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 #include "audio_merger.h"
21 #include "dcpomatic_time.h"
30 using boost::shared_ptr;
31 using boost::optional;
33 AudioMerger::AudioMerger (int frame_rate)
35 , _frame_rate (frame_rate)
40 /** Pull audio up to a given time; after this call, no more data can be pushed
41 * before the specified time.
43 list<pair<shared_ptr<AudioBuffers>, DCPTime> >
44 AudioMerger::pull (DCPTime time)
46 list<pair<shared_ptr<AudioBuffers>, DCPTime> > out;
48 DCPTimePeriod period (_last_pull, time);
49 _buffers.sort (AudioMerger::BufferComparator());
51 list<Buffer> new_buffers;
53 BOOST_FOREACH (Buffer i, _buffers) {
54 if (i.period().to <= time) {
55 /* Completely within the pull period */
56 out.push_back (make_pair (i.audio, i.time));
57 } else if (i.time < time) {
58 /* Overlaps the end of the pull period */
59 shared_ptr<AudioBuffers> audio (new AudioBuffers (i.audio->channels(), DCPTime(time - i.time).frames_floor(_frame_rate)));
60 audio->copy_from (i.audio.get(), audio->frames(), 0, 0);
61 out.push_back (make_pair (audio, i.time));
62 i.audio->trim_start (audio->frames ());
63 i.time += DCPTime::from_frames(audio->frames(), _frame_rate);
64 new_buffers.push_back (i);
67 new_buffers.push_back (i);
71 _buffers = new_buffers;
76 AudioMerger::push (boost::shared_ptr<const AudioBuffers> audio, DCPTime time)
78 DCPOMATIC_ASSERT (time >= _last_pull);
80 DCPTimePeriod period (time, time + DCPTime::from_frames (audio->frames(), _frame_rate));
82 /* Mix any parts of this new block with existing ones */
83 BOOST_FOREACH (Buffer i, _buffers) {
84 optional<DCPTimePeriod> overlap = i.period().overlap (period);
86 int32_t const offset = DCPTime(overlap->from - i.time).frames_floor(_frame_rate);
87 int32_t const frames = overlap->duration().frames_floor(_frame_rate);
89 i.audio->accumulate_frames(audio.get(), frames, 0, offset);
91 i.audio->accumulate_frames(audio.get(), frames, offset, 0);
96 list<DCPTimePeriod> periods;
97 BOOST_FOREACH (Buffer i, _buffers) {
98 periods.push_back (i.period ());
101 /* Add the non-overlapping parts */
102 BOOST_FOREACH (DCPTimePeriod i, subtract (period, periods)) {
103 list<Buffer>::iterator before = _buffers.end();
104 list<Buffer>::iterator after = _buffers.end();
105 for (list<Buffer>::iterator j = _buffers.begin(); j != _buffers.end(); ++j) {
106 if (j->period().to == i.from) {
109 if (j->period().from == i.to) {
114 /* Get the part of audio that we want to use */
115 shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), i.to.frames_floor(_frame_rate) - i.from.frames_floor(_frame_rate)));
116 part->copy_from (audio.get(), part->frames(), DCPTime(i.from - time).frames_floor(_frame_rate), 0);
118 if (before == _buffers.end() && after == _buffers.end()) {
120 _buffers.push_back (Buffer (part, time, _frame_rate));
121 } else if (before != _buffers.end() && after == _buffers.end()) {
122 /* We have an existing buffer before this one; append new data to it */
123 before->audio->append (part);
124 } else if (before ==_buffers.end() && after != _buffers.end()) {
125 /* We have an existing buffer after this one; append it to the new data and replace */
126 part->append (after->audio);
130 /* We have existing buffers both before and after; coalesce them all */
131 before->audio->append (part);
132 before->audio->append (after->audio);
133 _buffers.erase (after);