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/*
* Mpeg Layer-1,2,3 audio decoder
* ------------------------------
* copyright (c) 1995,1996,1997 by Michael Hipp, All rights reserved.
* See also 'README'
*
* N->M down/up sampling. Not optimized for speed.
*/
#include "asterisk.h"
#include "asterisk/logger.h"
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "mpg123.h"
#include "mpglib.h"
#define WRITE_SAMPLE(samples,sum,clip) \
if( (sum) > 32767.0) { *(samples) = 0x7fff; (clip)++; } \
else if( (sum) < -32768.0) { *(samples) = -0x8000; (clip)++; } \
else { *(samples) = sum; }
#define NTOM_MUL (32768)
static unsigned long ntom_val[2] = { NTOM_MUL>>1,NTOM_MUL>>1 };
static unsigned long ntom_step = NTOM_MUL;
int synth_ntom_set_step(long m,long n)
{
if(param.verbose > 1)
ast_log(LOG_WARNING,"Init rate converter: %ld->%ld\n",m,n);
if(n >= 96000 || m >= 96000 || m == 0 || n == 0) {
ast_log(LOG_WARNING,"NtoM converter: illegal rates\n");
return (1);
}
n *= NTOM_MUL;
ntom_step = n / m;
if(ntom_step > 8*NTOM_MUL) {
ast_log(LOG_WARNING,"max. 1:8 conversion allowed!\n");
return (1);
}
ntom_val[0] = ntom_val[1] = NTOM_MUL>>1;
return (0);
}
int synth_ntom_mono (struct mpstr *mp, real *bandPtr,unsigned char *samples,int *pnt)
{
short samples_tmp[8*64];
short *tmp1 = samples_tmp;
int i,ret;
int pnt1 = 0;
ret = synth_ntom(mp, bandPtr,0,(unsigned char *) samples_tmp,&pnt1);
samples += *pnt;
for(i=0;i<(pnt1>>2);i++) {
*( (short *)samples) = *tmp1;
samples += 2;
tmp1 += 2;
}
*pnt += pnt1 >> 1;
return ret;
}
int synth_ntom(struct mpstr *mp, real *bandPtr,int channel,unsigned char *out,int *pnt)
{
static const int step = 2;
int bo;
short *samples = (short *) (out + *pnt);
real *b0,(*buf)[0x110];
int clip = 0;
int bo1;
int ntom;
bo = mp->synth_bo;
if(!channel) {
bo--;
bo &= 0xf;
buf = mp->synth_buffs[0];
ntom = ntom_val[1] = ntom_val[0];
}
else {
samples++;
out += 2; /* to compute the right *pnt value */
buf = mp->synth_buffs[1];
ntom = ntom_val[1];
}
if(bo & 0x1) {
b0 = buf[0];
bo1 = bo;
dct64(buf[1]+((bo+1)&0xf),buf[0]+bo,bandPtr);
}
else {
b0 = buf[1];
bo1 = bo+1;
dct64(buf[0]+bo,buf[1]+bo+1,bandPtr);
}
mp->synth_bo = bo;
{
register int j;
real *window = (mp->decwin) + 16 - bo1;
for (j=16;j;j--,window+=0x10)
{
real sum;
ntom += ntom_step;
if(ntom < NTOM_MUL) {
window += 16;
b0 += 16;
continue;
}
sum = *window++ * *b0++;
sum -= *window++ * *b0++;
sum += *window++ * *b0++;
sum -= *window++ * *b0++;
sum += *window++ * *b0++;
sum -= *window++ * *b0++;
sum += *window++ * *b0++;
sum -= *window++ * *b0++;
sum += *window++ * *b0++;
sum -= *window++ * *b0++;
sum += *window++ * *b0++;
sum -= *window++ * *b0++;
sum += *window++ * *b0++;
sum -= *window++ * *b0++;
sum += *window++ * *b0++;
sum -= *window++ * *b0++;
while(ntom >= NTOM_MUL) {
WRITE_SAMPLE(samples,sum,clip);
samples += step;
ntom -= NTOM_MUL;
}
}
ntom += ntom_step;
if(ntom >= NTOM_MUL)
{
real sum;
sum = window[0x0] * b0[0x0];
sum += window[0x2] * b0[0x2];
sum += window[0x4] * b0[0x4];
sum += window[0x6] * b0[0x6];
sum += window[0x8] * b0[0x8];
sum += window[0xA] * b0[0xA];
sum += window[0xC] * b0[0xC];
sum += window[0xE] * b0[0xE];
while(ntom >= NTOM_MUL) {
WRITE_SAMPLE(samples,sum,clip);
samples += step;
ntom -= NTOM_MUL;
}
}
b0-=0x10,window-=0x20;
window += bo1<<1;
for (j=15;j;j--,b0-=0x20,window-=0x10)
{
real sum;
ntom += ntom_step;
if(ntom < NTOM_MUL) {
window -= 16;
b0 += 16;
continue;
}
sum = -*(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
sum -= *(--window) * *b0++;
while(ntom >= NTOM_MUL) {
WRITE_SAMPLE(samples,sum,clip);
samples += step;
ntom -= NTOM_MUL;
}
}
}
ntom_val[channel] = ntom;
*pnt = ((unsigned char *) samples - out);
return clip;
}
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