[Scummvm-cvs-logs] SF.net SVN: scummvm:[48506] scummvm/branches/branch-1-1-0/sound/decoders/ raw.cpp

[lordhoto at users.sourceforge.net]

Revision: 48506
          http://scummvm.svn.sourceforge.net/scummvm/?rev=48506&view=rev
Author:   lordhoto
Date:     2010-04-04 10:24:31 +0000 (Sun, 04 Apr 2010)

Log Message:
-----------
Restore slightly tweaked RawMemoryStream to fix bug #2961787: "HE SAM1: Music in kitchen slightly off (regression)".

The mentioned tweak is only the removal of the templated "stereo" parameter
like it was done for RawStream, thus that is totally safe and saves some
binary size. Note that I was unable to test whether the HE regression was
really fixed, since I do not have any of the affected games and the Moonbase
Commander demo does not work for me. I tried the RawMemoryStream code with
KYRA and it worked fine.

Modified Paths:
--------------
    scummvm/branches/branch-1-1-0/sound/decoders/raw.cpp

Modified: scummvm/branches/branch-1-1-0/sound/decoders/raw.cpp
===================================================================
--- scummvm/branches/branch-1-1-0/sound/decoders/raw.cpp	2010-04-04 10:09:49 UTC (rev 48505)
+++ scummvm/branches/branch-1-1-0/sound/decoders/raw.cpp	2010-04-04 10:24:31 UTC (rev 48506)
@@ -40,7 +40,83 @@
 #define READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, ptr, isLE) \
 	((is16Bit ? (isLE ? READ_LE_UINT16(ptr) : READ_BE_UINT16(ptr)) : (*ptr << 8)) ^ (isUnsigned ? 0x8000 : 0))
 
+#pragma mark -
+#pragma mark --- RawMemoryStream ---
+#pragma mark -
 
+/**
+ * A simple raw audio stream, purely memory based. It operates on a single
+ * block of data, which is passed to it upon creation.
+ * Optionally supports looping the sound.
+ *
+ * Design note: This code tries to be as efficient as possible (without
+ * resorting to assembly, that is). To this end, it is written as a template
+ * class. This way the compiler can create optimized code for each special
+ * case. This results in a total of 12 versions of the code being generated.
+ */
+template<bool is16Bit, bool isUnsigned, bool isLE>
+class RawMemoryStream : public SeekableAudioStream {
+protected:
+	const byte *_ptr;
+	const byte *_end;
+	const int _rate;
+	const byte *_origPtr;
+	const DisposeAfterUse::Flag _disposeAfterUse;
+	const Timestamp _playtime;
+	const bool _isStereo;
+
+public:
+	RawMemoryStream(int rate, bool stereo, const byte *ptr, uint len, DisposeAfterUse::Flag autoFreeMemory)
+	    : _ptr(ptr), _end(ptr+len), _rate(rate), _origPtr(ptr),
+	      _disposeAfterUse(autoFreeMemory),
+	      _playtime(0, len / (is16Bit ? 2 : 1) / (stereo ? 2 : 1), rate),
+	      _isStereo(stereo) {
+	}
+
+	virtual ~RawMemoryStream() {
+		if (_disposeAfterUse == DisposeAfterUse::YES)
+			free(const_cast<byte *>(_origPtr));
+	}
+
+	int readBuffer(int16 *buffer, const int numSamples);
+
+	bool isStereo() const			{ return _isStereo; }
+	bool endOfData() const			{ return _ptr >= _end; }
+
+	int getRate() const				{ return _rate; }
+	bool seek(const Timestamp &where);
+	Timestamp getLength() const { return _playtime; }
+};
+
+template<bool is16Bit, bool isUnsigned, bool isLE>
+int RawMemoryStream<is16Bit, isUnsigned, isLE>::readBuffer(int16 *buffer, const int numSamples) {
+	int samples = numSamples;
+	while (samples > 0 && _ptr < _end) {
+		int len = MIN(samples, (int)(_end - _ptr) / (is16Bit ? 2 : 1));
+		samples -= len;
+		do {
+			*buffer++ = READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, _ptr, isLE);
+			_ptr += (is16Bit ? 2 : 1);
+		} while (--len);
+	}
+	return numSamples-samples;
+}
+
+template<bool is16Bit, bool isUnsigned, bool isLE>
+bool RawMemoryStream<is16Bit, isUnsigned, isLE>::seek(const Timestamp &where) {
+	const uint8 *ptr = _origPtr + convertTimeToStreamPos(where, getRate(), isStereo()).totalNumberOfFrames() * (is16Bit ? 2 : 1);
+	if (ptr > _end) {
+		_ptr = _end;
+		return false;
+	} else if (ptr == _end) {
+		_ptr = _end;
+		return true;
+	} else {
+		_ptr = ptr;
+		return true;
+	}
+}
+
 #pragma mark -
 #pragma mark --- RawStream ---
 #pragma mark -
@@ -283,10 +359,34 @@
 	return makeRawStream(stream, blocks, rate, flags, disposeAfterUse);
 }
 
+#define MAKE_LINEAR(UNSIGNED) \
+		if (is16Bit) { \
+			if (isLE) \
+				return new RawMemoryStream<true, UNSIGNED, true>(rate, isStereo, buffer, size, disposeAfterUse); \
+			else  \
+				return new RawMemoryStream<true, UNSIGNED, false>(rate, isStereo, buffer, size, disposeAfterUse); \
+		} else \
+			return new RawMemoryStream<false, UNSIGNED, false>(rate, isStereo, buffer, size, disposeAfterUse)
+
 SeekableAudioStream *makeRawStream(const byte *buffer, uint32 size,
                                    int rate, byte flags,
                                    DisposeAfterUse::Flag disposeAfterUse) {
-	return makeRawStream(new Common::MemoryReadStream(buffer, size, disposeAfterUse), rate, flags, DisposeAfterUse::YES);
+	const bool isStereo   = (flags & Audio::FLAG_STEREO) != 0;
+	const bool is16Bit    = (flags & Audio::FLAG_16BITS) != 0;
+	const bool isUnsigned = (flags & Audio::FLAG_UNSIGNED) != 0;
+	const bool isLE       = (flags & Audio::FLAG_LITTLE_ENDIAN) != 0;
+
+	// Verify the buffer sizes are sane
+	if (is16Bit && isStereo) {
+		assert((size & 3) == 0);
+	} else if (is16Bit || isStereo) {
+		assert((size & 1) == 0);
+	}
+
+	if (isUnsigned)
+		MAKE_LINEAR(true);
+	else
+		MAKE_LINEAR(false);
 }
 
 SeekableAudioStream *makeRawDiskStream_OLD(Common::SeekableReadStream *stream, RawStreamBlock *block, int numBlocks,


This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.