lpp_tran_arm.cpp - Android社区 - https://www.androidos.net.cn/

/* -----------------------------------------------------------------------------------------------------------
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Attention: Audio and Multimedia Departments - FDK AAC LL
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----------------------------------------------------------------------------------------------------------- */

/********************************  Fraunhofer IIS  ***************************

Author(s):   Arthur Tritthart
   Description: (ARM optimised) LPP transposer subroutines

******************************************************************************/

#if defined(__arm__)

#define FUNCTION_LPPTRANSPOSER_func1

#ifdef FUNCTION_LPPTRANSPOSER_func1

/* Note: This code requires only 43 cycles per iteration instead of 61 on ARM926EJ-S */
__attribute__ ((noinline)) static void lppTransposer_func1(
  FIXP_DBL *lowBandReal,
  FIXP_DBL *lowBandImag,
  FIXP_DBL **qmfBufferReal,
  FIXP_DBL **qmfBufferImag,
  int loops,
  int hiBand,
  int dynamicScale,
  int descale,
  FIXP_SGL a0r,
  FIXP_SGL a0i,
  FIXP_SGL a1r,
  FIXP_SGL a1i)
{

FIXP_DBL real1, real2, imag1, imag2, accu1, accu2;

real2 = lowBandReal[-2];
  real1 = lowBandReal[-1];
  imag2 = lowBandImag[-2];
  imag1 = lowBandImag[-1];
  for(int i=0; i < loops; i++)
  {
    accu1 = fMultDiv2(         a0r,real1);
    accu2 = fMultDiv2(         a0i,imag1);
    accu1 = fMultAddDiv2(accu1,a1r,real2);
    accu2 = fMultAddDiv2(accu2,a1i,imag2);
    real2 = fMultDiv2(         a1i,real2);
    accu1 = accu1 - accu2;
    accu1 = accu1 >> dynamicScale;

accu2 = fMultAddDiv2(real2,a1r,imag2);
    real2 = real1;
    imag2 = imag1;
    accu2 = fMultAddDiv2(accu2,a0i,real1);
    real1 = lowBandReal[i];
    accu2 = fMultAddDiv2(accu2,a0r,imag1);
    imag1 = lowBandImag[i];
    accu2 = accu2 >> dynamicScale;

accu1 <<= 1;
    accu2 <<= 1;

qmfBufferReal[i][hiBand] = accu1 + (real1>>descale);
    qmfBufferImag[i][hiBand] = accu2 + (imag1>>descale);
  }
}
#endif  /* #ifdef FUNCTION_LPPTRANSPOSER_func1 */
#endif  /* __arm__ */

C++程序 | 152行 | 6.22 KB

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