2 Copyright (C) 2013-2017 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/audio_merger.cc
21 * @brief AudioMerger class.
24 #include "audio_merger.h"
25 #include "dcpomatic_time.h"
34 using boost::shared_ptr;
35 using boost::optional;
36 using namespace dcpomatic;
38 AudioMerger::AudioMerger (int frame_rate)
39 : _frame_rate (frame_rate)
45 AudioMerger::frames (DCPTime t) const
47 return t.frames_floor (_frame_rate);
50 /** Pull audio up to a given time; after this call, no more data can be pushed
51 * before the specified time.
52 * @param time Time to pull up to.
53 * @return Blocks of merged audio up to `time'.
55 list<pair<shared_ptr<AudioBuffers>, DCPTime> >
56 AudioMerger::pull (DCPTime time)
58 list<pair<shared_ptr<AudioBuffers>, DCPTime> > out;
60 list<Buffer> new_buffers;
62 _buffers.sort (AudioMerger::BufferComparator());
63 BOOST_FOREACH (Buffer i, _buffers) {
64 if (i.period().to <= time) {
65 /* Completely within the pull period */
66 DCPOMATIC_ASSERT (i.audio->frames() > 0);
67 out.push_back (make_pair (i.audio, i.time));
68 } else if (i.time < time) {
69 /* Overlaps the end of the pull period */
70 shared_ptr<AudioBuffers> audio (new AudioBuffers (i.audio->channels(), frames(DCPTime(time - i.time))));
71 /* Though time > i.time, audio->frames() could be 0 if the difference in time is less than one frame */
72 if (audio->frames() > 0) {
73 audio->copy_from (i.audio.get(), audio->frames(), 0, 0);
74 out.push_back (make_pair (audio, i.time));
75 i.audio->trim_start (audio->frames ());
76 i.time += DCPTime::from_frames(audio->frames(), _frame_rate);
77 DCPOMATIC_ASSERT (i.audio->frames() > 0);
78 new_buffers.push_back (i);
82 DCPOMATIC_ASSERT (i.audio->frames() > 0);
83 new_buffers.push_back (i);
87 _buffers = new_buffers;
89 for (list<pair<shared_ptr<AudioBuffers>, DCPTime> >::const_iterator i = out.begin(); i != out.end(); ++i) {
90 DCPOMATIC_ASSERT (i->first->frames() > 0);
96 /** Push some data into the merger at a given time */
98 AudioMerger::push (boost::shared_ptr<const AudioBuffers> audio, DCPTime time)
100 DCPOMATIC_ASSERT (audio->frames() > 0);
102 DCPTimePeriod period (time, time + DCPTime::from_frames (audio->frames(), _frame_rate));
104 /* Mix any overlapping parts of this new block with existing ones */
105 BOOST_FOREACH (Buffer i, _buffers) {
106 optional<DCPTimePeriod> overlap = i.period().overlap (period);
108 int32_t const offset = frames(DCPTime(overlap->from - i.time));
109 int32_t const frames_to_mix = frames(overlap->duration());
111 i.audio->accumulate_frames(audio.get(), frames_to_mix, 0, offset);
113 i.audio->accumulate_frames(audio.get(), frames_to_mix, offset, 0);
118 list<DCPTimePeriod> periods;
119 BOOST_FOREACH (Buffer i, _buffers) {
120 periods.push_back (i.period ());
123 /* Add the non-overlapping parts */
124 BOOST_FOREACH (DCPTimePeriod i, subtract (period, periods)) {
125 list<Buffer>::iterator before = _buffers.end();
126 list<Buffer>::iterator after = _buffers.end();
127 for (list<Buffer>::iterator j = _buffers.begin(); j != _buffers.end(); ++j) {
128 if (j->period().to == i.from) {
131 if (j->period().from == i.to) {
136 /* Get the part of audio that we want to use */
137 shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), frames(i.to) - frames(i.from)));
138 part->copy_from (audio.get(), part->frames(), frames(DCPTime(i.from - time)), 0);
140 if (before == _buffers.end() && after == _buffers.end()) {
141 if (part->frames() > 0) {
143 _buffers.push_back (Buffer (part, time, _frame_rate));
145 } else if (before != _buffers.end() && after == _buffers.end()) {
146 /* We have an existing buffer before this one; append new data to it */
147 before->audio->append (part);
148 } else if (before ==_buffers.end() && after != _buffers.end()) {
149 /* We have an existing buffer after this one; append it to the new data and replace */
150 part->append (after->audio);
154 /* We have existing buffers both before and after; coalesce them all */
155 before->audio->append (part);
156 before->audio->append (after->audio);
157 _buffers.erase (after);
163 AudioMerger::clear ()