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 && _first_video) {
311 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
312 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
313 indicate that the previous subtitle should stop.
315 if (sub.num_rects > 0) {
316 process_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub, _first_video.get())));
318 process_subtitle (shared_ptr<TimedSubtitle> ());
320 avsubtitle_free (&sub);
324 av_free_packet (&_packet);
329 FFmpegDecoder::frames_per_second () const
331 AVStream* s = _format_context->streams[_video_stream];
333 if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
334 return av_q2d (s->avg_frame_rate);
337 return av_q2d (s->r_frame_rate);
341 FFmpegDecoder::audio_channels () const
343 if (_audio_codec_context == 0) {
347 return _audio_codec_context->channels;
351 FFmpegDecoder::audio_sample_rate () const
353 if (_audio_codec_context == 0) {
357 return _audio_codec_context->sample_rate;
361 FFmpegDecoder::audio_sample_format () const
363 if (_audio_codec_context == 0) {
364 return (AVSampleFormat) 0;
367 return _audio_codec_context->sample_fmt;
371 FFmpegDecoder::audio_channel_layout () const
373 if (_audio_codec_context == 0) {
377 return _audio_codec_context->channel_layout;
381 FFmpegDecoder::native_size () const
383 return Size (_video_codec_context->width, _video_codec_context->height);
387 FFmpegDecoder::pixel_format () const
389 return _video_codec_context->pix_fmt;
393 FFmpegDecoder::time_base_numerator () const
395 return _video_codec_context->time_base.num;
399 FFmpegDecoder::time_base_denominator () const
401 return _video_codec_context->time_base.den;
405 FFmpegDecoder::sample_aspect_ratio_numerator () const
407 return _video_codec_context->sample_aspect_ratio.num;
411 FFmpegDecoder::sample_aspect_ratio_denominator () const
413 return _video_codec_context->sample_aspect_ratio.den;
417 FFmpegDecoder::has_subtitles () const
419 return (_subtitle_stream != -1);
423 FFmpegDecoder::audio_streams () const
425 return _audio_streams;
428 vector<SubtitleStream>
429 FFmpegDecoder::subtitle_streams () const
431 return _subtitle_streams;
435 FFmpegDecoder::stream_name (AVStream* s) const
439 AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
444 AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
446 if (!n.str().empty()) {
452 if (n.str().empty()) {