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"
45 #include "exceptions.h"
49 #include "ffmpeg_decoder.h"
54 using std::stringstream;
55 using boost::shared_ptr;
57 FFmpegDecoder::FFmpegDecoder (shared_ptr<Film> f, shared_ptr<const Options> o, Job* j, bool minimal, bool ignore_length)
58 : Decoder (f, o, j, minimal, ignore_length)
62 , _subtitle_stream (-1)
64 , _video_codec_context (0)
66 , _audio_codec_context (0)
68 , _subtitle_codec_context (0)
77 FFmpegDecoder::~FFmpegDecoder ()
79 if (_audio_codec_context) {
80 avcodec_close (_audio_codec_context);
83 if (_video_codec_context) {
84 avcodec_close (_video_codec_context);
87 if (_subtitle_codec_context) {
88 avcodec_close (_subtitle_codec_context);
92 avformat_close_input (&_format_context);
96 FFmpegDecoder::setup_general ()
102 if ((r = avformat_open_input (&_format_context, _film->content_path().c_str(), 0, 0)) != 0) {
103 throw OpenFileError (_film->content_path ());
106 if (avformat_find_stream_info (_format_context, 0) < 0) {
107 throw DecodeError ("could not find stream information");
110 /* Find video, audio and subtitle streams and choose the first of each */
112 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
113 AVStream* s = _format_context->streams[i];
114 if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
116 } else if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
117 if (_audio_stream == -1) {
120 _audio_streams.push_back (AudioStream (stream_name (s), i, s->codec->channels));
121 } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
122 if (_subtitle_stream == -1) {
123 _subtitle_stream = i;
125 _subtitle_streams.push_back (SubtitleStream (stream_name (s), i));
129 /* Now override audio and subtitle streams with those from the Film, if it has any */
131 if (_film->audio_stream_index() != -1) {
132 _audio_stream = _film->audio_stream().id();
135 if (_film->subtitle_stream_index() != -1) {
136 _subtitle_stream = _film->subtitle_stream().id ();
139 if (_video_stream < 0) {
140 throw DecodeError ("could not find video stream");
143 _frame = avcodec_alloc_frame ();
145 throw DecodeError ("could not allocate frame");
150 FFmpegDecoder::setup_video ()
152 _video_codec_context = _format_context->streams[_video_stream]->codec;
153 _video_codec = avcodec_find_decoder (_video_codec_context->codec_id);
155 if (_video_codec == 0) {
156 throw DecodeError ("could not find video decoder");
159 /* I think this prevents problems with green hash on decodes and
160 "changing frame properties on the fly is not supported by all filters"
161 messages with some content. Although I'm not sure; needs checking.
163 AVDictionary* opts = 0;
164 av_dict_set (&opts, "threads", "1", 0);
166 if (avcodec_open2 (_video_codec_context, _video_codec, &opts) < 0) {
167 throw DecodeError ("could not open video decoder");
172 FFmpegDecoder::setup_audio ()
174 if (_audio_stream < 0) {
178 _audio_codec_context = _format_context->streams[_audio_stream]->codec;
179 _audio_codec = avcodec_find_decoder (_audio_codec_context->codec_id);
181 if (_audio_codec == 0) {
182 throw DecodeError ("could not find audio decoder");
185 if (avcodec_open2 (_audio_codec_context, _audio_codec, 0) < 0) {
186 throw DecodeError ("could not open audio decoder");
189 /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
190 so bodge it here. No idea why we should have to do this.
193 if (_audio_codec_context->channel_layout == 0) {
194 _audio_codec_context->channel_layout = av_get_default_channel_layout (audio_channels ());
199 FFmpegDecoder::setup_subtitle ()
201 if (_subtitle_stream < 0) {
205 _subtitle_codec_context = _format_context->streams[_subtitle_stream]->codec;
206 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
208 if (_subtitle_codec == 0) {
209 throw DecodeError ("could not find subtitle decoder");
212 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
213 throw DecodeError ("could not open subtitle decoder");
219 FFmpegDecoder::do_pass ()
221 int r = av_read_frame (_format_context, &_packet);
224 if (r != AVERROR_EOF) {
225 throw DecodeError ("error on av_read_frame");
228 /* Get any remaining frames */
233 /* XXX: should we reset _packet.data and size after each *_decode_* call? */
237 while (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
238 process_video (_frame);
241 if (_audio_stream >= 0 && _opt->decode_audio) {
242 while (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
243 int const data_size = av_samples_get_buffer_size (
244 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
247 assert (_audio_codec_context->channels == _film->audio_channels());
248 process_audio (_frame->data[0], data_size);
255 double const pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base) * _packet.pts;
257 if (_packet.stream_index == _video_stream) {
260 _first_video = pts_seconds;
264 if (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
265 process_video (_frame);
268 } else if (_audio_stream >= 0 && _packet.stream_index == _audio_stream && _opt->decode_audio && _first_video && _first_video.get() <= pts_seconds) {
270 /* Note: We only decode audio if we've had our first video packet through, and if it
271 was before this packet. Until then audio is thrown away.
275 _first_audio = pts_seconds;
277 /* This is our first audio packet, and if we've arrived here we must have had our
278 first video packet. Push some silence to make up the gap between our first
279 video packet and our first audio.
282 /* frames of silence that we must push */
283 int const s = rint ((_first_audio.get() - _first_video.get()) * audio_sample_rate ());
287 "First video at %1, first audio at %2, pushing %3 frames of silence for %4 channels (%5 bytes per sample)",
288 _first_video.get(), _first_audio.get(), s, audio_channels(), bytes_per_audio_sample()
293 int const b = s * audio_channels() * bytes_per_audio_sample();
295 /* XXX: this assumes that it won't be too much, and there are shaky assumptions
296 that all sound representations are silent with memset()ed zero data.
299 memset (silence, 0, b);
300 process_audio (silence, b);
303 avcodec_get_frame_defaults (_frame);
306 if (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
307 int const data_size = av_samples_get_buffer_size (
308 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
311 assert (_audio_codec_context->channels == _film->audio_channels());
312 process_audio (_frame->data[0], data_size);
315 } else if (_subtitle_stream >= 0 && _packet.stream_index == _subtitle_stream && _opt->decode_subtitles && _first_video) {
319 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
320 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
321 indicate that the previous subtitle should stop.
323 if (sub.num_rects > 0) {
324 process_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub, _first_video.get())));
326 process_subtitle (shared_ptr<TimedSubtitle> ());
328 avsubtitle_free (&sub);
332 av_free_packet (&_packet);
337 FFmpegDecoder::frames_per_second () const
339 AVStream* s = _format_context->streams[_video_stream];
341 if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
342 return av_q2d (s->avg_frame_rate);
345 return av_q2d (s->r_frame_rate);
349 FFmpegDecoder::audio_channels () const
351 if (_audio_codec_context == 0) {
355 return _audio_codec_context->channels;
359 FFmpegDecoder::audio_sample_rate () const
361 if (_audio_codec_context == 0) {
365 return _audio_codec_context->sample_rate;
369 FFmpegDecoder::audio_sample_format () const
371 if (_audio_codec_context == 0) {
372 return (AVSampleFormat) 0;
375 return _audio_codec_context->sample_fmt;
379 FFmpegDecoder::audio_channel_layout () const
381 if (_audio_codec_context == 0) {
385 return _audio_codec_context->channel_layout;
389 FFmpegDecoder::native_size () const
391 return Size (_video_codec_context->width, _video_codec_context->height);
395 FFmpegDecoder::pixel_format () const
397 return _video_codec_context->pix_fmt;
401 FFmpegDecoder::time_base_numerator () const
403 return _video_codec_context->time_base.num;
407 FFmpegDecoder::time_base_denominator () const
409 return _video_codec_context->time_base.den;
413 FFmpegDecoder::sample_aspect_ratio_numerator () const
415 return _video_codec_context->sample_aspect_ratio.num;
419 FFmpegDecoder::sample_aspect_ratio_denominator () const
421 return _video_codec_context->sample_aspect_ratio.den;
425 FFmpegDecoder::has_subtitles () const
427 return (_subtitle_stream != -1);
431 FFmpegDecoder::audio_streams () const
433 return _audio_streams;
436 vector<SubtitleStream>
437 FFmpegDecoder::subtitle_streams () const
439 return _subtitle_streams;
443 FFmpegDecoder::stream_name (AVStream* s) const
447 AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
452 AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
454 if (!n.str().empty()) {
460 if (n.str().empty()) {