp></dt>
|
|
<dd><p>For lossy encoding, this controls image quality, 0 to 100. For lossless
|
|
encoding, this controls the effort and time spent at compressing more. The
|
|
default value is 75. Note that for usage via libavcodec, this option is called
|
|
<var>global_quality</var> and must be multiplied by <var>FF_QP2LAMBDA</var>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>-preset <var>type</var></samp></dt>
|
|
<dd><p>Configuration preset. This does some automatic settings based on the general
|
|
type of the image.
|
|
</p><dl compact="compact">
|
|
<dt><samp>none</samp></dt>
|
|
<dd><p>Do not use a preset.
|
|
</p></dd>
|
|
<dt><samp>default</samp></dt>
|
|
<dd><p>Use the encoder default.
|
|
</p></dd>
|
|
<dt><samp>picture</samp></dt>
|
|
<dd><p>Digital picture, like portrait, inner shot
|
|
</p></dd>
|
|
<dt><samp>photo</samp></dt>
|
|
<dd><p>Outdoor photograph, with natural lighting
|
|
</p></dd>
|
|
<dt><samp>drawing</samp></dt>
|
|
<dd><p>Hand or line drawing, with high-contrast details
|
|
</p></dd>
|
|
<dt><samp>icon</samp></dt>
|
|
<dd><p>Small-sized colorful images
|
|
</p></dd>
|
|
<dt><samp>text</samp></dt>
|
|
<dd><p>Text-like
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libx264_002c-libx264rgb"></a>
|
|
<h3 class="section">9.7 libx264, libx264rgb<span class="pull-right"><a class="anchor hidden-xs" href="#libx264_002c-libx264rgb" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libx264_002c-libx264rgb" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>x264 H.264/MPEG-4 AVC encoder wrapper.
|
|
</p>
|
|
<p>This encoder requires the presence of the libx264 headers and library
|
|
during configuration. You need to explicitly configure the build with
|
|
<code>--enable-libx264</code>.
|
|
</p>
|
|
<p>libx264 supports an impressive number of features, including 8x8 and
|
|
4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
|
|
entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
|
|
for detail retention (adaptive quantization, psy-RD, psy-trellis).
|
|
</p>
|
|
<p>Many libx264 encoder options are mapped to FFmpeg global codec
|
|
options, while unique encoder options are provided through private
|
|
options. Additionally the <samp>x264opts</samp> and <samp>x264-params</samp>
|
|
private options allows one to pass a list of key=value tuples as accepted
|
|
by the libx264 <code>x264_param_parse</code> function.
|
|
</p>
|
|
<p>The x264 project website is at
|
|
<a href="http://www.videolan.org/developers/x264.html">http://www.videolan.org/developers/x264.html</a>.
|
|
</p>
|
|
<p>The libx264rgb encoder is the same as libx264, except it accepts packed RGB
|
|
pixel formats as input instead of YUV.
|
|
</p>
|
|
<a name="Supported-Pixel-Formats"></a>
|
|
<h4 class="subsection">9.7.1 Supported Pixel Formats<span class="pull-right"><a class="anchor hidden-xs" href="#Supported-Pixel-Formats" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Supported-Pixel-Formats" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
|
|
x264’s configure time. FFmpeg only supports one bit depth in one particular
|
|
build. In other words, it is not possible to build one FFmpeg with multiple
|
|
versions of x264 with different bit depths.
|
|
</p>
|
|
<a name="Options-22"></a>
|
|
<h4 class="subsection">9.7.2 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-22" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-22" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by the libx264 wrapper. The
|
|
<code>x264</code>-equivalent options or values are listed in parentheses
|
|
for easy migration.
|
|
</p>
|
|
<p>To reduce the duplication of documentation, only the private options
|
|
and some others requiring special attention are documented here. For
|
|
the documentation of the undocumented generic options, see
|
|
<a href="#codec_002doptions">the Codec Options chapter</a>.
|
|
</p>
|
|
<p>To get a more accurate and extensive documentation of the libx264
|
|
options, invoke the command <code>x264 --full-help</code> or consult
|
|
the libx264 documentation.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b (<em>bitrate</em>)</samp></dt>
|
|
<dd><p>Set bitrate in bits/s. Note that FFmpeg’s <samp>b</samp> option is
|
|
expressed in bits/s, while <code>x264</code>’s <samp>bitrate</samp> is in
|
|
kilobits/s.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bf (<em>bframes</em>)</samp></dt>
|
|
<dt><samp>g (<em>keyint</em>)</samp></dt>
|
|
<dt><samp>qmin (<em>qpmin</em>)</samp></dt>
|
|
<dd><p>Minimum quantizer scale.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qmax (<em>qpmax</em>)</samp></dt>
|
|
<dd><p>Maximum quantizer scale.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qdiff (<em>qpstep</em>)</samp></dt>
|
|
<dd><p>Maximum difference between quantizer scales.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qblur (<em>qblur</em>)</samp></dt>
|
|
<dd><p>Quantizer curve blur
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qcomp (<em>qcomp</em>)</samp></dt>
|
|
<dd><p>Quantizer curve compression factor
|
|
</p>
|
|
</dd>
|
|
<dt><samp>refs (<em>ref</em>)</samp></dt>
|
|
<dd><p>Number of reference frames each P-frame can use. The range is from <var>0-16</var>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>sc_threshold (<em>scenecut</em>)</samp></dt>
|
|
<dd><p>Sets the threshold for the scene change detection.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>trellis (<em>trellis</em>)</samp></dt>
|
|
<dd><p>Performs Trellis quantization to increase efficiency. Enabled by default.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>nr (<em>nr</em>)</samp></dt>
|
|
<dt><samp>me_range (<em>merange</em>)</samp></dt>
|
|
<dd><p>Maximum range of the motion search in pixels.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>me_method (<em>me</em>)</samp></dt>
|
|
<dd><p>Set motion estimation method. Possible values in the decreasing order
|
|
of speed:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>dia (<em>dia</em>)</samp>’</dt>
|
|
<dt>‘<samp>epzs (<em>dia</em>)</samp>’</dt>
|
|
<dd><p>Diamond search with radius 1 (fastest). ‘<samp>epzs</samp>’ is an alias for
|
|
‘<samp>dia</samp>’.
|
|
</p></dd>
|
|
<dt>‘<samp>hex (<em>hex</em>)</samp>’</dt>
|
|
<dd><p>Hexagonal search with radius 2.
|
|
</p></dd>
|
|
<dt>‘<samp>umh (<em>umh</em>)</samp>’</dt>
|
|
<dd><p>Uneven multi-hexagon search.
|
|
</p></dd>
|
|
<dt>‘<samp>esa (<em>esa</em>)</samp>’</dt>
|
|
<dd><p>Exhaustive search.
|
|
</p></dd>
|
|
<dt>‘<samp>tesa (<em>tesa</em>)</samp>’</dt>
|
|
<dd><p>Hadamard exhaustive search (slowest).
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>subq (<em>subme</em>)</samp></dt>
|
|
<dd><p>Sub-pixel motion estimation method.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>b_strategy (<em>b-adapt</em>)</samp></dt>
|
|
<dd><p>Adaptive B-frame placement decision algorithm. Use only on first-pass.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>keyint_min (<em>min-keyint</em>)</samp></dt>
|
|
<dd><p>Minimum GOP size.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>coder</samp></dt>
|
|
<dd><p>Set entropy encoder. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>ac</samp>’</dt>
|
|
<dd><p>Enable CABAC.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>vlc</samp>’</dt>
|
|
<dd><p>Enable CAVLC and disable CABAC. It generates the same effect as
|
|
<code>x264</code>’s <samp>--no-cabac</samp> option.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>cmp</samp></dt>
|
|
<dd><p>Set full pixel motion estimation comparation algorithm. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>chroma</samp>’</dt>
|
|
<dd><p>Enable chroma in motion estimation.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>sad</samp>’</dt>
|
|
<dd><p>Ignore chroma in motion estimation. It generates the same effect as
|
|
<code>x264</code>’s <samp>--no-chroma-me</samp> option.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>threads (<em>threads</em>)</samp></dt>
|
|
<dd><p>Number of encoding threads.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>thread_type</samp></dt>
|
|
<dd><p>Set multithreading technique. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>slice</samp>’</dt>
|
|
<dd><p>Slice-based multithreading. It generates the same effect as
|
|
<code>x264</code>’s <samp>--sliced-threads</samp> option.
|
|
</p></dd>
|
|
<dt>‘<samp>frame</samp>’</dt>
|
|
<dd><p>Frame-based multithreading.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>flags</samp></dt>
|
|
<dd><p>Set encoding flags. It can be used to disable closed GOP and enable
|
|
open GOP by setting it to <code>-cgop</code>. The result is similar to
|
|
the behavior of <code>x264</code>’s <samp>--open-gop</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc_init_occupancy (<em>vbv-init</em>)</samp></dt>
|
|
<dt><samp>preset (<em>preset</em>)</samp></dt>
|
|
<dd><p>Set the encoding preset.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>tune (<em>tune</em>)</samp></dt>
|
|
<dd><p>Set tuning of the encoding params.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>profile (<em>profile</em>)</samp></dt>
|
|
<dd><p>Set profile restrictions.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>fastfirstpass</samp></dt>
|
|
<dd><p>Enable fast settings when encoding first pass, when set to 1. When set
|
|
to 0, it has the same effect of <code>x264</code>’s
|
|
<samp>--slow-firstpass</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>crf (<em>crf</em>)</samp></dt>
|
|
<dd><p>Set the quality for constant quality mode.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>crf_max (<em>crf-max</em>)</samp></dt>
|
|
<dd><p>In CRF mode, prevents VBV from lowering quality beyond this point.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qp (<em>qp</em>)</samp></dt>
|
|
<dd><p>Set constant quantization rate control method parameter.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aq-mode (<em>aq-mode</em>)</samp></dt>
|
|
<dd><p>Set AQ method. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>none (<em>0</em>)</samp>’</dt>
|
|
<dd><p>Disabled.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>variance (<em>1</em>)</samp>’</dt>
|
|
<dd><p>Variance AQ (complexity mask).
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>autovariance (<em>2</em>)</samp>’</dt>
|
|
<dd><p>Auto-variance AQ (experimental).
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>aq-strength (<em>aq-strength</em>)</samp></dt>
|
|
<dd><p>Set AQ strength, reduce blocking and blurring in flat and textured areas.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>psy</samp></dt>
|
|
<dd><p>Use psychovisual optimizations when set to 1. When set to 0, it has the
|
|
same effect as <code>x264</code>’s <samp>--no-psy</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>psy-rd (<em>psy-rd</em>)</samp></dt>
|
|
<dd><p>Set strength of psychovisual optimization, in
|
|
<var>psy-rd</var>:<var>psy-trellis</var> format.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>rc-lookahead (<em>rc-lookahead</em>)</samp></dt>
|
|
<dd><p>Set number of frames to look ahead for frametype and ratecontrol.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>weightb</samp></dt>
|
|
<dd><p>Enable weighted prediction for B-frames when set to 1. When set to 0,
|
|
it has the same effect as <code>x264</code>’s <samp>--no-weightb</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>weightp (<em>weightp</em>)</samp></dt>
|
|
<dd><p>Set weighted prediction method for P-frames. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>none (<em>0</em>)</samp>’</dt>
|
|
<dd><p>Disabled
|
|
</p></dd>
|
|
<dt>‘<samp>simple (<em>1</em>)</samp>’</dt>
|
|
<dd><p>Enable only weighted refs
|
|
</p></dd>
|
|
<dt>‘<samp>smart (<em>2</em>)</samp>’</dt>
|
|
<dd><p>Enable both weighted refs and duplicates
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>ssim (<em>ssim</em>)</samp></dt>
|
|
<dd><p>Enable calculation and printing SSIM stats after the encoding.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>intra-refresh (<em>intra-refresh</em>)</samp></dt>
|
|
<dd><p>Enable the use of Periodic Intra Refresh instead of IDR frames when set
|
|
to 1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>avcintra-class (<em>class</em>)</samp></dt>
|
|
<dd><p>Configure the encoder to generate AVC-Intra.
|
|
Valid values are 50,100 and 200
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bluray-compat (<em>bluray-compat</em>)</samp></dt>
|
|
<dd><p>Configure the encoder to be compatible with the bluray standard.
|
|
It is a shorthand for setting "bluray-compat=1 force-cfr=1".
|
|
</p>
|
|
</dd>
|
|
<dt><samp>b-bias (<em>b-bias</em>)</samp></dt>
|
|
<dd><p>Set the influence on how often B-frames are used.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>b-pyramid (<em>b-pyramid</em>)</samp></dt>
|
|
<dd><p>Set method for keeping of some B-frames as references. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>none (<em>none</em>)</samp>’</dt>
|
|
<dd><p>Disabled.
|
|
</p></dd>
|
|
<dt>‘<samp>strict (<em>strict</em>)</samp>’</dt>
|
|
<dd><p>Strictly hierarchical pyramid.
|
|
</p></dd>
|
|
<dt>‘<samp>normal (<em>normal</em>)</samp>’</dt>
|
|
<dd><p>Non-strict (not Blu-ray compatible).
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>mixed-refs</samp></dt>
|
|
<dd><p>Enable the use of one reference per partition, as opposed to one
|
|
reference per macroblock when set to 1. When set to 0, it has the
|
|
same effect as <code>x264</code>’s <samp>--no-mixed-refs</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>8x8dct</samp></dt>
|
|
<dd><p>Enable adaptive spatial transform (high profile 8x8 transform)
|
|
when set to 1. When set to 0, it has the same effect as
|
|
<code>x264</code>’s <samp>--no-8x8dct</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>fast-pskip</samp></dt>
|
|
<dd><p>Enable early SKIP detection on P-frames when set to 1. When set
|
|
to 0, it has the same effect as <code>x264</code>’s
|
|
<samp>--no-fast-pskip</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>aud (<em>aud</em>)</samp></dt>
|
|
<dd><p>Enable use of access unit delimiters when set to 1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mbtree</samp></dt>
|
|
<dd><p>Enable use macroblock tree ratecontrol when set to 1. When set
|
|
to 0, it has the same effect as <code>x264</code>’s
|
|
<samp>--no-mbtree</samp> option.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>deblock (<em>deblock</em>)</samp></dt>
|
|
<dd><p>Set loop filter parameters, in <var>alpha</var>:<var>beta</var> form.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>cplxblur (<em>cplxblur</em>)</samp></dt>
|
|
<dd><p>Set fluctuations reduction in QP (before curve compression).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>partitions (<em>partitions</em>)</samp></dt>
|
|
<dd><p>Set partitions to consider as a comma-separated list of. Possible
|
|
values in the list:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>p8x8</samp>’</dt>
|
|
<dd><p>8x8 P-frame partition.
|
|
</p></dd>
|
|
<dt>‘<samp>p4x4</samp>’</dt>
|
|
<dd><p>4x4 P-frame partition.
|
|
</p></dd>
|
|
<dt>‘<samp>b8x8</samp>’</dt>
|
|
<dd><p>4x4 B-frame partition.
|
|
</p></dd>
|
|
<dt>‘<samp>i8x8</samp>’</dt>
|
|
<dd><p>8x8 I-frame partition.
|
|
</p></dd>
|
|
<dt>‘<samp>i4x4</samp>’</dt>
|
|
<dd><p>4x4 I-frame partition.
|
|
(Enabling ‘<samp>p4x4</samp>’ requires ‘<samp>p8x8</samp>’ to be enabled. Enabling
|
|
‘<samp>i8x8</samp>’ requires adaptive spatial transform (<samp>8x8dct</samp>
|
|
option) to be enabled.)
|
|
</p></dd>
|
|
<dt>‘<samp>none (<em>none</em>)</samp>’</dt>
|
|
<dd><p>Do not consider any partitions.
|
|
</p></dd>
|
|
<dt>‘<samp>all (<em>all</em>)</samp>’</dt>
|
|
<dd><p>Consider every partition.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>direct-pred (<em>direct</em>)</samp></dt>
|
|
<dd><p>Set direct MV prediction mode. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>none (<em>none</em>)</samp>’</dt>
|
|
<dd><p>Disable MV prediction.
|
|
</p></dd>
|
|
<dt>‘<samp>spatial (<em>spatial</em>)</samp>’</dt>
|
|
<dd><p>Enable spatial predicting.
|
|
</p></dd>
|
|
<dt>‘<samp>temporal (<em>temporal</em>)</samp>’</dt>
|
|
<dd><p>Enable temporal predicting.
|
|
</p></dd>
|
|
<dt>‘<samp>auto (<em>auto</em>)</samp>’</dt>
|
|
<dd><p>Automatically decided.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>slice-max-size (<em>slice-max-size</em>)</samp></dt>
|
|
<dd><p>Set the limit of the size of each slice in bytes. If not specified
|
|
but RTP payload size (<samp>ps</samp>) is specified, that is used.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>stats (<em>stats</em>)</samp></dt>
|
|
<dd><p>Set the file name for multi-pass stats.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>nal-hrd (<em>nal-hrd</em>)</samp></dt>
|
|
<dd><p>Set signal HRD information (requires <samp>vbv-bufsize</samp> to be set).
|
|
Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>none (<em>none</em>)</samp>’</dt>
|
|
<dd><p>Disable HRD information signaling.
|
|
</p></dd>
|
|
<dt>‘<samp>vbr (<em>vbr</em>)</samp>’</dt>
|
|
<dd><p>Variable bit rate.
|
|
</p></dd>
|
|
<dt>‘<samp>cbr (<em>cbr</em>)</samp>’</dt>
|
|
<dd><p>Constant bit rate (not allowed in MP4 container).
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>x264opts (N.A.)</samp></dt>
|
|
<dd><p>Set any x264 option, see <code>x264 --fullhelp</code> for a list.
|
|
</p>
|
|
<p>Argument is a list of <var>key</var>=<var>value</var> couples separated by
|
|
":". In <var>filter</var> and <var>psy-rd</var> options that use ":" as a separator
|
|
themselves, use "," instead. They accept it as well since long ago but this
|
|
is kept undocumented for some reason.
|
|
</p>
|
|
<p>For example to specify libx264 encoding options with <code>ffmpeg</code>:
|
|
</p><div class="example">
|
|
<pre class="example">ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
|
|
</pre></div>
|
|
|
|
</dd>
|
|
<dt><samp>a53cc <var>boolean</var></samp></dt>
|
|
<dd><p>Import closed captions (which must be ATSC compatible format) into output.
|
|
Only the mpeg2 and h264 decoders provide these. Default is 0 (off).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>x264-params (N.A.)</samp></dt>
|
|
<dd><p>Override the x264 configuration using a :-separated list of key=value
|
|
parameters.
|
|
</p>
|
|
<p>This option is functionally the same as the <samp>x264opts</samp>, but is
|
|
duplicated for compatibility with the Libav fork.
|
|
</p>
|
|
<p>For example to specify libx264 encoding options with <code>ffmpeg</code>:
|
|
</p><div class="example">
|
|
<pre class="example">ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
|
|
cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
|
|
no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
|
|
</pre></div>
|
|
</dd>
|
|
</dl>
|
|
|
|
<p>Encoding ffpresets for common usages are provided so they can be used with the
|
|
general presets system (e.g. passing the <samp>pre</samp> option).
|
|
</p>
|
|
<a name="libx265"></a>
|
|
<h3 class="section">9.8 libx265<span class="pull-right"><a class="anchor hidden-xs" href="#libx265" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libx265" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>x265 H.265/HEVC encoder wrapper.
|
|
</p>
|
|
<p>This encoder requires the presence of the libx265 headers and library
|
|
during configuration. You need to explicitly configure the build with
|
|
<samp>--enable-libx265</samp>.
|
|
</p>
|
|
<a name="Options-23"></a>
|
|
<h4 class="subsection">9.8.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-23" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-23" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>preset</samp></dt>
|
|
<dd><p>Set the x265 preset.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>tune</samp></dt>
|
|
<dd><p>Set the x265 tune parameter.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>x265-params</samp></dt>
|
|
<dd><p>Set x265 options using a list of <var>key</var>=<var>value</var> couples separated
|
|
by ":". See <code>x265 --help</code> for a list of options.
|
|
</p>
|
|
<p>For example to specify libx265 encoding options with <samp>-x265-params</samp>:
|
|
</p>
|
|
<div class="example">
|
|
<pre class="example">ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
|
|
</pre></div>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="libxvid"></a>
|
|
<h3 class="section">9.9 libxvid<span class="pull-right"><a class="anchor hidden-xs" href="#libxvid" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libxvid" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Xvid MPEG-4 Part 2 encoder wrapper.
|
|
</p>
|
|
<p>This encoder requires the presence of the libxvidcore headers and library
|
|
during configuration. You need to explicitly configure the build with
|
|
<code>--enable-libxvid --enable-gpl</code>.
|
|
</p>
|
|
<p>The native <code>mpeg4</code> encoder supports the MPEG-4 Part 2 format, so
|
|
users can encode to this format without this library.
|
|
</p>
|
|
<a name="Options-24"></a>
|
|
<h4 class="subsection">9.9.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-24" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-24" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>The following options are supported by the libxvid wrapper. Some of
|
|
the following options are listed but are not documented, and
|
|
correspond to shared codec options. See <a href="#codec_002doptions">the Codec
|
|
Options chapter</a> for their documentation. The other shared options
|
|
which are not listed have no effect for the libxvid encoder.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dt><samp>g</samp></dt>
|
|
<dt><samp>qmin</samp></dt>
|
|
<dt><samp>qmax</samp></dt>
|
|
<dt><samp>mpeg_quant</samp></dt>
|
|
<dt><samp>threads</samp></dt>
|
|
<dt><samp>bf</samp></dt>
|
|
<dt><samp>b_qfactor</samp></dt>
|
|
<dt><samp>b_qoffset</samp></dt>
|
|
<dt><samp>flags</samp></dt>
|
|
<dd><p>Set specific encoding flags. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>mv4</samp>’</dt>
|
|
<dd><p>Use four motion vector by macroblock.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>aic</samp>’</dt>
|
|
<dd><p>Enable high quality AC prediction.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>gray</samp>’</dt>
|
|
<dd><p>Only encode grayscale.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>gmc</samp>’</dt>
|
|
<dd><p>Enable the use of global motion compensation (GMC).
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>qpel</samp>’</dt>
|
|
<dd><p>Enable quarter-pixel motion compensation.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>cgop</samp>’</dt>
|
|
<dd><p>Enable closed GOP.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>global_header</samp>’</dt>
|
|
<dd><p>Place global headers in extradata instead of every keyframe.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>trellis</samp></dt>
|
|
<dt><samp>me_method</samp></dt>
|
|
<dd><p>Set motion estimation method. Possible values in decreasing order of
|
|
speed and increasing order of quality:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>zero</samp>’</dt>
|
|
<dd><p>Use no motion estimation (default).
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>phods</samp>’</dt>
|
|
<dt>‘<samp>x1</samp>’</dt>
|
|
<dt>‘<samp>log</samp>’</dt>
|
|
<dd><p>Enable advanced diamond zonal search for 16x16 blocks and half-pixel
|
|
refinement for 16x16 blocks. ‘<samp>x1</samp>’ and ‘<samp>log</samp>’ are aliases for
|
|
‘<samp>phods</samp>’.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>epzs</samp>’</dt>
|
|
<dd><p>Enable all of the things described above, plus advanced diamond zonal
|
|
search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
|
|
estimation on chroma planes.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>full</samp>’</dt>
|
|
<dd><p>Enable all of the things described above, plus extended 16x16 and 8x8
|
|
blocks search.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>mbd</samp></dt>
|
|
<dd><p>Set macroblock decision algorithm. Possible values in the increasing
|
|
order of quality:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>simple</samp>’</dt>
|
|
<dd><p>Use macroblock comparing function algorithm (default).
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>bits</samp>’</dt>
|
|
<dd><p>Enable rate distortion-based half pixel and quarter pixel refinement for
|
|
16x16 blocks.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>rd</samp>’</dt>
|
|
<dd><p>Enable all of the things described above, plus rate distortion-based
|
|
half pixel and quarter pixel refinement for 8x8 blocks, and rate
|
|
distortion-based search using square pattern.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>lumi_aq</samp></dt>
|
|
<dd><p>Enable lumi masking adaptive quantization when set to 1. Default is 0
|
|
(disabled).
|
|
</p>
|
|
</dd>
|
|
<dt><samp>variance_aq</samp></dt>
|
|
<dd><p>Enable variance adaptive quantization when set to 1. Default is 0
|
|
(disabled).
|
|
</p>
|
|
<p>When combined with <samp>lumi_aq</samp>, the resulting quality will not
|
|
be better than any of the two specified individually. In other
|
|
words, the resulting quality will be the worse one of the two
|
|
effects.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>ssim</samp></dt>
|
|
<dd><p>Set structural similarity (SSIM) displaying method. Possible values:
|
|
</p>
|
|
<dl compact="compact">
|
|
<dt>‘<samp>off</samp>’</dt>
|
|
<dd><p>Disable displaying of SSIM information.
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>avg</samp>’</dt>
|
|
<dd><p>Output average SSIM at the end of encoding to stdout. The format of
|
|
showing the average SSIM is:
|
|
</p>
|
|
<div class="example">
|
|
<pre class="example">Average SSIM: %f
|
|
</pre></div>
|
|
|
|
<p>For users who are not familiar with C, %f means a float number, or
|
|
a decimal (e.g. 0.939232).
|
|
</p>
|
|
</dd>
|
|
<dt>‘<samp>frame</samp>’</dt>
|
|
<dd><p>Output both per-frame SSIM data during encoding and average SSIM at
|
|
the end of encoding to stdout. The format of per-frame information
|
|
is:
|
|
</p>
|
|
<div class="example">
|
|
<pre class="example"> SSIM: avg: %1.3f min: %1.3f max: %1.3f
|
|
</pre></div>
|
|
|
|
<p>For users who are not familiar with C, %1.3f means a float number
|
|
rounded to 3 digits after the dot (e.g. 0.932).
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>ssim_acc</samp></dt>
|
|
<dd><p>Set SSIM accuracy. Valid options are integers within the range of
|
|
0-4, while 0 gives the most accurate result and 4 computes the
|
|
fastest.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="mpeg2"></a>
|
|
<h3 class="section">9.10 mpeg2<span class="pull-right"><a class="anchor hidden-xs" href="#mpeg2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mpeg2" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>MPEG-2 video encoder.
|
|
</p>
|
|
<a name="Options-25"></a>
|
|
<h4 class="subsection">9.10.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-25" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-25" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>seq_disp_ext <var>integer</var></samp></dt>
|
|
<dd><p>Specifies if the encoder should write a sequence_display_extension to the
|
|
output.
|
|
</p><dl compact="compact">
|
|
<dt><samp>-1</samp></dt>
|
|
<dt><samp>auto</samp></dt>
|
|
<dd><p>Decide automatically to write it or not (this is the default) by checking if
|
|
the data to be written is different from the default or unspecified values.
|
|
</p></dd>
|
|
<dt><samp>0</samp></dt>
|
|
<dt><samp>never</samp></dt>
|
|
<dd><p>Never write it.
|
|
</p></dd>
|
|
<dt><samp>1</samp></dt>
|
|
<dt><samp>always</samp></dt>
|
|
<dd><p>Always write it.
|
|
</p></dd>
|
|
</dl>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="png"></a>
|
|
<h3 class="section">9.11 png<span class="pull-right"><a class="anchor hidden-xs" href="#png" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-png" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>PNG image encoder.
|
|
</p>
|
|
<a name="Private-options-1"></a>
|
|
<h4 class="subsection">9.11.1 Private options<span class="pull-right"><a class="anchor hidden-xs" href="#Private-options-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Private-options-1" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>dpi <var>integer</var></samp></dt>
|
|
<dd><p>Set physical density of pixels, in dots per inch, unset by default
|
|
</p></dd>
|
|
<dt><samp>dpm <var>integer</var></samp></dt>
|
|
<dd><p>Set physical density of pixels, in dots per meter, unset by default
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<a name="ProRes"></a>
|
|
<h3 class="section">9.12 ProRes<span class="pull-right"><a class="anchor hidden-xs" href="#ProRes" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ProRes" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Apple ProRes encoder.
|
|
</p>
|
|
<p>FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
|
|
The used encoder can be chosen with the <code>-vcodec</code> option.
|
|
</p>
|
|
<a name="Private-Options-for-prores_002dks"></a>
|
|
<h4 class="subsection">9.12.1 Private Options for prores-ks<span class="pull-right"><a class="anchor hidden-xs" href="#Private-Options-for-prores_002dks" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Private-Options-for-prores_002dks" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>profile <var>integer</var></samp></dt>
|
|
<dd><p>Select the ProRes profile to encode
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>proxy</samp>’</dt>
|
|
<dt>‘<samp>lt</samp>’</dt>
|
|
<dt>‘<samp>standard</samp>’</dt>
|
|
<dt>‘<samp>hq</samp>’</dt>
|
|
<dt>‘<samp>4444</samp>’</dt>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp>quant_mat <var>integer</var></samp></dt>
|
|
<dd><p>Select quantization matrix.
|
|
</p><dl compact="compact">
|
|
<dt>‘<samp>auto</samp>’</dt>
|
|
<dt>‘<samp>default</samp>’</dt>
|
|
<dt>‘<samp>proxy</samp>’</dt>
|
|
<dt>‘<samp>lt</samp>’</dt>
|
|
<dt>‘<samp>standard</samp>’</dt>
|
|
<dt>‘<samp>hq</samp>’</dt>
|
|
</dl>
|
|
<p>If set to <var>auto</var>, the matrix matching the profile will be picked.
|
|
If not set, the matrix providing the highest quality, <var>default</var>, will be
|
|
picked.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>bits_per_mb <var>integer</var></samp></dt>
|
|
<dd><p>How many bits to allot for coding one macroblock. Different profiles use
|
|
between 200 and 2400 bits per macroblock, the maximum is 8000.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>mbs_per_slice <var>integer</var></samp></dt>
|
|
<dd><p>Number of macroblocks in each slice (1-8); the default value (8)
|
|
should be good in almost all situations.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>vendor <var>string</var></samp></dt>
|
|
<dd><p>Override the 4-byte vendor ID.
|
|
A custom vendor ID like <var>apl0</var> would claim the stream was produced by
|
|
the Apple encoder.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>alpha_bits <var>integer</var></samp></dt>
|
|
<dd><p>Specify number of bits for alpha component.
|
|
Possible values are <var>0</var>, <var>8</var> and <var>16</var>.
|
|
Use <var>0</var> to disable alpha plane coding.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="Speed-considerations"></a>
|
|
<h4 class="subsection">9.12.2 Speed considerations<span class="pull-right"><a class="anchor hidden-xs" href="#Speed-considerations" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Speed-considerations" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<p>In the default mode of operation the encoder has to honor frame constraints
|
|
(i.e. not produce frames with size bigger than requested) while still making
|
|
output picture as good as possible.
|
|
A frame containing a lot of small details is harder to compress and the encoder
|
|
would spend more time searching for appropriate quantizers for each slice.
|
|
</p>
|
|
<p>Setting a higher <samp>bits_per_mb</samp> limit will improve the speed.
|
|
</p>
|
|
<p>For the fastest encoding speed set the <samp>qscale</samp> parameter (4 is the
|
|
recommended value) and do not set a size constraint.
|
|
</p>
|
|
<a name="libkvazaar"></a>
|
|
<h3 class="section">9.13 libkvazaar<span class="pull-right"><a class="anchor hidden-xs" href="#libkvazaar" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libkvazaar" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>Kvazaar H.265/HEVC encoder.
|
|
</p>
|
|
<p>Requires the presence of the libkvazaar headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
<samp>--enable-libkvazaar</samp>.
|
|
</p>
|
|
<a name="Options-26"></a>
|
|
<h4 class="subsection">9.13.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-26" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-26" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Set target video bitrate in bit/s and enable rate control.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>kvazaar-params</samp></dt>
|
|
<dd><p>Set kvazaar parameters as a list of <var>name</var>=<var>value</var> pairs separated
|
|
by commas (,). See kvazaar documentation for a list of options.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<a name="QSV-encoders"></a>
|
|
<h3 class="section">9.14 QSV encoders<span class="pull-right"><a class="anchor hidden-xs" href="#QSV-encoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-QSV-encoders" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>The family of Intel QuickSync Video encoders (MPEG-2, H.264 and HEVC)
|
|
</p>
|
|
<p>The ratecontrol method is selected as follows:
|
|
</p>
|
|
<ul>
|
|
<li> When <samp>global_quality</samp> is specified, a quality-based mode is used.
|
|
Specifically this means either
|
|
<ul class="no-bullet">
|
|
<li>- <var>CQP</var> - constant quantizer scale, when the <samp>qscale</samp> codec flag is
|
|
also set (the <samp>-qscale</samp> ffmpeg option).
|
|
|
|
</li><li>- <var>LA_ICQ</var> - intelligent constant quality with lookahead, when the
|
|
<samp>look_ahead</samp> option is also set.
|
|
|
|
</li><li>- <var>ICQ</var> – intelligent constant quality otherwise.
|
|
</li></ul>
|
|
|
|
</li><li> Otherwise, a bitrate-based mode is used. For all of those, you should specify at
|
|
least the desired average bitrate with the <samp>b</samp> option.
|
|
<ul class="no-bullet">
|
|
<li>- <var>LA</var> - VBR with lookahead, when the <samp>look_ahead</samp> option is specified.
|
|
|
|
</li><li>- <var>VCM</var> - video conferencing mode, when the <samp>vcm</samp> option is set.
|
|
|
|
</li><li>- <var>CBR</var> - constant bitrate, when <samp>maxrate</samp> is specified and equal to
|
|
the average bitrate.
|
|
|
|
</li><li>- <var>VBR</var> - variable bitrate, when <samp>maxrate</samp> is specified, but is higher
|
|
than the average bitrate.
|
|
|
|
</li><li>- <var>AVBR</var> - average VBR mode, when <samp>maxrate</samp> is not specified. This mode
|
|
is further configured by the <samp>avbr_accuracy</samp> and
|
|
<samp>avbr_convergence</samp> options.
|
|
</li></ul>
|
|
</li></ul>
|
|
|
|
<p>Note that depending on your system, a different mode than the one you specified
|
|
may be selected by the encoder. Set the verbosity level to <var>verbose</var> or
|
|
higher to see the actual settings used by the QSV runtime.
|
|
</p>
|
|
<p>Additional libavcodec global options are mapped to MSDK options as follows:
|
|
</p>
|
|
<ul>
|
|
<li> <samp>g/gop_size</samp> -> <samp>GopPicSize</samp>
|
|
|
|
</li><li> <samp>bf/max_b_frames</samp>+1 -> <samp>GopRefDist</samp>
|
|
|
|
</li><li> <samp>rc_init_occupancy/rc_initial_buffer_occupancy</samp> ->
|
|
<samp>InitialDelayInKB</samp>
|
|
|
|
</li><li> <samp>slices</samp> -> <samp>NumSlice</samp>
|
|
|
|
</li><li> <samp>refs</samp> -> <samp>NumRefFrame</samp>
|
|
|
|
</li><li> <samp>b_strategy/b_frame_strategy</samp> -> <samp>BRefType</samp>
|
|
|
|
</li><li> <samp>cgop/CLOSED_GOP</samp> codec flag -> <samp>GopOptFlag</samp>
|
|
|
|
</li><li> For the <var>CQP</var> mode, the <samp>i_qfactor/i_qoffset</samp> and
|
|
<samp>b_qfactor/b_qoffset</samp> set the difference between <var>QPP</var> and <var>QPI</var>,
|
|
and <var>QPP</var> and <var>QPB</var> respectively.
|
|
|
|
</li><li> Setting the <samp>coder</samp> option to the value <var>vlc</var> will make the H.264
|
|
encoder use CAVLC instead of CABAC.
|
|
|
|
</li></ul>
|
|
|
|
<a name="vc2"></a>
|
|
<h3 class="section">9.15 vc2<span class="pull-right"><a class="anchor hidden-xs" href="#vc2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-vc2" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>SMPTE VC-2 (previously BBC Dirac Pro). This codec was primarily aimed at
|
|
professional broadcasting but since it supports yuv420, yuv422 and yuv444 at
|
|
8 (limited range or full range), 10 or 12 bits, this makes it suitable for
|
|
other tasks which require low overhead and low compression (like screen
|
|
recording).
|
|
</p>
|
|
<a name="Options-27"></a>
|
|
<h4 class="subsection">9.15.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-27" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-27" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>b</samp></dt>
|
|
<dd><p>Sets target video bitrate. Usually that’s around 1:6 of the uncompressed
|
|
video bitrate (e.g. for 1920x1080 50fps yuv422p10 that’s around 400Mbps). Higher
|
|
values (close to the uncompressed bitrate) turn on lossless compression mode.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>field_order</samp></dt>
|
|
<dd><p>Enables field coding when set (e.g. to tt - top field first) for interlaced
|
|
inputs. Should increase compression with interlaced content as it splits the
|
|
fields and encodes each separately.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>wavelet_depth</samp></dt>
|
|
<dd><p>Sets the total amount of wavelet transforms to apply, between 1 and 5 (default).
|
|
Lower values reduce compression and quality. Less capable decoders may not be
|
|
able to handle values of <samp>wavelet_depth</samp> over 3.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>wavelet_type</samp></dt>
|
|
<dd><p>Sets the transform type. Currently only <var>5_3</var> (LeGall) and <var>9_7</var>
|
|
(Deslauriers-Dubuc)
|
|
are implemented, with 9_7 being the one with better compression and thus
|
|
is the default.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>slice_width</samp></dt>
|
|
<dt><samp>slice_height</samp></dt>
|
|
<dd><p>Sets the slice size for each slice. Larger values result in better compression.
|
|
For compatibility with other more limited decoders use <samp>slice_width</samp> of
|
|
32 and <samp>slice_height</samp> of 8.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>tolerance</samp></dt>
|
|
<dd><p>Sets the undershoot tolerance of the rate control system in percent. This is
|
|
to prevent an expensive search from being run.
|
|
</p>
|
|
</dd>
|
|
<dt><samp>qm</samp></dt>
|
|
<dd><p>Sets the quantization matrix preset to use by default or when <samp>wavelet_depth</samp>
|
|
is set to 5
|
|
</p><ul class="no-bullet">
|
|
<li>- <var>default</var>
|
|
Uses the default quantization matrix from the specifications, extended with
|
|
values for the fifth level. This provides a good balance between keeping detail
|
|
and omitting artifacts.
|
|
|
|
</li><li>- <var>flat</var>
|
|
Use a completely zeroed out quantization matrix. This increases PSNR but might
|
|
reduce perception. Use in bogus benchmarks.
|
|
|
|
</li><li>- <var>color</var>
|
|
Reduces detail but attempts to preserve color at extremely low bitrates.
|
|
</li></ul>
|
|
|
|
</dd>
|
|
</dl>
|
|
|
|
|
|
<a name="Subtitles-Encoders"></a>
|
|
<h2 class="chapter">10 Subtitles Encoders<span class="pull-right"><a class="anchor hidden-xs" href="#Subtitles-Encoders" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Subtitles-Encoders" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<a name="dvdsub-1"></a>
|
|
<h3 class="section">10.1 dvdsub<span class="pull-right"><a class="anchor hidden-xs" href="#dvdsub-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dvdsub-1" aria-hidden="true">TOC</a></span></h3>
|
|
|
|
<p>This codec encodes the bitmap subtitle format that is used in DVDs.
|
|
Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
|
|
and they can also be used in Matroska files.
|
|
</p>
|
|
<a name="Options-28"></a>
|
|
<h4 class="subsection">10.1.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-28" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-28" aria-hidden="true">TOC</a></span></h4>
|
|
|
|
<dl compact="compact">
|
|
<dt><samp>even_rows_fix</samp></dt>
|
|
<dd><p>When set to 1, enable a work-around that makes the number of pixel rows
|
|
even in all subtitles. This fixes a problem with some players that
|
|
cut off the bottom row if the number is odd. The work-around just adds
|
|
a fully transparent row if needed. The overhead is low, typically
|
|
one byte per subtitle on average.
|
|
</p>
|
|
<p>By default, this work-around is disabled.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
|
|
<a name="See-Also"></a>
|
|
<h2 class="chapter">11 See Also<span class="pull-right"><a class="anchor hidden-xs" href="#See-Also" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-See-Also" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p><a href="ffmpeg.html">ffmpeg</a>, <a href="ffplay.html">ffplay</a>, <a href="ffprobe.html">ffprobe</a>, <a href="ffserver.html">ffserver</a>,
|
|
<a href="libavcodec.html">libavcodec</a>
|
|
</p>
|
|
|
|
<a name="Authors"></a>
|
|
<h2 class="chapter">12 Authors<span class="pull-right"><a class="anchor hidden-xs" href="#Authors" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Authors" aria-hidden="true">TOC</a></span></h2>
|
|
|
|
<p>The FFmpeg developers.
|
|
</p>
|
|
<p>For details about the authorship, see the Git history of the project
|
|
(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
|
|
<code>git log</code> in the FFmpeg source directory, or browsing the
|
|
online repository at <a href="http://source.ffmpeg.org">http://source.ffmpeg.org</a>.
|
|
</p>
|
|
<p>Maintainers for the specific components are listed in the file
|
|
<samp>MAINTAINERS</samp> in the source code tree.
|
|
</p>
|
|
|
|
|
|
<p style="font-size: small;">
|
|
This document was generated using <a href="http://www.gnu.org/software/texinfo/"><em>makeinfo</em></a>.
|
|
</p>
|
|
</div>
|
|
</body>
|
|
</html>
|