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)
72 , _just_sought (false)
76 /* Audio and video frame PTS values may not start with 0. We want
77 to fiddle them so that:
79 1. One of them starts at time 0.
80 2. The first video PTS value ends up on a frame boundary.
82 Then we remove big initial gaps in PTS and we allow our
83 insertion of black frames to work.
86 audio_pts_to_use = audio_pts_from_ffmpeg + pts_offset;
87 video_pts_to_use = video_pts_from_ffmpeg + pts_offset;
90 bool const have_video = video && c->first_video();
91 bool const have_audio = audio && c->audio_stream() && c->audio_stream()->first_audio;
93 /* First, make one of them start at 0 */
95 if (have_audio && have_video) {
96 _pts_offset = - min (c->first_video().get(), c->audio_stream()->first_audio.get());
97 } else if (have_video) {
98 _pts_offset = - c->first_video().get();
99 } else if (have_audio) {
100 _pts_offset = - c->audio_stream()->first_audio.get();
103 /* Now adjust both so that the video pts starts on a frame */
104 if (have_video && have_audio) {
105 double first_video = c->first_video().get() + _pts_offset;
106 double const old_first_video = first_video;
108 /* Round the first video up to a frame boundary */
109 if (fabs (rint (first_video * c->video_frame_rate()) - first_video * c->video_frame_rate()) > 1e-6) {
110 first_video = ceil (first_video * c->video_frame_rate()) / c->video_frame_rate ();
113 _pts_offset += first_video - old_first_video;
117 FFmpegDecoder::~FFmpegDecoder ()
119 boost::mutex::scoped_lock lm (_mutex);
121 if (_subtitle_codec_context) {
122 avcodec_close (_subtitle_codec_context);
127 FFmpegDecoder::flush ()
129 /* Get any remaining frames */
134 /* XXX: should we reset _packet.data and size after each *_decode_* call? */
137 while (decode_video_packet ()) {}
140 if (_ffmpeg_content->audio_stream() && _decode_audio) {
141 decode_audio_packet ();
144 /* Stop us being asked for any more data */
145 _video_position = _ffmpeg_content->video_length ();
146 _audio_position = _ffmpeg_content->audio_length ();
150 FFmpegDecoder::pass ()
152 int r = av_read_frame (_format_context, &_packet);
155 if (r != AVERROR_EOF) {
156 /* Maybe we should fail here, but for now we'll just finish off instead */
158 av_strerror (r, buf, sizeof(buf));
159 shared_ptr<const Film> film = _film.lock ();
161 film->log()->log (String::compose (N_("error on av_read_frame (%1) (%2)"), buf, r));
168 shared_ptr<const Film> film = _film.lock ();
171 int const si = _packet.stream_index;
173 if (si == _video_stream && _decode_video) {
174 decode_video_packet ();
175 } else if (_ffmpeg_content->audio_stream() && si == _ffmpeg_content->audio_stream()->index (_format_context) && _decode_audio) {
176 decode_audio_packet ();
177 } else if (_ffmpeg_content->subtitle_stream() && si == _ffmpeg_content->subtitle_stream()->index (_format_context) && film->with_subtitles ()) {
178 decode_subtitle_packet ();
181 av_free_packet (&_packet);
184 /** @param data pointer to array of pointers to buffers.
185 * Only the first buffer will be used for non-planar data, otherwise there will be one per channel.
187 shared_ptr<AudioBuffers>
188 FFmpegDecoder::deinterleave_audio (uint8_t** data, int size)
190 assert (_ffmpeg_content->audio_channels());
191 assert (bytes_per_audio_sample());
193 /* Deinterleave and convert to float */
195 assert ((size % (bytes_per_audio_sample() * _ffmpeg_content->audio_channels())) == 0);
197 int const total_samples = size / bytes_per_audio_sample();
198 int const frames = total_samples / _ffmpeg_content->audio_channels();
199 shared_ptr<AudioBuffers> audio (new AudioBuffers (_ffmpeg_content->audio_channels(), frames));
201 switch (audio_sample_format()) {
202 case AV_SAMPLE_FMT_S16:
204 int16_t* p = reinterpret_cast<int16_t *> (data[0]);
207 for (int i = 0; i < total_samples; ++i) {
208 audio->data(channel)[sample] = float(*p++) / (1 << 15);
211 if (channel == _ffmpeg_content->audio_channels()) {
219 case AV_SAMPLE_FMT_S16P:
221 int16_t** p = reinterpret_cast<int16_t **> (data);
222 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
223 for (int j = 0; j < frames; ++j) {
224 audio->data(i)[j] = static_cast<float>(p[i][j]) / (1 << 15);
230 case AV_SAMPLE_FMT_S32:
232 int32_t* p = reinterpret_cast<int32_t *> (data[0]);
235 for (int i = 0; i < total_samples; ++i) {
236 audio->data(channel)[sample] = static_cast<float>(*p++) / (1 << 31);
239 if (channel == _ffmpeg_content->audio_channels()) {
247 case AV_SAMPLE_FMT_FLT:
249 float* p = reinterpret_cast<float*> (data[0]);
252 for (int i = 0; i < total_samples; ++i) {
253 audio->data(channel)[sample] = *p++;
256 if (channel == _ffmpeg_content->audio_channels()) {
264 case AV_SAMPLE_FMT_FLTP:
266 float** p = reinterpret_cast<float**> (data);
267 for (int i = 0; i < _ffmpeg_content->audio_channels(); ++i) {
268 memcpy (audio->data(i), p[i], frames * sizeof(float));
274 throw DecodeError (String::compose (_("Unrecognised audio sample format (%1)"), static_cast<int> (audio_sample_format())));
281 FFmpegDecoder::audio_sample_format () const
283 if (!_ffmpeg_content->audio_stream()) {
284 return (AVSampleFormat) 0;
287 return audio_codec_context()->sample_fmt;
291 FFmpegDecoder::bytes_per_audio_sample () const
293 return av_get_bytes_per_sample (audio_sample_format ());
297 FFmpegDecoder::seek (VideoContent::Frame frame, bool accurate)
299 double const time_base = av_q2d (_format_context->streams[_video_stream]->time_base);
301 /* If we are doing an accurate seek, our initial shot will be 5 frames (5 being
302 a number plucked from the air) earlier than we want to end up. The loop below
303 will hopefully then step through to where we want to be.
315 /* Initial seek time in the stream's timebase */
316 int64_t const initial_vt = ((initial / _ffmpeg_content->video_frame_rate()) - _pts_offset) / time_base;
318 av_seek_frame (_format_context, _video_stream, initial_vt, AVSEEK_FLAG_BACKWARD);
320 avcodec_flush_buffers (video_codec_context());
321 if (_subtitle_codec_context) {
322 avcodec_flush_buffers (_subtitle_codec_context);
326 _video_position = frame;
328 if (frame == 0 || !accurate) {
329 /* We're already there, or we're as close as we need to be */
334 int r = av_read_frame (_format_context, &_packet);
339 if (_packet.stream_index != _video_stream) {
340 av_free_packet (&_packet);
345 r = avcodec_decode_video2 (video_codec_context(), _frame, &finished, &_packet);
346 if (r >= 0 && finished) {
347 _video_position = rint (
348 (av_frame_get_best_effort_timestamp (_frame) * time_base + _pts_offset) * _ffmpeg_content->video_frame_rate()
351 if (_video_position >= (frame - 1)) {
352 av_free_packet (&_packet);
357 av_free_packet (&_packet);
362 FFmpegDecoder::decode_audio_packet ()
364 /* Audio packets can contain multiple frames, so we may have to call avcodec_decode_audio4
368 AVPacket copy_packet = _packet;
370 while (copy_packet.size > 0) {
373 int const decode_result = avcodec_decode_audio4 (audio_codec_context(), _frame, &frame_finished, ©_packet);
374 if (decode_result < 0) {
375 shared_ptr<const Film> film = _film.lock ();
377 film->log()->log (String::compose ("avcodec_decode_audio4 failed (%1)", decode_result));
381 if (frame_finished) {
383 if (_audio_position == 0) {
384 /* Where we are in the source, in seconds */
385 double const pts = av_q2d (_format_context->streams[copy_packet.stream_index]->time_base)
386 * av_frame_get_best_effort_timestamp(_frame) + _pts_offset;
389 /* Emit some silence */
390 shared_ptr<AudioBuffers> silence (
392 _ffmpeg_content->audio_channels(),
393 pts * _ffmpeg_content->content_audio_frame_rate()
397 silence->make_silent ();
398 audio (silence, _audio_position);
402 int const data_size = av_samples_get_buffer_size (
403 0, audio_codec_context()->channels, _frame->nb_samples, audio_sample_format (), 1
406 audio (deinterleave_audio (_frame->data, data_size), _audio_position);
409 copy_packet.data += decode_result;
410 copy_packet.size -= decode_result;
415 FFmpegDecoder::decode_video_packet ()
418 if (avcodec_decode_video2 (video_codec_context(), _frame, &frame_finished, &_packet) < 0 || !frame_finished) {
422 boost::mutex::scoped_lock lm (_filter_graphs_mutex);
424 shared_ptr<FilterGraph> graph;
426 list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
427 while (i != _filter_graphs.end() && !(*i)->can_process (libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) {
431 if (i == _filter_graphs.end ()) {
432 shared_ptr<const Film> film = _film.lock ();
435 graph.reset (new FilterGraph (_ffmpeg_content, libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
436 _filter_graphs.push_back (graph);
438 film->log()->log (String::compose (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format));
443 list<pair<shared_ptr<Image>, int64_t> > images = graph->process (_frame);
445 string post_process = Filter::ffmpeg_strings (_ffmpeg_content->filters()).second;
447 for (list<pair<shared_ptr<Image>, int64_t> >::iterator i = images.begin(); i != images.end(); ++i) {
449 shared_ptr<Image> image = i->first;
450 if (!post_process.empty ()) {
451 image = image->post_process (post_process, true);
454 if (i->second != AV_NOPTS_VALUE) {
456 double const pts = i->second * av_q2d (_format_context->streams[_video_stream]->time_base) + _pts_offset;
459 /* We just did a seek, so disable any attempts to correct for where we
462 _video_position = rint (pts * _ffmpeg_content->video_frame_rate ());
463 _just_sought = false;
466 double const next = _video_position / _ffmpeg_content->video_frame_rate();
467 double const one_frame = 1 / _ffmpeg_content->video_frame_rate ();
468 double delta = pts - next;
470 while (delta > one_frame) {
471 /* This PTS is more than one frame forward in time of where we think we should be; emit
475 /* XXX: I think this should be a copy of the last frame... */
476 boost::shared_ptr<Image> black (
478 static_cast<AVPixelFormat> (_frame->format),
479 libdcp::Size (video_codec_context()->width, video_codec_context()->height),
484 black->make_black ();
485 video (image, false, _video_position);
489 if (delta > -one_frame) {
490 /* This PTS is within a frame of being right; emit this (otherwise it will be dropped) */
491 video (image, false, _video_position);
495 shared_ptr<const Film> film = _film.lock ();
497 film->log()->log ("Dropping frame without PTS");
506 FFmpegDecoder::setup_subtitle ()
508 boost::mutex::scoped_lock lm (_mutex);
510 if (!_ffmpeg_content->subtitle_stream() || _ffmpeg_content->subtitle_stream()->index (_format_context) >= int (_format_context->nb_streams)) {
514 _subtitle_codec_context = _ffmpeg_content->subtitle_stream()->stream(_format_context)->codec;
515 _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
517 if (_subtitle_codec == 0) {
518 throw DecodeError (_("could not find subtitle decoder"));
521 if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
522 throw DecodeError (N_("could not open subtitle decoder"));
527 FFmpegDecoder::done () const
529 bool const vd = !_decode_video || (_video_position >= _ffmpeg_content->video_length());
530 bool const ad = !_decode_audio || !_ffmpeg_content->audio_stream() || (_audio_position >= _ffmpeg_content->audio_length());
535 FFmpegDecoder::decode_subtitle_packet ()
539 if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) < 0 || !got_subtitle) {
543 /* Sometimes we get an empty AVSubtitle, which is used by some codecs to
544 indicate that the previous subtitle should stop.
546 if (sub.num_rects <= 0) {
547 subtitle (shared_ptr<Image> (), dcpomatic::Rect<double> (), 0, 0);
549 } else if (sub.num_rects > 1) {
550 throw DecodeError (_("multi-part subtitles not yet supported"));
553 /* Subtitle PTS in seconds (within the source, not taking into account any of the
554 source that we may have chopped off for the DCP)
556 double const packet_time = (static_cast<double> (sub.pts ) / AV_TIME_BASE) + _pts_offset;
558 /* hence start time for this sub */
559 Time const from = (packet_time + (double (sub.start_display_time) / 1e3)) * TIME_HZ;
560 Time const to = (packet_time + (double (sub.end_display_time) / 1e3)) * TIME_HZ;
562 AVSubtitleRect const * rect = sub.rects[0];
564 if (rect->type != SUBTITLE_BITMAP) {
565 throw DecodeError (_("non-bitmap subtitles not yet supported"));
568 /* Note RGBA is expressed little-endian, so the first byte in the word is R, second
569 G, third B, fourth A.
571 shared_ptr<Image> image (new Image (PIX_FMT_RGBA, libdcp::Size (rect->w, rect->h), true));
573 /* Start of the first line in the subtitle */
574 uint8_t* sub_p = rect->pict.data[0];
575 /* sub_p looks up into a BGRA palette which is here
576 (i.e. first byte B, second G, third R, fourth A)
578 uint32_t const * palette = (uint32_t *) rect->pict.data[1];
579 /* Start of the output data */
580 uint32_t* out_p = (uint32_t *) image->data()[0];
582 for (int y = 0; y < rect->h; ++y) {
583 uint8_t* sub_line_p = sub_p;
584 uint32_t* out_line_p = out_p;
585 for (int x = 0; x < rect->w; ++x) {
586 uint32_t const p = palette[*sub_line_p++];
587 *out_line_p++ = ((p & 0xff) << 16) | (p & 0xff00) | ((p & 0xff0000) >> 16) | (p & 0xff000000);
589 sub_p += rect->pict.linesize[0];
590 out_p += image->stride()[0] / sizeof (uint32_t);
593 libdcp::Size const vs = _ffmpeg_content->video_size ();
597 dcpomatic::Rect<double> (
598 static_cast<double> (rect->x) / vs.width,
599 static_cast<double> (rect->y) / vs.height,
600 static_cast<double> (rect->w) / vs.width,
601 static_cast<double> (rect->h) / vs.height
608 avsubtitle_free (&sub);