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/decoder.cc
21 * @brief Parent class for decoders of content.
26 #include <boost/lexical_cast.hpp>
31 #include "exceptions.h"
36 #include "delay_line.h"
38 #include "filter_graph.h"
41 using std::stringstream;
45 using boost::shared_ptr;
49 * @param j Job that we are running within, or 0
50 * @param minimal true to do the bare minimum of work; just run through the content. Useful for acquiring
51 * accurate frame counts as quickly as possible. This generates no video or audio output.
53 Decoder::Decoder (boost::shared_ptr<Film> f, boost::shared_ptr<const Options> o, Job* j)
60 , _delay_in_frames (0)
70 /** Start off a decode processing run. This should only be called once on
71 * a given Decoder object.
74 Decoder::process_begin ()
76 _delay_in_frames = _film->audio_delay() * audio_sample_rate() / 1000;
77 _delay_line = new DelayLine (audio_channels(), _delay_in_frames);
80 /** Finish off a decode processing run */
82 Decoder::process_end ()
84 if (_delay_in_frames < 0 && _opt->decode_audio && audio_channels()) {
85 shared_ptr<AudioBuffers> b (new AudioBuffers (audio_channels(), -_delay_in_frames));
90 if (_opt->decode_audio && audio_channels()) {
92 /* Ensure that our video and audio emissions are the same length */
94 int64_t audio_short_by_frames = video_frames_to_audio_frames (_video_frame, audio_sample_rate(), frames_per_second()) - _audio_frame;
98 "Decoder has emitted %1 video frames (which equals %2 audio frames) and %3 audio frames",
100 video_frames_to_audio_frames (_video_frame, audio_sample_rate(), frames_per_second()),
105 if (audio_short_by_frames < 0) {
107 _film->log()->log (String::compose ("Emitted %1 too many audio frames", -audio_short_by_frames));
109 /* We have emitted more audio than video. Emit enough black video frames so that we reverse this */
110 int const black_video_frames = ceil (-audio_short_by_frames * frames_per_second() / audio_sample_rate());
112 _film->log()->log (String::compose ("Emitting %1 frames of black video", black_video_frames));
114 shared_ptr<Image> black (new CompactImage (pixel_format(), native_size()));
115 black->make_black ();
116 for (int i = 0; i < black_video_frames; ++i) {
117 emit_video (black, shared_ptr<Subtitle> ());
120 /* Now recompute our check value */
121 audio_short_by_frames = video_frames_to_audio_frames (_video_frame, audio_sample_rate(), frames_per_second()) - _audio_frame;
124 if (audio_short_by_frames > 0) {
125 _film->log()->log (String::compose ("Emitted %1 too few audio frames", audio_short_by_frames));
126 shared_ptr<AudioBuffers> b (new AudioBuffers (audio_channels(), audio_short_by_frames));
133 /** Start decoding */
139 if (_job && !_film->dcp_length()) {
140 _job->set_progress_unknown ();
143 while (pass () == false) {
144 if (_job && _film->dcp_length()) {
145 _job->set_progress (float (_video_frame) / _film->length().get());
152 /** Called by subclasses to tell the world that some audio data is ready
153 * @param data Audio data, in Film::audio_sample_format.
154 * @param size Number of bytes of data.
157 Decoder::process_audio (shared_ptr<AudioBuffers> audio)
159 /* Maybe apply gain */
160 if (_film->audio_gain() != 0) {
161 float const linear_gain = pow (10, _film->audio_gain() / 20);
162 for (int i = 0; i < audio->channels(); ++i) {
163 for (int j = 0; j < audio->frames(); ++j) {
164 audio->data(i)[j] *= linear_gain;
169 _delay_line->feed (audio);
173 /** Called by subclasses to tell the world that some video data is ready.
174 * We do some post-processing / filtering then emit it for listeners.
175 * @param frame to decode; caller manages memory.
178 Decoder::process_video (AVFrame* frame)
180 shared_ptr<FilterGraph> graph;
182 list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
183 while (i != _filter_graphs.end() && !(*i)->can_process (Size (frame->width, frame->height), (AVPixelFormat) frame->format)) {
187 if (i == _filter_graphs.end ()) {
188 graph.reset (new FilterGraph (_film, this, _opt->apply_crop, Size (frame->width, frame->height), (AVPixelFormat) frame->format));
189 _filter_graphs.push_back (graph);
190 _film->log()->log (String::compose ("New graph for %1x%2, pixel format %3", frame->width, frame->height, frame->format));
195 list<shared_ptr<Image> > images = graph->process (frame);
197 for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
198 shared_ptr<Subtitle> sub;
199 if (_timed_subtitle && _timed_subtitle->displayed_at (double (video_frame()) / _film->frames_per_second())) {
200 sub = _timed_subtitle->subtitle ();
203 emit_video (*i, sub);
208 Decoder::repeat_last_video ()
211 _last_image.reset (new CompactImage (pixel_format(), native_size()));
212 _last_image->make_black ();
215 emit_video (_last_image, _last_subtitle);
219 Decoder::emit_video (shared_ptr<Image> image, shared_ptr<Subtitle> sub)
221 TIMING ("Decoder emits %1", _video_frame);
222 Video (image, _video_frame, sub);
226 _last_subtitle = sub;
230 Decoder::emit_audio (shared_ptr<AudioBuffers> audio)
232 Audio (audio, _audio_frame);
233 _audio_frame += audio->frames ();
237 Decoder::process_subtitle (shared_ptr<TimedSubtitle> s)
241 if (_timed_subtitle && _opt->apply_crop) {
242 Position const p = _timed_subtitle->subtitle()->position ();
243 _timed_subtitle->subtitle()->set_position (Position (p.x - _film->crop().left, p.y - _film->crop().top));
248 Decoder::bytes_per_audio_sample () const
250 return av_get_bytes_per_sample (audio_sample_format ());