关于YUV420格式数据的问题
  int i ;
      width = h->pDCodecCtx->width;
      height = h->pDCodecCtx->height;

      pY = h->pDPicture->data[0];
      pU = h->pDPicture->data[1];
      pV = h->pDPicture->data[2];

      pY2 = h->pBufYUV;
      pU2 = h->pBufYUV+width*height;
      pV2 = h->pBufYUV+width*height*5/4;

for (i=0;i<height;i++)
                        {
                                memmove(pY2, pY, width);
                                pY += h->pDPicture->linesize[0];
                                pY2 += width;
                                if (i%2==0)
                                {
                                        memmove(pU2, pU, width/2);
                                        memmove(pV2, pV, width/2);
                                        pU2 += width/2;
                                        pU  += h->pDPicture->linesize[1];
                                        pV2 += width/2;
                                        pV  += h->pDPicture->linesize[2];
                                }
   &n