- Implemented sound decompression for Manhole EGA

svn-id: r36048

4 files changed, 147 insertions, 10 deletions

diff --git a/engines/made/made.cpp b/engines/made/made.cpp
index a7be211ada..e225f41c17 100644
--- a/engines/made/made.cpp
+++ b/engines/made/made.cpp
@@ -112,7 +112,7 @@ MadeEngine::MadeEngine(OSystem *syst, const MadeGameDescription *gameDesc) : Eng
 		_soundRate = 11025;
 		break;
 	case GID_MANHOLE:
-		_soundRate = getVersion() == 2 ? 11025 : 4000;
+		_soundRate = 11025;
 		break;
 	case GID_LGOP2:
 		_soundRate = 8000;
@@ -249,6 +249,23 @@ void MadeEngine::handleEvents() {
 
 Common::Error MadeEngine::go() {
 
+/*
+	byte source[200000], dest[500000];
+
+	int size;
+	FILE *f = fopen("Q:\\OldGames\\scummvm\\00000003.snd", "rb");
+	size = fread(source, 1, 200000, f);
+	fclose(f);
+
+	ManholeEgaSoundDecompressor dec;
+	dec.decompress(source, dest, size);
+
+	FILE *x = fopen("Q:\\OldGames\\scummvm\\test.0", "wb");
+	fwrite(dest, size * 4, 1, x);
+	fclose(x);
+
+	return Common::kNoError;
+*/
 	resetAllTimers();
 
 	if (getGameID() == GID_RTZ) {
diff --git a/engines/made/resource.cpp b/engines/made/resource.cpp
index c3c9195204..b44c2d100c 100644
--- a/engines/made/resource.cpp
+++ b/engines/made/resource.cpp
@@ -265,16 +265,10 @@ Audio::AudioStream *SoundResource::getAudioStream(int soundRate, bool loop) {
 }
 
 void SoundResourceV1::load(byte *source, int size) {
-	// TODO: This is all wrong. Seems like the sound is compressed
-	// but where is the compression info? (chunks, chunk size)
-	
-	_soundSize = size;
+	_soundSize = size * 4;
 	_soundData = new byte[_soundSize];
-
-	// TODO: We set the audio to silent for now
-	//memcpy(_soundData, source, _soundSize);
-	memset(_soundData, 0x80, _soundSize);
-
+	ManholeEgaSoundDecompressor dec;
+	dec.decompress(source, _soundData, size);
 }
 
 /* MenuResource */
diff --git a/engines/made/sound.cpp b/engines/made/sound.cpp
index 9c59232dd2..5af514d3bc 100644
--- a/engines/made/sound.cpp
+++ b/engines/made/sound.cpp
@@ -31,6 +31,113 @@
 
 namespace Made {
 
+void ManholeEgaSoundDecompressor::decompress(byte *source, byte *dest, uint32 size) {
+	/* Some kind of ADPCM compression. I hope this works on BE machines. */
+	int newmode;
+	_source = source;
+	_dest = dest;
+	_size = size;
+	_bitBuffer = 0;
+	_bitsLeft = 0;
+	_writeFlag = false;
+	_eof = false;
+	_sample1 = 0x80000;
+ 	_sample2 = 0x800000;
+ 	_sample3 = 0x800000;
+ 	_sample4 = 0x800000;
+ 	_mode = getBit();
+ 	while (!_eof) {
+		update1();
+		update3();
+		update0();
+		newmode = getBit();
+		if (_eof)
+			break;
+		if (newmode == _mode) {
+			update1();
+			update3();
+			do {
+				update0();
+				newmode = getBit();
+				if (_eof || newmode != _mode)
+					break;
+				update2();
+				update3();
+			} while (1);
+		}
+		_mode = newmode;
+	}
+}
+
+int ManholeEgaSoundDecompressor::getBit() {
+	if (_bitsLeft == 0) {
+		if (_size == 0) {
+			_eof = true;
+			return 0;
+		}
+		_bitBuffer = READ_BE_UINT16(_source);
+		_source += 2;
+		_bitsLeft = 16;
+		_size -= 2;
+	}
+	int temp = _bitBuffer & 0x8000;
+	_bitBuffer <<= 1;
+	_bitsLeft--;
+	return temp;
+}
+
+void ManholeEgaSoundDecompressor::update0() {
+	SWAP(_sample1, _sample3);
+	if (_sample2 & 0x80000000) {
+		_sample2 -= (_sample2 >> 8) | 0xFF000000;
+	} else {
+		_sample2 -= _sample2 >> 8;
+	}
+	_sample2 += 0x8000;
+	if (_sample2 & 0x80000000) {
+		_sample2 = 0;
+	} else if ((_sample2 & 0xFFFF0000) > 0x00FF0000) {
+		_sample2 = 0xFF0000;
+	}
+	_sample1 += _sample2;
+	_sample1 >>= 1;
+	_sample1 -= _sample4;
+	_sample1 >>= 2;
+	_sample4 += _sample1;
+	if (_writeFlag) {
+		*_dest++ = (_sample4 & 0xFF0000) >> 16;
+	}
+	_writeFlag = !_writeFlag;
+	_sample1 = _sample2;
+	SWAP(_sample1, _sample3);
+}
+
+void ManholeEgaSoundDecompressor::update1() {
+	if (_sample1 & 0x80000000) {
+		_sample1 -= (_sample1 >> 8) | 0xFF000000;
+	} else {
+		_sample1 -= _sample1 >> 8;
+	}
+	_sample1 += 500;
+}
+
+void ManholeEgaSoundDecompressor::update2() {
+	uint32 temp = (_sample1 >> 6) | ((_sample1 & 0xFF) << 27) | ((_sample1 & 0xC0) >> 5);
+	if (_sample1 & 0x80000000) {
+		_sample1 += temp | 0xFC000000;
+	} else {
+		_sample1 += temp & 0x03FFFFFF;
+	}
+	_sample1 += 500;
+}
+
+void ManholeEgaSoundDecompressor::update3() {
+	if (_mode)
+		_sample2 -= _sample1;
+	else
+		_sample2 += _sample1;
+}
+
 void decompressSound(byte *source, byte *dest, uint16 chunkSize, uint16 chunkCount, SoundEnergyArray *soundEnergyArray) {
 
 	int16 prevSample = 0, workSample = 0;
diff --git a/engines/made/sound.h b/engines/made/sound.h
index 02e046ed2e..eb2157bd42 100644
--- a/engines/made/sound.h
+++ b/engines/made/sound.h
@@ -33,6 +33,25 @@
 
 namespace Made {
 
+class ManholeEgaSoundDecompressor {
+public:
+	void decompress(byte *source, byte *dest, uint32 size);
+protected:
+	byte *_source, *_dest;
+	uint32 _size;
+	uint16 _bitBuffer;
+	int _bitsLeft;
+	int32 _sample1, _sample2, _sample3, _sample4;
+	bool _writeFlag;
+	bool _eof;
+	int _mode;
+	int getBit();
+	void update0();
+	void update1();
+	void update2();
+	void update3();
+};
+
 struct SoundEnergyItem {
 	uint32 position;
 	byte energy;