314 lines
8.9 KiB
C
314 lines
8.9 KiB
C
|
/*
|
||
|
* multitech.c
|
||
|
*
|
||
|
* Covert pvf <-> IMA ADPCM
|
||
|
*
|
||
|
* Modified for use with vgetty, Russell King (rmk@ecs.soton.ac.uk)
|
||
|
*
|
||
|
* $Id: multitech.c,v 1.3 1998/09/09 21:07:02 gert Exp $
|
||
|
*
|
||
|
*/
|
||
|
|
||
|
#include "../include/voice.h"
|
||
|
|
||
|
/***********************************************************
|
||
|
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.
|
||
|
**
|
||
|
** Change log:
|
||
|
** - Fixed a stupid bug, where the delta was computed as
|
||
|
** stepsize*code/4 in stead of stepsize*(code+0.5)/4.
|
||
|
** - There was an off-by-one error causing it to pick
|
||
|
** an incorrect delta once in a blue moon.
|
||
|
** - The NODIVMUL define has been removed. Computations are now always done
|
||
|
** using shifts, adds and subtracts. It turned out that, because the standard
|
||
|
** is defined using shift/add/subtract, you needed bits of fixup code
|
||
|
** (because the div/mul simulation using shift/add/sub made some rounding
|
||
|
** errors that real div/mul don't make) and all together the resultant code
|
||
|
** ran slower than just using the shifts all the time.
|
||
|
** - Changed some of the variable names to be more meaningful.
|
||
|
*/
|
||
|
|
||
|
#include "../include/adpcm.h"
|
||
|
#include <stdio.h> /*DBG*/
|
||
|
|
||
|
#ifndef __STDC__
|
||
|
#define signed
|
||
|
#endif
|
||
|
|
||
|
/* 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
|
||
|
};
|
||
|
|
||
|
static void
|
||
|
adpcm_coder(indata, outdata, len, state)
|
||
|
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 valprev */
|
||
|
int step; /* Stepsize */
|
||
|
int valpred; /* Predicted output value */
|
||
|
int vpdiff; /* Current change to valpred */
|
||
|
int index; /* Current step change index */
|
||
|
int outputbuffer = 0; /* place to keep previous 4-bit value */
|
||
|
int bufferstep; /* toggle between outputbuffer/output */
|
||
|
|
||
|
outp = (signed char *)outdata;
|
||
|
inp = indata;
|
||
|
|
||
|
valpred = state->valprev;
|
||
|
index = state->index;
|
||
|
step = stepsizeTable[index];
|
||
|
|
||
|
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 & 0x0f;
|
||
|
} else {
|
||
|
*outp++ = ((delta << 4) & 0xf0) | outputbuffer;
|
||
|
}
|
||
|
bufferstep = !bufferstep;
|
||
|
}
|
||
|
|
||
|
/* Output last step, if needed */
|
||
|
if ( !bufferstep )
|
||
|
*outp++ = outputbuffer;
|
||
|
|
||
|
state->valprev = valpred;
|
||
|
state->index = index;
|
||
|
}
|
||
|
|
||
|
static void
|
||
|
adpcm_decoder(indata, outdata, len, state)
|
||
|
char indata[];
|
||
|
short outdata[];
|
||
|
int len;
|
||
|
struct adpcm_state *state;
|
||
|
{
|
||
|
signed char *inp; /* Input buffer pointer */
|
||
|
short *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 = 0; /* place to keep next 4-bit value */
|
||
|
int bufferstep; /* toggle between inputbuffer/input */
|
||
|
|
||
|
outp = outdata;
|
||
|
inp = (signed char *)indata;
|
||
|
|
||
|
valpred = state->valprev;
|
||
|
index = state->index;
|
||
|
step = stepsizeTable[index];
|
||
|
|
||
|
bufferstep = 0;
|
||
|
|
||
|
for ( ; len > 0 ; len-- ) {
|
||
|
|
||
|
/* Step 1 - get the delta value */
|
||
|
if ( bufferstep ) {
|
||
|
delta = (inputbuffer >> 4) & 0xf;
|
||
|
} else {
|
||
|
inputbuffer = *inp++;
|
||
|
delta = inputbuffer & 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;
|
||
|
if ( delta & 4 ) vpdiff += step << 3;
|
||
|
if ( delta & 2 ) vpdiff += step << 2;
|
||
|
if ( delta & 1 ) vpdiff += step << 1;
|
||
|
|
||
|
if ( sign )
|
||
|
valpred -= vpdiff >> 3;
|
||
|
else
|
||
|
valpred += vpdiff >> 3;
|
||
|
|
||
|
/* 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 */
|
||
|
*outp++ = valpred;
|
||
|
}
|
||
|
|
||
|
state->valprev = valpred;
|
||
|
state->index = index;
|
||
|
}
|
||
|
|
||
|
#define SAMPLES 512
|
||
|
|
||
|
static short sbuffer[SAMPLES*2];
|
||
|
static char cbuffer[SAMPLES/2];
|
||
|
static struct adpcm_state state;
|
||
|
|
||
|
int
|
||
|
pvftoimaadpcm (FILE *fd_in, FILE *fd_out, pvf_header *header_in)
|
||
|
{
|
||
|
int i/*, j*/;
|
||
|
|
||
|
while (!feof (fd_in)) {
|
||
|
for (i = 0; !feof (fd_in) && i < SAMPLES; i++)
|
||
|
sbuffer[i] = header_in->read_pvf_data(fd_in) >> 8;
|
||
|
if (ferror (fd_in))
|
||
|
break;
|
||
|
|
||
|
adpcm_coder (sbuffer, cbuffer, i, &state);
|
||
|
|
||
|
if (fwrite (cbuffer, 1, i / 2, fd_out) != i /2)
|
||
|
return ERROR;
|
||
|
}
|
||
|
if (ferror (fd_in))
|
||
|
return ERROR;
|
||
|
return OK;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
imaadpcmtopvf (FILE *fd_in, FILE *fd_out, pvf_header *header_out)
|
||
|
{
|
||
|
int i, o/*, j*/;
|
||
|
|
||
|
while (!feof (fd_in)) {
|
||
|
i = fread (cbuffer, 1, SAMPLES / 2, fd_in);
|
||
|
|
||
|
adpcm_decoder (cbuffer, sbuffer, i * 2, &state);
|
||
|
|
||
|
for (o = 0; o < i * 2; o++)
|
||
|
header_out->write_pvf_data(fd_out, sbuffer[o] << 8);
|
||
|
|
||
|
if (ferror (fd_in))
|
||
|
break;
|
||
|
}
|
||
|
if (ferror (fd_in))
|
||
|
return ERROR;
|
||
|
return OK;
|
||
|
}
|