From 8563df673d03e7bbdc95fc1471ee7fddea78461c Mon Sep 17 00:00:00 2001 From: Carl Hetherington Date: Mon, 4 Mar 2013 20:19:01 +0000 Subject: [PATCH] Move audio decoding to separate method and fix incorrect decoding when there are multiple audio packets per frame (e.g. with wmapro). --- src/lib/ffmpeg_decoder.cc | 126 +++++++++++++++++++++----------------- src/lib/ffmpeg_decoder.h | 2 + 2 files changed, 72 insertions(+), 56 deletions(-) diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc index 462db283a..ca019e06a 100644 --- a/src/lib/ffmpeg_decoder.cc +++ b/src/lib/ffmpeg_decoder.cc @@ -245,14 +245,7 @@ FFmpegDecoder::pass () } if (_audio_stream && _opt.decode_audio) { - while (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) { - int const data_size = av_samples_get_buffer_size ( - 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1 - ); - - assert (_audio_codec_context->channels == _film->audio_channels()); - Audio (deinterleave_audio (_frame->data, data_size)); - } + decode_audio_packet (); } return true; @@ -280,54 +273,7 @@ FFmpegDecoder::pass () } } else if (ffa && _packet.stream_index == ffa->id() && _opt.decode_audio) { - - int frame_finished; - if (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) { - - /* Where we are in the source, in seconds */ - double const source_pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base) - * av_frame_get_best_effort_timestamp(_frame); - - /* We only decode audio if we've had our first video packet through, and if it - was before this packet. Until then audio is thrown away. - */ - - if ((_first_video && _first_video.get() <= source_pts_seconds) || !_opt.decode_video) { - - if (!_first_audio && _opt.decode_video) { - _first_audio = source_pts_seconds; - - /* This is our first audio frame, and if we've arrived here we must have had our - first video frame. Push some silence to make up any gap between our first - video frame and our first audio. - */ - - /* frames of silence that we must push */ - int const s = rint ((_first_audio.get() - _first_video.get()) * ffa->sample_rate ()); - - _film->log()->log ( - String::compose ( - N_("First video at %1, first audio at %2, pushing %3 audio frames of silence for %4 channels (%5 bytes per sample)"), - _first_video.get(), _first_audio.get(), s, ffa->channels(), bytes_per_audio_sample() - ) - ); - - if (s) { - shared_ptr audio (new AudioBuffers (ffa->channels(), s)); - audio->make_silent (); - Audio (audio); - } - } - - int const data_size = av_samples_get_buffer_size ( - 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1 - ); - - assert (_audio_codec_context->channels == _film->audio_channels()); - Audio (deinterleave_audio (_frame->data, data_size)); - } - } - + decode_audio_packet (); } else if (_subtitle_stream && _packet.stream_index == _subtitle_stream->id() && _opt.decode_subtitles && _first_video) { int got_subtitle; @@ -744,3 +690,71 @@ FFmpegDecoder::frame_time () const return av_frame_get_best_effort_timestamp(_frame) * av_q2d (_format_context->streams[_video_stream]->time_base); } +void +FFmpegDecoder::decode_audio_packet () +{ + shared_ptr ffa = dynamic_pointer_cast (_audio_stream); + assert (ffa); + + /* Audio packets can contain multiple frames, so we may have to call avcodec_decode_audio4 + several times. + */ + + AVPacket copy_packet = _packet; + + while (copy_packet.size > 0) { + + int frame_finished; + int const decode_result = avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, ©_packet); + if (decode_result >= 0 && frame_finished) { + + /* Where we are in the source, in seconds */ + double const source_pts_seconds = av_q2d (_format_context->streams[copy_packet.stream_index]->time_base) + * av_frame_get_best_effort_timestamp(_frame); + + /* We only decode audio if we've had our first video packet through, and if it + was before this packet. Until then audio is thrown away. + */ + + if ((_first_video && _first_video.get() <= source_pts_seconds) || !_opt.decode_video) { + + if (!_first_audio && _opt.decode_video) { + _first_audio = source_pts_seconds; + + /* This is our first audio frame, and if we've arrived here we must have had our + first video frame. Push some silence to make up any gap between our first + video frame and our first audio. + */ + + /* frames of silence that we must push */ + int const s = rint ((_first_audio.get() - _first_video.get()) * ffa->sample_rate ()); + + _film->log()->log ( + String::compose ( + N_("First video at %1, first audio at %2, pushing %3 audio frames of silence for %4 channels (%5 bytes per sample)"), + _first_video.get(), _first_audio.get(), s, ffa->channels(), bytes_per_audio_sample() + ) + ); + + if (s) { + shared_ptr audio (new AudioBuffers (ffa->channels(), s)); + audio->make_silent (); + Audio (audio); + } + } + + int const data_size = av_samples_get_buffer_size ( + 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1 + ); + + assert (_audio_codec_context->channels == _film->audio_channels()); + Audio (deinterleave_audio (_frame->data, data_size)); + } + } + + if (decode_result >= 0) { + copy_packet.data += decode_result; + copy_packet.size -= decode_result; + } + } +} diff --git a/src/lib/ffmpeg_decoder.h b/src/lib/ffmpeg_decoder.h index c383b8d13..1bb14ce9c 100644 --- a/src/lib/ffmpeg_decoder.h +++ b/src/lib/ffmpeg_decoder.h @@ -120,6 +120,8 @@ private: void setup_audio (); void setup_subtitle (); + void decode_audio_packet (); + void maybe_add_subtitle (); boost::shared_ptr deinterleave_audio (uint8_t** data, int size); -- 2.30.2