AVFrame    *m_pFrameRGB,*m_pFrameYUV;

uint8_t *m_rgbBuffer,*m_yuvBuffer;

struct SwsContext *m_img_convert_ctx;

void init（） //分配两个Frame，两段buff，一个转换上下文

{

　//为每帧图像分配内存

    m_pFrameYUV = av_frame_alloc();

    m_pFrameRGB = av_frame_alloc();

// width和heigt为传入的分辨率的大小，分辨率有变化时可以以最大标准申请

    int numBytes = avpicture_get_size(AV_PIX_FMT_RGB32, nwidth,nheight);

    m_rgbBuffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));

    int yuvSize = nwidth * nheight *  /;

    m_yuvBuffer = (uint8_t *)av_malloc(yuvSize);

    //特别注意sws_getContext内存泄露问题，

    //注意sws_getContext只能调用一次，在初始化时候调用即可，另外调用完后，在析构函数中使用sws_freeContext，将它的内存释放。

    //设置图像转换上下文

    m_img_convert_ctx = sws_getContext(nwidth, nheight, AV_PIX_FMT_YUV420P, \

　　　　　　　　　　　　　　　　　　　　　　　 nwidth, nheight, AV_PIX_FMT_RGB32, SWS_BICUBIC, NULL, NULL, NULL);

}

void play（char* pbuff_in,int nwidth,int nheight）
{

    avpicture_fill((AVPicture *) m_pFrameRGB, m_rgbBuffer, AV_PIX_FMT_RGB32,nwidth, nheight);

    avpicture_fill((AVPicture *) m_pFrameYUV, (uint8_t *)pbuff_in, AV_PIX_FMT_YUV420P, nwidth, nheight);

    //转换图像格式，将解压出来的YUV420P的图像转换为RGB的图像

    sws_scale(m_img_convert_ctx,

            (uint8_t const * const *) m_pFrameYUV->data,

            m_pFrameYUV->linesize, , nheight, m_pFrameRGB->data,

            m_pFrameRGB->linesize);

    //把这个RGB数据 用QImage加载

    QImage tmpImg((uchar *)m_rgbBuffer,nwidth,nheight,QImage::Format_RGB32);

     //把图像复制一份 传递给界面显示

    m_mapImage[nWindowIndex] = tmpImg.copy();

}

void release()

{

    av_frame_free(&m_pFrameYUV);

    av_frame_free(&m_pFrameRGB);

    av_free(m_rgbBuffer);

    av_free(m_yuvBuffer);

    sws_freeContext(m_img_convert_ctx);

}
 

bool YV12ToBGR24_FFmpeg(unsigned char* pYUV,unsigned char* pBGR24,int width,int height)

{

    if (width <  || height <  || pYUV == NULL || pBGR24 == NULL)

        return false;

    //int srcNumBytes,dstNumBytes;

    //uint8_t *pSrc,*pDst;

    AVPicture pFrameYUV,pFrameBGR;

    //pFrameYUV = avpicture_alloc();

    //srcNumBytes = avpicture_get_size(PIX_FMT_YUV420P,width,height);

    //pSrc = (uint8_t *)malloc(sizeof(uint8_t) * srcNumBytes);

    avpicture_fill(&pFrameYUV,pYUV,PIX_FMT_YUV420P,width,height);

    //U,V互换

    uint8_t * ptmp=pFrameYUV.data[];

    pFrameYUV.data[]=pFrameYUV.data[];

    pFrameYUV.data []=ptmp;

    //pFrameBGR = avcodec_alloc_frame();

    //dstNumBytes = avpicture_get_size(PIX_FMT_BGR24,width,height);

    //pDst = (uint8_t *)malloc(sizeof(uint8_t) * dstNumBytes);

    avpicture_fill(&pFrameBGR,pBGR24,PIX_FMT_BGR24,width,height);

    struct SwsContext* imgCtx = NULL;

    imgCtx = sws_getContext(width,height,PIX_FMT_YUV420P,width,height,PIX_FMT_BGR24,SWS_BILINEAR,,,);

    if (imgCtx != NULL){

        sws_scale(imgCtx,pFrameYUV.data,pFrameYUV.linesize,,height,pFrameBGR.data,pFrameBGR.linesize);

        if(imgCtx){

            sws_freeContext(imgCtx);

            imgCtx = NULL;

        }

        return true;

    }

    else{

        sws_freeContext(imgCtx);

        imgCtx = NULL;

        return false;

    }

}