ac3dec_rematrix.cpp

这是在PCA下的基于IPP库示例代码例子,在网上下了IPP的库之后,设置相关参数就可以编译该代码.

/*//////////////////////////////////////////////////////////////////////////////
//
//                  INTEL CORPORATION PROPRIETARY INFORMATION
//     This software is supplied under the terms of a license agreement or
//     nondisclosure agreement with Intel Corporation and may not be copied
//     or disclosed except in accordance with the terms of that agreement.
//          Copyright(c) 2002-2005 Intel Corporation. All Rights Reserved.
//
*/

#include "umc_ac3_decoder.h"
#include "ipps.h"

typedef struct rematrix_band_s {
  Ipp32u  start;
  Ipp32u  end;
} rematrix_band_t;

static const rematrix_band_t rematrix_band[] = {
  {13, 24}, {25, 36}, {37, 60}, {61, 252}
};

#define min(a,b)    (((a) < (b)) ? (a) : (b))

int UMC::AC3Decoder::Rematrix(int nblk)
{
  Ipp32s num_bands;
  Ipp32s start;
  Ipp32s end;
  Ipp32s minEndmant;
  Ipp32s i;

  if (!audblk[nblk]->cplinu)
    num_bands = 4; /* coupling is not in use, num_bands = 4 */
  else {           /* coupling is in use */
    if (audblk[nblk]->cplbegf > 2)
      num_bands = 4;
    else if (audblk[nblk]->cplbegf > 0)
      num_bands = 3;
    else
      num_bands = 2;
  }

  minEndmant = min((int)audblk[nblk]->endmant[0],
                   (int)audblk[nblk]->endmant[1]);
  for (i = 0; i < num_bands; i++) {
    int j;

    if (!audblk[nblk]->rematflg[i])
      continue;

    start = rematrix_band[i].start;
    end =
      (audblk[nblk]->
       cplinu ? min((int)rematrix_band[i].end,
                    12 * audblk[nblk]->cplbegf + 36) : rematrix_band[i].end);

    if (end > minEndmant - 1) end = minEndmant - 1;

    for (j = start; j <= end; j++) {
      float a = data_vectors.stream_coeffs.channel[0][j];
      float b = data_vectors.stream_coeffs.channel[1][j];

      data_vectors.stream_coeffs.channel[0][j] = (a + b);
      data_vectors.stream_coeffs.channel[1][j] = (a - b);
    }
  }

  return 1;
}