diff options
Diffstat (limited to 'src/base/QXmppCodec.cpp')
| -rw-r--r-- | src/base/QXmppCodec.cpp | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/src/base/QXmppCodec.cpp b/src/base/QXmppCodec.cpp index 0e47de63..3252b9e8 100644 --- a/src/base/QXmppCodec.cpp +++ b/src/base/QXmppCodec.cpp @@ -65,6 +65,7 @@ #define SEG_SHIFT (4) /* Left shift for segment number. */ #define SEG_MASK (0x70) /* Segment field mask. */ +// Distance (in frames) between two key frames (video only). #define GOPSIZE 32 enum FragmentType { @@ -411,6 +412,7 @@ QXmppOpusCodec::QXmppOpusCodec(int clockrate, int channels): else qCritical() << "Opus encoder initialization error:" << opus_strerror(error); + // Here, clockrate is synonym of sampleRate. decoder = opus_decoder_create(clockrate, channels, &error); if (!encoder || error != OPUS_OK) @@ -424,7 +426,7 @@ QXmppOpusCodec::QXmppOpusCodec(int clockrate, int channels): // so now, calculate the equivalent number of samples to process in each // frame. // - // nSamples = t * frameRate + // nSamples = t * sampleRate for (int i = 0; i < validFrameSize.size(); i++) validFrameSize[i] *= clockrate; @@ -1103,6 +1105,8 @@ public: bool QXmppVpxDecoderPrivate::decodeFrame(const QByteArray &buffer, QXmppVideoFrame *frame) { + // With the VPX_DL_REALTIME option, tries to decode the frame as quick as + // possible, if not possible discard it. if (vpx_codec_decode(&codec, (const uint8_t*)buffer.constData(), buffer.size(), @@ -1148,6 +1152,7 @@ QXmppVpxDecoder::QXmppVpxDecoder() d = new QXmppVpxDecoderPrivate; vpx_codec_flags_t flags = 0; + // Enable FEC if codec support it. if (vpx_codec_get_caps(vpx_codec_vp8_dx()) & VPX_CODEC_CAP_ERROR_CONCEALMENT) flags |= VPX_CODEC_USE_ERROR_CONCEALMENT; @@ -1198,6 +1203,14 @@ QList<QXmppVideoFrame> QXmppVpxDecoder::handlePacket(const QXmppRtpPacket &packe QXmppVideoFrame frame; static quint16 sequence = 0; + // If the incomming packet sequence is wrong discard all packets until a + // complete keyframe arrives. + // If a partition of a keyframe is missing, discard it until a next + // keyframe. + // + // NOTE: https://tools.ietf.org/html/draft-ietf-payload-vp8-13#section-4.3 + // Sections: 4.3, 4.5, 4.5.1 + if (frag_type == NoFragment) { // unfragmented packet if ((packet.payload[1] & 0x1) == 0 // is key frame @@ -1292,6 +1305,7 @@ QXmppVpxEncoder::QXmppVpxEncoder(uint clockrate) if (d->cfg.kf_max_dist > GOPSIZE) d->cfg.kf_max_dist = GOPSIZE; + // Here, clockrate is synonym of bitrate. d->cfg.rc_target_bitrate = clockrate / 1000; } |