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"
50 #include "filter_graph.h"
56 using std::stringstream;
58 using boost::shared_ptr;
59 using boost::optional;
60 using boost::dynamic_pointer_cast;
63 FFmpegDecoder::FFmpegDecoder (shared_ptr<Film> f, DecodeOptions o, Job* j)
65 , VideoDecoder (f, o, j)
66 , AudioDecoder (f, o, j)
70 , _video_codec_context (0)
72 , _audio_codec_context (0)
74 , _subtitle_codec_context (0)
87 FFmpegDecoder::~FFmpegDecoder ()
89 if (_audio_codec_context) {
90 avcodec_close (_audio_codec_context);
93 if (_video_codec_context) {
94 avcodec_close (_video_codec_context);
97 if (_subtitle_codec_context) {
98 avcodec_close (_subtitle_codec_context);
103 avformat_close_input (&_format_context);
107 FFmpegDecoder::setup_general ()
111 if (avformat_open_input (&_format_context, _film->content_path().c_str(), 0, 0) < 0) {
112 throw OpenFileError (_film->content_path ());
115 if (avformat_find_stream_info (_format_context, 0) < 0) {
116 throw DecodeError ("could not find stream information");
119 /* Find video, audio and subtitle streams and choose the first of each */
121 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
122 AVStream* s = _format_context->streams[i];
123 if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
125 } else if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
127 /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
128 so bodge it here. No idea why we should have to do this.
131 if (s->codec->channel_layout == 0) {
132 s->codec->channel_layout = av_get_default_channel_layout (s->codec->channels);
135 _audio_streams.push_back (
136 shared_ptr<AudioStream> (
137 new FFmpegAudioStream (stream_name (s), i, s->codec->sample_rate, s->codec->channel_layout)
141 } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
142 _subtitle_streams.push_back (
143 shared_ptr<SubtitleStream> (
144 new SubtitleStream (stream_name (s), i)
150 if (_video_stream < 0) {
151 throw DecodeError ("could not find video stream");
154 _frame = avcodec_alloc_frame ();
156 throw DecodeError ("could not allocate frame");
161 FFmpegDecoder::setup_video ()
163 _video_codec_context = _format_context->streams[_video_stream]->codec;
164 _video_codec = avcodec_find_decoder (_video_codec_context->codec_id);
166 if (_video_codec == 0) {
167 throw DecodeError ("could not find video decoder");
170 if (avcodec_open2 (_video_codec_context, _video_codec, 0) < 0) {
171 throw DecodeError ("could not open video decoder");
176 FFmpegDecoder::setup_audio ()
178 if (!_audio_stream) {
182 shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
185 _audio_codec_context = _format_context->streams[ffa->id()]->codec;
186 _audio_codec = avcodec_find_decoder (_audio_codec_context->codec_id);
188 if (_audio_codec == 0) {
189 throw DecodeError ("could not find audio decoder");
192 if (avcodec_open2 (_audio_codec_context, _audio_codec, 0) < 0) {
193 throw DecodeError ("could not open audio decoder");
198 FFmpegDecoder::setup_subtitle ()
200 if (!_subtitle_stream) {
204 _subtitle_codec_context = _format_context->streams[_subtitle_stream->id()]->codec;
205 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
207 if (_subtitle_codec == 0) {
208 throw DecodeError ("could not find subtitle decoder");
211 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
212 throw DecodeError ("could not open subtitle decoder");
218 FFmpegDecoder::pass ()
220 int r = av_read_frame (_format_context, &_packet);
223 if (r != AVERROR_EOF) {
224 /* Maybe we should fail here, but for now we'll just finish off instead */
226 av_strerror (r, buf, sizeof(buf));
227 _film->log()->log (String::compose ("error on av_read_frame (%1) (%2)", buf, r));
230 /* Get any remaining frames */
235 /* XXX: should we reset _packet.data and size after each *_decode_* call? */
239 while (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
240 filter_and_emit_video (_frame);
243 if (_audio_stream && _opt.decode_audio) {
244 while (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
245 int const data_size = av_samples_get_buffer_size (
246 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
249 assert (_audio_codec_context->channels == _film->audio_channels());
250 Audio (deinterleave_audio (_frame->data[0], data_size));
257 avcodec_get_frame_defaults (_frame);
259 shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
261 if (_packet.stream_index == _video_stream) {
264 int const r = avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet);
265 if (r >= 0 && frame_finished) {
267 if (r != _packet.size) {
268 _film->log()->log (String::compose ("Used only %1 bytes of %2 in packet", r, _packet.size));
271 if (_opt.video_sync) {
274 filter_and_emit_video (_frame);
278 } else if (ffa && _packet.stream_index == ffa->id() && _opt.decode_audio) {
281 if (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
283 /* Where we are in the source, in seconds */
284 double const source_pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base)
285 * av_frame_get_best_effort_timestamp(_frame);
287 /* We only decode audio if we've had our first video packet through, and if it
288 was before this packet. Until then audio is thrown away.
291 if (_first_video && _first_video.get() <= source_pts_seconds) {
294 _first_audio = source_pts_seconds;
296 /* This is our first audio frame, and if we've arrived here we must have had our
297 first video frame. Push some silence to make up any gap between our first
298 video frame and our first audio.
301 /* frames of silence that we must push */
302 int const s = rint ((_first_audio.get() - _first_video.get()) * ffa->sample_rate ());
306 "First video at %1, first audio at %2, pushing %3 audio frames of silence for %4 channels (%5 bytes per sample)",
307 _first_video.get(), _first_audio.get(), s, ffa->channels(), bytes_per_audio_sample()
312 shared_ptr<AudioBuffers> audio (new AudioBuffers (ffa->channels(), s));
313 audio->make_silent ();
318 int const data_size = av_samples_get_buffer_size (
319 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
322 assert (_audio_codec_context->channels == _film->audio_channels());
323 Audio (deinterleave_audio (_frame->data[0], data_size));
327 } else if (_subtitle_stream && _packet.stream_index == _subtitle_stream->id() && _opt.decode_subtitles && _first_video) {
331 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
332 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
333 indicate that the previous subtitle should stop.
335 if (sub.num_rects > 0) {
336 shared_ptr<TimedSubtitle> ts;
338 emit_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub)));
340 /* some problem with the subtitle; we probably didn't understand it */
343 emit_subtitle (shared_ptr<TimedSubtitle> ());
345 avsubtitle_free (&sub);
349 av_free_packet (&_packet);
353 shared_ptr<AudioBuffers>
354 FFmpegDecoder::deinterleave_audio (uint8_t* data, int size)
356 assert (_film->audio_channels());
357 assert (bytes_per_audio_sample());
359 shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
362 /* Deinterleave and convert to float */
364 assert ((size % (bytes_per_audio_sample() * ffa->channels())) == 0);
366 int const total_samples = size / bytes_per_audio_sample();
367 int const frames = total_samples / _film->audio_channels();
368 shared_ptr<AudioBuffers> audio (new AudioBuffers (ffa->channels(), frames));
370 switch (audio_sample_format()) {
371 case AV_SAMPLE_FMT_S16:
373 int16_t* p = reinterpret_cast<int16_t *> (data);
376 for (int i = 0; i < total_samples; ++i) {
377 audio->data(channel)[sample] = float(*p++) / (1 << 15);
380 if (channel == _film->audio_channels()) {
388 case AV_SAMPLE_FMT_S16P:
390 int16_t* p = reinterpret_cast<int16_t *> (data);
391 for (int i = 0; i < _film->audio_channels(); ++i) {
392 for (int j = 0; j < frames; ++j) {
393 audio->data(i)[j] = static_cast<float>(*p++) / (1 << 15);
399 case AV_SAMPLE_FMT_S32:
401 int32_t* p = reinterpret_cast<int32_t *> (data);
404 for (int i = 0; i < total_samples; ++i) {
405 audio->data(channel)[sample] = static_cast<float>(*p++) / (1 << 31);
408 if (channel == _film->audio_channels()) {
416 case AV_SAMPLE_FMT_FLT:
418 float* p = reinterpret_cast<float*> (data);
421 for (int i = 0; i < total_samples; ++i) {
422 audio->data(channel)[sample] = *p++;
425 if (channel == _film->audio_channels()) {
433 case AV_SAMPLE_FMT_FLTP:
435 float* p = reinterpret_cast<float*> (data);
436 for (int i = 0; i < _film->audio_channels(); ++i) {
437 memcpy (audio->data(i), p, frames * sizeof(float));
444 throw DecodeError (String::compose ("Unrecognised audio sample format (%1)", static_cast<int> (audio_sample_format())));
451 FFmpegDecoder::frames_per_second () const
453 AVStream* s = _format_context->streams[_video_stream];
455 if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
456 return av_q2d (s->avg_frame_rate);
459 return av_q2d (s->r_frame_rate);
463 FFmpegDecoder::audio_sample_format () const
465 if (_audio_codec_context == 0) {
466 return (AVSampleFormat) 0;
469 return _audio_codec_context->sample_fmt;
473 FFmpegDecoder::native_size () const
475 return Size (_video_codec_context->width, _video_codec_context->height);
479 FFmpegDecoder::pixel_format () const
481 return _video_codec_context->pix_fmt;
485 FFmpegDecoder::time_base_numerator () const
487 return _video_codec_context->time_base.num;
491 FFmpegDecoder::time_base_denominator () const
493 return _video_codec_context->time_base.den;
497 FFmpegDecoder::sample_aspect_ratio_numerator () const
499 return _video_codec_context->sample_aspect_ratio.num;
503 FFmpegDecoder::sample_aspect_ratio_denominator () const
505 return _video_codec_context->sample_aspect_ratio.den;
509 FFmpegDecoder::stream_name (AVStream* s) const
513 AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
518 AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
520 if (!n.str().empty()) {
526 if (n.str().empty()) {
534 FFmpegDecoder::bytes_per_audio_sample () const
536 return av_get_bytes_per_sample (audio_sample_format ());
540 FFmpegDecoder::set_audio_stream (shared_ptr<AudioStream> s)
542 AudioDecoder::set_audio_stream (s);
547 FFmpegDecoder::set_subtitle_stream (shared_ptr<SubtitleStream> s)
549 VideoDecoder::set_subtitle_stream (s);
555 FFmpegDecoder::filter_and_emit_video (AVFrame* frame)
557 boost::mutex::scoped_lock lm (_filter_graphs_mutex);
559 shared_ptr<FilterGraph> graph;
561 list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
562 while (i != _filter_graphs.end() && !(*i)->can_process (Size (frame->width, frame->height), (AVPixelFormat) frame->format)) {
566 if (i == _filter_graphs.end ()) {
567 graph.reset (new FilterGraph (_film, this, Size (frame->width, frame->height), (AVPixelFormat) frame->format));
568 _filter_graphs.push_back (graph);
569 _film->log()->log (String::compose ("New graph for %1x%2, pixel format %3", frame->width, frame->height, frame->format));
574 list<shared_ptr<Image> > images = graph->process (frame);
576 for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
577 emit_video (*i, frame_time ());
582 FFmpegDecoder::seek (double p)
584 return do_seek (p, false);
588 FFmpegDecoder::seek_to_last ()
590 /* This AVSEEK_FLAG_BACKWARD in do_seek is a bit of a hack; without it, if we ask for a seek to the same place as last time
591 (used when we change decoder parameters and want to re-fetch the frame) we end up going forwards rather than
592 staying in the same place.
594 return do_seek (last_source_time(), true);
598 FFmpegDecoder::do_seek (double p, bool backwards)
600 int64_t const vt = p / av_q2d (_format_context->streams[_video_stream]->time_base);
602 int const r = av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0);
604 avcodec_flush_buffers (_video_codec_context);
605 if (_subtitle_codec_context) {
606 avcodec_flush_buffers (_subtitle_codec_context);
612 shared_ptr<FFmpegAudioStream>
613 FFmpegAudioStream::create (string t, optional<int> v)
616 /* version < 1; no type in the string, and there's only FFmpeg streams anyway */
617 return shared_ptr<FFmpegAudioStream> (new FFmpegAudioStream (t, v));
623 if (type != "ffmpeg") {
624 return shared_ptr<FFmpegAudioStream> ();
627 return shared_ptr<FFmpegAudioStream> (new FFmpegAudioStream (t, v));
630 FFmpegAudioStream::FFmpegAudioStream (string t, optional<int> version)
638 n >> _id >> channels;
639 _channel_layout = av_get_default_channel_layout (channels);
643 /* Current (marked version 1) */
644 n >> type >> _id >> _sample_rate >> _channel_layout;
645 assert (type == "ffmpeg");
648 for (int i = 0; i < name_index; ++i) {
649 size_t const s = t.find (' ');
650 if (s != string::npos) {
651 t = t.substr (s + 1);
659 FFmpegAudioStream::to_string () const
661 return String::compose ("ffmpeg %1 %2 %3 %4", _id, _sample_rate, _channel_layout, _name);
665 FFmpegDecoder::out_with_sync ()
667 /* Where we are in the output, in seconds */
668 double const out_pts_seconds = video_frame() / frames_per_second();
670 /* Where we are in the source, in seconds */
671 double const source_pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base)
672 * av_frame_get_best_effort_timestamp(_frame);
675 String::compose ("Source video frame ready; source at %1, output at %2", source_pts_seconds, out_pts_seconds),
680 _first_video = source_pts_seconds;
683 /* Difference between where we are and where we should be */
684 double const delta = source_pts_seconds - _first_video.get() - out_pts_seconds;
685 double const one_frame = 1 / frames_per_second();
687 /* Insert frames if required to get out_pts_seconds up to pts_seconds */
688 if (delta > one_frame) {
689 int const extra = rint (delta / one_frame);
690 for (int i = 0; i < extra; ++i) {
691 repeat_last_video ();
694 "Extra video frame inserted at %1s; source frame %2, source PTS %3 (at %4 fps)",
695 out_pts_seconds, video_frame(), source_pts_seconds, frames_per_second()
701 if (delta > -one_frame) {
702 /* Process this frame */
703 filter_and_emit_video (_frame);
705 /* Otherwise we are omitting a frame to keep things right */
706 _film->log()->log (String::compose ("Frame removed at %1s", out_pts_seconds));
711 FFmpegDecoder::film_changed (Film::Property p)
717 boost::mutex::scoped_lock lm (_filter_graphs_mutex);
718 _filter_graphs.clear ();
728 /** @return Length (in video frames) according to our content's header */
730 FFmpegDecoder::length () const
732 return (double(_format_context->duration) / AV_TIME_BASE) * frames_per_second();
736 FFmpegDecoder::frame_time () const
738 return av_frame_get_best_effort_timestamp(_frame) * av_q2d (_format_context->streams[_video_stream]->time_base);