[Scummvm-cvs-logs] SF.net SVN: scummvm:[54929] scummvm/trunk

[mthreepwood at users.sourceforge.net]

Revision: 54929
          http://scummvm.svn.sourceforge.net/scummvm/?rev=54929&view=rev
Author:   mthreepwood
Date:     2010-12-16 01:49:29 +0000 (Thu, 16 Dec 2010)

Log Message:
-----------
VIDEO: Remove the need to call updateAudioBuffer() externally for QuickTime

Modified Paths:
--------------
    scummvm/trunk/engines/mohawk/video.cpp
    scummvm/trunk/graphics/video/qt_decoder.cpp
    scummvm/trunk/graphics/video/qt_decoder.h

Modified: scummvm/trunk/engines/mohawk/video.cpp
===================================================================
--- scummvm/trunk/engines/mohawk/video.cpp	2010-12-16 01:41:11 UTC (rev 54928)
+++ scummvm/trunk/engines/mohawk/video.cpp	2010-12-16 01:49:29 UTC (rev 54929)
@@ -223,9 +223,6 @@
 				}
 			}
 		}
-
-		// Update the audio buffer too
-		_videoStreams[i]->updateAudioBuffer();
 	}
 
 	// Return true if we need to update the screen

Modified: scummvm/trunk/graphics/video/qt_decoder.cpp
===================================================================
--- scummvm/trunk/graphics/video/qt_decoder.cpp	2010-12-16 01:41:11 UTC (rev 54928)
+++ scummvm/trunk/graphics/video/qt_decoder.cpp	2010-12-16 01:49:29 UTC (rev 54929)
@@ -226,6 +226,9 @@
 	_curFrame++;
 	_nextFrameStartTime += getFrameDuration();
 
+	// Update the audio while we're at it
+	updateAudioBuffer();
+
 	// Get the next packet
 	uint32 descId;
 	Common::SeekableReadStream *frameData = getNextFramePacket(descId);
@@ -1277,23 +1280,49 @@
 	return NULL;
 }
 
+uint32 QuickTimeDecoder::getAudioChunkSampleCount(uint chunk) {
+	if (_audioStreamIndex < 0)
+		return 0;
+
+	uint32 sampleCount = 0;
+
+	for (uint32 j = 0; j < _streams[_audioStreamIndex]->sample_to_chunk_sz; j++)
+		if (chunk >= (_streams[_audioStreamIndex]->sample_to_chunk[j].first - 1))
+			sampleCount = _streams[_audioStreamIndex]->sample_to_chunk[j].count;
+
+	return sampleCount;
+}
+
 void QuickTimeDecoder::updateAudioBuffer() {
 	if (!_audStream)
 		return;
 
 	STSDEntry *entry = &_streams[_audioStreamIndex]->stsdEntries[0];
 
+	// Calculate the amount of chunks we need in memory until the next frame
+	uint32 timeToNextFrame = getTimeToNextFrame();
+	uint32 numberOfChunksNeeded = 0;
+	uint32 timeFilled = 0;
+	uint32 curAudioChunk = _curAudioChunk - _audStream->numQueuedStreams();
+
+	for (; timeFilled < timeToNextFrame && curAudioChunk < _streams[_audioStreamIndex]->chunk_count; numberOfChunksNeeded++, curAudioChunk++) {
+		uint32 sampleCount = getAudioChunkSampleCount(curAudioChunk);
+		assert(sampleCount);
+
+		timeFilled += sampleCount * 1000 / entry->sampleRate;
+	}
+
+	// Add a couple extra to ensure we don't underrun
+	numberOfChunksNeeded += 3;
+
 	// Keep three streams in buffer so that if/when the first two end, it goes right into the next
-	for (; _audStream->numQueuedStreams() < 3 && _curAudioChunk < _streams[_audioStreamIndex]->chunk_count; _curAudioChunk++) {
+	for (; _audStream->numQueuedStreams() < numberOfChunksNeeded && _curAudioChunk < _streams[_audioStreamIndex]->chunk_count; _curAudioChunk++) {
 		Common::MemoryWriteStreamDynamic *wStream = new Common::MemoryWriteStreamDynamic();
 
 		_fd->seek(_streams[_audioStreamIndex]->chunk_offsets[_curAudioChunk]);
 
 		// First, we have to get the sample count
-		uint32 sampleCount = 0;
-		for (uint32 j = 0; j < _streams[_audioStreamIndex]->sample_to_chunk_sz; j++)
-			if (_curAudioChunk >= (_streams[_audioStreamIndex]->sample_to_chunk[j].first - 1))
-				sampleCount = _streams[_audioStreamIndex]->sample_to_chunk[j].count;
+		uint32 sampleCount = getAudioChunkSampleCount(_curAudioChunk);
 		assert(sampleCount);
 
 		// Then calculate the right sizes

Modified: scummvm/trunk/graphics/video/qt_decoder.h
===================================================================
--- scummvm/trunk/graphics/video/qt_decoder.h	2010-12-16 01:41:11 UTC (rev 54928)
+++ scummvm/trunk/graphics/video/qt_decoder.h	2010-12-16 01:49:29 UTC (rev 54929)
@@ -116,13 +116,7 @@
 	// RewindableVideoDecoder API
 	void rewind();
 
-	// TODO: This audio function need to be removed from the public and/or added to
-	// the VideoDecoder API directly. I plan on replacing this function with something
-	// that can figure out how much audio is needed instead of constantly keeping two
-	// chunks in memory.
-	void updateAudioBuffer();
-
-protected:
+private:
 	// This is the file handle from which data is read from. It can be the actual file handle or a decompressed stream.
 	Common::SeekableReadStream *_fd;
 
@@ -245,6 +239,8 @@
 	Audio::QueuingAudioStream *_audStream;
 	void startAudio();
 	void stopAudio();
+	void updateAudioBuffer();
+	uint32 getAudioChunkSampleCount(uint chunk);
 	int8 _audioStreamIndex;
 	uint _curAudioChunk;
 	Audio::SoundHandle _audHandle;


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