/*
- Copyright (C) 2013 Carl Hetherington <cth@carlh.net>
+ 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
*/
+/** @file src/audio_merger.h
+ * @brief AudioMerger class.
+ */
+
#include "audio_buffers.h"
+#include "dcpomatic_time.h"
#include "util.h"
-template <class T, class F>
+/** @class AudioMerger.
+ * @brief A class that can merge audio data from many sources.
+ */
class AudioMerger
{
public:
- AudioMerger (int channels, boost::function<F (T)> t_to_f, boost::function<T (F)> f_to_t)
- : _buffers (new AudioBuffers (channels, 0))
- , _last_pull (0)
- , _t_to_f (t_to_f)
- , _f_to_t (f_to_t)
- {}
-
- /** Pull audio up to a given time; after this call, no more data can be pushed
- * before the specified time.
- */
- TimedAudioBuffers<T>
- pull (T time)
- {
- assert (time >= _last_pull);
-
- TimedAudioBuffers<T> out;
-
- F const to_return = _t_to_f (time - _last_pull);
- out.audio.reset (new AudioBuffers (_buffers->channels(), to_return));
- /* And this is how many we will get from our buffer */
- F const to_return_from_buffers = min (to_return, _buffers->frames ());
-
- /* Copy the data that we have to the back end of the return buffer */
- out.audio->copy_from (_buffers.get(), to_return_from_buffers, 0, to_return - to_return_from_buffers);
- /* Silence any gap at the start */
- out.audio->make_silent (0, to_return - to_return_from_buffers);
-
- out.time = _last_pull;
- _last_pull = time;
-
- /* And remove the data we're returning from our buffers */
- if (_buffers->frames() > to_return_from_buffers) {
- _buffers->move (to_return_from_buffers, 0, _buffers->frames() - to_return_from_buffers);
- }
- _buffers->set_frames (_buffers->frames() - to_return_from_buffers);
-
- return out;
- }
-
- void
- push (boost::shared_ptr<const AudioBuffers> audio, T time)
- {
- assert (time >= _last_pull);
+ AudioMerger (int frame_rate);
- F frame = _t_to_f (time);
- F after = max (_buffers->frames(), frame + audio->frames() - _t_to_f (_last_pull));
- _buffers->ensure_size (after);
- _buffers->accumulate_frames (audio.get(), 0, frame - _t_to_f (_last_pull), audio->frames ());
- _buffers->set_frames (after);
- }
+ std::list<std::pair<boost::shared_ptr<AudioBuffers>, DCPTime> > pull (DCPTime time);
+ void push (boost::shared_ptr<const AudioBuffers> audio, DCPTime time);
+ void clear ();
- F min (F a, int b)
- {
- if (a < b) {
- return a;
- }
-
- return b;
- }
+private:
+ Frame frames (DCPTime t) const;
- F max (int a, F b)
+ class Buffer
{
- if (a > b) {
- return a;
+ public:
+ /** @param c Channels
+ * @param f Frames
+ * @param t Time
+ * @param r Frame rate.
+ */
+ Buffer (int c, int32_t f, DCPTime t, int r)
+ : audio (new AudioBuffers (c, f))
+ , time (t)
+ , frame_rate (r)
+ {}
+
+ Buffer (boost::shared_ptr<AudioBuffers> a, DCPTime t, int r)
+ : audio (a)
+ , time (t)
+ , frame_rate (r)
+ {}
+
+ boost::shared_ptr<AudioBuffers> audio;
+ DCPTime time;
+ int frame_rate;
+
+ DCPTimePeriod period () const {
+ return DCPTimePeriod (time, time + DCPTime::from_frames (audio->frames(), frame_rate));
}
+ };
- return b;
- }
-
- TimedAudioBuffers<T>
- flush ()
+ class BufferComparator
{
- if (_buffers->frames() == 0) {
- return TimedAudioBuffers<T> ();
+ public:
+ bool operator() (AudioMerger::Buffer const & a, AudioMerger::Buffer const & b)
+ {
+ return a.time < b.time;
}
+ };
- return TimedAudioBuffers<T> (_buffers, _last_pull);
- }
-
- void
- clear (DCPTime t)
- {
- _last_pull = t;
- _buffers.reset (new AudioBuffers (_buffers->channels(), 0));
- }
-
-private:
- boost::shared_ptr<AudioBuffers> _buffers;
- T _last_pull;
- boost::function<F (T)> _t_to_f;
- boost::function<T (F)> _f_to_t;
+ std::list<Buffer> _buffers;
+ int _frame_rate;
};