Xash3DArchive/engine/snd_wavelet.c

//=======================================================================
//			Copyright XashXT Group 2007 ©
//			 snd_wavelet.c - wave decoder
//=======================================================================

#include "client.h"
#include "snd_loc.h"

#define C0 0.4829629131445341
#define C1 0.8365163037378079
#define C2 0.2241438680420134
#define C3 -0.1294095225512604

void daub4(float b[], dword n, int isign)
{
	float	wksp[4097];
	float	*a=b-1; // numerical recipies so a[1] = b[0]
	dword	nh,nh1,i,j;

	if (n < 4) return;

	nh1 = (nh = n>>1)+1;
	if (isign >= 0)
	{
		for (i = 1, j = 1; j <= n - 3; j += 2, i++)
		{
			wksp[i] = C0*a[j]+C1*a[j+1]+C2*a[j+2]+C3*a[j+3];
			wksp[i+nh] = C3*a[j]-C2*a[j+1]+C1*a[j+2]-C0*a[j+3];
		}
		wksp[i] = C0*a[n-1]+C1*a[n]+C2*a[1]+C3*a[2];
		wksp[i+nh] = C3*a[n-1]-C2*a[n]+C1*a[1]-C0*a[2];
	}
	else
	{
		wksp[1] = C2*a[nh]+C1*a[n]+C0*a[1]+C3*a[nh1];
		wksp[2] = C3*a[nh]-C0*a[n]+C1*a[1]-C2*a[nh1];
		for (i = 1, j = 3; i < nh; i++)
		{
			wksp[j++] = C2*a[i]+C1*a[i+nh]+C0*a[i+1]+C3*a[i+nh1];
			wksp[j++] = C3*a[i]-C0*a[i+nh]+C1*a[i+1]-C2*a[i+nh1];
		}
	}
	for (i = 1; i <= n; i++) a[i] = wksp[i];
}

void wt1(float a[], dword n, int isign)
{
	dword	nn;
	int	inverseStartLength = n/4;
	if (n < inverseStartLength) return;
	if (isign >= 0) for (nn = n; nn >= inverseStartLength; nn >>= 1) daub4(a, nn, isign);
	else for (nn = inverseStartLength; nn <= n; nn <<= 1) daub4(a, nn, isign);
}

// The number of bits required by each value
static byte numBits[] =
{
0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
};

byte MuLawEncode(short s)
{
	dword	adjusted;
	byte	sign, exponent, mantissa;

	sign = (s < 0) ? 0:0x80;

	if (s < 0) s = -s;
	adjusted = (long)s<<(16-sizeof(short)*8);
	adjusted += 128L + 4L;
	if (adjusted > 32767) adjusted = 32767;
	exponent = numBits[(adjusted>>7)&0xff] - 1;
	mantissa = (adjusted>>(exponent+3))&0xf;
	return ~(sign | (exponent<<4) | mantissa);
}

short MuLawDecode(byte uLaw)
{
	signed long adjusted;
	byte exponent, mantissa;

	uLaw = ~uLaw;
	exponent = (uLaw>>4) & 0x7;
	mantissa = (uLaw&0xf) + 16;
	adjusted = (mantissa << (exponent +3)) - 128 - 4;

	return (uLaw & 0x80)? adjusted : -adjusted;
}

short mulawToShort[256];
static bool madeTable = false;
static int NXStreamCount;

void NXPutc(NXStream *stream, char out)
{
	stream[NXStreamCount++] = out;
}

void encodeWavelet( sfx_t *sfx, short *packets)
{
	float	wksp[4097], temp;
	int	i, samples, size;
	sndBuffer	*newchunk, *chunk;
	byte	*out;

	if (!madeTable)
	{
		for (i = 0; i < 256; i++) mulawToShort[i] = (float)MuLawDecode((byte)i);
		madeTable = true;
	}
	chunk = NULL;

	samples = sfx->soundLength;
	while(samples > 0)
	{
		size = samples;
		if(size > (SND_CHUNK_SIZE*2)) size = (SND_CHUNK_SIZE*2);
		if(size < 4) size = 4;

		newchunk = SND_malloc();
		if (sfx->soundData == NULL) sfx->soundData = newchunk;
		else chunk->next = newchunk;
		chunk = newchunk;
		for(i = 0; i < size; i++)
		{
			wksp[i] = *packets;
			packets++;
		}
		wt1(wksp, size, 1);
		out = (byte *)chunk->sndChunk;

		for(i = 0; i < size; i++)
		{
			temp = wksp[i];
			if (temp > 32767) temp = 32767; else if (temp<-32768) temp = -32768;
			out[i] = MuLawEncode((short)temp);
		}
		chunk->size = size;
		samples -= size;
	}
}

void decodeWavelet(sndBuffer *chunk, short *to)
{
	float	wksp[4097];
	int	i, size = chunk->size;
	byte	*out;
	
	out = (byte *)chunk->sndChunk;
	for(i = 0; i < size; i++) wksp[i] = mulawToShort[out[i]];

	wt1(wksp, size, -1);
	if(!to) return;

	for(i = 0; i < size; i++) to[i] = wksp[i];
}

void encodeMuLaw( sfx_t *sfx, short *packets)
{
	int	i, samples, size, grade, poop;
	sndBuffer	*newchunk, *chunk;
	byte	*out;

	if (!madeTable)
	{
		for (i = 0; i < 256; i++)
		{
			mulawToShort[i] = (float)MuLawDecode((byte)i);
		}
		madeTable = true;
	}

	chunk = NULL;
	samples = sfx->soundLength;
	grade = 0;

	while(samples > 0)
	{
		size = samples;
		if (size > (SND_CHUNK_SIZE * 2)) size = (SND_CHUNK_SIZE * 2);

		newchunk = SND_malloc();
		if (sfx->soundData == NULL) sfx->soundData = newchunk;
		else chunk->next = newchunk;
		chunk = newchunk;
		out = (byte *)chunk->sndChunk;
		for(i = 0; i < size; i++)
		{
			poop = packets[0]+grade;
			if (poop > 32767) poop = 32767;
			else if (poop<-32768) poop = -32768;
			out[i] = MuLawEncode((short)poop);
			grade = poop - mulawToShort[out[i]];
			packets++;
		}
		chunk->size = size;
		samples -= size;
	}
}

void decodeMuLaw(sndBuffer *chunk, short *to)
{
	byte	*out;
	int	i, size = chunk->size;
	
	out = (byte *)chunk->sndChunk;
	for(i = 0; i < size; i++) to[i] = mulawToShort[out[i]];
}