h261decoder.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) 2005 Intel Corporation. All Rights Reserved.
//
*/

#include "h261decoder.h"


static Ipp32u _ShowBits(H261DEC_STATE* dec_state, int n)
{
    Ipp8u* ptr = dec_state->bufptr;
    Ipp32u tmp = (ptr[0] << 24) | (ptr[1] << 16) | (ptr[2] <<  8) | (ptr[3]);
    tmp <<= dec_state->bitoff;
    tmp >>= 32 - n;
    return tmp;
}

static void _FlushBits(H261DEC_STATE* dec_state, int n)
{
    n = n + dec_state->bitoff;
    dec_state->bufptr += n >> 3;
    dec_state->bitoff = n & 7;
}

static Ipp32u _GetBits(H261DEC_STATE* dec_state, int n)
{
    Ipp8u* ptr = dec_state->bufptr;
    Ipp32u tmp = (ptr[0] << 24) | (ptr[1] << 16) | (ptr[2] <<  8) | (ptr[3]);
    tmp <<= dec_state->bitoff;
    tmp >>= 32 - n;
    n = n + dec_state->bitoff;
    dec_state->bufptr += n >> 3;
    dec_state->bitoff = n & 7;
    return tmp;
}


int getPictureHeader(H261DEC_STATE* dec_state)
{
  Ipp32u code;

  // PSC
  code = _GetBits(dec_state, 20);
  if (code != 16)
      return 1;

  // decode TR
  code = _GetBits(dec_state, 5);

  // set picture time
  if (code < dec_state->tr)
      code += 32;
  dec_state->time += code - dec_state->tr;
  dec_state->tr = (Ipp8u)(code & 0x1F);

  // decode PTYPE
  code = _GetBits(dec_state, 6);

  // Split screen indicator is ignored
//  if (code & 0x20) {
//    ErrMsg("Split Screen Indicator not supported");
//    return -1;
//  }

  // Document camera indicator is ignored
//  if (code & 0x10) {
//    ErrMsg("Document Camera Indicator not supported");
//    return -1;
//  }

  // Freeze Picture Release bit is ignored
//  if (code & 0x8) {
//    ErrMsg("Freeze Picture Release not supported");
//    return -1;
//  }

  // Source format
  if (code & 0x4) {
    dec_state->picture_format = 1;  // CIF
    dec_state->picture_width = 352;
    dec_state->picture_height = 288;
    dec_state->numgob = 12;
  } else {
    dec_state->picture_format = 0;  // QCIF
    dec_state->picture_width = 352/2;
    dec_state->picture_height = 288/2;
    dec_state->numgob = 3;
  }

//  Still image bit is ignored - Annex D not supported
//  if ((code & 0x2) == 0) {
//    ErrMsg("Still Image Mode not supported");
//    return -1;
//  }
  // bit 6 of PTYPE is spare

  while (_GetBits(dec_state, 1)) { // extra insertion information (PEI)
    _FlushBits(dec_state, 8); // PSPARE
  }

  return 0;
} // getPictureHeader()


static void reconstruct(int bx, int by, int mvx, int mvy, int filter, H261DEC_STATE* dec_state)
{
  Ipp8u* src;
  Ipp8u* dst;
  int i;
  int lx = dec_state->picture_width;

  /* Y */
  src = dec_state->refPic[0] + lx * (by + mvy) + bx + mvx;
  dst = dec_state->curPic[0] + lx * by + bx;

  if (filter) {
    Ipp8u *dblock, *sblock;
    for (i = 0; i < 4; i++) {
      dblock = dst + (i & 2)*4*lx + (i & 1)*8;
      sblock = src + (i & 2)*4*lx + (i & 1)*8;
      ippiFilter8x8_H261_8u_C1R(sblock, lx, dblock, lx);
    }
  } else {
    ippiCopy16x16_8u_C1R(src, lx, dst, lx);
  }

  /* Chroma */
  lx  >>= 1;
  bx >>= 1;
  by >>= 1;
  mvx /= 2;   // truncate towards zero, can be negative
  mvy /= 2;

  src = dec_state->refPic[1] + lx * (by + mvy) + bx + mvx;
  dst = dec_state->curPic[1] + lx * by + bx;

  if (filter)
    ippiFilter8x8_H261_8u_C1R(src, lx, dst, lx);
  else
    ippiCopy8x8_8u_C1R(src, lx, dst, lx);

  src = dec_state->refPic[2] + lx * (by + mvy) + bx + mvx;
  dst = dec_state->curPic[2] + lx * by + bx;
  if (filter)
    ippiFilter8x8_H261_8u_C1R(src, lx, dst, lx);
  else
    ippiCopy8x8_8u_C1R(src, lx, dst, lx);

} // reconstruct()


static int fillBlock(int bx, int by, int i, int quant, H261DEC_STATE* dec_state)
{
  __ALIGN16(Ipp16s, coeffs, 64);
  int       step;
  Ipp8u*    pDst;
  IppStatus status;
  int iLNZ;
  int picture_width = dec_state->picture_width;

#if 0
  {
    __ALIGN16(Ipp16s, coeffsZ, 64);
    status = ippiDecodeCoeffsIntra_H261_1u16s(&dec_state->bufptr, &dec_state->bitoff,
                                              coeffsZ, &iLNZ, -1);
    if (status != ippStsNoErr)
      return -1;
    status = ippiQuantInvIntra_H263_16s_C1I(coeffsZ, iLNZ, quant, 0, 0);
    if (status != ippStsNoErr)
      return -1;
    status = ippiScanInv_16s_C1(coeffsZ, coeffs, iLNZ, IPPVC_SCAN_ZIGZAG);
  }
#else

  status = ippiReconstructCoeffsIntra_H261_1u16s(&dec_state->bufptr, &dec_state->bitoff,
                                                  coeffs, &iLNZ, quant);
#endif
  if (status != ippStsNoErr)
    return -1;

  if (i > 3) {
    step = picture_width >> 1;
    bx >>= 1;
    by >>= 1;
    pDst = dec_state->curPic[i-3] + step*by + bx;
  } else {
    step = picture_width;
    pDst = dec_state->curPic[0] + picture_width*(by + (i & 2)*4) + bx + (i & 1)*8;
  }

  ippiDCT8x8Inv_16s8u_C1R(coeffs, pDst, step);

  return 0;
} // fillBlock()


static int reconBlock(int bx, int by, int i, int quant, H261DEC_STATE* dec_state)
{
  __ALIGN16(Ipp16s, coeffs, 64);
  int       step;
  Ipp8u*    pSrcDst;
  IppStatus status = ippStsErr;
  int iLNZ;
  int picture_width = dec_state->picture_width;

#if 0
  {
    __ALIGN16(Ipp16s, coeffsZ, 64);
    status = ippiDecodeCoeffsInter_H261_1u16s(&dec_state->bufptr, &dec_state->bitoff,
                                              coeffsZ, &iLNZ, -1);
    if (status != ippStsNoErr)
      return -1;
    status = ippiQuantInvInter_H263_16s_C1I(coeffsZ, iLNZ, quant, 0);
    if (status != ippStsNoErr)
      return -1;
    status = ippiScanInv_16s_C1(coeffsZ, coeffs, iLNZ, IPPVC_SCAN_ZIGZAG);
  }
#else
  status = ippiReconstructCoeffsInter_H261_1u16s(&dec_state->bufptr, &dec_state->bitoff,
                                                  coeffs, &iLNZ, quant);
#endif
  if (status != ippStsNoErr)
    return -1;

  if ((iLNZ < 5) && (!coeffs[16]))
    ippiDCT8x8Inv_2x2_16s_C1I(coeffs);
  else if ((iLNZ < 10) || ((iLNZ < 14) && (!coeffs[10])) ||
    ((iLNZ < 19) && (!(coeffs[10] | coeffs[14] | coeffs[15] | coeffs[16]))))
    ippiDCT8x8Inv_4x4_16s_C1I(coeffs);
  else
    ippiDCT8x8Inv_16s_C1I(coeffs);

  if (i > 3) {
    step = picture_width >> 1;
    bx >>= 1;
    by >>= 1;
    pSrcDst = dec_state->curPic[i-3] + step*by + bx;
  } else {
    step = picture_width;
    pSrcDst = dec_state->curPic[0] + picture_width*(by + (i & 2)*4) + bx + (i & 1)*8;
  }
  ippiAdd8x8_16s8u_C1IRS(coeffs, 16, pSrcDst, step);

  return 0;
} // reconBlock()


/*-------------------------------------------------------------*/

typedef struct {
  unsigned short val;
  unsigned short len;
} H261_vlc;

#define VLC_ERR   -1

static const H261_vlc mba_tab1[15] =
{
  {7,5}, {6,5}, {5,4}, {5,4}, {4,4}, {4,4}, {3,3}, {3,3}, {3,3}, {3,3},
  {2,3}, {2,3}, {2,3}, {2,3}, {1,1}
};

static const H261_vlc mba_tab2[46] =
{
  {21,6}, {20,6}, {19,6}, {18,6}, {17,6}, {16,6},
  {15,4}, {15,4}, {15,4}, {15,4}, {14,4}, {14,4}, {14,4}, {14,4},
  {13,4}, {13,4}, {13,4}, {13,4}, {12,4}, {12,4}, {12,4}, {12,4},
  {11,4}, {11,4}, {11,4}, {11,4}, {10,4}, {10,4}, {10,4}, {10,4},
  {9, 3}, {9, 3}, {9, 3}, {9, 3}, {9, 3}, {9, 3}, {9, 3}, {9, 3},
  {8, 3}, {8, 3}, {8, 3}, {8, 3}, {8, 3}, {8, 3}, {8, 3}, {8, 3},
};

static int dec_MBA(H261DEC_STATE* dec_state)
{
  unsigned int code;
  int mba, len;
  H261_vlc vlc;

  code = _ShowBits(dec_state, 5);
  if (code >= 16) {
    _FlushBits(dec_state, 1);
    mba = 1;
  } else if (code > 1) {
    vlc = mba_tab1[code - 2];
    mba = vlc.val;
    len = vlc.len;
    _FlushBits(dec_state, len);
  } else {
    _FlushBits(dec_state, 4);
    code = _ShowBits(dec_state, 7);
    if ((code >> 1) >= 18) {
      vlc = mba_tab2[(code >> 1) - 18];
      mba = vlc.val;
      len = vlc.len;
    } else {
      len = 7;
      if (code >= 16) {
        mba = 57 - code;
      } else
//        mba = (code == 15) ? IPPVC_MB_STUFFING : VLC_ERR;
        mba = -1;
    }
    _FlushBits(dec_state, len);
  }
  return mba;
}

/*-------------------------------------------------------------*/

#define MTYPE_INTRA   1
#define MTYPE_MQUANT  2
#define MTYPE_MVD     4
#define MTYPE_TCOEFF  8
#define MTYPE_FIL     16

static const Ipp8u mtype_tab[10] =
{
  MTYPE_TCOEFF,
  MTYPE_TCOEFF | MTYPE_MVD | MTYPE_FIL,
  MTYPE_MVD | MTYPE_FIL,
  MTYPE_INTRA, // | MTYPE_TCOEFF,
  MTYPE_TCOEFF | MTYPE_MQUANT,
  MTYPE_TCOEFF | MTYPE_MQUANT | MTYPE_MVD | MTYPE_FIL,
  MTYPE_INTRA  | MTYPE_MQUANT, // | MTYPE_TCOEFF,
  MTYPE_TCOEFF | MTYPE_MVD,
  MTYPE_MVD,
  MTYPE_TCOEFF | MTYPE_MQUANT | MTYPE_MVD
};

static int dec_MTYPE(H261DEC_STATE* dec_state)
{
  unsigned int code;
  int mtype;
  int i;

  code = _ShowBits(dec_state, 10);
  for (i = 0; i < 10; i++) {
    if (code & (512 >> i)) break;
  }

  if (i > 9) return VLC_ERR;
  mtype = mtype_tab[i];
  _FlushBits(dec_state, i+1);

  return mtype;
}

/*-------------------------------------------------------------*/

static const H261_vlc mvd_tab1[14] =
{
  {3,5}, {29,5}, {2,4}, {2,4}, {30,4}, {30,4},
  {1,3}, {1,3}, {1,3}, {1,3}, {31,3}, {31,3}, {31,3}, {31,3}
};

static const H261_vlc mvd_tab2[103] =
{
  {16,11}, {15,11}, {17,11}, {14,11}, {18,11}, {13,11}, {19,11}, {12,11},