2 Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 /** @file src/ffmpeg_decoder.cc
21 * @brief A decoder using FFmpeg to decode content.
30 #include <boost/lexical_cast.hpp>
33 #include <libavcodec/avcodec.h>
34 #include <libavformat/avformat.h>
35 #include <libswscale/swscale.h>
36 #include <libpostproc/postprocess.h>
41 #include "transcoder.h"
44 #include "film_state.h"
46 #include "exceptions.h"
50 #include "ffmpeg_decoder.h"
54 using namespace boost;
56 FFmpegDecoder::FFmpegDecoder (boost::shared_ptr<const FilmState> s, boost::shared_ptr<const Options> o, Job* j, Log* l, bool minimal, bool ignore_length)
57 : Decoder (s, o, j, l, minimal, ignore_length)
61 , _subtitle_stream (-1)
63 , _video_codec_context (0)
65 , _audio_codec_context (0)
67 , _subtitle_codec_context (0)
76 FFmpegDecoder::~FFmpegDecoder ()
78 if (_audio_codec_context) {
79 avcodec_close (_audio_codec_context);
82 if (_video_codec_context) {
83 avcodec_close (_video_codec_context);
86 if (_subtitle_codec_context) {
87 avcodec_close (_subtitle_codec_context);
91 avformat_close_input (&_format_context);
95 FFmpegDecoder::setup_general ()
101 if ((r = avformat_open_input (&_format_context, _fs->content_path().c_str(), 0, 0)) != 0) {
102 throw OpenFileError (_fs->content_path ());
105 if (avformat_find_stream_info (_format_context, 0) < 0) {
106 throw DecodeError ("could not find stream information");
109 /* Find video, audio and subtitle streams and choose the first of each */
111 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
112 AVStream* s = _format_context->streams[i];
113 if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
115 } else if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
116 if (_audio_stream == -1) {
119 _audio_streams.push_back (AudioStream (stream_name (s), i, s->codec->channels));
120 } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
121 if (_subtitle_stream == -1) {
122 _subtitle_stream = i;
124 _subtitle_streams.push_back (SubtitleStream (stream_name (s), i));
128 /* Now override audio and subtitle streams with those from the Film, if it has any */
130 if (_fs->audio_stream_index() != -1) {
131 _audio_stream = _fs->audio_stream().id();
134 if (_fs->subtitle_stream_index() != -1) {
135 _subtitle_stream = _fs->subtitle_stream().id ();
138 if (_video_stream < 0) {
139 throw DecodeError ("could not find video stream");
142 _frame = avcodec_alloc_frame ();
144 throw DecodeError ("could not allocate frame");
149 FFmpegDecoder::setup_video ()
151 _video_codec_context = _format_context->streams[_video_stream]->codec;
152 _video_codec = avcodec_find_decoder (_video_codec_context->codec_id);
154 if (_video_codec == 0) {
155 throw DecodeError ("could not find video decoder");
158 if (avcodec_open2 (_video_codec_context, _video_codec, 0) < 0) {
159 throw DecodeError ("could not open video decoder");
164 FFmpegDecoder::setup_audio ()
166 if (_audio_stream < 0) {
170 _audio_codec_context = _format_context->streams[_audio_stream]->codec;
171 _audio_codec = avcodec_find_decoder (_audio_codec_context->codec_id);
173 if (_audio_codec == 0) {
174 throw DecodeError ("could not find audio decoder");
177 if (avcodec_open2 (_audio_codec_context, _audio_codec, 0) < 0) {
178 throw DecodeError ("could not open audio decoder");
181 /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
182 so bodge it here. No idea why we should have to do this.
185 if (_audio_codec_context->channel_layout == 0) {
186 _audio_codec_context->channel_layout = av_get_default_channel_layout (audio_channels ());
191 FFmpegDecoder::setup_subtitle ()
193 if (_subtitle_stream < 0) {
197 _subtitle_codec_context = _format_context->streams[_subtitle_stream]->codec;
198 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
200 if (_subtitle_codec == 0) {
201 throw DecodeError ("could not find subtitle decoder");
204 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
205 throw DecodeError ("could not open subtitle decoder");
211 FFmpegDecoder::do_pass ()
213 int r = av_read_frame (_format_context, &_packet);
216 if (r != AVERROR_EOF) {
217 throw DecodeError ("error on av_read_frame");
220 /* Get any remaining frames */
225 /* XXX: should we reset _packet.data and size after each *_decode_* call? */
229 while (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
230 process_video (_frame);
233 if (_audio_stream >= 0 && _opt->decode_audio) {
234 while (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
235 int const data_size = av_samples_get_buffer_size (
236 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
239 assert (_audio_codec_context->channels == _fs->audio_channels());
240 process_audio (_frame->data[0], data_size);
247 double const pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base) * _packet.pts;
249 if (_packet.stream_index == _video_stream) {
252 _first_video = pts_seconds;
256 if (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
257 process_video (_frame);
260 } else if (_audio_stream >= 0 && _packet.stream_index == _audio_stream && _opt->decode_audio && _first_video && _first_video.get() <= pts_seconds) {
262 /* Note: We only decode audio if we've had our first video packet through, and if it
263 was before this packet. Until then audio is thrown away.
267 _first_audio = pts_seconds;
269 /* This is our first audio packet, and if we've arrived here we must have had our
270 first video packet. Push some silence to make up the gap between our first
271 video packet and our first audio.
274 /* frames of silence that we must push */
275 int const s = rint ((_first_audio.get() - _first_video.get()) * audio_sample_rate ());
279 "First video at %1, first audio at %2, pushing %3 frames of silence for %4 channels (%5 bytes per sample)",
280 _first_video.get(), _first_audio.get(), s, audio_channels(), bytes_per_audio_sample()
285 int const b = s * audio_channels() * bytes_per_audio_sample();
287 /* XXX: this assumes that it won't be too much, and there are shaky assumptions
288 that all sound representations are silent with memset()ed zero data.
291 memset (silence, 0, b);
292 process_audio (silence, b);
295 avcodec_get_frame_defaults (_frame);
298 if (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
299 int const data_size = av_samples_get_buffer_size (
300 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
303 assert (_audio_codec_context->channels == _fs->audio_channels());
304 process_audio (_frame->data[0], data_size);
307 } else if (_subtitle_stream >= 0 && _packet.stream_index == _subtitle_stream && _opt->decode_subtitles) {
311 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
312 /* I'm not entirely sure why, but sometimes we get an AVSubtitle with
315 if (sub.num_rects > 0) {
316 process_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub)));
318 avsubtitle_free (&sub);
322 av_free_packet (&_packet);
327 FFmpegDecoder::frames_per_second () const
329 AVStream* s = _format_context->streams[_video_stream];
331 if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
332 return av_q2d (s->avg_frame_rate);
335 return av_q2d (s->r_frame_rate);
339 FFmpegDecoder::audio_channels () const
341 if (_audio_codec_context == 0) {
345 return _audio_codec_context->channels;
349 FFmpegDecoder::audio_sample_rate () const
351 if (_audio_codec_context == 0) {
355 return _audio_codec_context->sample_rate;
359 FFmpegDecoder::audio_sample_format () const
361 if (_audio_codec_context == 0) {
362 return (AVSampleFormat) 0;
365 return _audio_codec_context->sample_fmt;
369 FFmpegDecoder::audio_channel_layout () const
371 if (_audio_codec_context == 0) {
375 return _audio_codec_context->channel_layout;
379 FFmpegDecoder::native_size () const
381 return Size (_video_codec_context->width, _video_codec_context->height);
385 FFmpegDecoder::pixel_format () const
387 return _video_codec_context->pix_fmt;
391 FFmpegDecoder::time_base_numerator () const
393 return _video_codec_context->time_base.num;
397 FFmpegDecoder::time_base_denominator () const
399 return _video_codec_context->time_base.den;
403 FFmpegDecoder::sample_aspect_ratio_numerator () const
405 return _video_codec_context->sample_aspect_ratio.num;
409 FFmpegDecoder::sample_aspect_ratio_denominator () const
411 return _video_codec_context->sample_aspect_ratio.den;
415 FFmpegDecoder::has_subtitles () const
417 return (_subtitle_stream != -1);
421 FFmpegDecoder::audio_streams () const
423 return _audio_streams;
426 vector<SubtitleStream>
427 FFmpegDecoder::subtitle_streams () const
429 return _subtitle_streams;
433 FFmpegDecoder::stream_name (AVStream* s) const
437 AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
442 AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
444 if (!n.str().empty()) {
450 if (n.str().empty()) {