mp3internals.cpp

网络MPEG4IP流媒体开发源代码

/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

This library is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
more details.

You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2001 Live Networks, Inc.  All rights reserved.
// MP3 internal implementation details
// Implementation


#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#include "MP3Internals.hh"

// This is crufty old code that needs to be cleaned up #####

unsigned tabsel_123[2][3][16] = {
   { {32,32,64,96,128,160,192,224,256,288,320,352,384,416,448,448},
     {32,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,384},
     {32,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,320} },

   { {32,32,48,56,64,80,96,112,128,144,160,176,192,224,256,256},
     {8,8,16,24,32,40,48,56,64,80,96,112,128,144,160,160},
     {8,8,16,24,32,40,48,56,64,80,96,112,128,144,160,160} }
};
/* Note: tabsel_123[*][*][0 or 15] shouldn't occur; use dummy values there */

long freqs[7] = { 44100, 48000, 32000, 22050, 24000, 16000 , 11025 };

static float ispow[8207];
static float aa_ca[8], aa_cs[8];
static float COS1[12][6];
static float win[4][36];
static float win1[4][36];
static float COS9[9];
static float COS6_1,COS6_2;
static float tfcos36[9];
static float tfcos12[3];

int longLimit[7][23];
int shortLimit[7][14];
struct bandInfoStruct {
  int longIdx[23];
  int longDiff[22];
  int shortIdx[14];
  int shortDiff[13];
};

struct bandInfoStruct bandInfo[7] = { 
/* MPEG 1.0 */
 { {0,4,8,12,16,20,24,30,36,44,52,62,74, 90,110,134,162,196,238,288,342,418,576},
   {4,4,4,4,4,4,6,6,8, 8,10,12,16,20,24,28,34,42,50,54, 76,158},
   {0,4*3,8*3,12*3,16*3,22*3,30*3,40*3,52*3,66*3, 84*3,106*3,136*3,192*3},
   {4,4,4,4,6,8,10,12,14,18,22,30,56} } ,

 { {0,4,8,12,16,20,24,30,36,42,50,60,72, 88,106,128,156,190,230,276,330,384,576},
   {4,4,4,4,4,4,6,6,6, 8,10,12,16,18,22,28,34,40,46,54, 54,192},
   {0,4*3,8*3,12*3,16*3,22*3,28*3,38*3,50*3,64*3, 80*3,100*3,126*3,192*3},
   {4,4,4,4,6,6,10,12,14,16,20,26,66} } ,

 { {0,4,8,12,16,20,24,30,36,44,54,66,82,102,126,156,194,240,296,364,448,550,576} ,
   {4,4,4,4,4,4,6,6,8,10,12,16,20,24,30,38,46,56,68,84,102, 26} ,
   {0,4*3,8*3,12*3,16*3,22*3,30*3,42*3,58*3,78*3,104*3,138*3,180*3,192*3} ,
   {4,4,4,4,6,8,12,16,20,26,34,42,12} }  ,

/* MPEG 2.0 */
 { {0,6,12,18,24,30,36,44,54,66,80,96,116,140,168,200,238,284,336,396,464,522,576},
   {6,6,6,6,6,6,8,10,12,14,16,20,24,28,32,38,46,52,60,68,58,54 } ,
   {0,4*3,8*3,12*3,18*3,24*3,32*3,42*3,56*3,74*3,100*3,132*3,174*3,192*3} ,
   {4,4,4,6,6,8,10,14,18,26,32,42,18 } } ,

 { {0,6,12,18,24,30,36,44,54,66,80,96,114,136,162,194,232,278,330,394,464,540,576},
   {6,6,6,6,6,6,8,10,12,14,16,18,22,26,32,38,46,52,64,70,76,36 } ,
   {0,4*3,8*3,12*3,18*3,26*3,36*3,48*3,62*3,80*3,104*3,136*3,180*3,192*3} ,
   {4,4,4,6,8,10,12,14,18,24,32,44,12 } } ,

 { {0,6,12,18,24,30,36,44,54,66,80,96,116,140,168,200,238,284,336,396,464,522,576},
   {6,6,6,6,6,6,8,10,12,14,16,20,24,28,32,38,46,52,60,68,58,54 },
   {0,4*3,8*3,12*3,18*3,26*3,36*3,48*3,62*3,80*3,104*3,134*3,174*3,192*3},
   {4,4,4,6,8,10,12,14,18,24,30,40,18 } } ,

/* MPEG 2.5, wrong! table (it's just a copy of MPEG 2.0/44.1kHz) */
 { {0,6,12,18,24,30,36,44,54,66,80,96,116,140,168,200,238,284,336,396,464,522,576},
   {6,6,6,6,6,6,8,10,12,14,16,20,24,28,32,38,46,52,60,68,58,54 } ,
   {0,4*3,8*3,12*3,18*3,24*3,32*3,42*3,56*3,74*3,100*3,132*3,174*3,192*3} ,
   {4,4,4,6,6,8,10,14,18,26,32,42,18 } } ,
};

static int mapbuf0[7][152];
static int mapbuf1[7][156];
static int mapbuf2[7][44];
static int *map[7][3];
static int *mapend[7][3];

unsigned int n_slen2[512]; /* MPEG 2.0 slen for 'normal' mode */
unsigned int i_slen2[256]; /* MPEG 2.0 slen for intensity stereo */

static float tan1_1[16],tan2_1[16],tan1_2[16],tan2_2[16];
static float pow1_1[2][16],pow2_1[2][16],pow1_2[2][16],pow2_2[2][16];

// Init tables for layer-3 
static float gainpow2[256+118+4];

#define MPG_MD_MONO 3 

#ifndef M_PI
#define  M_PI            3.14159265358979323846  /* pi */
#endif
#ifndef M_SQRT2
#define  M_SQRT2         1.41421356237309504880  /* sqrt(2) */
#endif

////////// MP3FrameParams //////////

MP3FrameParams::MP3FrameParams()
  : bv(frameBytes, 0, sizeof frameBytes) /* by default */ {
  oldHdr = firstHdr = 0;

  static Boolean doneInit = False;
  if (doneInit) return;
  doneInit = True;

  int i,j,k,l;

  for (i=-256;i<118+4;i++) {
    gainpow2[i+256] = pow((double)2.0,-0.25 * (double) (i+210) );
  }

  for (i=0;i<8207;i++) {
    ispow[i] = pow((double)i,(double)4.0/3.0);
  }

  for (i=0;i<8;i++) {
    static double Ci[8]={-0.6,-0.535,-0.33,-0.185,-0.095,-0.041,-0.0142,-0.0037};
    double sq=sqrt(1.0+Ci[i]*Ci[i]);
    aa_cs[i] = 1.0/sq;
    aa_ca[i] = Ci[i]/sq;
  }

  for (i=0;i<18;i++) {
    win[0][i]    = win[1][i]    = 0.5 * sin( M_PI / 72.0 * (double) (2*(i+0) +1) ) / cos ( M_PI * (double) (2*(i+0) +19) / 72.0 );
    win[0][i+18] = win[3][i+18] = 0.5 * sin( M_PI / 72.0 * (double) (2*(i+18)+1) ) / cos ( M_PI * (double) (2*(i+18)+19) / 72.0 );
  }
  for (i=0;i<6;i++) {
    win[1][i+18] = 0.5 / cos ( M_PI * (double) (2*(i+18)+19) / 72.0 );
    win[3][i+12] = 0.5 / cos ( M_PI * (double) (2*(i+12)+19) / 72.0 );
    win[1][i+24] = 0.5 * sin( M_PI / 24.0 * (double) (2*i+13) ) / cos ( M_PI * (double) (2*(i+24)+19) / 72.0 );
    win[1][i+30] = win[3][i] = 0.0;
    win[3][i+6 ] = 0.5 * sin( M_PI / 24.0 * (double) (2*i+1) )  / cos ( M_PI * (double) (2*(i+6 )+19) / 72.0 );
  }

  for (i=0;i<9;i++) {
    COS9[i] = cos( M_PI / 18.0 * (double) i);
  }

  for (i=0;i<9;i++) {
    tfcos36[i] = 0.5 / cos ( M_PI * (double) (i*2+1) / 36.0 );
  }
  for(i=0;i<3;i++) {
    tfcos12[i] = 0.5 / cos ( M_PI * (double) (i*2+1) / 12.0 );
  }

  COS6_1 = cos( M_PI / 6.0 * (double) 1);
  COS6_2 = cos( M_PI / 6.0 * (double) 2);

  for (i=0;i<12;i++) {
    win[2][i]  = 0.5 * sin( M_PI / 24.0 * (double) (2*i+1) ) / cos ( M_PI * (double) (2*i+7) / 24.0 );
    for (j=0;j<6;j++) {
      COS1[i][j] = cos( M_PI / 24.0 * (double) ((2*i+7)*(2*j+1)) );
    }
  }

  for (j=0;j<4;j++) {
    static int len[4] = { 36,36,12,36 };
    for (i=0;i<len[j];i+=2) {
      win1[j][i] = + win[j][i];
    }
    for (i=1;i<len[j];i+=2) {
      win1[j][i] = - win[j][i];
    }
  }

  for (i=0;i<16;i++) {
    double t = tan( (double) i * M_PI / 12.0 );
    tan1_1[i] = t / (1.0+t);
    tan2_1[i] = 1.0 / (1.0 + t);
    tan1_2[i] = M_SQRT2 * t / (1.0+t);
    tan2_2[i] = M_SQRT2 / (1.0 + t);

    for (j=0;j<2;j++) {
      double base = pow(2.0,-0.25*(j+1.0));
      double p1=1.0,p2=1.0;
      if (i > 0) {
        if (i & 1) {
          p1 = pow(base,(i+1.0)*0.5);
	} else {
          p2 = pow(base,i*0.5);
	}
      }
      pow1_1[j][i] = p1;
      pow2_1[j][i] = p2;
      pow1_2[j][i] = M_SQRT2 * p1;
      pow2_2[j][i] = M_SQRT2 * p2;
    }
  }

  for (j=0;j<7;j++) {
    struct bandInfoStruct *bi = &bandInfo[j];
    int *mp;
    int cb,lwin;
    int *bdf;
    
    mp = map[j][0] = mapbuf0[j];
    bdf = bi->longDiff;
    for (i=0,cb = 0; cb < 8 ; cb++,i+=*bdf++) {
      *mp++ = (*bdf) >> 1;
      *mp++ = i;
      *mp++ = 3;
      *mp++ = cb;
    }
    bdf = bi->shortDiff+3;
    for (cb=3;cb<13;cb++) {
      int l = (*bdf++) >> 1;
      for(lwin=0;lwin<3;lwin++) {
	*mp++ = l;
	*mp++ = i + lwin;
	*mp++ = lwin;
	*mp++ = cb;
      }
      i += 6*l;
    }
    mapend[j][0] = mp;
    
    mp = map[j][1] = mapbuf1[j];
    bdf = bi->shortDiff+0;
    for (i=0,cb=0;cb<13;cb++) {
      int l = (*bdf++) >> 1;
      for (lwin=0;lwin<3;lwin++) {
	*mp++ = l;
	*mp++ = i + lwin;
	*mp++ = lwin;
	*mp++ = cb;
      }
      i += 6*l;
    }
    mapend[j][1] = mp;
    
    mp = map[j][2] = mapbuf2[j];
    bdf = bi->longDiff;
    for (cb = 0; cb < 22 ; cb++) {
      *mp++ = (*bdf++) >> 1;
      *mp++ = cb;
    }
    mapend[j][2] = mp;
  }

  for (j=0;j<7;j++) {
    for (i=0;i<23;i++) {
      longLimit[j][i] = (bandInfo[j].longIdx[i] - 1 + 8) / 18 + 1;
      if (longLimit[j][i] > SBLIMIT) {
        longLimit[j][i] = SBLIMIT;
      }
    }
    for (i=0;i<14;i++) {
      shortLimit[j][i] = (bandInfo[j].shortIdx[i] - 1) / 18 + 1;
      if (shortLimit[j][i] > SBLIMIT) {
        shortLimit[j][i] = SBLIMIT;
      }
    }
  }

  for (i=0;i<5;i++) {
    for (j=0;j<6;j++) {
      for (k=0;k<6;k++) {
        int n = k + j * 6 + i * 36;
        i_slen2[n] = i|(j<<3)|(k<<6)|(3<<12);
      }
    }
  }
  for (i=0;i<4;i++) {
    for (j=0;j<4;j++) {
      for (k=0;k<4;k++) {
        int n = k + j * 4 + i * 16;
        i_slen2[n+180] = i|(j<<3)|(k<<6)|(4<<12);
      }
    }
  }
  for (i=0;i<4;i++) {
    for (j=0;j<3;j++) {
      int n = j + i * 3;
      i_slen2[n+244] = i|(j<<3) | (5<<12);
      n_slen2[n+500] = i|(j<<3) | (2<<12) | (1<<15);
    }
  }

  for (i=0;i<5;i++) {
    for (j=0;j<5;j++) {
      for (k=0;k<4;k++) {
        for (l=0;l<4;l++) {
          int n = l + k * 4 + j * 16 + i * 80;
          n_slen2[n] = i|(j<<3)|(k<<6)|(l<<9)|(0<<12);
        }
      }
    }
  }
  for (i=0;i<5;i++) {
    for (j=0;j<5;j++) {
      for (k=0;k<4;k++) {
        int n = k + j * 4 + i * 20;
        n_slen2[n+400] = i|(j<<3)|(k<<6)|(1<<12);
      }