123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288 |
- /*
- * 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 <stdlib.h>
- #include <math.h>
- #include <string.h>
- #include "mpg123.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;
- void synth_ntom_set_step(long m,long n)
- {
- if(param.verbose > 1)
- fprintf(stderr,"Init rate converter: %ld->%ld\n",m,n);
- if(n >= 96000 || m >= 96000 || m == 0 || n == 0) {
- fprintf(stderr,"NtoM converter: illegal rates\n");
- exit(1);
- }
- n *= NTOM_MUL;
- ntom_step = n / m;
- if(ntom_step > 8*NTOM_MUL) {
- fprintf(stderr,"max. 1:8 conversion allowed!\n");
- exit(1);
- }
- ntom_val[0] = ntom_val[1] = NTOM_MUL>>1;
- }
- int synth_ntom_8bit(real *bandPtr,int channel,unsigned char *samples,int *pnt)
- {
- short samples_tmp[8*64];
- short *tmp1 = samples_tmp + channel;
- int i,ret;
- int pnt1 = 0;
- ret = synth_ntom(bandPtr,channel,(unsigned char *) samples_tmp,&pnt1);
- samples += channel + *pnt;
- for(i=0;i<(pnt1>>2);i++) {
- *samples = conv16to8[*tmp1>>AUSHIFT];
- samples += 2;
- tmp1 += 2;
- }
- *pnt += pnt1>>1;
- return ret;
- }
- int synth_ntom_8bit_mono(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(bandPtr,0,(unsigned char *) samples_tmp,&pnt1);
- samples += *pnt;
- for(i=0;i<(pnt1>>2);i++) {
- *samples++ = conv16to8[*tmp1>>AUSHIFT];
- tmp1 += 2;
- }
- *pnt += pnt1 >> 2;
-
- return ret;
- }
- int synth_ntom_8bit_mono2stereo(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(bandPtr,0,(unsigned char *) samples_tmp,&pnt1);
- samples += *pnt;
- for(i=0;i<(pnt1>>2);i++) {
- *samples++ = conv16to8[*tmp1>>AUSHIFT];
- *samples++ = conv16to8[*tmp1>>AUSHIFT];
- tmp1 += 2;
- }
- *pnt += pnt1 >> 1;
- return ret;
- }
- int synth_ntom_mono(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(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_mono2stereo(real *bandPtr,unsigned char *samples,int *pnt)
- {
- int i,ret;
- int pnt1 = *pnt;
- ret = synth_ntom(bandPtr,0,samples,pnt);
- samples += pnt1;
-
- for(i=0;i<((*pnt-pnt1)>>2);i++) {
- ((short *)samples)[1] = ((short *)samples)[0];
- samples+=4;
- }
- return ret;
- }
- int synth_ntom(real *bandPtr,int channel,unsigned char *out,int *pnt)
- {
- static real buffs[2][2][0x110];
- static const int step = 2;
- static int bo = 1;
- short *samples = (short *) (out + *pnt);
- real *b0,(*buf)[0x110];
- int clip = 0;
- int bo1;
- int ntom;
- if(equalfile)
- do_equalizer(bandPtr,channel);
- if(!channel) {
- bo--;
- bo &= 0xf;
- buf = buffs[0];
- ntom = ntom_val[1] = ntom_val[0];
- }
- else {
- samples++;
- out += 2; /* to compute the right *pnt value */
- buf = 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);
- }
- {
- register int j;
- real *window = 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;
- }
|