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>
38 #include "exceptions.h"
42 #include "ffmpeg_decoder.h"
43 #include "filter_graph.h"
45 #include "audio_buffers.h"
52 using std::stringstream;
55 using boost::shared_ptr;
56 using boost::optional;
57 using boost::dynamic_pointer_cast;
60 FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> f, shared_ptr<const FFmpegContent> c, bool video, bool audio)
65 , _subtitle_codec_context (0)
67 , _decode_video (video)
68 , _decode_audio (audio)
73 FFmpegDecoder::~FFmpegDecoder ()
75 if (_subtitle_codec_context) {
76 avcodec_close (_subtitle_codec_context);
81 FFmpegDecoder::pass ()
83 int r = av_read_frame (_format_context, &_packet);
86 if (r != AVERROR_EOF) {
87 /* Maybe we should fail here, but for now we'll just finish off instead */
89 av_strerror (r, buf, sizeof(buf));
90 shared_ptr<const Film> film = _film.lock ();
92 film->log()->log (String::compose (N_("error on av_read_frame (%1) (%2)"), buf, r));
95 /* Get any remaining frames */
100 /* XXX: should we reset _packet.data and size after each *_decode_* call? */
103 while (decode_video_packet ());
106 if (_ffmpeg_content->audio_stream() && _decode_audio) {
107 decode_audio_packet ();
110 /* Stop us being asked for any more data */
111 _next_video_frame = _ffmpeg_content->video_length ();
112 _next_audio_frame = _ffmpeg_content->audio_length ();
116 avcodec_get_frame_defaults (_frame);
118 if (_packet.stream_index == _video_stream && _decode_video) {
119 decode_video_packet ();
120 } else if (_ffmpeg_content->audio_stream() && _packet.stream_index == _ffmpeg_content->audio_stream()->id && _decode_audio) {
121 decode_audio_packet ();
122 } else if (_ffmpeg_content->subtitle_stream() && _packet.stream_index == _ffmpeg_content->subtitle_stream()->id) {
127 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
128 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
129 indicate that the previous subtitle should stop.
131 if (sub.num_rects > 0) {
132 shared_ptr<TimedSubtitle> ts;
134 subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub)));
136 /* some problem with the subtitle; we probably didn't understand it */
139 subtitle (shared_ptr<TimedSubtitle> ());
141 avsubtitle_free (&sub);
146 av_free_packet (&_packet);
149 /** @param data pointer to array of pointers to buffers.
150 * Only the first buffer will be used for non-planar data, otherwise there will be one per channel.
152 shared_ptr<AudioBuffers>
153 FFmpegDecoder::deinterleave_audio (uint8_t** data, int size)
155 assert (_ffmpeg_content->audio_channels());
156 assert (bytes_per_audio_sample());
158 /* Deinterleave and convert to float */
160 assert ((size % (bytes_per_audio_sample() * _ffmpeg_content->audio_channels())) == 0);
162 int const total_samples = size / bytes_per_audio_sample();
163 int const frames = total_samples / _ffmpeg_content->audio_channels();
164 shared_ptr<AudioBuffers> audio (new AudioBuffers (_ffmpeg_content->audio_channels(), frames));
166 switch (audio_sample_format()) {
167 case AV_SAMPLE_FMT_S16:
169 int16_t* p = reinterpret_cast<int16_t *> (data[0]);
172 for (int i = 0; i < total_samples; ++i) {
173 audio->data(channel)[sample] = float(*p++) / (1 << 15);
176 if (channel == _ffmpeg_content->audio_channels()) {
184 case AV_SAMPLE_FMT_S16P:
186 int16_t** p = reinterpret_cast<int16_t **> (data);
187 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
188 for (int j = 0; j < frames; ++j) {
189 audio->data(i)[j] = static_cast<float>(p[i][j]) / (1 << 15);
195 case AV_SAMPLE_FMT_S32:
197 int32_t* p = reinterpret_cast<int32_t *> (data[0]);
200 for (int i = 0; i < total_samples; ++i) {
201 audio->data(channel)[sample] = static_cast<float>(*p++) / (1 << 31);
204 if (channel == _ffmpeg_content->audio_channels()) {
212 case AV_SAMPLE_FMT_FLT:
214 float* p = reinterpret_cast<float*> (data[0]);
217 for (int i = 0; i < total_samples; ++i) {
218 audio->data(channel)[sample] = *p++;
221 if (channel == _ffmpeg_content->audio_channels()) {
229 case AV_SAMPLE_FMT_FLTP:
231 float** p = reinterpret_cast<float**> (data);
232 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
233 memcpy (audio->data(i), p[i], frames * sizeof(float));
239 throw DecodeError (String::compose (_("Unrecognised audio sample format (%1)"), static_cast<int> (audio_sample_format())));
246 FFmpegDecoder::audio_sample_format () const
248 if (!_ffmpeg_content->audio_stream()) {
249 return (AVSampleFormat) 0;
252 return audio_codec_context()->sample_fmt;
256 FFmpegDecoder::bytes_per_audio_sample () const
258 return av_get_bytes_per_sample (audio_sample_format ());
262 FFmpegDecoder::seek (VideoContent::Frame frame)
264 do_seek (frame, false, false);
268 FFmpegDecoder::seek_back ()
270 if (_next_video_frame == 0) {
274 do_seek (_next_video_frame - 1, true, true);
275 VideoDecoder::seek_back ();
279 FFmpegDecoder::do_seek (VideoContent::Frame frame, bool backwards, bool accurate)
281 int64_t const vt = frame * _ffmpeg_content->video_frame_rate() / av_q2d (_format_context->streams[_video_stream]->time_base);
282 av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0);
284 avcodec_flush_buffers (video_codec_context());
285 if (_subtitle_codec_context) {
286 avcodec_flush_buffers (_subtitle_codec_context);
291 int r = av_read_frame (_format_context, &_packet);
296 avcodec_get_frame_defaults (_frame);
298 if (_packet.stream_index == _video_stream) {
300 int const r = avcodec_decode_video2 (video_codec_context(), _frame, &finished, &_packet);
301 if (r >= 0 && finished) {
302 int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
309 av_free_packet (&_packet);
317 FFmpegDecoder::decode_audio_packet ()
319 /* Audio packets can contain multiple frames, so we may have to call avcodec_decode_audio4
323 AVPacket copy_packet = _packet;
325 while (copy_packet.size > 0) {
328 int const decode_result = avcodec_decode_audio4 (audio_codec_context(), _frame, &frame_finished, ©_packet);
329 if (decode_result >= 0) {
330 if (frame_finished) {
332 /* Where we are in the source, in seconds */
333 double const source_pts_seconds = av_q2d (_format_context->streams[copy_packet.stream_index]->time_base)
334 * av_frame_get_best_effort_timestamp(_frame);
336 int const data_size = av_samples_get_buffer_size (
337 0, audio_codec_context()->channels, _frame->nb_samples, audio_sample_format (), 1
340 assert (audio_codec_context()->channels == _ffmpeg_content->audio_channels());
341 Audio (deinterleave_audio (_frame->data, data_size), source_pts_seconds * _ffmpeg_content->content_audio_frame_rate());
344 copy_packet.data += decode_result;
345 copy_packet.size -= decode_result;
351 FFmpegDecoder::decode_video_packet ()
354 if (avcodec_decode_video2 (video_codec_context(), _frame, &frame_finished, &_packet) < 0 || !frame_finished) {
358 boost::mutex::scoped_lock lm (_filter_graphs_mutex);
360 shared_ptr<FilterGraph> graph;
362 list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
363 while (i != _filter_graphs.end() && !(*i)->can_process (libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) {
367 if (i == _filter_graphs.end ()) {
368 shared_ptr<const Film> film = _film.lock ();
371 graph.reset (new FilterGraph (_ffmpeg_content, libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
372 _filter_graphs.push_back (graph);
374 film->log()->log (String::compose (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format));
379 list<shared_ptr<Image> > images = graph->process (_frame);
381 string post_process = Filter::ffmpeg_strings (_ffmpeg_content->filters()).second;
383 for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
385 shared_ptr<Image> image = *i;
386 if (!post_process.empty ()) {
387 image = image->post_process (post_process, true);
390 int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
391 if (bet != AV_NOPTS_VALUE) {
393 double const pts = bet * av_q2d (_format_context->streams[_video_stream]->time_base);
394 double const next = _next_video_frame / _ffmpeg_content->video_frame_rate();
395 double const one_frame = 1 / _ffmpeg_content->video_frame_rate ();
396 double delta = pts - next;
398 while (delta > one_frame) {
399 /* This PTS is more than one frame forward in time of where we think we should be; emit
402 boost::shared_ptr<Image> black (
404 static_cast<AVPixelFormat> (_frame->format),
405 libdcp::Size (video_codec_context()->width, video_codec_context()->height),
410 black->make_black ();
411 video (image, false, _next_video_frame);
415 if (delta > -one_frame) {
416 /* This PTS is within a frame of being right; emit this (otherwise it will be dropped) */
417 video (image, false, _next_video_frame);
420 shared_ptr<const Film> film = _film.lock ();
422 film->log()->log ("Dropping frame without PTS");
431 FFmpegDecoder::setup_subtitle ()
433 boost::mutex::scoped_lock lm (_mutex);
435 if (!_ffmpeg_content->subtitle_stream() || _ffmpeg_content->subtitle_stream()->id >= int (_format_context->nb_streams)) {
439 _subtitle_codec_context = _format_context->streams[_ffmpeg_content->subtitle_stream()->id]->codec;
440 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
442 if (_subtitle_codec == 0) {
443 throw DecodeError (_("could not find subtitle decoder"));
446 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
447 throw DecodeError (N_("could not open subtitle decoder"));
452 FFmpegDecoder::done () const
454 bool const vd = !_decode_video || (_next_video_frame >= _ffmpeg_content->video_length());
455 bool const ad = !_decode_audio || !_ffmpeg_content->audio_stream() || (_next_audio_frame >= _ffmpeg_content->audio_length());