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"
44 #include "audio_buffers.h"
45 #include "ffmpeg_content.h"
52 using std::stringstream;
56 using boost::shared_ptr;
57 using boost::optional;
58 using boost::dynamic_pointer_cast;
61 FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> f, shared_ptr<const FFmpegContent> c, bool video, bool audio)
67 , _subtitle_codec_context (0)
69 , _decode_video (video)
70 , _decode_audio (audio)
75 /* Audio and video frame PTS values may not start with 0. We want
76 to fiddle them so that:
78 1. One of them starts at time 0.
79 2. The first video PTS value ends up on a frame boundary.
81 Then we remove big initial gaps in PTS and we allow our
82 insertion of black frames to work.
84 We will do pts_to_use = pts_from_ffmpeg + pts_offset;
87 bool const have_video = video && c->first_video();
88 bool const have_audio = _decode_audio && c->audio_stream () && c->audio_stream()->first_audio;
90 /* First, make one of them start at 0 */
92 if (have_audio && have_video) {
93 _pts_offset = - min (c->first_video().get(), c->audio_stream()->first_audio.get());
94 } else if (have_video) {
95 _pts_offset = - c->first_video().get();
96 } else if (have_audio) {
97 _pts_offset = - c->audio_stream()->first_audio.get();
100 /* Now adjust both so that the video pts starts on a frame */
101 if (have_video && have_audio) {
102 double first_video = c->first_video().get() + _pts_offset;
103 double const old_first_video = first_video;
105 /* Round the first video up to a frame boundary */
106 if (fabs (rint (first_video * c->video_frame_rate()) - first_video * c->video_frame_rate()) > 1e-6) {
107 first_video = ceil (first_video * c->video_frame_rate()) / c->video_frame_rate ();
110 _pts_offset += first_video - old_first_video;
114 FFmpegDecoder::~FFmpegDecoder ()
116 boost::mutex::scoped_lock lm (_mutex);
118 if (_subtitle_codec_context) {
119 avcodec_close (_subtitle_codec_context);
124 FFmpegDecoder::flush ()
126 /* Get any remaining frames */
131 /* XXX: should we reset _packet.data and size after each *_decode_* call? */
134 while (decode_video_packet ()) {}
137 if (_ffmpeg_content->audio_stream() && _decode_audio) {
138 decode_audio_packet ();
139 AudioDecoder::flush ();
144 FFmpegDecoder::pass ()
146 int r = av_read_frame (_format_context, &_packet);
149 if (r != AVERROR_EOF) {
150 /* Maybe we should fail here, but for now we'll just finish off instead */
152 av_strerror (r, buf, sizeof(buf));
153 shared_ptr<const Film> film = _film.lock ();
155 film->log()->log (String::compose (N_("error on av_read_frame (%1) (%2)"), buf, r));
162 shared_ptr<const Film> film = _film.lock ();
165 int const si = _packet.stream_index;
167 if (si == _video_stream && _decode_video) {
168 decode_video_packet ();
169 } else if (_ffmpeg_content->audio_stream() && _ffmpeg_content->audio_stream()->uses_index (_format_context, si) && _decode_audio) {
170 decode_audio_packet ();
171 } else if (_ffmpeg_content->subtitle_stream() && _ffmpeg_content->subtitle_stream()->uses_index (_format_context, si) && film->with_subtitles ()) {
172 decode_subtitle_packet ();
175 av_free_packet (&_packet);
179 /** @param data pointer to array of pointers to buffers.
180 * Only the first buffer will be used for non-planar data, otherwise there will be one per channel.
182 shared_ptr<AudioBuffers>
183 FFmpegDecoder::deinterleave_audio (uint8_t** data, int size)
185 assert (_ffmpeg_content->audio_channels());
186 assert (bytes_per_audio_sample());
188 /* Deinterleave and convert to float */
190 assert ((size % (bytes_per_audio_sample() * _ffmpeg_content->audio_channels())) == 0);
192 int const total_samples = size / bytes_per_audio_sample();
193 int const frames = total_samples / _ffmpeg_content->audio_channels();
194 shared_ptr<AudioBuffers> audio (new AudioBuffers (_ffmpeg_content->audio_channels(), frames));
196 switch (audio_sample_format()) {
197 case AV_SAMPLE_FMT_S16:
199 int16_t* p = reinterpret_cast<int16_t *> (data[0]);
202 for (int i = 0; i < total_samples; ++i) {
203 audio->data(channel)[sample] = float(*p++) / (1 << 15);
206 if (channel == _ffmpeg_content->audio_channels()) {
214 case AV_SAMPLE_FMT_S16P:
216 int16_t** p = reinterpret_cast<int16_t **> (data);
217 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
218 for (int j = 0; j < frames; ++j) {
219 audio->data(i)[j] = static_cast<float>(p[i][j]) / (1 << 15);
225 case AV_SAMPLE_FMT_S32:
227 int32_t* p = reinterpret_cast<int32_t *> (data[0]);
230 for (int i = 0; i < total_samples; ++i) {
231 audio->data(channel)[sample] = static_cast<float>(*p++) / (1 << 31);
234 if (channel == _ffmpeg_content->audio_channels()) {
242 case AV_SAMPLE_FMT_FLT:
244 float* p = reinterpret_cast<float*> (data[0]);
247 for (int i = 0; i < total_samples; ++i) {
248 audio->data(channel)[sample] = *p++;
251 if (channel == _ffmpeg_content->audio_channels()) {
259 case AV_SAMPLE_FMT_FLTP:
261 float** p = reinterpret_cast<float**> (data);
262 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
263 memcpy (audio->data(i), p[i], frames * sizeof(float));
269 throw DecodeError (String::compose (_("Unrecognised audio sample format (%1)"), static_cast<int> (audio_sample_format())));
276 FFmpegDecoder::audio_sample_format () const
278 if (!_ffmpeg_content->audio_stream()) {
279 return (AVSampleFormat) 0;
282 return audio_codec_context()->sample_fmt;
286 FFmpegDecoder::bytes_per_audio_sample () const
288 return av_get_bytes_per_sample (audio_sample_format ());
292 FFmpegDecoder::minimal_run (boost::function<bool (optional<ContentTime>, optional<ContentTime>, int)> finished)
295 optional<ContentTime> last_video;
296 optional<ContentTime> last_audio;
298 while (!finished (last_video, last_audio, frames_read)) {
299 int r = av_read_frame (_format_context, &_packet);
301 /* We should flush our decoders here, possibly yielding a few more frames,
302 but the consequence of having to do that is too hideous to contemplate.
303 Instead we give up and say that you can't seek too close to the end
311 double const time_base = av_q2d (_format_context->streams[_packet.stream_index]->time_base);
313 if (_packet.stream_index == _video_stream) {
315 avcodec_get_frame_defaults (_frame);
318 r = avcodec_decode_video2 (video_codec_context(), _frame, &finished, &_packet);
319 if (r >= 0 && finished) {
320 last_video = ContentTime::from_seconds (av_frame_get_best_effort_timestamp (_frame) * time_base + _pts_offset);
323 } else if (_ffmpeg_content->audio_stream() && _ffmpeg_content->audio_stream()->uses_index (_format_context, _packet.stream_index)) {
324 AVPacket copy_packet = _packet;
325 while (copy_packet.size > 0) {
328 r = avcodec_decode_audio4 (audio_codec_context(), _frame, &finished, &_packet);
329 if (r >= 0 && finished) {
330 last_audio = ContentTime::from_seconds (av_frame_get_best_effort_timestamp (_frame) * time_base + _pts_offset);
333 copy_packet.data += r;
334 copy_packet.size -= r;
338 av_free_packet (&_packet);
345 FFmpegDecoder::seek_overrun_finished (ContentTime seek, optional<ContentTime> last_video, optional<ContentTime> last_audio) const
347 return (last_video && last_video.get() >= seek) || (last_audio && last_audio.get() >= seek);
351 FFmpegDecoder::seek_final_finished (int n, int done) const
357 FFmpegDecoder::seek_and_flush (ContentTime t)
359 int64_t s = (t.seconds() - _pts_offset) / av_q2d (_format_context->streams[_video_stream]->time_base);
361 if (_ffmpeg_content->audio_stream ()) {
363 s, int64_t ((t.seconds() - _pts_offset) / av_q2d (_ffmpeg_content->audio_stream()->stream(_format_context)->time_base))
367 /* Ridiculous empirical hack */
373 av_seek_frame (_format_context, _video_stream, s, 0);
375 avcodec_flush_buffers (video_codec_context());
376 if (audio_codec_context ()) {
377 avcodec_flush_buffers (audio_codec_context ());
379 if (_subtitle_codec_context) {
380 avcodec_flush_buffers (_subtitle_codec_context);
385 FFmpegDecoder::seek (ContentTime time, bool accurate)
387 Decoder::seek (time, accurate);
389 AudioDecoder::seek (time, accurate);
392 /* If we are doing an accurate seek, our initial shot will be 200ms (200 being
393 a number plucked from the air) earlier than we want to end up. The loop below
394 will hopefully then step through to where we want to be.
397 ContentTime pre_roll = accurate ? ContentTime::from_seconds (0.2) : ContentTime (0);
398 ContentTime initial_seek = time - pre_roll;
399 if (initial_seek < ContentTime (0)) {
400 initial_seek = ContentTime (0);
403 /* Initial seek time in the video stream's timebase */
405 seek_and_flush (initial_seek);
412 int const N = minimal_run (boost::bind (&FFmpegDecoder::seek_overrun_finished, this, time, _1, _2));
414 seek_and_flush (initial_seek);
416 minimal_run (boost::bind (&FFmpegDecoder::seek_final_finished, this, N - 1, _3));
421 FFmpegDecoder::decode_audio_packet ()
423 /* Audio packets can contain multiple frames, so we may have to call avcodec_decode_audio4
427 AVPacket copy_packet = _packet;
429 while (copy_packet.size > 0) {
432 int const decode_result = avcodec_decode_audio4 (audio_codec_context(), _frame, &frame_finished, ©_packet);
434 if (decode_result < 0) {
435 shared_ptr<const Film> film = _film.lock ();
437 film->log()->log (String::compose ("avcodec_decode_audio4 failed (%1)", decode_result));
441 if (frame_finished) {
442 ContentTime const ct = ContentTime::from_seconds (
443 av_frame_get_best_effort_timestamp (_frame) *
444 av_q2d (_ffmpeg_content->audio_stream()->stream (_format_context)->time_base)
448 int const data_size = av_samples_get_buffer_size (
449 0, audio_codec_context()->channels, _frame->nb_samples, audio_sample_format (), 1
452 audio (deinterleave_audio (_frame->data, data_size), ct);
455 copy_packet.data += decode_result;
456 copy_packet.size -= decode_result;
461 FFmpegDecoder::decode_video_packet ()
464 if (avcodec_decode_video2 (video_codec_context(), _frame, &frame_finished, &_packet) < 0 || !frame_finished) {
468 boost::mutex::scoped_lock lm (_filter_graphs_mutex);
470 shared_ptr<FilterGraph> graph;
472 list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
473 while (i != _filter_graphs.end() && !(*i)->can_process (dcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) {
477 if (i == _filter_graphs.end ()) {
478 shared_ptr<const Film> film = _film.lock ();
481 graph.reset (new FilterGraph (_ffmpeg_content, dcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
482 _filter_graphs.push_back (graph);
484 film->log()->log (String::compose (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format));
489 list<pair<shared_ptr<Image>, int64_t> > images = graph->process (_frame);
491 string post_process = Filter::ffmpeg_strings (_ffmpeg_content->filters()).second;
493 for (list<pair<shared_ptr<Image>, int64_t> >::iterator i = images.begin(); i != images.end(); ++i) {
495 shared_ptr<Image> image = i->first;
496 if (!post_process.empty ()) {
497 image = image->post_process (post_process, true);
500 if (i->second != AV_NOPTS_VALUE) {
501 video (image, false, ContentTime::from_seconds (i->second * av_q2d (_format_context->streams[_video_stream]->time_base) + _pts_offset));
503 shared_ptr<const Film> film = _film.lock ();
505 film->log()->log ("Dropping frame without PTS");
514 FFmpegDecoder::setup_subtitle ()
516 boost::mutex::scoped_lock lm (_mutex);
518 if (!_ffmpeg_content->subtitle_stream()) {
522 _subtitle_codec_context = _ffmpeg_content->subtitle_stream()->stream(_format_context)->codec;
523 if (_subtitle_codec_context == 0) {
524 throw DecodeError (N_("could not find subtitle stream"));
527 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
529 if (_subtitle_codec == 0) {
530 throw DecodeError (N_("could not find subtitle decoder"));
533 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
534 throw DecodeError (N_("could not open subtitle decoder"));
539 FFmpegDecoder::decode_subtitle_packet ()
543 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) < 0 || !got_subtitle) {
547 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
548 indicate that the previous subtitle should stop.
550 if (sub.num_rects <= 0) {
551 image_subtitle (shared_ptr<Image> (), dcpomatic::Rect<double> (), ContentTime (), ContentTime ());
553 } else if (sub.num_rects > 1) {
554 throw DecodeError (_("multi-part subtitles not yet supported"));
557 /* Subtitle PTS in seconds (within the source, not taking into account any of the
558 source that we may have chopped off for the DCP)
560 double const packet_time = (static_cast<double> (sub.pts) / AV_TIME_BASE) + _pts_offset;
562 /* hence start time for this sub */
563 ContentTime const from = ContentTime::from_seconds (packet_time + (double (sub.start_display_time) / 1e3));
564 ContentTime const to = ContentTime::from_seconds (packet_time + (double (sub.end_display_time) / 1e3));
566 AVSubtitleRect const * rect = sub.rects[0];
568 if (rect->type != SUBTITLE_BITMAP) {
569 throw DecodeError (_("non-bitmap subtitles not yet supported"));
572 /* Note RGBA is expressed little-endian, so the first byte in the word is R, second
573 G, third B, fourth A.
575 shared_ptr<Image> image (new Image (PIX_FMT_RGBA, dcp::Size (rect->w, rect->h), true));
577 /* Start of the first line in the subtitle */
578 uint8_t* sub_p = rect->pict.data[0];
579 /* sub_p looks up into a BGRA palette which is here
580 (i.e. first byte B, second G, third R, fourth A)
582 uint32_t const * palette = (uint32_t *) rect->pict.data[1];
583 /* Start of the output data */
584 uint32_t* out_p = (uint32_t *) image->data()[0];
586 for (int y = 0; y < rect->h; ++y) {
587 uint8_t* sub_line_p = sub_p;
588 uint32_t* out_line_p = out_p;
589 for (int x = 0; x < rect->w; ++x) {
590 uint32_t const p = palette[*sub_line_p++];
591 *out_line_p++ = ((p & 0xff) << 16) | (p & 0xff00) | ((p & 0xff0000) >> 16) | (p & 0xff000000);
593 sub_p += rect->pict.linesize[0];
594 out_p += image->stride()[0] / sizeof (uint32_t);
597 dcp::Size const vs = _ffmpeg_content->video_size ();
601 dcpomatic::Rect<double> (
602 static_cast<double> (rect->x) / vs.width,
603 static_cast<double> (rect->y) / vs.height,
604 static_cast<double> (rect->w) / vs.width,
605 static_cast<double> (rect->h) / vs.height
612 avsubtitle_free (&sub);