2 Copyright (C) 2013 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_buffers.h"
23 template <class T, class F>
27 AudioMerger (int channels, boost::function<F (T)> t_to_f, boost::function<T (F)> f_to_t)
28 : _buffers (new AudioBuffers (channels, 0))
34 /** Pull audio up to a given time; after this call, no more data can be pushed
35 * before the specified time.
40 TimedAudioBuffers<T> out;
42 F const to_return = _t_to_f (time - _last_pull);
43 out.audio.reset (new AudioBuffers (_buffers->channels(), to_return));
44 /* And this is how many we will get from our buffer */
45 F const to_return_from_buffers = min (to_return, _buffers->frames ());
47 /* Copy the data that we have to the back end of the return buffer */
48 out.audio->copy_from (_buffers.get(), to_return_from_buffers, 0, to_return - to_return_from_buffers);
49 /* Silence any gap at the start */
50 out.audio->make_silent (0, to_return - to_return_from_buffers);
52 out.time = _last_pull;
55 /* And remove the data we're returning from our buffers */
56 if (_buffers->frames() > to_return_from_buffers) {
57 _buffers->move (to_return_from_buffers, 0, _buffers->frames() - to_return_from_buffers);
59 _buffers->set_frames (_buffers->frames() - to_return_from_buffers);
65 push (boost::shared_ptr<const AudioBuffers> audio, T time)
67 assert (time >= _last_pull);
69 F frame = _t_to_f (time);
70 F after = max (_buffers->frames(), frame + audio->frames() - _t_to_f (_last_pull));
71 _buffers->ensure_size (after);
72 _buffers->accumulate_frames (audio.get(), 0, frame - _t_to_f (_last_pull), audio->frames ());
73 _buffers->set_frames (after);
97 if (_buffers->frames() == 0) {
98 return TimedAudioBuffers<T> ();
101 return TimedAudioBuffers<T> (_buffers, _last_pull);
105 boost::shared_ptr<AudioBuffers> _buffers;
107 boost::function<F (T)> _t_to_f;
108 boost::function<T (F)> _f_to_t;