DST，蝶形运算

来源：互联网发布：怎么更新windows系统编辑：程序博客网时间：2024/06/06 01:53
转自：http://blog.csdn.net/tianzhaixing2013/article/details/8723204
/** MxN forward transform (2D)*  \param block input data (residual)*  \param coeff output data (transform coefficients)*  \param iWidth input data (width of transform)*  \param iHeight input data (height of transform)*///对帧内预测模式的4x4块进行DST变换，其余的根据块大小分别做蝶形快速变换（4x4，8x8，16x16，32x32）void xTrMxN(Int bitDepth, Short *block,Short *coeff, Int iWidth, Int iHeight, UInt uiMode){  Int shift_1st = g_aucConvertToBit[iWidth]  + 1 + bitDepth-8; // log2(iWidth) - 1 + g_bitDepth - 8  Int shift_2nd = g_aucConvertToBit[iHeight]  + 8;             // log2(iHeight) + 6  Short tmp[ 64 * 64 ];  if( iWidth == 4 && iHeight == 4)  {    if (uiMode != REG_DCT)    {//离散正弦变换DST      fastForwardDst(block,tmp,shift_1st); // Forward DST BY FAST ALGORITHM, block input, tmp output      fastForwardDst(tmp,coeff,shift_2nd); // Forward DST BY FAST ALGORITHM, tmp input, coeff output    }    else    {//4*4蝶形运算      partialButterfly4(block, tmp, shift_1st, iHeight);      partialButterfly4(tmp, coeff, shift_2nd, iWidth);    }  }  else if( iWidth == 8 && iHeight == 8)  { //8*8蝶形运算    partialButterfly8( block, tmp, shift_1st, iHeight );    partialButterfly8( tmp, coeff, shift_2nd, iWidth );  }  else if( iWidth == 16 && iHeight == 16)  { //16*16蝶形运算    partialButterfly16( block, tmp, shift_1st, iHeight );    partialButterfly16( tmp, coeff, shift_2nd, iWidth );  }  else if( iWidth == 32 && iHeight == 32)  { //32*32蝶形运算    partialButterfly32( block, tmp, shift_1st, iHeight );    partialButterfly32( tmp, coeff, shift_2nd, iWidth );  }}/** MxN inverse transform (2D)反变换针对2D的情况*  \param coeff input data (transform coefficients)*  \param block output data (residual)*  \param iWidth input data (width of transform)*  \param iHeight input data (height of transform)*/void xITrMxN(Int bitDepth, Short *coeff,Short *block, Int iWidth, Int iHeight, UInt uiMode){  Int shift_1st = SHIFT_INV_1ST;  Int shift_2nd = SHIFT_INV_2ND - (bitDepth-8);  Short tmp[ 64*64];  if( iWidth == 4 && iHeight == 4)  {    if (uiMode != REG_DCT)    {      fastInverseDst(coeff,tmp,shift_1st); // Inverse DST by FAST Algorithm, coeff input, tmp output      fastInverseDst(tmp,block,shift_2nd); // Inverse DST by FAST Algorithm, tmp input, coeff output    }    else    {      partialButterflyInverse4(coeff,tmp,shift_1st,iWidth);      partialButterflyInverse4(tmp,block,shift_2nd,iHeight);    }  }  else if( iWidth == 8 && iHeight == 8)  {    partialButterflyInverse8(coeff,tmp,shift_1st,iWidth);    partialButterflyInverse8(tmp,block,shift_2nd,iHeight);  }  else if( iWidth == 16 && iHeight == 16)  {    partialButterflyInverse16(coeff,tmp,shift_1st,iWidth);    partialButterflyInverse16(tmp,block,shift_2nd,iHeight);  }  else if( iWidth == 32 && iHeight == 32)  {    partialButterflyInverse32(coeff,tmp,shift_1st,iWidth);    partialButterflyInverse32(tmp,block,shift_2nd,iHeight);  }}
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