使用FFMPEG的sws_scale函数实现各种原始颜色格式互转(YUV\RGB\)

一、环境介绍

FFMPEG版本: 4.2.2 

测试系统：ubuntu18.04

二、示例代码

/*
YUYV转QImage格式
*/
QImage YUYV422_TO_QImage(uint8_t *yuyv422,int image_width,int image_height)
{
    uint8_t *out_buffer= nullptr;
    AVFrame *Input_pFrame= nullptr;
    AVFrame *Output_pFrame = nullptr;
    struct SwsContext *img_convert_ctx=nullptr;  //用于解码后的视频格式转换
    /*1. 申请空间*/
    Output_pFrame = av_frame_alloc();  //存放RGB数据的缓冲区
    Input_pFrame = av_frame_alloc();//存放YUV数据的缓冲区
    /*2.设置转码参数*/
    img_convert_ctx=sws_getContext(image_width, image_height,AV_PIX_FMT_YUYV422,
                                   image_width, image_height,AV_PIX_FMT_RGB24,
                                   SWS_BICUBIC, nullptr, nullptr, nullptr);
    /*3. 申请转码需要空间*/
    //获取转码后数据需要的内存空间大小
    int numBytes = avpicture_get_size(AV_PIX_FMT_RGB24,image_width,image_height);
    //申请空间
    out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
    /*4. 设置转码的源数据地址*/
    avpicture_fill((AVPicture *) Output_pFrame, out_buffer, AV_PIX_FMT_RGB24,image_width, image_height);
    avpicture_fill((AVPicture *) Input_pFrame, yuyv422, AV_PIX_FMT_YUYV422,image_width, image_height);

    //转格式
    sws_scale(img_convert_ctx,
     (uint8_t const **) Input_pFrame->data,
     Input_pFrame->linesize, 0, image_height, Output_pFrame->data,
     Output_pFrame->linesize);

    //加载图片数据
    QImage image(out_buffer,image_width,image_height,QImage::Format_RGB888);

    //释放空间
    if(Input_pFrame)av_free(Input_pFrame);
    if(Output_pFrame)av_free(Output_pFrame);
    if(out_buffer) av_free(out_buffer);
    if(img_convert_ctx)sws_freeContext(img_convert_ctx);
    return image.copy();
}

/*
YUYV转YUV420P格式
*/
void YUYV422_TO_YUV420P(uint8_t *yuyv422,uint8_t *yuv420p,int video_width,int video_height)
{
    AVFrame *Input_pFrame= nullptr;
    AVFrame *Output_pFrame = nullptr;
    struct SwsContext *img_convert_ctx=nullptr; //用于解码后的格式转换
    /*1. 申请空间*/
    Input_pFrame = av_frame_alloc();
    Output_pFrame = av_frame_alloc();
    /*2.设置转码参数*/
    img_convert_ctx=sws_getContext(video_width, video_height,AV_PIX_FMT_YUYV422, //输入
                                   video_width, video_height,AV_PIX_FMT_YUV420P,   //输出
                                   SWS_BICUBIC, nullptr, nullptr, nullptr);
    /*3. 申请转码需要空间*/
    /*4. 设置转码的源数据地址*/
    avpicture_fill((AVPicture *) Input_pFrame, yuyv422, AV_PIX_FMT_YUYV422,video_width, video_height);
    avpicture_fill((AVPicture *) Output_pFrame, yuv420p, AV_PIX_FMT_YUV420P,video_width, video_height);

    //转格式
    sws_scale(img_convert_ctx,
     (uint8_t const **) Input_pFrame->data,Input_pFrame->linesize,
      0, video_height, Output_pFrame->data,Output_pFrame->linesize);
    //释放空间
    if(Input_pFrame)av_free(Input_pFrame);
    if(Output_pFrame)av_free(Output_pFrame);
    if(img_convert_ctx)sws_freeContext(img_convert_ctx);
}

/*
YUYV422转RGB888格式
*/
void YUYV422_TO_RGB888(uint8_t *yuyv422,uint8_t *rgb888,int image_width,int image_height)
{
    AVFrame *Input_pFrame= nullptr;
    AVFrame *Output_pFrame = nullptr;
    struct SwsContext *img_convert_ctx=nullptr;  //用于解码后的视频格式转换
    /*1. 申请空间*/
    Output_pFrame = av_frame_alloc();  //存放RGB数据的缓冲区
    Input_pFrame = av_frame_alloc();//存放YUV数据的缓冲区
    /*2.设置转码参数*/
    img_convert_ctx=sws_getContext(image_width, image_height,AV_PIX_FMT_YUYV422,
                                   image_width, image_height,AV_PIX_FMT_RGB24,
                                   SWS_BICUBIC, nullptr, nullptr, nullptr);
    /*4. 设置转码的源数据地址*/
    avpicture_fill((AVPicture *) Output_pFrame, rgb888, AV_PIX_FMT_RGB24,image_width, image_height);
    avpicture_fill((AVPicture *) Input_pFrame, yuyv422, AV_PIX_FMT_YUYV422,image_width, image_height);

    //转格式
    sws_scale(img_convert_ctx,
     (uint8_t const **) Input_pFrame->data,
     Input_pFrame->linesize, 0, image_height, Output_pFrame->data,
     Output_pFrame->linesize);

    //释放空间
    if(Input_pFrame)av_free(Input_pFrame);
    if(Output_pFrame)av_free(Output_pFrame);
    if(img_convert_ctx)sws_freeContext(img_convert_ctx);
}