mpeglayer3.cpp

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

/* MPEG/WAVE Sound library

   (C) 1997 by Jung woo-jae */

// Mpeglayer3.cc
// It's for MPEG Layer 3
// I've made array of superior functions for speed.
// Extend TO_FOUR_THIRDS to negative.
// Bug fix : maplay 1.2+ have wrong TO_FOUR_THIRDS ranges.
// Force to mono!!
// MPEG-2 is implemented
// Speed up in fixstereo (maybe buggy) 

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <math.h>
#include <stdlib.h>

#include "MPEGaudio.h"
#if defined(_WIN32) && defined(_MSC_VER)
// disable warnings about double to float conversions
#pragma warning(disable: 4244 4305)
#endif

inline void Mpegbitwindow::wrap(void)
{
  int p=bitindex>>3;
  point&=(WINDOWSIZE-1);

  if(p>=point)
  {
    for(register int i=4;i<point;i++)
      buffer[WINDOWSIZE+i]=buffer[i];
  }
  *((int *)(buffer+WINDOWSIZE))=*((int *)buffer);
}

#define MUL3(a) (((a)<<1)+(a))

#define REAL0 0

#define ARRAYSIZE (SBLIMIT*SSLIMIT)
#define REALSIZE (sizeof(REAL))

#ifdef PI
#undef PI
#endif
#define PI     3.141593
#define PI_12  (PI/12.0)
#define PI_18  (PI/18.0)
#define PI_24  (PI/24.0)
#define PI_36  (PI/36.0)
#define PI_72  (PI/72.0)

#ifdef NATIVE_ASSEMBLY
inline void long_memset(void * s,unsigned int c,int count)
{
__asm__ __volatile__(
  "cld\n\t"
  "rep ; stosl\n\t"
  : /* no output */
  :"a" (c), "c" (count/4), "D" ((long) s)
  :"cx","di","memory");
}
#endif

#define FOURTHIRDSTABLENUMBER (1<<13)

static REAL two_to_negative_half_pow[40];
static REAL TO_FOUR_THIRDSTABLE[FOURTHIRDSTABLENUMBER*2];
static REAL POW2[256];
static REAL POW2_1[8][2][16];
static REAL ca[8],cs[8];



static REAL cos1_6=cos(PI/6.0*1.0);
static REAL cos2_6=cos(PI/6.0*2.0);
static REAL win[4][36];
static REAL cos_18[9];
static REAL hsec_36[9],hsec_12[3];

typedef struct
{
  REAL l,r;
}RATIOS;

static RATIOS rat_1[16],rat_2[2][64];

void MPEGaudio::layer3initialize(void)
{
  static bool initializedlayer3=false;
  register int i;
  int j,k,l;
#if 0
	double td = 0.0;
printf( "%f\n", td );
    //pow( 0.0, 1.333333 );
printf( "A\n" );
    pow( td, 1.333333 );
printf( "B\n" );
#endif

  layer3framestart=0;
  currentprevblock=0;

  {
    for(l=0;l<2;l++)
      for(i=0;i<2;i++)
	for(j=0;j<SBLIMIT;j++)
	  for(k=0;k<SSLIMIT;k++)
	    prevblck[l][i][j][k]=0.0f;
  }

  bitwindow.initialize();

  if(initializedlayer3)return;

  // Calculate win
  {
    for(i=0;i<18;i++)
      win[0][i]=win[1][i]=0.5*sin(PI_72*(double)(2*i+1))/cos(PI_72*(double)(2*i+19));
    for(;i<36;i++)
      win[0][i]=win[3][i]=0.5*sin(PI_72*(double)(2*i+1))/cos(PI_72*(double)(2*i+19));

    for(i=0;i<6;i++)
    {
      win[1][i+18]=0.5/cos(PI_72*(double)(2*(i+18)+19));
      win[3][i+12]=0.5/cos(PI_72*(double)(2*(i+12)+19));
      win[1][i+24]=0.5*sin(PI_24*(double)(2*i+13))/cos(PI_72*(double)(2*(i+24)+19));
      win[1][i+30]=win[3][i]=0.0;
      win[3][i+6 ]=0.5*sin(PI_24*(double)(2*i+1))/cos(PI_72*(double)(2*(i+6)+19));
    }
    for(i=0;i<12;i++)
      win[2][i]=0.5*sin(PI_24*(double)(2*i+1))/cos(PI_24*(double)(2*i+7));
  }

  for(i=0;i<9;i++)
    cos_18[i]=cos(PI_18*double(i));
  for(i=0;i<9;i++)
    hsec_36[i]=0.5/cos(PI_36*double(i*2+1));
  for(i=0;i<3;i++)
    hsec_12[i]=0.5/cos(PI_12*double(i*2+1));

  for(i=0;i<40;i++)
    two_to_negative_half_pow[i]=(REAL)pow(2.0,-0.5*(double)i);

  {
    REAL *TO_FOUR_THIRDS=TO_FOUR_THIRDSTABLE+FOURTHIRDSTABLENUMBER;

//KR
    for( i = 0; i < FOURTHIRDSTABLENUMBER; i++ )
	{
      TO_FOUR_THIRDS[-i]= -(TO_FOUR_THIRDS[i] = (REAL)pow((double)i,4.0/3.0));
	}
  }

  for(i=0;i<256;i++)POW2[i]=(REAL)pow(2.0,(0.25*(i-210.0)));
  for(i=0;i<8;i++)
    for(j=0;j<2;j++)
      for(k=0;k<16;k++)POW2_1[i][j][k]=pow(2.0,(-2.0*i)-(0.5*(1.0+j)*k));

  {
    static REAL TAN12[16]=
    { 0.0,        0.26794919, 0.57735027  , 1.0,
      1.73205081, 3.73205081, 9.9999999e10,-3.73205081,
      -1.73205081,-1.01,      -0.57735027,  -0.26794919,
      0.0,        0.26794919, 0.57735027,   1.0};

    for(i=0;i<16;i++)
    {
      rat_1[i].l=TAN12[i]/(1.0+TAN12[i]);
      rat_1[i].r=1.0/(1.0+TAN12[i]);
    }
  }

#define IO0 ((double)0.840896415256)
#define IO1 ((double)0.707106781188)
  rat_2[0][0].l=rat_2[0][0].r=
  rat_2[1][0].l=rat_2[1][0].r=1.;

  for(i=1;i<64;i++)
    if((i%2)==1)
    {
      rat_2[0][i].l=pow(IO0,(i+1)/2);
      rat_2[1][i].l=pow(IO1,(i+1)/2);
      rat_2[0][i].r=
      rat_2[1][i].r=1.;
    }
    else
    {
      rat_2[0][i].l=
      rat_2[1][i].l=1.;
      rat_2[0][i].r=pow(IO0,i/2);
      rat_2[1][i].r=pow(IO1,i/2);
    }

  {
    static REAL Ci[8]=
    {-0.6f,-0.535f,-0.33f,-0.185f,-0.095f,-0.041f,-0.0142f,-0.0037f};
    REAL sq;

    for(int i=0;i<8;i++)
    {
      sq=sqrt(1.0f+Ci[i]*Ci[i]);
      cs[i]=1.0f/sq;
      ca[i]=Ci[i]*cs[i];
    }
  }

  initializedlayer3=true;
}

bool MPEGaudio::layer3getsideinfo(void)
{
  sideinfo.main_data_begin=getbits(9);

  if(!inputstereo)sideinfo.private_bits=getbits(5);
  else sideinfo.private_bits=getbits(3);
  
    sideinfo.ch[LS].scfsi[0]=getbit();
    sideinfo.ch[LS].scfsi[1]=getbit();
    sideinfo.ch[LS].scfsi[2]=getbit();
    sideinfo.ch[LS].scfsi[3]=getbit();
  if(inputstereo)
  {
    sideinfo.ch[RS].scfsi[0]=getbit();
    sideinfo.ch[RS].scfsi[1]=getbit();
    sideinfo.ch[RS].scfsi[2]=getbit();
    sideinfo.ch[RS].scfsi[3]=getbit();
  }

  for(int gr=0,ch;gr<2;gr++)
    for(ch=0;;ch++)
    {
      layer3grinfo *gi=&(sideinfo.ch[ch].gr[gr]);

      gi->part2_3_length       =getbits(12);
      gi->big_values           =getbits(9);
      gi->global_gain          =getbits(8);
      gi->scalefac_compress    =getbits(4);
      gi->window_switching_flag=getbit();
      if(gi->window_switching_flag)
      {
	gi->block_type      =getbits(2);
	gi->mixed_block_flag=getbit();
	
	gi->table_select[0] =getbits(5);
	gi->table_select[1] =getbits(5);
	
	gi->subblock_gain[0]=getbits(3);
	gi->subblock_gain[1]=getbits(3);
	gi->subblock_gain[2]=getbits(3);
	
	/* Set region_count parameters since they are implicit in this case. */
	if(gi->block_type==0)
	{
	  /* printf("Side info bad: block_type == 0 in split block.\n");
	     exit(0); */
	  return false;
	}
	else if (gi->block_type==2 && gi->mixed_block_flag==0)
	     gi->region0_count=8; /* MI 9; */
	else gi->region0_count=7; /* MI 8; */
	gi->region1_count=20-(gi->region0_count);
      }
      else
      {
	gi->table_select[0] =getbits(5);
	gi->table_select[1] =getbits(5);
	gi->table_select[2] =getbits(5);
	gi->region0_count   =getbits(4);
	gi->region1_count   =getbits(3);
	gi->block_type      =0;
      }
      gi->preflag           =getbit();
      gi->scalefac_scale    =getbit();
      gi->count1table_select=getbit();

      gi->generalflag=gi->window_switching_flag && (gi->block_type==2);

      if(!inputstereo || ch)break;
    }

  return true;
}

bool MPEGaudio::layer3getsideinfo_2(void)
{
  sideinfo.main_data_begin=getbits(8);

  if(!inputstereo)sideinfo.private_bits=getbit();
  else sideinfo.private_bits=getbits(2);
  
  for(int ch=0;;ch++)
  {
    layer3grinfo *gi=&(sideinfo.ch[ch].gr[0]);

    gi->part2_3_length       =getbits(12);
    gi->big_values           =getbits(9);
    gi->global_gain          =getbits(8);
    gi->scalefac_compress    =getbits(9);
    gi->window_switching_flag=getbit();
    if(gi->window_switching_flag)
    {
      gi->block_type      =getbits(2);
      gi->mixed_block_flag=getbit();

      gi->table_select[0] =getbits(5);
      gi->table_select[1] =getbits(5);
	
      gi->subblock_gain[0]=getbits(3);
      gi->subblock_gain[1]=getbits(3);
      gi->subblock_gain[2]=getbits(3);
	
      /* Set region_count parameters since they are implicit in this case. */
      if(gi->block_type==0)
      {
	/* printf("Side info bad: block_type == 0 in split block.\n");
	   exit(0); */
	return false;
      }
      else if (gi->block_type==2 && gi->mixed_block_flag==0)
	gi->region0_count=8; /* MI 9; */
      else gi->region0_count=7; /* MI 8; */
      gi->region1_count=20-(gi->region0_count);
    }
    else
    {
      gi->table_select[0] =getbits(5);
      gi->table_select[1] =getbits(5);
      gi->table_select[2] =getbits(5);
      gi->region0_count   =getbits(4);
      gi->region1_count   =getbits(3);
      gi->block_type      =0;
    }
    gi->scalefac_scale    =getbit();
    gi->count1table_select=getbit();
    
    gi->generalflag=gi->window_switching_flag && (gi->block_type==2);
    
    if(!inputstereo || ch)break;
  }

  return true;
}

void MPEGaudio::layer3getscalefactors(int ch,int gr)
{
  static int slen[2][16]={{0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4},
			  {0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3}};

  layer3grinfo *gi=&(sideinfo.ch[ch].gr[gr]);
  register layer3scalefactor *sf=(&scalefactors[ch]);
  int l0,l1;

  {
    int scale_comp=gi->scalefac_compress;

    l0=slen[0][scale_comp];
    l1=slen[1][scale_comp];
  }  
  if(gi->generalflag)
  {
    if(gi->mixed_block_flag)
    {                                 /* MIXED */ /* NEW-ag 11/25 */
      sf->l[0]=wgetbits9(l0);sf->l[1]=wgetbits9(l0);
      sf->l[2]=wgetbits9(l0);sf->l[3]=wgetbits9(l0);
      sf->l[4]=wgetbits9(l0);sf->l[5]=wgetbits9(l0);
      sf->l[6]=wgetbits9(l0);sf->l[7]=wgetbits9(l0);

      sf->s[0][ 3]=wgetbits9(l0);sf->s[1][ 3]=wgetbits9(l0);
      sf->s[2][ 3]=wgetbits9(l0);
      sf->s[0][ 4]=wgetbits9(l0);sf->s[1][ 4]=wgetbits9(l0);
      sf->s[2][ 4]=wgetbits9(l0);
      sf->s[0][ 5]=wgetbits9(l0);sf->s[1][ 5]=wgetbits9(l0);
      sf->s[2][ 5]=wgetbits9(l0);

      sf->s[0][ 6]=wgetbits9(l1);sf->s[1][ 6]=wgetbits9(l1);
      sf->s[2][ 6]=wgetbits9(l1);
      sf->s[0][ 7]=wgetbits9(l1);sf->s[1][ 7]=wgetbits9(l1);
      sf->s[2][ 7]=wgetbits9(l1);
      sf->s[0][ 8]=wgetbits9(l1);sf->s[1][ 8]=wgetbits9(l1);
      sf->s[2][ 8]=wgetbits9(l1);
      sf->s[0][ 9]=wgetbits9(l1);sf->s[1][ 9]=wgetbits9(l1);
      sf->s[2][ 9]=wgetbits9(l1);
      sf->s[0][10]=wgetbits9(l1);sf->s[1][10]=wgetbits9(l1);
      sf->s[2][10]=wgetbits9(l1);
      sf->s[0][11]=wgetbits9(l1);sf->s[1][11]=wgetbits9(l1);
      sf->s[2][11]=wgetbits9(l1);

      sf->s[0][12]=sf->s[1][12]=sf->s[2][12]=0;
    }
    else 
    {  /* SHORT*/
      sf->s[0][ 0]=wgetbits9(l0);sf->s[1][ 0]=wgetbits9(l0);
      sf->s[2][ 0]=wgetbits9(l0);
      sf->s[0][ 1]=wgetbits9(l0);sf->s[1][ 1]=wgetbits9(l0);
      sf->s[2][ 1]=wgetbits9(l0);
      sf->s[0][ 2]=wgetbits9(l0);sf->s[1][ 2]=wgetbits9(l0);
      sf->s[2][ 2]=wgetbits9(l0);
      sf->s[0][ 3]=wgetbits9(l0);sf->s[1][ 3]=wgetbits9(l0);
      sf->s[2][ 3]=wgetbits9(l0);
      sf->s[0][ 4]=wgetbits9(l0);sf->s[1][ 4]=wgetbits9(l0);
      sf->s[2][ 4]=wgetbits9(l0);
      sf->s[0][ 5]=wgetbits9(l0);sf->s[1][ 5]=wgetbits9(l0);
      sf->s[2][ 5]=wgetbits9(l0);

      sf->s[0][ 6]=wgetbits9(l1);sf->s[1][ 6]=wgetbits9(l1);
      sf->s[2][ 6]=wgetbits9(l1);
      sf->s[0][ 7]=wgetbits9(l1);sf->s[1][ 7]=wgetbits9(l1);
      sf->s[2][ 7]=wgetbits9(l1);
      sf->s[0][ 8]=wgetbits9(l1);sf->s[1][ 8]=wgetbits9(l1);
      sf->s[2][ 8]=wgetbits9(l1);
      sf->s[0][ 9]=wgetbits9(l1);sf->s[1][ 9]=wgetbits9(l1);
      sf->s[2][ 9]=wgetbits9(l1);
      sf->s[0][10]=wgetbits9(l1);sf->s[1][10]=wgetbits9(l1);
      sf->s[2][10]=wgetbits9(l1);
      sf->s[0][11]=wgetbits9(l1);sf->s[1][11]=wgetbits9(l1);
      sf->s[2][11]=wgetbits9(l1);

      sf->s[0][12]=sf->s[1][12]=sf->s[2][12]=0;
    }
  }
  else
  {   /* LONG types 0,1,3 */
    if(gr==0)
    {
      sf->l[ 0]=wgetbits9(l0);sf->l[ 1]=wgetbits9(l0);
      sf->l[ 2]=wgetbits9(l0);sf->l[ 3]=wgetbits9(l0);
      sf->l[ 4]=wgetbits9(l0);sf->l[ 5]=wgetbits9(l0);
      sf->l[ 6]=wgetbits9(l0);sf->l[ 7]=wgetbits9(l0);
      sf->l[ 8]=wgetbits9(l0);sf->l[ 9]=wgetbits9(l0);
      sf->l[10]=wgetbits9(l0);
      sf->l[11]=wgetbits9(l1);sf->l[12]=wgetbits9(l1);
      sf->l[13]=wgetbits9(l1);sf->l[14]=wgetbits9(l1);
      sf->l[15]=wgetbits9(l1);
      sf->l[16]=wgetbits9(l1);sf->l[17]=wgetbits9(l1);
      sf->l[18]=wgetbits9(l1);sf->l[19]=wgetbits9(l1);
      sf->l[20]=wgetbits9(l1);
    }
    else
    {
      if(sideinfo.ch[ch].scfsi[0]==0)
      {
	sf->l[ 0]=wgetbits9(l0);sf->l[ 1]=wgetbits9(l0);
	sf->l[ 2]=wgetbits9(l0);sf->l[ 3]=wgetbits9(l0);
	sf->l[ 4]=wgetbits9(l0);sf->l[ 5]=wgetbits9(l0);
      }
      if(sideinfo.ch[ch].scfsi[1]==0)
      {
	sf->l[ 6]=wgetbits9(l0);sf->l[ 7]=wgetbits9(l0);
	sf->l[ 8]=wgetbits9(l0);sf->l[ 9]=wgetbits9(l0);
	sf->l[10]=wgetbits9(l0);
      }
      if(sideinfo.ch[ch].scfsi[2]==0)
      {
	sf->l[11]=wgetbits9(l1);sf->l[12]=wgetbits9(l1);
	sf->l[13]=wgetbits9(l1);sf->l[14]=wgetbits9(l1);
	sf->l[15]=wgetbits9(l1);
      }
      if(sideinfo.ch[ch].scfsi[3]==0)
      {
	sf->l[16]=wgetbits9(l1);sf->l[17]=wgetbits9(l1);
	sf->l[18]=wgetbits9(l1);sf->l[19]=wgetbits9(l1);
	sf->l[20]=wgetbits9(l1);
      }
    }
    sf->l[21]=sf->l[22]=0;
  }
}