mpeglayer3.cpp

This code is based on mpeg_play, available from: http://bmrc.berkeley.edu/frame/research/mpeg/

      register REAL *ts = out;
      
      REAL ta33,ta66,tb33,tb66;

      ta33=in[2*3+0]*c[3];
      ta66=in[2*6+0]*c[6];
      tb33=in[2*3+1]*c[3];
      tb66=in[2*6+1]*c[6];

      { 
	REAL tmp1a,tmp2a,tmp1b,tmp2b;
	tmp1a=          in[2*1+0]*c[1]+ta33          +in[2*5+0]*c[5]+in[2*7+0]*c[7];
	tmp1b=          in[2*1+1]*c[1]+tb33          +in[2*5+1]*c[5]+in[2*7+1]*c[7];
	tmp2a=in[2*0+0]+in[2*2+0]*c[2]+in[2*4+0]*c[4]+ta66          +in[2*8+0]*c[8];
	tmp2b=in[2*0+1]+in[2*2+1]*c[2]+in[2*4+1]*c[4]+tb66          +in[2*8+1]*c[8];
	MACRO1(0);
	MACRO2(8);
      }

      {
	REAL tmp1a,tmp2a,tmp1b,tmp2b;
	tmp1a=(in[2*1+0]-in[2*5+0]-in[2*7+0])*c[3];
	tmp1b=(in[2*1+1]-in[2*5+1]-in[2*7+1])*c[3];
	tmp2a=(in[2*2+0]-in[2*4+0]-in[2*8+0])*c[6]-in[2*6+0]+in[2*0+0];
	tmp2b=(in[2*2+1]-in[2*4+1]-in[2*8+1])*c[6]-in[2*6+1]+in[2*0+1];
	MACRO1(1);
	MACRO2(7);
      }

      {
	REAL tmp1a,tmp2a,tmp1b,tmp2b;
	tmp1a=          in[2*1+0]*c[5]-ta33          -in[2*5+0]*c[7]+in[2*7+0]*c[1];
	tmp1b=          in[2*1+1]*c[5]-tb33          -in[2*5+1]*c[7]+in[2*7+1]*c[1];
	tmp2a=in[2*0+0]-in[2*2+0]*c[8]-in[2*4+0]*c[2]+ta66          +in[2*8+0]*c[4];
	tmp2b=in[2*0+1]-in[2*2+1]*c[8]-in[2*4+1]*c[2]+tb66          +in[2*8+1]*c[4];
	MACRO1(2);
	MACRO2(6);
      }

      {
	REAL tmp1a,tmp2a,tmp1b,tmp2b;
	tmp1a=          in[2*1+0]*c[7]-ta33          +in[2*5+0]*c[1]-in[2*7+0]*c[5];
	tmp1b=          in[2*1+1]*c[7]-tb33          +in[2*5+1]*c[1]-in[2*7+1]*c[5];
	tmp2a=in[2*0+0]-in[2*2+0]*c[4]+in[2*4+0]*c[8]+ta66          -in[2*8+0]*c[2];
	tmp2b=in[2*0+1]-in[2*2+1]*c[4]+in[2*4+1]*c[8]+tb66          -in[2*8+1]*c[2];
	MACRO1(3);
	MACRO2(5);
      }

      {
        REAL sum0,sum1;
    	sum0= in[2*0+0]-in[2*2+0]+in[2*4+0]-in[2*6+0]+in[2*8+0];
    	sum1=(in[2*0+1]-in[2*2+1]+in[2*4+1]-in[2*6+1]+in[2*8+1])*hsec_36[4];
	MACRO0(4);
      }
    }
  }
}


static void dct12(REAL *in,REAL *prevblk1,REAL *prevblk2,register REAL *wi,register REAL *out)
{
#define DCT12_PART1   \
        in5=in[5*3];  \
  in5+=(in4=in[4*3]); \
  in4+=(in3=in[3*3]); \
  in3+=(in2=in[2*3]); \
  in2+=(in1=in[1*3]); \
  in1+=(in0=in[0*3]); \
                      \
  in5+=in3;in3+=in1;  \
                      \
  in2*=cos1_6;        \
  in3*=cos1_6;

#define DCT12_PART2         \
  in0+=in4*cos2_6;          \
                            \
  in4=in0+in2;              \
  in0-=in2;                 \
                            \
  in1+=in5*cos2_6;          \
                            \
  in5=(in1+in3)*hsec_12[0]; \
  in1=(in1-in3)*hsec_12[2]; \
                            \
  in3=in4+in5;              \
  in4-=in5;                 \
                            \
  in2=in0+in1;              \
  in0-=in1;

  {
    REAL in0,in1,in2,in3,in4,in5;
    register REAL *pb1=prevblk1;
    out[SBLIMIT*0]=pb1[0];out[SBLIMIT*1]=pb1[1];out[SBLIMIT*2]=pb1[2];
    out[SBLIMIT*3]=pb1[3];out[SBLIMIT*4]=pb1[4];out[SBLIMIT*5]=pb1[5];
 
    DCT12_PART1;
    
    {
      REAL tmp0,tmp1=(in0-in4);
      {
	register REAL tmp2=(in1-in5)*hsec_12[1];
	tmp0=tmp1+tmp2;
	tmp1-=tmp2;
      }
      out[(17-1)*SBLIMIT]=pb1[17-1]+tmp0*wi[11-1];
      out[(12+1)*SBLIMIT]=pb1[12+1]+tmp0*wi[ 6+1];
      out[(6 +1)*SBLIMIT]=pb1[6 +1]+tmp1*wi[ 1  ];
      out[(11-1)*SBLIMIT]=pb1[11-1]+tmp1*wi[ 5-1];
    }

    DCT12_PART2;
    out[(17-0)*SBLIMIT]=pb1[17-0]+in2*wi[11-0];
    out[(12+0)*SBLIMIT]=pb1[12+0]+in2*wi[ 6+0];
    out[(12+2)*SBLIMIT]=pb1[12+2]+in3*wi[ 6+2];
    out[(17-2)*SBLIMIT]=pb1[17-2]+in3*wi[11-2];

    out[( 6+0)*SBLIMIT]=pb1[ 6+0]+in0*wi[0];
    out[(11-0)*SBLIMIT]=pb1[11-0]+in0*wi[5-0];
    out[( 6+2)*SBLIMIT]=pb1[ 6+2]+in4*wi[2];
    out[(11-2)*SBLIMIT]=pb1[11-2]+in4*wi[5-2];
  }

  in++;
  {
    REAL in0,in1,in2,in3,in4,in5;
    register REAL *pb2 = prevblk2;
 
    DCT12_PART1;

    {
      REAL tmp0,tmp1=(in0-in4);
      {
	REAL tmp2=(in1-in5)*hsec_12[1];
	tmp0=tmp1+tmp2;
	tmp1-=tmp2;
      }
      pb2[5-1]=tmp0*wi[11-1];
      pb2[0+1]=tmp0*wi[6+1];
      out[(12+1)*SBLIMIT]+=tmp1*wi[1];
      out[(17-1)*SBLIMIT]+=tmp1*wi[5-1];
    }

    DCT12_PART2;

    pb2[5-0]=in2*wi[11-0];
    pb2[0+0]=in2*wi[6+0];
    pb2[0+2]=in3*wi[6+2];
    pb2[5-2]=in3*wi[11-2];

    out[(12+0)*SBLIMIT]+=in0*wi[0];
    out[(17-0)*SBLIMIT]+=in0*wi[5-0];
    out[(12+2)*SBLIMIT]+=in4*wi[2];
    out[(17-2)*SBLIMIT]+=in4*wi[5-2];
  }

  in++; 
  {
    REAL in0,in1,in2,in3,in4,in5;
    register REAL *pb2 = prevblk2;
    pb2[12]=pb2[13]=pb2[14]=pb2[15]=pb2[16]=pb2[17]=0.0;

    DCT12_PART1;

    {
      REAL tmp0,tmp1=(in0-in4);
      {
	REAL tmp2=(in1-in5)*hsec_12[1];
	tmp0=tmp1+tmp2;
	tmp1-=tmp2;
      }
      pb2[11-1]=tmp0*wi[11-1];
      pb2[ 6+1]=tmp0*wi[6+1];
      pb2[ 0+1]+=tmp1*wi[1];
      pb2[ 5-1]+=tmp1*wi[5-1];
    }

    DCT12_PART2;
    pb2[11-0]=in2*wi[11-0];
    pb2[ 6+0]=in2*wi[ 6+0];
    pb2[ 6+2]=in3*wi[ 6+2];
    pb2[11-2]=in3*wi[11-2];

    pb2[ 0+0]+=in0*wi[0  ];
    pb2[ 5-0]+=in0*wi[5-0];
    pb2[ 0+2]+=in4*wi[2  ];
    pb2[ 5-2]+=in4*wi[5-2];
  }
}

void MPEGaudio::layer3hybrid(int ch,int gr,REAL in[SBLIMIT][SSLIMIT],
			                   REAL out[SSLIMIT][SBLIMIT])
{
  layer3grinfo *gi=&(sideinfo.ch[ch].gr[gr]);
  int bt1,bt2;
  REAL *prev1,*prev2;

  prev1=prevblck[ch][currentprevblock][0];
  prev2=prevblck[ch][currentprevblock^1][0];

  bt1 = gi->mixed_block_flag ? 0 : gi->block_type;
  bt2 = gi->block_type;

  {
    REAL *ci=(REAL *)in,
         *co=(REAL *)out;
    int  i;

    if(downfrequency)i=(SBLIMIT/2)-2;
    else i=SBLIMIT-2;

    if(bt2==2)
    {
      if(!bt1)
      {
 	dct36(ci,prev1,prev2,win[0],co);
	ci+=SSLIMIT;prev1+=SSLIMIT;prev2+=SSLIMIT;co++;
 	dct36(ci,prev1,prev2,win[0],co);
      }
      else
      {
	dct12(ci,prev1,prev2,win[2],co);
	ci+=SSLIMIT;prev1+=SSLIMIT;prev2+=SSLIMIT;co++;
	dct12(ci,prev1,prev2,win[2],co);
      }

      do{
	ci+=SSLIMIT;prev1+=SSLIMIT;prev2+=SSLIMIT;co++;
	dct12(ci,prev1,prev2,win[2],co);
      }while(--i);
    }
    else
    {
      dct36(ci,prev1,prev2,win[bt1],co);
      ci+=SSLIMIT;prev1+=SSLIMIT;prev2+=SSLIMIT;co++;
      dct36(ci,prev1,prev2,win[bt1],co);

      do
      {
	ci+=SSLIMIT;prev1+=SSLIMIT;prev2+=SSLIMIT;co++;
	dct36(ci,prev1,prev2,win[bt2],co);
      }while(--i);
    }
  }
}

#define NEG(a)  (a)=-(a)

void MPEGaudio::extractlayer3(void)
{
  if(version)
  {
    extractlayer3_2();
    return;
  }

  {
    int main_data_end,flush_main;
    int bytes_to_discard;

    layer3getsideinfo();
	 
    if(issync())
    {
      for(register int i=layer3slots;i>0;i--)  // read main data.
	bitwindow.putbyte(getbyte());
    }
    else
    {
      for(register int i=layer3slots;i>0;i--)  // read main data.
	bitwindow.putbyte(getbits8());
    }

    main_data_end=bitwindow.gettotalbit()>>3;// of previous frame
    if (main_data_end < 0) // Fix from Michael Vogt
    {
      return;
    }

    if((flush_main=(bitwindow.gettotalbit() & 0x7)))
    {
      bitwindow.forward(8-flush_main);
      main_data_end++;
    }

    bytes_to_discard=layer3framestart-(main_data_end+sideinfo.main_data_begin);
    if(main_data_end>WINDOWSIZE)
    {
      layer3framestart-=WINDOWSIZE;
      bitwindow.rewind(WINDOWSIZE*8);
    }
  
    layer3framestart+=layer3slots;
  
    bitwindow.wrap();

    if(bytes_to_discard<0)return;
    bitwindow.forward(bytes_to_discard<<3);
  }

  for(int gr=0;gr<2;gr++)
  {
    union
    {
      int  is      [SBLIMIT][SSLIMIT];
      REAL hin  [2][SBLIMIT][SSLIMIT];
    }b1;
    union
    {
      REAL ro   [2][SBLIMIT][SSLIMIT];
      REAL lr   [2][SBLIMIT][SSLIMIT];
      REAL hout [2][SSLIMIT][SBLIMIT];
    }b2;


      layer3part2start=bitwindow.gettotalbit();
      layer3getscalefactors (LS,gr);
      layer3huffmandecode   (LS,gr      ,b1.is);
      layer3dequantizesample(LS,gr,b1.is,b2.ro[LS]);
    if(inputstereo)
    {
      layer3part2start=bitwindow.gettotalbit();
      layer3getscalefactors (RS,gr);
      layer3huffmandecode   (RS,gr      ,b1.is);
      layer3dequantizesample(RS,gr,b1.is,b2.ro[RS]);
    }

    layer3fixtostereo(gr,b2.ro);   // b2.ro -> b2.lr
    
    currentprevblock^=1;
      layer3reorderandantialias(LS,gr,b2.lr[LS],b1.hin[LS]);
      layer3hybrid (LS,gr,b1.hin[LS],b2.hout[LS]);
    if(outputstereo)
    {
      layer3reorderandantialias(RS,gr,b2.lr[RS],b1.hin[RS]);
      layer3hybrid (RS,gr,b1.hin[RS],b2.hout[RS]);

      register int i=2*SSLIMIT*SBLIMIT-1;
      do{
	NEG(b2.hout[0][0][i   ]);NEG(b2.hout[0][0][i- 2]);
	NEG(b2.hout[0][0][i- 4]);NEG(b2.hout[0][0][i- 6]);
	NEG(b2.hout[0][0][i- 8]);NEG(b2.hout[0][0][i-10]);
	NEG(b2.hout[0][0][i-12]);NEG(b2.hout[0][0][i-14]);
	NEG(b2.hout[0][0][i-16]);NEG(b2.hout[0][0][i-18]);
	NEG(b2.hout[0][0][i-20]);NEG(b2.hout[0][0][i-22]);
	NEG(b2.hout[0][0][i-24]);NEG(b2.hout[0][0][i-26]);
	NEG(b2.hout[0][0][i-28]);NEG(b2.hout[0][0][i-30]);
      }while((i-=2*SBLIMIT)>0);
    }
    else
    {
      register int i=SSLIMIT*SBLIMIT-1;
      do{
	NEG(b2.hout[0][0][i   ]);NEG(b2.hout[0][0][i- 2]);
	NEG(b2.hout[0][0][i- 4]);NEG(b2.hout[0][0][i- 6]);
	NEG(b2.hout[0][0][i- 8]);NEG(b2.hout[0][0][i-10]);
	NEG(b2.hout[0][0][i-12]);NEG(b2.hout[0][0][i-14]);
	NEG(b2.hout[0][0][i-16]);NEG(b2.hout[0][0][i-18]);
	NEG(b2.hout[0][0][i-20]);NEG(b2.hout[0][0][i-22]);
	NEG(b2.hout[0][0][i-24]);NEG(b2.hout[0][0][i-26]);
	NEG(b2.hout[0][0][i-28]);NEG(b2.hout[0][0][i-30]);
      }while((i-=2*SBLIMIT)>0);
    }

    for(int ss=0;ss<SSLIMIT;ss++)
      subbandsynthesis(b2.hout[LS][ss],b2.hout[RS][ss]);
  }
}

void MPEGaudio::extractlayer3_2(void)
{
  {
    int main_data_end,flush_main;
    int bytes_to_discard;

    layer3getsideinfo_2();
	 
    if(issync())
    {
      for(register int i=layer3slots;i>0;i--)  // read main data.
	bitwindow.putbyte(getbyte());
    }
    else
    {
      for(register int i=layer3slots;i>0;i--)  // read main data.
	bitwindow.putbyte(getbits8());
    }
    bitwindow.wrap();

    main_data_end=bitwindow.gettotalbit()>>3;// of previous frame

    if((flush_main=(bitwindow.gettotalbit() & 0x7)))
    {
      bitwindow.forward(8-flush_main);
      main_data_end++;
    }

    bytes_to_discard=layer3framestart-main_data_end-sideinfo.main_data_begin;
    if(main_data_end>WINDOWSIZE)
    {
      layer3framestart-=WINDOWSIZE;
      bitwindow.rewind(WINDOWSIZE*8);
    }
  
    layer3framestart+=layer3slots;
  
    if(bytes_to_discard<0) return;
    bitwindow.forward(bytes_to_discard<<3);
  }

  //  for(int gr=0;gr<2;gr++)
  {
    union
    {
      int  is      [SBLIMIT][SSLIMIT];
      REAL hin  [2][SBLIMIT][SSLIMIT];
    }b1;
    union
    {
      REAL ro   [2][SBLIMIT][SSLIMIT];
      REAL lr   [2][SBLIMIT][SSLIMIT];
      REAL hout [2][SSLIMIT][SBLIMIT];
    }b2;


      layer3part2start=bitwindow.gettotalbit();
      layer3getscalefactors_2(LS);
      layer3huffmandecode    (LS,0      ,b1.is);
      layer3dequantizesample (LS,0,b1.is,b2.ro[LS]);
    if(inputstereo)
    {
      layer3part2start=bitwindow.gettotalbit();
      layer3getscalefactors_2(RS);
      layer3huffmandecode    (RS,0      ,b1.is);
      layer3dequantizesample (RS,0,b1.is,b2.ro[RS]);
    }

    layer3fixtostereo(0,b2.ro);          // b2.ro -> b2.lr
    
    currentprevblock^=1;
      layer3reorderandantialias(LS,0,b2.lr[LS],b1.hin[LS]);
      layer3hybrid (LS,0,b1.hin[LS],b2.hout[LS]);
    if(outputstereo)
    {
      layer3reorderandantialias(RS,0,b2.lr[RS],b1.hin[RS]);
      layer3hybrid (RS,0,b1.hin[RS],b2.hout[RS]);

      register int i=2*SSLIMIT*SBLIMIT-1;
      do{
	NEG(b2.hout[0][0][i-16]);NEG(b2.hout[0][0][i-18]);
	NEG(b2.hout[0][0][i-20]);NEG(b2.hout[0][0][i-22]);
	NEG(b2.hout[0][0][i-24]);NEG(b2.hout[0][0][i-26]);
	NEG(b2.hout[0][0][i-28]);NEG(b2.hout[0][0][i-30]);
      }while((i-=2*SBLIMIT)>0);
    }
    else
    {
      register int i=SSLIMIT*SBLIMIT-1;
      do{
	NEG(b2.hout[0][0][i-16]);NEG(b2.hout[0][0][i-18]);
	NEG(b2.hout[0][0][i-20]);NEG(b2.hout[0][0][i-22]);
	NEG(b2.hout[0][0][i-24]);NEG(b2.hout[0][0][i-26]);
	NEG(b2.hout[0][0][i-28]);NEG(b2.hout[0][0][i-30]);
      }while((i-=2*SBLIMIT)>0);
    }

    for(int ss=0;ss<SSLIMIT;ss++)
      subbandsynthesis(b2.hout[LS][ss],b2.hout[RS][ss]);
  }
}