mfc 中ffmpeg yuy2字节流转图片代码

以下是在MFC中使用FFmpeg将YUY2格式的字节流转换为图片的代码示例：

#include <Windows.h>
#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <exception>
#include <algorithm>
#include <functional>
#include <codecvt>
#include <locale>
#include "ffmpeg.h"

// YUV420P转RGB24
void YUV420P_to_RGB24(unsigned char* yuvData, unsigned char* rgbData, int width, int height)
{
    unsigned char* yData = yuvData;
    unsigned char* uData = yuvData + width * height;
    unsigned char* vData = yuvData + width * height * 5 / 4;
    int r, g, b, y, u, v;
    for (int i = 0, j = 0; i < width * height; i++, j += 3)
    {
        y = (int)(yData[i] - 16);
        u = (int)(uData[i / 4] - 128);
        v = (int)(vData[i / 4] - 128);
        r = (int)(1.164 * y + 1.596 * v);
        g = (int)(1.164 * y - 0.813 * v - 0.391 * u);
        b = (int)(1.164 * y + 2.018 * u);
        r = std::max(0, std::min(255, r));
        g = std::max(0, std::min(255, g));
        b = std::max(0, std::min(255, b));
        rgbData[j] = r;
        rgbData[j + 1] = g;
        rgbData[j + 2] = b;
    }
}

// YUY2转RGB24
void YUY2_to_RGB24(unsigned char* yuy2Data, unsigned char* rgbData, int width, int height)
{
    unsigned char* yData = yuy2Data;
    unsigned char* uData = yuy2Data + 1;
    unsigned char* vData = yuy2Data + 3;
    int r, g, b, y, u, v;
    for (int i = 0, j = 0; i < width * height / 2; i++, j += 6)
    {
        y = (int)(yData[i * 2] - 16);
        u = (int)(uData[i] - 128);
        v = (int)(vData[i] - 128);
        r = (int)(1.164 * y + 1.596 * v);
        g = (int)(1.164 * y - 0.813 * v - 0.391 * u);
        b = (int)(1.164 * y + 2.018 * u);
        r = std::max(0, std::min(255, r));
        g = std::max(0, std::min(255, g));
        b = std::max(0, std::min(255, b));
        rgbData[j] = r;
        rgbData[j + 1] = g;
        rgbData[j + 2] = b;

        y = (int)(yData[i * 2 + 1] - 16);
        r = (int)(1.164 * y + 1.596 * v);
        g = (int)(1.164 * y - 0.813 * v - 0.391 * u);
        b = (int)(1.164 * y + 2.018 * u);
        r = std::max(0, std::min(255, r));
        g = std::max(0, std::min(255, g));
        b = std::max(0, std::min(255, b));
        rgbData[j + 3] = r;
        rgbData[j + 4] = g;
        rgbData[j + 5] = b;
    }
}

// YUY2字节流转换为图片
bool YUY2ToImage(const char* yuy2Data, int dataSize, int width, int height, const char* imageFile)
{
    bool ret = false;
    try
    {
        // 初始化FFmpeg
        av_register_all();
        avcodec_register_all();

        // 获取YUY2格式解码器
        AVCodec* codec = avcodec_find_decoder(AV_CODEC_ID_YUYV422);
        if (!codec)
        {
            throw std::exception("avcodec_find_decoder failed");
        }

        // 创建解码器上下文
        AVCodecContext* codecCtx = avcodec_alloc_context3(codec);
        if (!codecCtx)
        {
            throw std::exception("avcodec_alloc_context3 failed");
        }

        // 打开解码器
        if (avcodec_open2(codecCtx, codec, NULL) < 0)
        {
            throw std::exception("avcodec_open2 failed");
        }

        // 创建AVPacket和AVFrame
        AVPacket pkt;
        av_init_packet(&pkt);
        pkt.data = (uint8_t*)yuy2Data;
        pkt.size = dataSize;
        AVFrame* frame = av_frame_alloc();
        if (!frame)
        {
            throw std::exception("av_frame_alloc failed");
        }

        // 填充AVFrame数据
        frame->width = width;
        frame->height = height;
        frame->format = AV_PIX_FMT_YUYV422;
        avpicture_fill((AVPicture*)frame, (uint8_t*)yuy2Data, AV_PIX_FMT_YUYV422, width, height);

        // 创建AVFrame用于存储转换后的RGB24数据
        AVFrame* rgbFrame = av_frame_alloc();
        if (!rgbFrame)
        {
            throw std::exception("av_frame_alloc failed");
        }

        // 设置AVFrame的参数
        rgbFrame->width = width;
        rgbFrame->height = height;
        rgbFrame->format = AV_PIX_FMT_RGB24;
        int numBytes = avpicture_get_size(AV_PIX_FMT_RGB24, width, height);
        uint8_t* buffer = (uint8_t*)av_malloc(numBytes * sizeof(uint8_t));
        avpicture_fill((AVPicture*)rgbFrame, buffer, AV_PIX_FMT_RGB24, width, height);

        // 转换YUY2到RGB24
        YUY2_to_RGB24(yuy2Data, rgbFrame->data[0], width, height);

        // 创建输出文件
        FILE* outFile = NULL;
        fopen_s(&outFile, imageFile, "wb");
        if (!outFile)
        {
            throw std::exception("open output file failed");
        }

        // 初始化AVFormatContext
        AVFormatContext* formatCtx = avformat_alloc_context();
        if (!formatCtx)
        {
            throw std::exception("avformat_alloc_context failed");
        }

        // 设置输出格式
        AVOutputFormat* outputFmt = av_guess_format(NULL, imageFile, NULL);
        if (!outputFmt)
        {
            throw std::exception("av_guess_format failed");
        }
        formatCtx->oformat = outputFmt;

        // 创建AVIOContext
        if (avio_open(&formatCtx->pb, imageFile, AVIO_FLAG_WRITE) < 0)
        {
            throw std::exception("avio_open failed");
        }

        // 创建AVStream
        AVStream* stream = avformat_new_stream(formatCtx, codec);
        if (!stream)
        {
            throw std::exception("avformat_new_stream failed");
        }

        // 设置AVCodecContext
        AVCodecContext* outCodecCtx = stream->codec;
        outCodecCtx->codec = codec;
        outCodecCtx->codec_id = codec->id;
        outCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
        outCodecCtx->width = width;
        outCodecCtx->height = height;
        outCodecCtx->pix_fmt = AV_PIX_FMT_RGB24;
        outCodecCtx->time_base.num = 1;
        outCodecCtx->time_base.den = 25;

        // 写入文件头
        avformat_write_header(formatCtx, NULL);

        // 写入视频帧
        AVPacket packet;
        av_init_packet(&packet);
        packet.data = rgbFrame->data[0];
        packet.size = numBytes;
        packet.pts = 0;
        packet.dts = 0;
        packet.duration = 1;
        packet.stream_index = stream->index;
        av_interleaved_write_frame(formatCtx, &packet);

        // 写入文件尾
        av_write_trailer(formatCtx);

        // 释放资源
        av_frame_free(&rgbFrame);
        av_free(buffer);
        av_frame_free(&frame);
        avcodec_close(codecCtx);
        avcodec_free_context(&codecCtx);
        avformat_free_context(formatCtx);
        fclose(outFile);

        ret = true;
    }
    catch (std::exception& e)
    {
        std::cout << e.what() << std::endl;
    }
    return ret;
}

在函数 `YUY2ToImage` 中，首先初始化FFmpeg库，并获取YUY2格式的解码器。然后创建解码器上下文，并打开解码器。接着创建AVPacket和AVFrame，填充AVFrame数据，并创建AVFrame用于存储转换后的RGB24数据。通过调用转换函数`YUY2_to_RGB24`，将YUY2格式的字节流转换为RGB24格式。然后创建输出文件，并初始化AVFormatContext，设置输出格式和AVIOContext。接着创建AVStream，设置AVCodecContext，并写入文件头。最后，将转换后的RGB24数据写入文件，并写入文件尾，最后释放资源。

请注意，在使用这个函数之前，在项目属性中添加FFmpeg库和头文件路径，以及链接FFmpeg库。

希望这可以帮助到你！