2 Copyright (C) 2012-2018 Carl Hetherington <cth@carlh.net>
4 This file is part of DCP-o-matic.
6 DCP-o-matic is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 DCP-o-matic is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
21 #include "audio_decoder.h"
22 #include "audio_buffers.h"
23 #include "audio_content.h"
24 #include "dcpomatic_log.h"
26 #include "resampler.h"
27 #include "compose.hpp"
35 using std::shared_ptr;
36 using boost::optional;
37 using namespace dcpomatic;
39 AudioDecoder::AudioDecoder (Decoder* parent, shared_ptr<const AudioContent> content, bool fast)
40 : DecoderPart (parent)
44 /* Set up _positions so that we have one for each stream */
45 for (auto i: content->streams ()) {
50 /** @param time_already_delayed true if the delay should not be added to time */
52 AudioDecoder::emit (shared_ptr<const Film> film, AudioStreamPtr stream, shared_ptr<const AudioBuffers> data, ContentTime time, bool time_already_delayed)
58 /* Amount of error we will tolerate on audio timestamps; see comment below.
59 * We'll use 1 24fps video frame at 48kHz as this seems to be roughly how
62 static Frame const slack_frames = 48000 / 24;
64 int const resampled_rate = _content->resampled_frame_rate(film);
65 if (!time_already_delayed) {
66 time += ContentTime::from_seconds (_content->delay() / 1000.0);
70 if (_positions[stream] == 0) {
71 /* This is the first data we have received since initialisation or seek. Set
72 the position based on the ContentTime that was given. After this first time
73 we just count samples unless the timestamp is more than slack_frames away
74 from where we think it should be. This is because ContentTimes seem to be
75 slightly unreliable from FFmpegDecoder (i.e. not sample accurate), but we still
76 need to obey them sometimes otherwise we get sync problems such as #1833.
78 if (_content->delay() > 0) {
79 /* Insert silence to give the delay */
80 silence (_content->delay ());
83 } else if (std::abs(_positions[stream] - time.frames_round(resampled_rate)) > slack_frames) {
86 "Reset audio position: was %1, new data at %2, slack: %3 frames",
88 time.frames_round(resampled_rate),
89 std::abs(_positions[stream] - time.frames_round(resampled_rate))
94 _positions[stream] = time.frames_round (resampled_rate);
97 shared_ptr<Resampler> resampler;
98 ResamplerMap::iterator i = _resamplers.find(stream);
99 if (i != _resamplers.end ()) {
100 resampler = i->second;
102 if (stream->frame_rate() != resampled_rate) {
104 "Creating new resampler from %1 to %2 with %3 channels",
105 stream->frame_rate(),
110 resampler.reset (new Resampler(stream->frame_rate(), resampled_rate, stream->channels()));
112 resampler->set_fast ();
114 _resamplers[stream] = resampler;
119 shared_ptr<const AudioBuffers> ro = resampler->run (data);
120 if (ro->frames() == 0) {
126 Data(stream, ContentAudio (data, _positions[stream]));
127 _positions[stream] += data->frames();
130 /** @return Time just after the last thing that was emitted from a given stream */
132 AudioDecoder::stream_position (shared_ptr<const Film> film, AudioStreamPtr stream) const
134 PositionMap::const_iterator i = _positions.find (stream);
135 DCPOMATIC_ASSERT (i != _positions.end ());
136 return ContentTime::from_frames (i->second, _content->resampled_frame_rate(film));
139 boost::optional<ContentTime>
140 AudioDecoder::position (shared_ptr<const Film> film) const
142 optional<ContentTime> p;
143 for (PositionMap::const_iterator i = _positions.begin(); i != _positions.end(); ++i) {
144 ContentTime const ct = stream_position (film, i->first);
154 AudioDecoder::seek ()
156 for (ResamplerMap::iterator i = _resamplers.begin(); i != _resamplers.end(); ++i) {
161 for (PositionMap::iterator i = _positions.begin(); i != _positions.end(); ++i) {
167 AudioDecoder::flush ()
169 for (ResamplerMap::iterator i = _resamplers.begin(); i != _resamplers.end(); ++i) {
170 shared_ptr<const AudioBuffers> ro = i->second->flush ();
171 if (ro->frames() > 0) {
172 Data (i->first, ContentAudio (ro, _positions[i->first]));
173 _positions[i->first] += ro->frames();
177 if (_content->delay() < 0) {
178 /* Finish off with the gap caused by the delay */
179 silence (-_content->delay ());
184 AudioDecoder::silence (int milliseconds)
186 for (auto i: _content->streams()) {
187 int const samples = ContentTime::from_seconds(milliseconds / 1000.0).frames_round(i->frame_rate());
188 shared_ptr<AudioBuffers> silence (new AudioBuffers (i->channels(), samples));
189 silence->make_silent ();
190 Data (i, ContentAudio (silence, _positions[i]));