X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Faudio_merger.cc;h=74bb7717d4719fcde04d54bce70e29304435adbe;hb=fa5f3a8bf77209da27acc33cf144e2e4500a2600;hp=10a71535b4794e7e80cebe792898d5deab03ed17;hpb=2c4102e14362ef445d1b97a3aa26a889c05578c2;p=dcpomatic.git

diff --git a/src/lib/audio_merger.cc b/src/lib/audio_merger.cc
index 10a71535b..74bb7717d 100644
--- a/src/lib/audio_merger.cc
+++ b/src/lib/audio_merger.cc
@@ -17,6 +17,10 @@
 
 */
 
+/** @file  src/audio_merger.cc
+ *  @brief AudioMerger class.
+ */
+
 #include "audio_merger.h"
 #include "dcpomatic_time.h"
 #include <iostream>
@@ -29,66 +33,84 @@ using std::cout;
 using std::make_pair;
 using boost::shared_ptr;
 using boost::optional;
+using namespace dcpomatic;
 
 AudioMerger::AudioMerger (int frame_rate)
-	: _last_pull (0)
-	, _frame_rate (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;
 
-	DCPTimePeriod period (_last_pull, time);
-	_buffers.sort (AudioMerger::BufferComparator());
-
 	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(), DCPTime(time - i.time).frames_floor(_frame_rate)));
-			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);
-			new_buffers.push_back (i);
+			int32_t const overlap = frames(DCPTime(time - i.time));
+			/* Though time > i.time, overlap could be 0 if the difference in time is less than one frame */
+			if (overlap > 0) {
+				shared_ptr<AudioBuffers> audio(new AudioBuffers(i.audio, overlap, 0));
+				out.push_back (make_pair(audio, i.time));
+				i.audio->trim_start (overlap);
+				i.time += DCPTime::from_frames(overlap, _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 (time >= _last_pull);
+	DCPOMATIC_ASSERT (audio->frames() > 0);
 
 	DCPTimePeriod period (time, time + DCPTime::from_frames (audio->frames(), _frame_rate));
 
-	/* Mix any parts of this new block with existing ones */
+	/* 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 = DCPTime(overlap->from - i.time).frames_floor(_frame_rate);
-			int32_t const frames = overlap->duration().frames_floor(_frame_rate);
+			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, 0, offset);
+				i.audio->accumulate_frames(audio.get(), frames_to_mix, 0, offset);
 			} else {
-				i.audio->accumulate_frames(audio.get(), frames, offset, 0);
+				i.audio->accumulate_frames(audio.get(), frames_to_mix, offset, 0);
 			}
 		}
 	}
@@ -112,12 +134,13 @@ AudioMerger::push (boost::shared_ptr<const AudioBuffers> audio, DCPTime time)
 		}
 
 		/* Get the part of audio that we want to use */
-		shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), i.to.frames_floor(_frame_rate) - i.from.frames_floor(_frame_rate)));
-		part->copy_from (audio.get(), part->frames(), DCPTime(i.from - time).frames_floor(_frame_rate), 0);
+		shared_ptr<AudioBuffers> part (new AudioBuffers(audio, frames(i.to) - frames(i.from), frames(DCPTime(i.from - time))));
 
 		if (before == _buffers.end() && after == _buffers.end()) {
-			/* New buffer */
-			_buffers.push_back (Buffer (part, time, _frame_rate));
+			if (part->frames() > 0) {
+				/* New buffer */
+				_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);
@@ -134,3 +157,9 @@ AudioMerger::push (boost::shared_ptr<const AudioBuffers> audio, DCPTime time)
 		}
 	}
 }
+
+void
+AudioMerger::clear ()
+{
+	_buffers.clear ();
+}