diff options
Diffstat (limited to 'mpg123_artsplugin/mpg123/decode_2to1.c')
| -rw-r--r-- | mpg123_artsplugin/mpg123/decode_2to1.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/mpg123_artsplugin/mpg123/decode_2to1.c b/mpg123_artsplugin/mpg123/decode_2to1.c new file mode 100644 index 00000000..2eb5e07d --- /dev/null +++ b/mpg123_artsplugin/mpg123/decode_2to1.c @@ -0,0 +1,233 @@ +/* + * Mpeg Layer-1,2,3 audio decoder + * ------------------------------ + * copyright (c) 1995 by Michael Hipp, All rights reserved. See also 'README' + * version for slower machines .. decodes only every second sample + * sounds like 24000,22050 or 16000 kHz .. (depending on original sample freq.) + * + */ + +#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; } + +int synth_2to1_8bit(real *bandPtr,int channel,unsigned char *samples,int *pnt) +{ + short samples_tmp[32]; + short *tmp1 = samples_tmp + channel; + int i,ret; + int pnt1 = 0; + + ret = synth_2to1(bandPtr,channel,(unsigned char *) samples_tmp,&pnt1); + samples += channel + *pnt; + + for(i=0;i<16;i++) { + *samples = conv16to8[*tmp1>>AUSHIFT]; + samples += 2; + tmp1 += 2; + } + *pnt += 32; + + return ret; +} + +int synth_2to1_8bit_mono(real *bandPtr,unsigned char *samples,int *pnt) +{ + short samples_tmp[32]; + short *tmp1 = samples_tmp; + int i,ret; + int pnt1 = 0; + + ret = synth_2to1(bandPtr,0,(unsigned char *) samples_tmp,&pnt1); + samples += *pnt; + + for(i=0;i<16;i++) { + *samples++ = conv16to8[*tmp1>>AUSHIFT]; + tmp1 += 2; + } + *pnt += 16; + + return ret; +} + + +int synth_2to1_8bit_mono2stereo(real *bandPtr,unsigned char *samples,int *pnt) +{ + short samples_tmp[32]; + short *tmp1 = samples_tmp; + int i,ret; + int pnt1 = 0; + + ret = synth_2to1(bandPtr,0,(unsigned char *) samples_tmp,&pnt1); + samples += *pnt; + + for(i=0;i<16;i++) { + *samples++ = conv16to8[*tmp1>>AUSHIFT]; + *samples++ = conv16to8[*tmp1>>AUSHIFT]; + tmp1 += 2; + } + *pnt += 32; + + return ret; +} + +int synth_2to1_mono(real *bandPtr,unsigned char *samples,int *pnt) +{ + short samples_tmp[32]; + short *tmp1 = samples_tmp; + int i,ret; + int pnt1=0; + + ret = synth_2to1(bandPtr,0,(unsigned char *) samples_tmp,&pnt1); + samples += *pnt; + + for(i=0;i<16;i++) { + *( (short *) samples) = *tmp1; + samples += 2; + tmp1 += 2; + } + *pnt += 32; + + return ret; +} + +int synth_2to1_mono2stereo(real *bandPtr,unsigned char *samples,int *pnt) +{ + int i,ret; + + ret = synth_2to1(bandPtr,0,samples,pnt); + samples = samples + *pnt - 64; + + for(i=0;i<16;i++) { + ((short *)samples)[1] = ((short *)samples)[0]; + samples+=4; + } + + return ret; +} + +int synth_2to1(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; + +#ifndef NO_EQUALIZER + if(param.enable_equalizer) + do_equalizer(bandPtr,channel); +#endif + + if(!channel) { + bo--; + bo &= 0xf; + buf = buffs[0]; + } + else { + samples++; + buf = buffs[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=8;j;j--,b0+=0x10,window+=0x30) + { + real sum; + 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++; + + WRITE_SAMPLE(samples,sum,clip); samples += step; +#if 0 + WRITE_SAMPLE(samples,sum,clip); samples += step; +#endif + } + + { + 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]; + WRITE_SAMPLE(samples,sum,clip); samples += step; +#if 0 + WRITE_SAMPLE(samples,sum,clip); samples += step; +#endif + b0-=0x20,window-=0x40; + } + window += bo1<<1; + + for (j=7;j;j--,b0-=0x30,window-=0x30) + { + real sum; + 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++; + + WRITE_SAMPLE(samples,sum,clip); samples += step; +#if 0 + WRITE_SAMPLE(samples,sum,clip); samples += step; +#endif + } + } + + *pnt += 64; + + return clip; +} + + |