summaryrefslogtreecommitdiff
path: root/src/lib/audio_merger.cc
blob: a422580124ff5ac8b2736e3732b142088ea11e66 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/*
    Copyright (C) 2013-2017 Carl Hetherington <cth@carlh.net>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

/** @file  src/audio_merger.cc
 *  @brief AudioMerger class.
 */

#include "audio_merger.h"
#include "dcpomatic_time.h"
#include "dcpomatic_log.h"
#include <iostream>

using std::pair;
using std::min;
using std::max;
using std::list;
using std::cout;
using std::make_pair;
using boost::shared_ptr;
using boost::optional;

AudioMerger::AudioMerger (int frame_rate)
	: _frame_rate (frame_rate)
{

}

Frame
AudioMerger::frames (DCPTime t) const
{
	return t.frames_floor (_frame_rate);
}

/** Pull audio up to a given time; after this call, no more data can be pushed
 *  before the specified time.
 *  @param time Time to pull up to.
 *  @return Blocks of merged audio up to `time'.
 */
list<pair<shared_ptr<AudioBuffers>, DCPTime> >
AudioMerger::pull (DCPTime time)
{
	list<pair<shared_ptr<AudioBuffers>, DCPTime> > out;

	list<Buffer> new_buffers;

	_buffers.sort (AudioMerger::BufferComparator());
	BOOST_FOREACH (Buffer i, _buffers) {
		if (i.period().to <= time) {
			/* Completely within the pull period */
			DCPOMATIC_ASSERT (i.audio->frames() > 0);
			out.push_back (make_pair (i.audio, i.time));
		} else if (i.time < time) {
			/* Overlaps the end of the pull period */
			shared_ptr<AudioBuffers> audio (new AudioBuffers (i.audio->channels(), frames(DCPTime(time - i.time))));
			/* Though time > i.time, audio->frames() could be 0 if the difference in time is less than one frame */
			if (audio->frames() > 0) {
				LOG_GENERAL("copy_from #1; pulling from %2", to_string(time));
				audio->copy_from (i.audio.get(), audio->frames(), 0, 0);
				out.push_back (make_pair (audio, i.time));
				i.audio->trim_start (audio->frames ());
				i.time += DCPTime::from_frames(audio->frames(), _frame_rate);
				DCPOMATIC_ASSERT (i.audio->frames() > 0);
				new_buffers.push_back (i);
			}
		} else {
			/* Not involved */
			DCPOMATIC_ASSERT (i.audio->frames() > 0);
			new_buffers.push_back (i);
		}
	}

	_buffers = new_buffers;

	for (list<pair<shared_ptr<AudioBuffers>, DCPTime> >::const_iterator i = out.begin(); i != out.end(); ++i) {
		DCPOMATIC_ASSERT (i->first->frames() > 0);
	}

	return out;
}

/** Push some data into the merger at a given time */
void
AudioMerger::push (boost::shared_ptr<const AudioBuffers> audio, DCPTime time)
{
	DCPOMATIC_ASSERT (audio->frames() > 0);

	DCPTimePeriod period (time, time + DCPTime::from_frames (audio->frames(), _frame_rate));

	/* Mix any overlapping parts of this new block with existing ones */
	BOOST_FOREACH (Buffer i, _buffers) {
		optional<DCPTimePeriod> overlap = i.period().overlap (period);
		if (overlap) {
			int32_t const offset = frames(DCPTime(overlap->from - i.time));
			int32_t const frames_to_mix = frames(overlap->duration());
			if (i.time < time) {
				i.audio->accumulate_frames(audio.get(), frames_to_mix, 0, offset);
			} else {
				i.audio->accumulate_frames(audio.get(), frames_to_mix, offset, 0);
			}
		}
	}

	list<DCPTimePeriod> periods;
	BOOST_FOREACH (Buffer i, _buffers) {
		periods.push_back (i.period ());
	}

	/* Add the non-overlapping parts */
	BOOST_FOREACH (DCPTimePeriod i, subtract (period, periods)) {
		list<Buffer>::iterator before = _buffers.end();
		list<Buffer>::iterator after = _buffers.end();
		for (list<Buffer>::iterator j = _buffers.begin(); j != _buffers.end(); ++j) {
			if (j->period().to == i.from) {
				before = j;
			}
			if (j->period().from == i.to) {
				after = j;
			}
		}

		/* Get the part of audio that we want to use */
		shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), frames(i.to) - frames(i.from)));
		LOG_GENERAL_NC("copy_from #2");
		part->copy_from (audio.get(), part->frames(), frames(DCPTime(i.from - time)), 0);

		if (before == _buffers.end() && after == _buffers.end()) {
			/* New buffer */
			DCPOMATIC_ASSERT (part->frames() > 0);
			_buffers.push_back (Buffer (part, time, _frame_rate));
		} else if (before != _buffers.end() && after == _buffers.end()) {
			/* We have an existing buffer before this one; append new data to it */
			before->audio->append (part);
		} else if (before ==_buffers.end() && after != _buffers.end()) {
			/* We have an existing buffer after this one; append it to the new data and replace */
			part->append (after->audio);
			after->audio = part;
			after->time = time;
		} else {
			/* We have existing buffers both before and after; coalesce them all */
			before->audio->append (part);
			before->audio->append (after->audio);
			_buffers.erase (after);
		}
	}
}

void
AudioMerger::clear ()
{
	_buffers.clear ();
}