APE reader: optimize seeking

* The APE SDK can only decode rather big chunks at a time (several
seconds), so our reader keeps an internal buffer of the last decoded
chunk.
* However, this was always dropped when seeking, meaning the same few
seconds of sound were decoded again and again.
* I'm not sure why MediaPlayer is trying to seek to the position it
already is at, but we can make it work, so why not.

Now the existing buffer is reused if possible when seeking. This makes
it possible to play APE files in MediaPlayer.

Also, several more style fixes.

src/add-ons/media/plugins/ape_reader/APEReader.cpp

@@ -81,20 +81,22 @@ TAPEReader::GetNextChunk(void* oCookie, const void** oChunkBuffer,
 	int64		aOutSize;
 
 	// check whether song is finished or not
-	if ( mReadPosTotal-mReadPos+mPlayPos >= mDataSize )
+	if (mReadPosTotal - mReadPos + mPlayPos >= mDataSize)
 		return B_ERROR;
+
 	// reading data
-	if ( mPlayPos >= mReadPos ) {
+	if (mPlayPos >= mReadPos )
 		ReadBlocks();
-	}
+
 	// passing data
-	if ( mReadPos-mPlayPos >= BUFFER_SIZE ) {
+	if (mReadPos-mPlayPos >= BUFFER_SIZE)
 		aOutSize = BUFFER_SIZE;
-	} else {
+	else
 		aOutSize = mReadPos-mPlayPos;
-	}
+
 	*oChunkBuffer = &mDecodedData[mPlayPos];
 	mPlayPos += aOutSize;
+
 	// passing info
 	*oChunkSize = aOutSize;
 	oMediaHeader->start_time = CurrentTime();
@@ -108,8 +110,9 @@ TAPEReader::GetStreamInfo(void* oCookie, int64* oFrameCount,
 	bigtime_t* oDuration, media_format* oFormat, const void** oInfoBuffer,
 	size_t* oInfoSize)
 {
-	if ( LoadAPECheck() != B_OK )
+	if (LoadAPECheck() != B_OK)
 		return LoadAPECheck();
+
 	*oFrameCount = mDataSize / (mDecomp->GetInfo(APE_INFO_BITS_PER_SAMPLE) / 8
 			* mDecomp->GetInfo(APE_INFO_CHANNELS));
 	*oDuration = mDecomp->GetInfo(APE_INFO_LENGTH_MS)
@@ -118,11 +121,11 @@ TAPEReader::GetStreamInfo(void* oCookie, int64* oFrameCount,
 	oFormat->type = B_MEDIA_RAW_AUDIO;
 	oFormat->u.raw_audio.frame_rate = mDecomp->GetInfo(APE_INFO_SAMPLE_RATE);
 	oFormat->u.raw_audio.channel_count = mDecomp->GetInfo(APE_INFO_CHANNELS);
-	if ( mDecomp->GetInfo(APE_INFO_BITS_PER_SAMPLE) == 16 ) {
+	if ( mDecomp->GetInfo(APE_INFO_BITS_PER_SAMPLE) == 16 )
 		oFormat->u.raw_audio.format = media_raw_audio_format::B_AUDIO_SHORT;
-	} else {
+	else
 		oFormat->u.raw_audio.format = media_raw_audio_format::B_AUDIO_UCHAR;
-	}
+
 	oFormat->u.raw_audio.byte_order = B_MEDIA_LITTLE_ENDIAN;
 	oFormat->u.raw_audio.buffer_size = BUFFER_SIZE;
 	oInfoBuffer = NULL;
@@ -141,12 +144,12 @@ TAPEReader::LoadAPECheck() const
 status_t
 TAPEReader::ReadBlocks()
 {
-	int		aBlocksRead;
+	int aBlocksRead;
-	int		aRetVal = 0;
+	int aRetVal = 0;
 
 	aRetVal = mDecomp->GetData(reinterpret_cast<char*>(mDecodedData),
 		BLOCK_COUNT, &aBlocksRead);
-	if ( aRetVal != ERROR_SUCCESS )
+	if (aRetVal != ERROR_SUCCESS)
 		return B_ERROR;
 
 	mPlayPos = 0;
@@ -160,12 +163,12 @@ status_t
 TAPEReader::FindKeyFrame(void* cookie, uint32 flags, int64* frame,
 	bigtime_t* time)
 {
-	if ( flags & B_MEDIA_SEEK_TO_FRAME ) {
+	if (flags & B_MEDIA_SEEK_TO_FRAME) {
 		*time = *frame * 1000 /  mDecomp->GetInfo(APE_DECOMPRESS_TOTAL_BLOCKS)
 			* mDecomp->GetInfo(APE_DECOMPRESS_LENGTH_MS);
 		printf("FindKeyFrame for frame %Ld: %Ld\n", *frame, *time);
-	} else if ( flags & B_MEDIA_SEEK_TO_TIME ) {
+	} else if (flags & B_MEDIA_SEEK_TO_TIME) {
-		*frame = (*time)/1000*mDecomp->GetInfo(APE_DECOMPRESS_TOTAL_BLOCKS)
+		*frame = (*time) / 1000 * mDecomp->GetInfo(APE_DECOMPRESS_TOTAL_BLOCKS)
 			/ mDecomp->GetInfo(APE_DECOMPRESS_LENGTH_MS);
 		printf("FindKeyFrame for time %Ld: %Ld\n", *time, *frame);
 	} else
@@ -178,21 +181,28 @@ TAPEReader::FindKeyFrame(void* cookie, uint32 flags, int64* frame,
 status_t
 TAPEReader::Seek(void *cookie, uint32 flags, int64 *frame, bigtime_t *time)
 {
-	int32		aNewBlock;
+	int32 aNewBlock;
 
-	if ( flags & B_MEDIA_SEEK_TO_FRAME ) {
+	if (flags & B_MEDIA_SEEK_TO_FRAME) {
 		printf("Seek to frame %Ld\n", *frame);
 		aNewBlock = *frame;
-	} else if ( flags & B_MEDIA_SEEK_TO_TIME ) {
+	} else if (flags & B_MEDIA_SEEK_TO_TIME) {
 		printf("Seek for time %Ld\n", *time);
-		aNewBlock = (*time)/1000*mDecomp->GetInfo(APE_DECOMPRESS_TOTAL_BLOCKS)
+		aNewBlock = (*time) / 1000 * mDecomp->GetInfo(APE_DECOMPRESS_TOTAL_BLOCKS)
 			/ mDecomp->GetInfo(APE_DECOMPRESS_LENGTH_MS);
 	} else
 		return B_ERROR;
 
-	mReadPosTotal = aNewBlock*mDecomp->GetInfo(APE_INFO_BLOCK_ALIGN);
+	int64 aNewTime = aNewBlock * mDecomp->GetInfo(APE_INFO_BLOCK_ALIGN);
-	mDecomp->Seek(aNewBlock);
+	if (mReadPosTotal - mReadPos < aNewTime && mReadPosTotal > aNewTime) {
-	ReadBlocks();
+		// Requested seek frame is already in the current buffer, no need to
+		// actually seek, just set the play position
+		mPlayPos = aNewTime - mReadPosTotal + mReadPos;
+	} else {
+		mReadPosTotal = aNewBlock * mDecomp->GetInfo(APE_INFO_BLOCK_ALIGN);
+		mDecomp->Seek(aNewBlock);
+		ReadBlocks();
+	}
 	return B_OK;
 }
 
@@ -203,12 +213,14 @@ TAPEReader::Sniff(int32* oStreamCount)
 	Unset();
 	// prepare about file
 	mSrcPIO = dynamic_cast<BPositionIO*>(Source());
-	if ( mSrcPIO == NULL )
+	if (mSrcPIO == NULL)
 		return B_ERROR;
+
 	mPositionBridgeIO.SetPositionIO(mSrcPIO);
 	mDecomp = CreateIAPEDecompressEx(&mPositionBridgeIO);
-	if ( mDecomp == NULL )
+	if (mDecomp == NULL)
 		return B_ERROR;
+
 	// prepare about data
 	mDataSize = static_cast<int64>(mDecomp->GetInfo(APE_DECOMPRESS_TOTAL_BLOCKS))
 			*mDecomp->GetInfo(APE_INFO_BLOCK_ALIGN);

src/add-ons/media/plugins/ape_reader/APEReader.h

@@ -1,23 +1,24 @@
 #ifndef	___APEReader_H_
 #define	___APEReader_H_
-//------------------------------------------------------------------------------
+
-// BeOS
+
-// MAC
 #include "MACLib.h"
 #include "MonkeysAudioMIMEType.h"
 #include "PositionBridgeIO.h"
-// Proj
+
 #include "ReaderPlugin.h"		// Haiku private header
-//------------------------------------------------------------------------------
+
-const int32		BLOCK_COUNT = 1024*4;				// number of blocks, get from MACLib at once
+
-const int32		BUFFER_SIZE = 1024*4;				// size of audio data passing to Media Kit
+const int32		BLOCK_COUNT = 1024*4;	// number of blocks, get from MACLib at once
+const int32		BUFFER_SIZE = 1024*4;	// size of audio data passing to Media Kit
 const int32		MEDIA_FILE_FORMAT_VERSION = 100;	// media_file_format::version
-//==============================================================================
+
+
 class	TAPEReader : public Reader
 {
 public:
 	TAPEReader();
-	virtual	~TAPEReader();
+	virtual				~TAPEReader();
 
 	virtual	const char*	Copyright();
 
@@ -28,16 +29,18 @@ public:
 	virtual	status_t	AllocateCookie(int32 oStreamNumber, void** oCookie);
 	virtual	status_t	FreeCookie(void* oCookie);
 
-	virtual	status_t	GetStreamInfo(void* oCookie, int64* oFrameCount, bigtime_t* oDuration, media_format* oFormat,
+	virtual	status_t	GetStreamInfo(void* oCookie, int64* oFrameCount,
-								const void** oInfoBuffer, size_t* oInfoSize);
+							bigtime_t* oDuration, media_format* oFormat,
+							const void** oInfoBuffer, size_t* oInfoSize);
 
 	virtual	status_t		Seek(void *cookie, uint32 flags,
-					 			int64 *frame, bigtime_t *time);
+								int64 *frame, bigtime_t *time);
 
 	virtual	status_t		FindKeyFrame(void* cookie, uint32 flags,
 								int64* frame, bigtime_t* time);
 
-	virtual	status_t	GetNextChunk(void* oCookie, const void** oChunkBuffer, size_t* oChunkSize, media_header* oMediaHeader);
+	virtual	status_t	GetNextChunk(void* oCookie, const void** oChunkBuffer,
+								size_t* oChunkSize, media_header* oMediaHeader);
 
 private:
 	typedef	Reader	SUPER;
@@ -57,7 +60,8 @@ private:
 	IAPEDecompress*		mDecomp;
 	TPositionBridgeIO	mPositionBridgeIO;
 };
-//==============================================================================
+
+
 class	TAPEReaderPlugin : public ReaderPlugin
 {
 public:
@@ -66,7 +70,9 @@ public:
 
 	virtual	Reader*	NewReader();
 };
-//==============================================================================
+
+
 MediaPlugin*	instantiate_plugin();
-//==============================================================================
+
+
 #endif	// ___APEReader_H_