rnd_ph16.c

关于AMR-WB+语音压缩编码的实现代码

/*------------------------------------------------------------------*
 * function rnd_ph16                                                *
 * ~~~~~~~~~~~~~~~~~                                                *
 * phase random generator (16 phasef, output lg/2 real+imag)         *
 *------------------------------------------------------------------*/
#include "../include/amr_plus.h"

void rnd_ph16(short *seed, float *xri, int lg)
{
  int i;
  unsigned short phase;
  for (i=0; i<lg; i+=2)
  {
    /* random phase from 0 to 15 */
    phase = ((unsigned short)E_UTIL_random(seed)) >> 12;
    xri[i] = sin20[phase+4];
    xri[i+1] = sin20[phase];
  }
  return;
}