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 = _next_audio = _ffmpeg_content->length ();
115 avcodec_get_frame_defaults (_frame);
117 if (_packet.stream_index == _video_stream && _decode_video) {
118 decode_video_packet ();
119 } else if (_ffmpeg_content->audio_stream() && _packet.stream_index == _ffmpeg_content->audio_stream()->id && _decode_audio) {
120 decode_audio_packet ();
121 } else if (_ffmpeg_content->subtitle_stream() && _packet.stream_index == _ffmpeg_content->subtitle_stream()->id) {
125 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
126 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
127 indicate that the previous subtitle should stop.
129 if (sub.num_rects > 0) {
130 shared_ptr<TimedSubtitle> ts;
132 subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub)));
134 /* some problem with the subtitle; we probably didn't understand it */
137 subtitle (shared_ptr<TimedSubtitle> ());
139 avsubtitle_free (&sub);
143 av_free_packet (&_packet);
146 /** @param data pointer to array of pointers to buffers.
147 * Only the first buffer will be used for non-planar data, otherwise there will be one per channel.
149 shared_ptr<AudioBuffers>
150 FFmpegDecoder::deinterleave_audio (uint8_t** data, int size)
152 assert (_ffmpeg_content->audio_channels());
153 assert (bytes_per_audio_sample());
155 /* Deinterleave and convert to float */
157 assert ((size % (bytes_per_audio_sample() * _ffmpeg_content->audio_channels())) == 0);
159 int const total_samples = size / bytes_per_audio_sample();
160 int const frames = total_samples / _ffmpeg_content->audio_channels();
161 shared_ptr<AudioBuffers> audio (new AudioBuffers (_ffmpeg_content->audio_channels(), frames));
163 switch (audio_sample_format()) {
164 case AV_SAMPLE_FMT_S16:
166 int16_t* p = reinterpret_cast<int16_t *> (data[0]);
169 for (int i = 0; i < total_samples; ++i) {
170 audio->data(channel)[sample] = float(*p++) / (1 << 15);
173 if (channel == _ffmpeg_content->audio_channels()) {
181 case AV_SAMPLE_FMT_S16P:
183 int16_t** p = reinterpret_cast<int16_t **> (data);
184 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
185 for (int j = 0; j < frames; ++j) {
186 audio->data(i)[j] = static_cast<float>(p[i][j]) / (1 << 15);
192 case AV_SAMPLE_FMT_S32:
194 int32_t* p = reinterpret_cast<int32_t *> (data[0]);
197 for (int i = 0; i < total_samples; ++i) {
198 audio->data(channel)[sample] = static_cast<float>(*p++) / (1 << 31);
201 if (channel == _ffmpeg_content->audio_channels()) {
209 case AV_SAMPLE_FMT_FLT:
211 float* p = reinterpret_cast<float*> (data[0]);
214 for (int i = 0; i < total_samples; ++i) {
215 audio->data(channel)[sample] = *p++;
218 if (channel == _ffmpeg_content->audio_channels()) {
226 case AV_SAMPLE_FMT_FLTP:
228 float** p = reinterpret_cast<float**> (data);
229 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
230 memcpy (audio->data(i), p[i], frames * sizeof(float));
236 throw DecodeError (String::compose (_("Unrecognised audio sample format (%1)"), static_cast<int> (audio_sample_format())));
243 FFmpegDecoder::audio_sample_format () const
245 if (!_ffmpeg_content->audio_stream()) {
246 return (AVSampleFormat) 0;
249 return audio_codec_context()->sample_fmt;
253 FFmpegDecoder::bytes_per_audio_sample () const
255 return av_get_bytes_per_sample (audio_sample_format ());
259 FFmpegDecoder::seek (Time t)
261 do_seek (t, false, false);
262 VideoDecoder::seek (t);
266 FFmpegDecoder::seek_back ()
268 if (position() < (2.5 * TIME_HZ / _ffmpeg_content->video_frame_rate())) {
272 do_seek (position() - 2.5 * TIME_HZ / _ffmpeg_content->video_frame_rate(), true, true);
273 VideoDecoder::seek_back ();
277 FFmpegDecoder::seek_forward ()
279 if (position() >= (_ffmpeg_content->length() - 0.5 * TIME_HZ / _ffmpeg_content->video_frame_rate())) {
283 do_seek (position() - 0.5 * TIME_HZ / _ffmpeg_content->video_frame_rate(), true, true);
284 VideoDecoder::seek_forward ();
288 FFmpegDecoder::do_seek (Time t, bool backwards, bool accurate)
290 int64_t const vt = t / (av_q2d (_format_context->streams[_video_stream]->time_base) * TIME_HZ);
291 av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0);
293 avcodec_flush_buffers (video_codec_context());
294 if (_subtitle_codec_context) {
295 avcodec_flush_buffers (_subtitle_codec_context);
300 int r = av_read_frame (_format_context, &_packet);
305 avcodec_get_frame_defaults (_frame);
307 if (_packet.stream_index == _video_stream) {
309 int const r = avcodec_decode_video2 (video_codec_context(), _frame, &finished, &_packet);
310 if (r >= 0 && finished) {
311 int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
318 av_free_packet (&_packet);
326 FFmpegDecoder::decode_audio_packet ()
328 /* Audio packets can contain multiple frames, so we may have to call avcodec_decode_audio4
332 AVPacket copy_packet = _packet;
334 while (copy_packet.size > 0) {
337 int const decode_result = avcodec_decode_audio4 (audio_codec_context(), _frame, &frame_finished, ©_packet);
338 if (decode_result >= 0) {
339 if (frame_finished) {
341 /* Where we are in the source, in seconds */
342 double const source_pts_seconds = av_q2d (_format_context->streams[copy_packet.stream_index]->time_base)
343 * av_frame_get_best_effort_timestamp(_frame);
345 int const data_size = av_samples_get_buffer_size (
346 0, audio_codec_context()->channels, _frame->nb_samples, audio_sample_format (), 1
349 assert (audio_codec_context()->channels == _ffmpeg_content->audio_channels());
350 audio (deinterleave_audio (_frame->data, data_size), source_pts_seconds * TIME_HZ);
353 copy_packet.data += decode_result;
354 copy_packet.size -= decode_result;
360 FFmpegDecoder::decode_video_packet ()
363 if (avcodec_decode_video2 (video_codec_context(), _frame, &frame_finished, &_packet) < 0 || !frame_finished) {
367 boost::mutex::scoped_lock lm (_filter_graphs_mutex);
369 shared_ptr<FilterGraph> graph;
371 list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
372 while (i != _filter_graphs.end() && !(*i)->can_process (libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) {
376 if (i == _filter_graphs.end ()) {
377 shared_ptr<const Film> film = _film.lock ();
380 graph.reset (new FilterGraph (_ffmpeg_content, libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
381 _filter_graphs.push_back (graph);
383 film->log()->log (String::compose (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format));
388 list<shared_ptr<Image> > images = graph->process (_frame);
390 string post_process = Filter::ffmpeg_strings (_ffmpeg_content->filters()).second;
392 for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
394 shared_ptr<Image> image = *i;
395 if (!post_process.empty ()) {
396 image = image->post_process (post_process, true);
399 int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
400 if (bet != AV_NOPTS_VALUE) {
401 /* XXX: may need to insert extra frames / remove frames here ...
404 Time const t = bet * av_q2d (_format_context->streams[_video_stream]->time_base) * TIME_HZ;
405 video (image, false, t);
407 shared_ptr<const Film> film = _film.lock ();
409 film->log()->log ("Dropping frame without PTS");
417 FFmpegDecoder::position () const
419 if (_decode_video && _decode_audio && _ffmpeg_content->audio_stream()) {
420 return min (_next_video, _next_audio);
423 if (_decode_audio && _ffmpeg_content->audio_stream()) {
431 FFmpegDecoder::done () const
433 bool const ad = !_decode_audio || !_ffmpeg_content->audio_stream() || audio_done();
434 bool const vd = !_decode_video || video_done();
439 FFmpegDecoder::setup_subtitle ()
441 boost::mutex::scoped_lock lm (_mutex);
443 if (!_ffmpeg_content->subtitle_stream() || _ffmpeg_content->subtitle_stream()->id >= int (_format_context->nb_streams)) {
447 _subtitle_codec_context = _format_context->streams[_ffmpeg_content->subtitle_stream()->id]->codec;
448 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
450 if (_subtitle_codec == 0) {
451 throw DecodeError (_("could not find subtitle decoder"));
454 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
455 throw DecodeError (N_("could not open subtitle decoder"));