Adjust AudioMerger to non-signalling API.

1 files changed, 34 insertions, 29 deletions

diff --git a/src/lib/audio_merger.h b/src/lib/audio_merger.h
index 126325a9d..afb21871b 100644
--- a/src/lib/audio_merger.h
+++ b/src/lib/audio_merger.h
@@ -18,6 +18,7 @@
 */
 
 #include "audio_buffers.h"
+#include "util.h"
 
 template <class T, class F>
 class AudioMerger
@@ -25,47 +26,50 @@ 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)
+		, _next_out (0)
 		, _t_to_f (t_to_f)
 		, _f_to_t (f_to_t)
 	{}
 
-	void push (boost::shared_ptr<const AudioBuffers> audio, T time)
+	TimedAudioBuffers<T>
+	push (boost::shared_ptr<const AudioBuffers> audio, 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));
+		assert (time >= _next_out);
 
+		TimedAudioBuffers<T> out;
+		
+		if (time > _next_out) {
+			/* We can return some audio from our buffer; this is how many frames
+			   we are going to return.
+			*/
+			F const to_return = _t_to_f (time - _next_out);
+			out.audio.reset (new AudioBuffers (_buffers->channels(), to_return));
 			/* 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);
+			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 */
-			emit->make_silent (0, to_emit - to_emit_from_buffers);
+			out.audio->make_silent (0, to_return - to_return_from_buffers);
 
-			/* Emit that */
-			Audio (emit, _next_emission);
+			out.time = _next_out;
+			_next_out += _f_to_t (to_return);
 
-			_next_emission += _f_to_t (to_emit);
-
-			/* 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);
+			/* 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_emit_from_buffers);
+			_buffers->set_frames (_buffers->frames() - to_return_from_buffers);
 		}
 
 		/* 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 (_next_out));
 		_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 (_next_out), audio->frames ());
 		_buffers->set_frames (after);
+
+		return out;
 	}
 
 	F min (F a, int b)
@@ -86,18 +90,19 @@ public:
 		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, _next_out);
 	}
 	
-	boost::signals2::signal<void (boost::shared_ptr<const AudioBuffers>, T)> Audio;
-
 private:
 	boost::shared_ptr<AudioBuffers> _buffers;
-	T _next_emission;
+	T _next_out;
 	boost::function<F (T)> _t_to_f;
 	boost::function<T (F)> _f_to_t;
 };