Moved Oki ADPCM aka VOX decoder from SAGA engine to common sound/ directory.

Implemented IMA ADPCM decoder.

svn-id: r17903

2 files changed, 10 insertions, 110 deletions

diff --git a/saga/sound.cpp b/saga/sound.cpp
index 0a6a2bd061..9c2400fb65 100644
--- a/saga/sound.cpp
+++ b/saga/sound.cpp
@@ -26,119 +26,12 @@
 
 #include "sound/audiostream.h"
 #include "sound/mixer.h"
+#include "sound/adpcm.h"
 
 namespace Saga {
-#define BUFFER_SIZE 4096
-
-// Routines to convert 12 bit linear samples to the
-// Dialogic or Oki ADPCM coding format.
-class VOXInputStream : public AudioStream {
-private:
-	const byte *_buf;
-	uint32 _pos;
-	uint32 _inputLen;
-	bool _evenPos;
-
-	struct adpcmStatus {
-		int16 last;
-		int16 stepIndex;
-	} _status;
-
-	int16 stepAdjust(byte);
-	int16 adpcmDecode(byte);
-
-public:
-	VOXInputStream(const byte *input, int inputLen);
-	~VOXInputStream() {};
-
-	int readBuffer(int16 *buffer, const int numSamples);
-
-	bool endOfData() const	{ return _pos >= _inputLen; }
-	bool isStereo() const	{ return false; }
-	int getRate() const	{ return 22050; }
-};
-
-
-VOXInputStream::VOXInputStream(const byte *input, int inputLen)
-	: _buf(input), _pos(0), _inputLen(inputLen), _evenPos(true) {
-
-	_status.last = 0;
-	_status.stepIndex = 0;
-}
-
-int VOXInputStream::readBuffer(int16 *buffer, const int numSamples) {
-	int samples = 0;
-
-	while (samples < numSamples && !endOfData()) {
-		const int len = MIN(numSamples - samples, (int) (_inputLen - _pos));
-
-		// * 16 effectively converts 12-bit input to 16-bit output
-		for (int i = 0; i < len; i++) {
-			if (_evenPos)
-				buffer[i] = adpcmDecode((_buf[_pos] >> 4) & 0x0f) * 16;
-			else {
-				buffer[i] = adpcmDecode(_buf[_pos] & 0x0f) * 16;
-				_pos++;
-			}
-			_evenPos = !_evenPos;
-		}
-
-		samples += len;
-	}
-	return samples;
-}
-
-// adjust the step for use on the next sample.
-int16 VOXInputStream::stepAdjust(byte code) {
-	static int16 adjusts[] = {-1, -1, -1, -1, 2, 4, 6, 8};
-
-	return adjusts[code & 0x07];
-}
-
-static int16 stepSize[49] = { 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41,
-	45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173,
-	190, 209, 230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658,
-	724, 796, 876, 963, 1060, 1166, 1282, 1408, 1552 };
-
-// Decode Linear to ADPCM
-int16 VOXInputStream::adpcmDecode(byte code) {
-	int16 diff, E, SS, samp;
-
-	SS = stepSize[_status.stepIndex];
-	E = SS/8;
-	if (code & 0x01)
-		E += SS/4;
-	if (code & 0x02)
-		E += SS/2;
-	if (code & 0x04)
-		E += SS;
-	diff = (code & 0x08) ? -E : E;
-	samp = _status.last + diff;
-
-    // Clip the values to +/- 2^11 (supposed to be 12 bits)
-	if(samp > 2048)
-		samp = 2048;
-	if(samp < -2048)
-		samp = -2048;
-
-	_status.last = samp;
-	_status.stepIndex += stepAdjust(code);
-	if(_status.stepIndex < 0)
-		_status.stepIndex = 0;
-	if(_status.stepIndex > 48)
-		_status.stepIndex = 48;
-
-	return samp;
-}
-
-AudioStream *makeVOXStream(const byte *input, int size) {
-	AudioStream *audioStream = new VOXInputStream(input, size);
-
-	return audioStream;
-}
 
 Sound::Sound(SagaEngine *vm, SoundMixer *mixer, int enabled) : 
-	_vm(vm), _mixer(mixer), _enabled(enabled) {
+	_vm(vm), _mixer(mixer), _enabled(enabled), _voxStream(0) {
 
 	_soundInitialized = 1;
 	return;
@@ -149,6 +42,7 @@ Sound::~Sound() {
 		return;
 	}
 
+	delete _voxStream;
 	_soundInitialized = 0;
 }
 
@@ -220,7 +114,12 @@ int Sound::playVoice(SOUNDBUFFER *buf) {
 int Sound::playVoxVoice(SOUNDBUFFER *buf) {
 	AudioStream *audioStream;
 
-	audioStream = makeVOXStream(buf->s_buf, buf->s_buf_len);
+	if (_voxStream)
+		delete _voxStream;
+
+	_voxStream = new Common::MemoryReadStream(buf->s_buf, buf->s_buf_len);
+
+	audioStream = makeADPCMStream(*_voxStream, kADPCMOki);
 	_mixer->playInputStream(SoundMixer::kSFXSoundType, &_voiceHandle, audioStream);
 
 	return SUCCESS;
diff --git a/saga/sound.h b/saga/sound.h
index a0b73d69e0..4418583acb 100644
--- a/saga/sound.h
+++ b/saga/sound.h
@@ -71,6 +71,7 @@ public:
 
 	SagaEngine *_vm;
 	SoundMixer *_mixer;
+	Common::MemoryReadStream *_voxStream;
 
 	SoundHandle _effectHandle;
 	SoundHandle _voiceHandle;