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diff --git a/Music/ffmpeg/doc/ffmpeg-codecs.html b/Music/ffmpeg/doc/ffmpeg-codecs.html new file mode 100755 index 0000000..2ef2465 --- /dev/null +++ b/Music/ffmpeg/doc/ffmpeg-codecs.html @@ -0,0 +1,5026 @@ +<!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> |