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;
62 FFmpegDecoder::FFmpegDecoder (shared_ptr<Film> f, shared_ptr<const Options> o, Job* j)
64 , VideoDecoder (f, o, j)
65 , AudioDecoder (f, o, j)
69 , _video_codec_context (0)
71 , _audio_codec_context (0)
73 , _subtitle_codec_context (0)
82 FFmpegDecoder::~FFmpegDecoder ()
84 if (_audio_codec_context) {
85 avcodec_close (_audio_codec_context);
88 if (_video_codec_context) {
89 avcodec_close (_video_codec_context);
92 if (_subtitle_codec_context) {
93 avcodec_close (_subtitle_codec_context);
98 avformat_close_input (&_format_context);
102 FFmpegDecoder::setup_general ()
106 if (avformat_open_input (&_format_context, _film->content_path().c_str(), 0, 0) < 0) {
107 throw OpenFileError (_film->content_path ());
110 if (avformat_find_stream_info (_format_context, 0) < 0) {
111 throw DecodeError ("could not find stream information");
114 /* Find video, audio and subtitle streams and choose the first of each */
116 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
117 AVStream* s = _format_context->streams[i];
118 if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
120 } else if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
122 /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
123 so bodge it here. No idea why we should have to do this.
126 if (s->codec->channel_layout == 0) {
127 s->codec->channel_layout = av_get_default_channel_layout (s->codec->channels);
130 _audio_streams.push_back (
131 shared_ptr<AudioStream> (
132 new FFmpegAudioStream (stream_name (s), i, s->codec->sample_rate, s->codec->channel_layout)
136 } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
137 _subtitle_streams.push_back (
138 shared_ptr<SubtitleStream> (
139 new SubtitleStream (stream_name (s), i)
145 if (_video_stream < 0) {
146 throw DecodeError ("could not find video stream");
149 _frame = avcodec_alloc_frame ();
151 throw DecodeError ("could not allocate frame");
156 FFmpegDecoder::setup_video ()
158 _video_codec_context = _format_context->streams[_video_stream]->codec;
159 _video_codec = avcodec_find_decoder (_video_codec_context->codec_id);
161 if (_video_codec == 0) {
162 throw DecodeError ("could not find video decoder");
165 /* I think this prevents problems with green hash on decodes and
166 "changing frame properties on the fly is not supported by all filters"
167 messages with some content. Although I'm not sure; needs checking.
169 AVDictionary* opts = 0;
170 av_dict_set (&opts, "threads", "1", 0);
172 if (avcodec_open2 (_video_codec_context, _video_codec, &opts) < 0) {
173 throw DecodeError ("could not open video decoder");
178 FFmpegDecoder::setup_audio ()
180 if (!_audio_stream) {
184 shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
187 _audio_codec_context = _format_context->streams[ffa->id()]->codec;
188 _audio_codec = avcodec_find_decoder (_audio_codec_context->codec_id);
190 if (_audio_codec == 0) {
191 throw DecodeError ("could not find audio decoder");
194 if (avcodec_open2 (_audio_codec_context, _audio_codec, 0) < 0) {
195 throw DecodeError ("could not open audio decoder");
200 FFmpegDecoder::setup_subtitle ()
202 if (!_subtitle_stream) {
206 _subtitle_codec_context = _format_context->streams[_subtitle_stream->id()]->codec;
207 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
209 if (_subtitle_codec == 0) {
210 throw DecodeError ("could not find subtitle decoder");
213 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
214 throw DecodeError ("could not open subtitle decoder");
220 FFmpegDecoder::pass ()
222 int r = av_read_frame (_format_context, &_packet);
225 if (r != AVERROR_EOF) {
226 /* Maybe we should fail here, but for now we'll just finish off instead */
228 av_strerror (r, buf, sizeof(buf));
229 _film->log()->log (String::compose ("error on av_read_frame (%1) (%2)", buf, r));
232 /* Get any remaining frames */
237 /* XXX: should we reset _packet.data and size after each *_decode_* call? */
241 while (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
242 filter_and_emit_video (_frame);
245 if (_audio_stream && _opt->decode_audio) {
246 while (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
247 int const data_size = av_samples_get_buffer_size (
248 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
251 assert (_audio_codec_context->channels == _film->audio_channels());
252 Audio (deinterleave_audio (_frame->data[0], data_size));
259 avcodec_get_frame_defaults (_frame);
261 shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
263 if (_packet.stream_index == _video_stream) {
266 int const r = avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet);
267 if (r >= 0 && frame_finished) {
269 if (r != _packet.size) {
270 _film->log()->log (String::compose ("Used only %1 bytes of %2 in packet", r, _packet.size));
273 /* Where we are in the output, in seconds */
274 double const out_pts_seconds = video_frame() / frames_per_second();
276 /* Where we are in the source, in seconds */
277 double const source_pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base)
278 * av_frame_get_best_effort_timestamp(_frame);
281 String::compose ("Source video frame ready; source at %1, output at %2", source_pts_seconds, out_pts_seconds),
286 _first_video = source_pts_seconds;
289 /* Difference between where we are and where we should be */
290 double const delta = source_pts_seconds - _first_video.get() - out_pts_seconds;
291 double const one_frame = 1 / frames_per_second();
293 /* Insert frames if required to get out_pts_seconds up to pts_seconds */
294 if (delta > one_frame) {
295 int const extra = rint (delta / one_frame);
296 for (int i = 0; i < extra; ++i) {
297 repeat_last_video ();
300 "Extra video frame inserted at %1s; source frame %2, source PTS %3 (at %4 fps)",
301 out_pts_seconds, video_frame(), source_pts_seconds, frames_per_second()
307 if (delta > -one_frame) {
308 /* Process this frame */
309 filter_and_emit_video (_frame);
311 /* Otherwise we are omitting a frame to keep things right */
312 _film->log()->log (String::compose ("Frame removed at %1s", out_pts_seconds));
316 } else if (ffa && _packet.stream_index == ffa->id() && _opt->decode_audio) {
319 if (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
321 /* Where we are in the source, in seconds */
322 double const source_pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base)
323 * av_frame_get_best_effort_timestamp(_frame);
325 /* We only decode audio if we've had our first video packet through, and if it
326 was before this packet. Until then audio is thrown away.
329 if (_first_video && _first_video.get() <= source_pts_seconds) {
332 _first_audio = source_pts_seconds;
334 /* This is our first audio frame, and if we've arrived here we must have had our
335 first video frame. Push some silence to make up any gap between our first
336 video frame and our first audio.
339 /* frames of silence that we must push */
340 int const s = rint ((_first_audio.get() - _first_video.get()) * ffa->sample_rate ());
344 "First video at %1, first audio at %2, pushing %3 audio frames of silence for %4 channels (%5 bytes per sample)",
345 _first_video.get(), _first_audio.get(), s, ffa->channels(), bytes_per_audio_sample()
350 shared_ptr<AudioBuffers> audio (new AudioBuffers (ffa->channels(), s));
351 audio->make_silent ();
356 int const data_size = av_samples_get_buffer_size (
357 0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
360 assert (_audio_codec_context->channels == _film->audio_channels());
361 Audio (deinterleave_audio (_frame->data[0], data_size));
365 } else if (_subtitle_stream && _packet.stream_index == _subtitle_stream->id() && _opt->decode_subtitles && _first_video) {
369 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
370 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
371 indicate that the previous subtitle should stop.
373 if (sub.num_rects > 0) {
374 shared_ptr<TimedSubtitle> ts;
376 emit_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub, _first_video.get())));
378 /* some problem with the subtitle; we probably didn't understand it */
381 emit_subtitle (shared_ptr<TimedSubtitle> ());
383 avsubtitle_free (&sub);
387 av_free_packet (&_packet);
391 shared_ptr<AudioBuffers>
392 FFmpegDecoder::deinterleave_audio (uint8_t* data, int size)
394 assert (_film->audio_channels());
395 assert (bytes_per_audio_sample());
397 shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
400 /* Deinterleave and convert to float */
402 assert ((size % (bytes_per_audio_sample() * ffa->channels())) == 0);
404 int const total_samples = size / bytes_per_audio_sample();
405 int const frames = total_samples / _film->audio_channels();
406 shared_ptr<AudioBuffers> audio (new AudioBuffers (ffa->channels(), frames));
408 switch (audio_sample_format()) {
409 case AV_SAMPLE_FMT_S16:
411 int16_t* p = (int16_t *) data;
414 for (int i = 0; i < total_samples; ++i) {
415 audio->data(channel)[sample] = float(*p++) / (1 << 15);
418 if (channel == _film->audio_channels()) {
426 case AV_SAMPLE_FMT_S32:
428 int32_t* p = (int32_t *) data;
431 for (int i = 0; i < total_samples; ++i) {
432 audio->data(channel)[sample] = float(*p++) / (1 << 31);
435 if (channel == _film->audio_channels()) {
442 case AV_SAMPLE_FMT_FLTP:
444 float* p = reinterpret_cast<float*> (data);
445 for (int i = 0; i < _film->audio_channels(); ++i) {
446 memcpy (audio->data(i), p, frames * sizeof(float));
453 throw DecodeError (String::compose ("Unrecognised audio sample format (%1)", static_cast<int> (audio_sample_format())));
460 FFmpegDecoder::frames_per_second () const
462 AVStream* s = _format_context->streams[_video_stream];
464 if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
465 return av_q2d (s->avg_frame_rate);
468 return av_q2d (s->r_frame_rate);
472 FFmpegDecoder::audio_sample_format () const
474 if (_audio_codec_context == 0) {
475 return (AVSampleFormat) 0;
478 return _audio_codec_context->sample_fmt;
482 FFmpegDecoder::native_size () const
484 return Size (_video_codec_context->width, _video_codec_context->height);
488 FFmpegDecoder::pixel_format () const
490 return _video_codec_context->pix_fmt;
494 FFmpegDecoder::time_base_numerator () const
496 return _video_codec_context->time_base.num;
500 FFmpegDecoder::time_base_denominator () const
502 return _video_codec_context->time_base.den;
506 FFmpegDecoder::sample_aspect_ratio_numerator () const
508 return _video_codec_context->sample_aspect_ratio.num;
512 FFmpegDecoder::sample_aspect_ratio_denominator () const
514 return _video_codec_context->sample_aspect_ratio.den;
518 FFmpegDecoder::stream_name (AVStream* s) const
522 AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
527 AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
529 if (!n.str().empty()) {
535 if (n.str().empty()) {
543 FFmpegDecoder::bytes_per_audio_sample () const
545 return av_get_bytes_per_sample (audio_sample_format ());
549 FFmpegDecoder::set_audio_stream (shared_ptr<AudioStream> s)
551 AudioDecoder::set_audio_stream (s);
556 FFmpegDecoder::set_subtitle_stream (shared_ptr<SubtitleStream> s)
558 VideoDecoder::set_subtitle_stream (s);
563 FFmpegDecoder::filter_and_emit_video (AVFrame* frame)
565 shared_ptr<FilterGraph> graph;
567 list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
568 while (i != _filter_graphs.end() && !(*i)->can_process (Size (frame->width, frame->height), (AVPixelFormat) frame->format)) {
572 if (i == _filter_graphs.end ()) {
573 graph.reset (new FilterGraph (_film, this, _opt->apply_crop, Size (frame->width, frame->height), (AVPixelFormat) frame->format));
574 _filter_graphs.push_back (graph);
575 _film->log()->log (String::compose ("New graph for %1x%2, pixel format %3", frame->width, frame->height, frame->format));
580 list<shared_ptr<Image> > images = graph->process (frame);
582 for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
587 shared_ptr<FFmpegAudioStream>
588 FFmpegAudioStream::create (string t, optional<int> v)
591 /* version < 1; no type in the string, and there's only FFmpeg streams anyway */
592 return shared_ptr<FFmpegAudioStream> (new FFmpegAudioStream (t, v));
598 if (type != "ffmpeg") {
599 return shared_ptr<FFmpegAudioStream> ();
602 return shared_ptr<FFmpegAudioStream> (new FFmpegAudioStream (t, v));
605 FFmpegAudioStream::FFmpegAudioStream (string t, optional<int> version)
613 n >> _id >> channels;
614 _channel_layout = av_get_default_channel_layout (channels);
618 /* Current (marked version 1) */
619 n >> type >> _id >> _sample_rate >> _channel_layout;
620 assert (type == "ffmpeg");
623 for (int i = 0; i < name_index; ++i) {
624 size_t const s = t.find (' ');
625 if (s != string::npos) {
626 t = t.substr (s + 1);
634 FFmpegAudioStream::to_string () const
636 return String::compose ("ffmpeg %1 %2 %3 %4", _id, _sample_rate, _channel_layout, _name);