*/
#include "audio_buffers.h"
+#include "util.h"
template <class T, class F>
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))
- , _next_emission (0)
+ , _last_pull (0)
, _t_to_f (t_to_f)
, _f_to_t (f_to_t)
{}
- void push (boost::shared_ptr<const AudioBuffers> audio, T time)
+ /** 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)
{
- if (time > _next_emission) {
- /* We can emit some audio from our buffer; this is how many frames
- we are going to emit.
- */
- F const to_emit = _t_to_f (time - _next_emission);
- boost::shared_ptr<AudioBuffers> emit (new AudioBuffers (_buffers->channels(), to_emit));
-
- /* And this is how many we will get from our buffer */
- F const to_emit_from_buffers = min (to_emit, _buffers->frames ());
-
- /* Copy the data that we have to the back end of `emit' */
- emit->copy_from (_buffers.get(), to_emit_from_buffers, 0, to_emit - to_emit_from_buffers);
-
- /* Silence any gap at the start */
- emit->make_silent (0, to_emit - to_emit_from_buffers);
-
- /* Emit that */
- Audio (emit, _next_emission);
+ 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);
- _next_emission += _f_to_t (to_emit);
+ return out;
+ }
- /* And remove the data we've emitted from our buffers */
- if (_buffers->frames() > to_emit_from_buffers) {
- _buffers->move (to_emit_from_buffers, 0, _buffers->frames() - to_emit_from_buffers);
- }
- _buffers->set_frames (_buffers->frames() - to_emit_from_buffers);
- }
+ void
+ push (boost::shared_ptr<const AudioBuffers> audio, T time)
+ {
+ assert (time >= _last_pull);
- /* Now accumulate the new audio into our buffers */
F frame = _t_to_f (time);
- F after = max (_buffers->frames(), frame + audio->frames() - _t_to_f (_next_emission));
+ 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 (_next_emission), audio->frames ());
+ _buffers->accumulate_frames (audio.get(), 0, frame - _t_to_f (_last_pull), audio->frames ());
_buffers->set_frames (after);
}
return b;
}
- void flush ()
+ TimedAudioBuffers<T>
+ flush ()
{
- if (_buffers->frames() > 0) {
- Audio (_buffers, _next_emission);
+ if (_buffers->frames() == 0) {
+ return TimedAudioBuffers<T> ();
}
+
+ return TimedAudioBuffers<T> (_buffers, _last_pull);
}
- boost::signals2::signal<void (boost::shared_ptr<const AudioBuffers>, T)> Audio;
-
private:
boost::shared_ptr<AudioBuffers> _buffers;
- T _next_emission;
+ T _last_pull;
boost::function<F (T)> _t_to_f;
boost::function<T (F)> _f_to_t;
};