Some tweaks on the GP32 sound code.

svn-id: r19800

3 files changed, 102 insertions, 44 deletions

diff --git a/backends/gp32/gp32_osys.cpp b/backends/gp32/gp32_osys.cpp
index 37f8a318a5..f4a86635c8 100644
--- a/backends/gp32/gp32_osys.cpp
+++ b/backends/gp32/gp32_osys.cpp
@@ -636,7 +636,6 @@ bool OSystem_GP32::setSoundCallback(SoundProc proc, void *param) {
 	NP("OSys::setSoundCallback()");
 
 	GPSOUNDBUF gpSoundBuf;
-	PCM_SR sampleFreq;
 
 	if (ConfMan.hasKey("output_rate"))
 		_samplesPerSec = ConfMan.getInt("output_rate");
@@ -658,31 +657,19 @@ bool OSystem_GP32::setSoundCallback(SoundProc proc, void *param) {
 
 	switch(_samplesPerSec) {
 		case 44100:
-			sampleFreq = PCM_S44;
-			break;
 		case 22050:
-			sampleFreq = PCM_S22;
-			break;
 		case 11025:
-			sampleFreq = PCM_S11;
 			break;
 		default:
-			_samplesPerSec = 22050;
-			sampleFreq = PCM_S22;
+			_samplesPerSec = 11025;
 	}
 
-	gpSoundBuf.freq = sampleFreq;
-	gpSoundBuf.format = PCM_16BIT;
+	gpSoundBuf.freq = _samplesPerSec;
+	gpSoundBuf.format = 16;
+	gpSoundBuf.channels = 2;
 	gpSoundBuf.samples = samples;
 	gpSoundBuf.userdata = param;
 	gpSoundBuf.callback = proc;
-//	gpSoundBuf.pollfreq = 2 * (SAMPLES_PER_SEC / gpSoundBuf.samples);
-	gpSoundBuf.pollfreq = 2 * 4 * (SAMPLES_PER_SEC / gpSoundBuf.samples); // FIXME?
-	// Frequency of the timer interrupt which polls the playing position
-	// recommended value: 2*(playingfreq in Hz/GPSOUNDBUF.samples)
-	//s.samplesize;  // Size of one sample (8bit mono->1, 16bit stereo->4) - don't touch this
-
-	GpPcmInit(gpSoundBuf.freq, gpSoundBuf.format);
 	gp_soundBufStart(&gpSoundBuf);
 
 	// For Safety...
diff --git a/backends/gp32/gp32std_sound.cpp b/backends/gp32/gp32std_sound.cpp
index 2bef7aac3a..c235cc0af8 100644
--- a/backends/gp32/gp32std_sound.cpp
+++ b/backends/gp32/gp32std_sound.cpp
@@ -42,16 +42,61 @@ static GPSOUNDBUF soundBuf;
 // polls the current playing position within the buffer.
 
 static void soundTimer() {
+	unsigned int sampleshiftVal = soundBuf.samples << shiftVal;
 	unsigned int t = (((unsigned int)(*soundPos) - (unsigned int)buffer) >> shiftVal) >= soundBuf.samples ? 1 : 0;
 	if (t != frame) {
-		unsigned int offs = ((frame == 1) ? (soundBuf.samples << shiftVal) : 0);
-		soundBuf.callback(soundBuf.userdata, (uint8 *)((unsigned int)buffer + offs), soundBuf.samples << shiftVal);
+		unsigned int offs = ((frame == 1) ? (sampleshiftVal) : 0);
+		//memset((uint8 *)buffer + offs, 0, sampleshiftVal);
+		soundBuf.callback(soundBuf.userdata, (uint8 *)((unsigned int)buffer + offs), sampleshiftVal);
 		frame = t;
+		{
+			// Play silence
+			register uint16 *d = (uint16 *)((uint8 *)buffer + offs); // alignment-safe
+			register uint32 max = (uint32)((uint8 *)buffer + offs + sampleshiftVal);
+			do {
+				*d++ ^= 0x8000; // 1
+				*d++ ^= 0x8000; // 2
+				*d++ ^= 0x8000; // 3
+				*d++ ^= 0x8000; // 4
+				*d++ ^= 0x8000; // 5
+				*d++ ^= 0x8000; // 6
+				*d++ ^= 0x8000; // 7
+				*d++ ^= 0x8000; // 8
+				*d++ ^= 0x8000; // 9
+				*d++ ^= 0x8000; // 10
+				*d++ ^= 0x8000; // 11
+				*d++ ^= 0x8000; // 12
+				*d++ ^= 0x8000; // 13
+				*d++ ^= 0x8000; // 14
+				*d++ ^= 0x8000; // 15
+				*d++ ^= 0x8000; // 16
+				*d++ ^= 0x8000; // 17
+				*d++ ^= 0x8000; // 18
+				*d++ ^= 0x8000; // 19
+				*d++ ^= 0x8000; // 20
+				*d++ ^= 0x8000; // 21
+				*d++ ^= 0x8000; // 22
+				*d++ ^= 0x8000; // 23
+				*d++ ^= 0x8000; // 24
+				*d++ ^= 0x8000; // 25
+				*d++ ^= 0x8000; // 26
+				*d++ ^= 0x8000; // 27
+				*d++ ^= 0x8000; // 28
+				*d++ ^= 0x8000; // 29
+				*d++ ^= 0x8000; // 30
+				*d++ ^= 0x8000; // 31
+				*d++ ^= 0x8000; // 32
+			} while((uint32)d < max);
+		}
 	}
 }
 
 int gp_soundBufStart(GPSOUNDBUF *sb) {
 	int bufferSize = 0;
+
+	PCM_SR gpFreq = PCM_S11;
+	PCM_BIT gpFormat = PCM_16BIT;
+
 	frame = 0;
 
 	// Copy the structure
@@ -60,39 +105,63 @@ int gp_soundBufStart(GPSOUNDBUF *sb) {
 	// Calculate size of a single sample in bytes
 	// and a corresponding shift value
 	shiftVal = 0;
-	switch (soundBuf.freq) {
-	case PCM_S11:
-		break;
-	case PCM_S22:
+
+	switch(soundBuf.format) {
+	case 8:
+		gpFormat = PCM_8BIT;
 		break;
-	case PCM_S44:
+	case 16:
+		gpFormat = PCM_16BIT;
 		shiftVal++;
 		break;
-	case PCM_M11:
+	}
+
+	switch(soundBuf.freq) {
+	case 11025:
+		if (soundBuf.channels == 2) {
+			gpFreq = PCM_S11;
+			shiftVal++;
+		} else
+			gpFreq = PCM_M11;
 		break;
-	case PCM_M22:
+	case 22050:
+		if (soundBuf.channels == 2) {
+			gpFreq = PCM_S22;
+			shiftVal++;
+		} else
+			gpFreq = PCM_M22;
 		break;
-	case PCM_M44:
-		shiftVal++;
+	case 44100:
+		if (soundBuf.channels == 2) {
+			gpFreq = PCM_S44;
+			shiftVal++;
+		} else
+			gpFreq = PCM_M44;
 		break;
 	}
-	if (soundBuf.format == PCM_16BIT)
-		shiftVal++;
-	soundBuf.samplesize = 1 << shiftVal;
 
+	soundBuf.samplesize = 1 << shiftVal;
+	
 	// Allocate memory for the playing buffer
 	bufferSize = soundBuf.samplesize * soundBuf.samples * 2;
 	buffer = malloc(bufferSize);
-	memset(buffer, 0, bufferSize);
+
+	// Clear the buffer
+	uint16 *tmpBuf = (uint16 *)buffer;
+	for(int i = 0; i < bufferSize / 2; i++)
+		tmpBuf[i] = 0x8000;
+
+	// Frequency of the timer interrupt which polls the playing position
+	soundBuf.pollfreq = 4 * (2 * soundBuf.freq) / soundBuf.samples;
 
 	// Set timer interrupt
 	if (GpTimerOptSet(GP32_TIMER_AUDIO_IDX, soundBuf.pollfreq, 0, soundTimer) == GPOS_ERR_ALREADY_USED) {
-		NP(" Timer is already used... kill timer");
+		GPDEBUG(" Timer is already used... kill timer");
 		GpTimerKill(GP32_TIMER_AUDIO_IDX);
 	}
 	GpTimerSet(GP32_TIMER_AUDIO_IDX);
-	// Start playing
-    GpPcmInit(soundBuf.freq, soundBuf.format);
+
+	GpPcmInit(gpFreq, gpFormat);
 	GpPcmPlay((unsigned short *)buffer, bufferSize, 1);
 	GpPcmLock((unsigned short *)buffer, (int *)&idx_buf, (unsigned int *)&soundPos);
 
@@ -100,8 +169,8 @@ int gp_soundBufStart(GPSOUNDBUF *sb) {
 }
 
 void gp_soundBufStop() {
+	GpTimerKill(GP32_TIMER_AUDIO_IDX);
 	GpPcmStop();
 	GpPcmRemove((unsigned short *)buffer);
-	GpTimerKill(GP32_TIMER_AUDIO_IDX);
 	free(buffer);
 }
diff --git a/backends/gp32/gp32std_sound.h b/backends/gp32/gp32std_sound.h
index 90613029a2..41851490b7 100644
--- a/backends/gp32/gp32std_sound.h
+++ b/backends/gp32/gp32std_sound.h
@@ -29,14 +29,16 @@
 typedef void SoundProc(void *param, byte *buf, int len);
 
 typedef struct TGPSOUNDBUF {
-    PCM_SR freq;              // Taken from gpmm.h
-    PCM_BIT format;           // Taken from gpmm.h
-    unsigned int samples;     // Buffer length (in samples)
-    void *userdata;           // Userdata which gets passed to the callback function
-    SoundProc *callback;      // Callback function (just like in SDL)
-    unsigned int pollfreq;    // Frequency of the timer interrupt which polls the playing position
-                              // recommended value: 2*(playingfreq in Hz/GPSOUNDBUF.samples)
-    unsigned int samplesize;  // Size of one sample (8bit mono->1, 16bit stereo->4) - don't touch this
+	int32 freq;
+	uint16 format;
+	uint16 samples;				// Buffer length (in samples)
+	uint16 channels;
+	uint16 padding;				// Fix alignment problem
+	void *userdata;				// Userdata which gets passed to the callback function
+	SoundProc *callback;		// Callback function (just like in SDL)
+	unsigned int pollfreq;		// Frequency of the timer interrupt which polls the playing position
+								// recommended value: 2*(playingfreq in Hz/GPSOUNDBUF.samples)
+	unsigned int samplesize;	// Size of one sample (8bit mono->1, 16bit stereo->4) - don't touch this
 } GPSOUNDBUF;
 
 int gp_soundBufStart(GPSOUNDBUF *sb);