tabinit.c

从 IEEE 1394总线接收传输流

#include <stdlib.h>

#include "mpg123.h"

#ifdef USE_3DNOW
real decwin[2*(512+32)];
static real cos64[32],cos32[16],cos16[8],cos8[4],cos4[2];
#else
real decwin[512+32];
static real cos64[16],cos32[8],cos16[4],cos8[2],cos4[1];
#endif

real *pnts[] = { cos64,cos32,cos16,cos8,cos4 };

static unsigned char *conv16to8_buf = NULL;
unsigned char *conv16to8;

static long intwinbase[] = {
     0,    -1,    -1,    -1,    -1,    -1,    -1,    -2,    -2,    -2,
    -2,    -3,    -3,    -4,    -4,    -5,    -5,    -6,    -7,    -7,
    -8,    -9,   -10,   -11,   -13,   -14,   -16,   -17,   -19,   -21,
   -24,   -26,   -29,   -31,   -35,   -38,   -41,   -45,   -49,   -53,
   -58,   -63,   -68,   -73,   -79,   -85,   -91,   -97,  -104,  -111,
  -117,  -125,  -132,  -139,  -147,  -154,  -161,  -169,  -176,  -183,
  -190,  -196,  -202,  -208,  -213,  -218,  -222,  -225,  -227,  -228,
  -228,  -227,  -224,  -221,  -215,  -208,  -200,  -189,  -177,  -163,
  -146,  -127,  -106,   -83,   -57,   -29,     2,    36,    72,   111,
   153,   197,   244,   294,   347,   401,   459,   519,   581,   645,
   711,   779,   848,   919,   991,  1064,  1137,  1210,  1283,  1356,
  1428,  1498,  1567,  1634,  1698,  1759,  1817,  1870,  1919,  1962,
  2001,  2032,  2057,  2075,  2085,  2087,  2080,  2063,  2037,  2000,
  1952,  1893,  1822,  1739,  1644,  1535,  1414,  1280,  1131,   970,
   794,   605,   402,   185,   -45,  -288,  -545,  -814, -1095, -1388,
 -1692, -2006, -2330, -2663, -3004, -3351, -3705, -4063, -4425, -4788,
 -5153, -5517, -5879, -6237, -6589, -6935, -7271, -7597, -7910, -8209,
 -8491, -8755, -8998, -9219, -9416, -9585, -9727, -9838, -9916, -9959,
 -9966, -9935, -9863, -9750, -9592, -9389, -9139, -8840, -8492, -8092,
 -7640, -7134, -6574, -5959, -5288, -4561, -3776, -2935, -2037, -1082,
   -70,   998,  2122,  3300,  4533,  5818,  7154,  8540,  9975, 11455,
 12980, 14548, 16155, 17799, 19478, 21189, 22929, 24694, 26482, 28289,
 30112, 31947, 33791, 35640, 37489, 39336, 41176, 43006, 44821, 46617,
 48390, 50137, 51853, 53534, 55178, 56778, 58333, 59838, 61289, 62684,
 64019, 65290, 66494, 67629, 68692, 69679, 70590, 71420, 72169, 72835,
 73415, 73908, 74313, 74630, 74856, 74992, 75038 };

void make_decode_tables(long scaleval)
{
  int i,j,k,kr,divv;
  real *costab;
  int idx;

  
  for(i=0;i<5;i++)
  {
    kr=0x10>>i; divv=0x40>>i;
    costab = pnts[i];
    for(k=0;k<kr;k++)
      costab[k] = 1.0 / (2.0 * cos(M_PI * ((double) k * 2.0 + 1.0) / (double) divv));
#ifdef USE_3DNOW
    for(k=0;k<kr;k++)
      costab[k+kr] = -costab[k];
#endif

  }

  idx = 0;
  scaleval = -scaleval;
  for(i=0,j=0;i<256;i++,j++,idx+=32)
  {
    if(idx < 512+16)
      decwin[idx+16] = decwin[idx] = (double) intwinbase[j] / 65536.0 * (double) scaleval;

    if(i % 32 == 31)
      idx -= 1023;
    if(i % 64 == 63)
      scaleval = - scaleval;
  }

  for( /* i=256 */ ;i<512;i++,j--,idx+=32)
  {
    if(idx < 512+16)
      decwin[idx+16] = decwin[idx] = (double) intwinbase[j] / 65536.0 * (double) scaleval;

    if(i % 32 == 31)
      idx -= 1023;
    if(i % 64 == 63)
      scaleval = - scaleval;
  }

#ifdef USE_3DNOW
  if(!param.down_sample) {
    for(i=0;i<512+32;i++) {
      decwin[512+31-i] *= 65536.0; /* allows faster clipping in 3dnow code */
      decwin[512+32+i] = decwin[512+31-i];
    }
  }
#endif

}

void make_conv16to8_table(int mode)
{
  int i;

  /*
   * ????: 8.0 is right but on SB cards '2.0' is a better value ???
   */
  const double mul = 8.0;

  if(!conv16to8_buf) {
    conv16to8_buf = (unsigned char *) malloc(8192);
    if(!conv16to8_buf) {
      fprintf(stderr,"Can't allocate 16 to 8 converter table!\n");
      exit(1);
    }
    conv16to8 = conv16to8_buf + 4096;
  }

  if(mode == AUDIO_FORMAT_ULAW_8) {
    double m=127.0 / log(256.0);
    int c1;

    for(i=-4096;i<4096;i++) {
/* dunno whether this is a valid transformation rule ?!?!? */
      if(i < 0)
        c1 = 127 - (int) (log( 1.0 - 255.0 * (double) i*mul / 32768.0 ) * m);
      else
        c1 = 255 - (int) (log( 1.0 + 255.0 * (double) i*mul / 32768.0 ) * m);
      if(c1 < 0 || c1 > 255) 
	fprintf(stderr,"Converror %d %d\n",i,c1);
      if(c1 == 0)
        c1 = 2;
      conv16to8[i] = (unsigned char) c1;
    }
  }
  else if(mode == AUDIO_FORMAT_SIGNED_8) {
    for(i=-4096;i<4096;i++) {
      conv16to8[i] = i>>5;
    }
  }
  else if(mode == AUDIO_FORMAT_UNSIGNED_8) {
    for(i=-4096;i<4096;i++) {
      conv16to8[i] = (i>>5)+128;
    }
  }
  else {
    for(i=-4096;i<4096;i++) {
      conv16to8[i] = 0;
    }
  }
}