www.pudn.com > MyPlayerbylqh.rar > decode_i386.cpp

 
//mpeg 1,2,3²ãÉùÒô½âÂë 
#include  
#include  
#include  
 
#include "mpg123.h" 
#include "mpglib.h" 
 
extern struct mpstr *gmp; 
 
 
#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_1to1_mono(real *bandPtr,unsigned char *samples,int *pnt) 
{ 
  short samples_tmp[64]; 
  short *tmp1 = samples_tmp; 
  int i,ret; 
  int pnt1 = 0; 
 
  ret = synth_1to1(bandPtr,0,(unsigned char *) samples_tmp,&pnt1); 
  samples += *pnt; 
 
  for(i=0;i<32;i++) { 
    *( (short *) samples) = *tmp1; 
    samples += 2; 
    tmp1 += 2; 
  } 
  *pnt += 64; 
 
  return ret; 
} 
 
 
int synth_1to1(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; 
 
  bo = gmp->synth_bo; 
 
  if(!channel) { 
    bo--; 
    bo &= 0xf; 
    buf = gmp->synth_buffs[0]; 
  } 
  else { 
    samples++; 
    buf = gmp->synth_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); 
  } 
 
  gmp->synth_bo = bo; 
   
  { 
    register int j; 
    real *window = decwin + 16 - bo1; 
 
    for (j=16;j;j--,b0+=0x10,window+=0x20,samples+=step) 
    { 
      real sum; 
      sum  = window[0x0] * b0[0x0]; 
      sum -= window[0x1] * b0[0x1]; 
      sum += window[0x2] * b0[0x2]; 
      sum -= window[0x3] * b0[0x3]; 
      sum += window[0x4] * b0[0x4]; 
      sum -= window[0x5] * b0[0x5]; 
      sum += window[0x6] * b0[0x6]; 
      sum -= window[0x7] * b0[0x7]; 
      sum += window[0x8] * b0[0x8]; 
      sum -= window[0x9] * b0[0x9]; 
      sum += window[0xA] * b0[0xA]; 
      sum -= window[0xB] * b0[0xB]; 
      sum += window[0xC] * b0[0xC]; 
      sum -= window[0xD] * b0[0xD]; 
      sum += window[0xE] * b0[0xE]; 
      sum -= window[0xF] * b0[0xF]; 
 
      WRITE_SAMPLE(samples,sum,clip); 
    } 
 
    { 
      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); 
      b0-=0x10,window-=0x20,samples+=step; 
    } 
    window += bo1<<1; 
 
    for (j=15;j;j--,b0-=0x10,window-=0x20,samples+=step) 
    { 
      real sum; 
      sum = -window[-0x1] * b0[0x0]; 
      sum -= window[-0x2] * b0[0x1]; 
      sum -= window[-0x3] * b0[0x2]; 
      sum -= window[-0x4] * b0[0x3]; 
      sum -= window[-0x5] * b0[0x4]; 
      sum -= window[-0x6] * b0[0x5]; 
      sum -= window[-0x7] * b0[0x6]; 
      sum -= window[-0x8] * b0[0x7]; 
      sum -= window[-0x9] * b0[0x8]; 
      sum -= window[-0xA] * b0[0x9]; 
      sum -= window[-0xB] * b0[0xA]; 
      sum -= window[-0xC] * b0[0xB]; 
      sum -= window[-0xD] * b0[0xC]; 
      sum -= window[-0xE] * b0[0xD]; 
      sum -= window[-0xF] * b0[0xE]; 
      sum -= window[-0x0] * b0[0xF]; 
 
      WRITE_SAMPLE(samples,sum,clip); 
    } 
  } 
  *pnt += 128; 
 
  return clip; 
}