Variables:
	AVPixelFormat                   m_AVPixelFormat;
    AVCodecContext*                 m_lpCodecCtx;
    AVCodec*                        m_lpCodec;
    AVFrame*                        m_lpFrame;
    AVPacket                        m_lpPacket;
    AVPicture                       m_lpPict;
    SwsContext*                     m_lpSwsContext;
    INT                             m_iThreadCount;
    LPBYTE                          m_lpFFMPEGBuffer;
	INT                              iImageWidth, iImageHeigh;


BOOL FFMpegDecompress( LPBYTE lpImageData, DWORD dwImageSize)
{	 if (m_lpCodec==NULL)
      { // find_decoder
	    m_lpCodec = avcodec_find_decoder(CODEC_ID_H264);
      }

     if ((m_lpCodec != NULL)&&(m_lpCodecCtx == NULL))
      { // Alloc codecContext
        m_lpCodecCtx = avcodec_alloc_context3(m_lpCodec);
        if (m_lpCodecCtx != NULL)
         { // Init  CodecContext
           if (m_lpCodecCtx->width == 0)
            { m_lpCodecCtx->pix_fmt           = AV_PIX_FMT_YUV420P;
              m_lpCodecCtx->codec_type        = AVMEDIA_TYPE_VIDEO;
              m_lpCodecCtx->codec_id          = CODEC_ID_H264;
              m_lpCodecCtx->coded_width       = iImageWidth;
              m_lpCodecCtx->coded_height      = iImageHeight;
              m_lpCodecCtx->width             = iImageWidth;
              m_lpCodecCtx->height            = iImageHeight;
              m_lpCodecCtx->thread_count      = 3;
              m_lpCodecCtx->thread_type       = FF_THREAD_SLICE;
              m_lpCodecCtx->err_recognition   = AV_EF_EXPLODE;
            }
         }
      }
     dwWidth  = iImageWidth;
     dwHeight = iImageHeight;
     // open decoder if not...
     if ((m_lpCodecCtx!=NULL) && (m_lpCodec!=NULL)&&(!lpfnavcodec_is_open(m_lpCodecCtx)))
      { if ( m_lpCodec != NULL)
         { if(m_lpCodec->capabilities&CODEC_CAP_TRUNCATED)
            m_lpCodecCtx->flags|= CODEC_FLAG_TRUNCATED;

           iResult = avcodec_open2( m_lpCodecCtx,  m_lpCodec, &optionsDict);
           // if error
           if (iResult < 0)
            { avcodec_close(m_lpCodecCtx);
              av_free(m_lpCodecCtx);
              m_lpCodecCtx = NULL;
              m_lpCodec    = NULL;
            }
         }
      }

     if ((m_lpCodecCtx!=NULL) && (m_lpCodec!=NULL))
      { // Allouer la frame video
        if (m_lpFrame == NULL)
         { m_lpFrame = avcodec_alloc_frame();
         }
        // Si l'allocation à réussi
        if (m_lpFrame!=NULL)
         { // Affecter les dimensions
           m_lpFrame->width  = m_lpCodecCtx->width;
           m_lpFrame->height = m_lpCodecCtx->height;
         }

        if ((m_lpCodecCtx != NULL) && ( m_lpCodec != NULL) &&(m_lpFrame != NULL) && (pddsDesc != NULL))
        if ((dwWidth>0)&&(dwHeight>0))
         { int iRes = 0;
           // init  packet
           av_init_packet(&m_lpPacket);
           if (m_lpFFMPEGBuffer == NULL)
            { m_lpFFMPEGBuffer = new BYTE[MAX_MPEG4VIDEO_FRAMESIZE+FF_INPUT_BUFFER_PADDING_SIZE];
            }
           if (m_lpFFMPEGBuffer !=NULL)
            { ZeroMemory( m_lpFFMPEGBuffer, MAX_MPEG4VIDEO_FRAMESIZE+FF_INPUT_BUFFER_PADDING_SIZE);
              CopyMemory(m_lpFFMPEGBuffer, lpImageData, dwImageSize);
            }

           // set data
           m_lpPacket.data = m_lpFFMPEGBuffer;
           // Set size
           m_lpPacket.size = dwImageSize;
           // Decode  H264
           if ((m_lpFrame!=NULL)&&(m_lpPacket.size>0))
            { while (m_lpPacket.size>0)
               { iRes = lpfnavcodec_decode_video2( m_lpCodecCtx, m_lpFrame, &iFrameFinished, &m_lpPacket);
                 if (iRes<0)
                  { break;
                  }
                 if (iRes>0)
                  { m_lpPacket.data+=iRes;
                    m_lpPacket.size-=iRes;
                  }
               }
            }

           // free Packet
           av_free_packet(&m_lpPacket);
         }
      }