db8ca37fa3
git-svn-id: https://svn.code.sf.net/p/q3cellshading/code/trunk@2 db09e94b-7117-0410-a7e6-85ae5ff6e0e9
330 lines
8.9 KiB
C
330 lines
8.9 KiB
C
/***********************************************************
|
|
Copyright 1992 by Stichting Mathematisch Centrum, Amsterdam, The
|
|
Netherlands.
|
|
|
|
All Rights Reserved
|
|
|
|
Permission to use, copy, modify, and distribute this software and its
|
|
documentation for any purpose and without fee is hereby granted,
|
|
provided that the above copyright notice appear in all copies and that
|
|
both that copyright notice and this permission notice appear in
|
|
supporting documentation, and that the names of Stichting Mathematisch
|
|
Centrum or CWI not be used in advertising or publicity pertaining to
|
|
distribution of the software without specific, written prior permission.
|
|
|
|
STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
|
|
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
|
FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
|
|
FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
|
|
OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
|
|
******************************************************************/
|
|
|
|
/*
|
|
** Intel/DVI ADPCM coder/decoder.
|
|
**
|
|
** The algorithm for this coder was taken from the IMA Compatability Project
|
|
** proceedings, Vol 2, Number 2; May 1992.
|
|
**
|
|
** Version 1.2, 18-Dec-92.
|
|
*/
|
|
|
|
#include "snd_local.h"
|
|
|
|
|
|
/* Intel ADPCM step variation table */
|
|
static int indexTable[16] = {
|
|
-1, -1, -1, -1, 2, 4, 6, 8,
|
|
-1, -1, -1, -1, 2, 4, 6, 8,
|
|
};
|
|
|
|
static int stepsizeTable[89] = {
|
|
7, 8, 9, 10, 11, 12, 13, 14, 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, 1411, 1552, 1707, 1878, 2066,
|
|
2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
|
|
5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
|
|
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
|
|
};
|
|
|
|
|
|
void S_AdpcmEncode( short indata[], char outdata[], int len, struct adpcm_state *state ) {
|
|
short *inp; /* Input buffer pointer */
|
|
signed char *outp; /* output buffer pointer */
|
|
int val; /* Current input sample value */
|
|
int sign; /* Current adpcm sign bit */
|
|
int delta; /* Current adpcm output value */
|
|
int diff; /* Difference between val and sample */
|
|
int step; /* Stepsize */
|
|
int valpred; /* Predicted output value */
|
|
int vpdiff; /* Current change to valpred */
|
|
int index; /* Current step change index */
|
|
int outputbuffer; /* place to keep previous 4-bit value */
|
|
int bufferstep; /* toggle between outputbuffer/output */
|
|
|
|
outp = (signed char *)outdata;
|
|
inp = indata;
|
|
|
|
valpred = state->sample;
|
|
index = state->index;
|
|
step = stepsizeTable[index];
|
|
|
|
outputbuffer = 0; // quiet a compiler warning
|
|
bufferstep = 1;
|
|
|
|
for ( ; len > 0 ; len-- ) {
|
|
val = *inp++;
|
|
|
|
/* Step 1 - compute difference with previous value */
|
|
diff = val - valpred;
|
|
sign = (diff < 0) ? 8 : 0;
|
|
if ( sign ) diff = (-diff);
|
|
|
|
/* Step 2 - Divide and clamp */
|
|
/* Note:
|
|
** This code *approximately* computes:
|
|
** delta = diff*4/step;
|
|
** vpdiff = (delta+0.5)*step/4;
|
|
** but in shift step bits are dropped. The net result of this is
|
|
** that even if you have fast mul/div hardware you cannot put it to
|
|
** good use since the fixup would be too expensive.
|
|
*/
|
|
delta = 0;
|
|
vpdiff = (step >> 3);
|
|
|
|
if ( diff >= step ) {
|
|
delta = 4;
|
|
diff -= step;
|
|
vpdiff += step;
|
|
}
|
|
step >>= 1;
|
|
if ( diff >= step ) {
|
|
delta |= 2;
|
|
diff -= step;
|
|
vpdiff += step;
|
|
}
|
|
step >>= 1;
|
|
if ( diff >= step ) {
|
|
delta |= 1;
|
|
vpdiff += step;
|
|
}
|
|
|
|
/* Step 3 - Update previous value */
|
|
if ( sign )
|
|
valpred -= vpdiff;
|
|
else
|
|
valpred += vpdiff;
|
|
|
|
/* Step 4 - Clamp previous value to 16 bits */
|
|
if ( valpred > 32767 )
|
|
valpred = 32767;
|
|
else if ( valpred < -32768 )
|
|
valpred = -32768;
|
|
|
|
/* Step 5 - Assemble value, update index and step values */
|
|
delta |= sign;
|
|
|
|
index += indexTable[delta];
|
|
if ( index < 0 ) index = 0;
|
|
if ( index > 88 ) index = 88;
|
|
step = stepsizeTable[index];
|
|
|
|
/* Step 6 - Output value */
|
|
if ( bufferstep ) {
|
|
outputbuffer = (delta << 4) & 0xf0;
|
|
} else {
|
|
*outp++ = (delta & 0x0f) | outputbuffer;
|
|
}
|
|
bufferstep = !bufferstep;
|
|
}
|
|
|
|
/* Output last step, if needed */
|
|
if ( !bufferstep )
|
|
*outp++ = outputbuffer;
|
|
|
|
state->sample = valpred;
|
|
state->index = index;
|
|
}
|
|
|
|
|
|
/* static */ void S_AdpcmDecode( const char indata[], short *outdata, int len, struct adpcm_state *state ) {
|
|
signed char *inp; /* Input buffer pointer */
|
|
int outp; /* output buffer pointer */
|
|
int sign; /* Current adpcm sign bit */
|
|
int delta; /* Current adpcm output value */
|
|
int step; /* Stepsize */
|
|
int valpred; /* Predicted value */
|
|
int vpdiff; /* Current change to valpred */
|
|
int index; /* Current step change index */
|
|
int inputbuffer; /* place to keep next 4-bit value */
|
|
int bufferstep; /* toggle between inputbuffer/input */
|
|
|
|
outp = 0;
|
|
inp = (signed char *)indata;
|
|
|
|
valpred = state->sample;
|
|
index = state->index;
|
|
step = stepsizeTable[index];
|
|
|
|
bufferstep = 0;
|
|
inputbuffer = 0; // quiet a compiler warning
|
|
for ( ; len > 0 ; len-- ) {
|
|
|
|
/* Step 1 - get the delta value */
|
|
if ( bufferstep ) {
|
|
delta = inputbuffer & 0xf;
|
|
} else {
|
|
inputbuffer = *inp++;
|
|
delta = (inputbuffer >> 4) & 0xf;
|
|
}
|
|
bufferstep = !bufferstep;
|
|
|
|
/* Step 2 - Find new index value (for later) */
|
|
index += indexTable[delta];
|
|
if ( index < 0 ) index = 0;
|
|
if ( index > 88 ) index = 88;
|
|
|
|
/* Step 3 - Separate sign and magnitude */
|
|
sign = delta & 8;
|
|
delta = delta & 7;
|
|
|
|
/* Step 4 - Compute difference and new predicted value */
|
|
/*
|
|
** Computes 'vpdiff = (delta+0.5)*step/4', but see comment
|
|
** in adpcm_coder.
|
|
*/
|
|
vpdiff = step >> 3;
|
|
if ( delta & 4 ) vpdiff += step;
|
|
if ( delta & 2 ) vpdiff += step>>1;
|
|
if ( delta & 1 ) vpdiff += step>>2;
|
|
|
|
if ( sign )
|
|
valpred -= vpdiff;
|
|
else
|
|
valpred += vpdiff;
|
|
|
|
/* Step 5 - clamp output value */
|
|
if ( valpred > 32767 )
|
|
valpred = 32767;
|
|
else if ( valpred < -32768 )
|
|
valpred = -32768;
|
|
|
|
/* Step 6 - Update step value */
|
|
step = stepsizeTable[index];
|
|
|
|
/* Step 7 - Output value */
|
|
outdata[outp] = valpred;
|
|
outp++;
|
|
}
|
|
|
|
state->sample = valpred;
|
|
state->index = index;
|
|
}
|
|
|
|
|
|
/*
|
|
====================
|
|
S_AdpcmMemoryNeeded
|
|
|
|
Returns the amount of memory (in bytes) needed to store the samples in out internal adpcm format
|
|
====================
|
|
*/
|
|
int S_AdpcmMemoryNeeded( const wavinfo_t *info ) {
|
|
float scale;
|
|
int scaledSampleCount;
|
|
int sampleMemory;
|
|
int blockCount;
|
|
int headerMemory;
|
|
|
|
// determine scale to convert from input sampling rate to desired sampling rate
|
|
scale = (float)info->rate / dma.speed;
|
|
|
|
// calc number of samples at playback sampling rate
|
|
scaledSampleCount = info->samples / scale;
|
|
|
|
// calc memory need to store those samples using ADPCM at 4 bits per sample
|
|
sampleMemory = scaledSampleCount / 2;
|
|
|
|
// calc number of sample blocks needed of PAINTBUFFER_SIZE
|
|
blockCount = scaledSampleCount / PAINTBUFFER_SIZE;
|
|
if( scaledSampleCount % PAINTBUFFER_SIZE ) {
|
|
blockCount++;
|
|
}
|
|
|
|
// calc memory needed to store the block headers
|
|
headerMemory = blockCount * sizeof(adpcm_state_t);
|
|
|
|
return sampleMemory + headerMemory;
|
|
}
|
|
|
|
|
|
/*
|
|
====================
|
|
S_AdpcmGetSamples
|
|
====================
|
|
*/
|
|
void S_AdpcmGetSamples(sndBuffer *chunk, short *to) {
|
|
adpcm_state_t state;
|
|
byte *out;
|
|
|
|
// get the starting state from the block header
|
|
state.index = chunk->adpcm.index;
|
|
state.sample = chunk->adpcm.sample;
|
|
|
|
out = (byte *)chunk->sndChunk;
|
|
// get samples
|
|
S_AdpcmDecode( out, to, SND_CHUNK_SIZE_BYTE*2, &state );
|
|
}
|
|
|
|
|
|
/*
|
|
====================
|
|
S_AdpcmEncodeSound
|
|
====================
|
|
*/
|
|
void S_AdpcmEncodeSound( sfx_t *sfx, short *samples ) {
|
|
adpcm_state_t state;
|
|
int inOffset;
|
|
int count;
|
|
int n;
|
|
sndBuffer *newchunk, *chunk;
|
|
byte *out;
|
|
|
|
inOffset = 0;
|
|
count = sfx->soundLength;
|
|
state.index = 0;
|
|
state.sample = samples[0];
|
|
|
|
chunk = NULL;
|
|
while( count ) {
|
|
n = count;
|
|
if( n > SND_CHUNK_SIZE_BYTE*2 ) {
|
|
n = SND_CHUNK_SIZE_BYTE*2;
|
|
}
|
|
|
|
newchunk = SND_malloc();
|
|
if (sfx->soundData == NULL) {
|
|
sfx->soundData = newchunk;
|
|
} else {
|
|
chunk->next = newchunk;
|
|
}
|
|
chunk = newchunk;
|
|
|
|
// output the header
|
|
chunk->adpcm.index = state.index;
|
|
chunk->adpcm.sample = state.sample;
|
|
|
|
out = (byte *)chunk->sndChunk;
|
|
|
|
// encode the samples
|
|
S_AdpcmEncode( samples + inOffset, out, n, &state );
|
|
|
|
inOffset += n;
|
|
count -= n;
|
|
}
|
|
}
|