ffmpeg+sdl解码h264数据流程

我在分析网上大神的博客后使用ffmpeg + sdl 成功地播放了h264数据，所以做了下面的记录.

解码h264数据为yuv240p

ffmpeg 头文件
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"

    AVFormatContext *pFormatCtx; 
    int             i, videoindex;
    AVCodecContext  *pCodecCtx;
    AVCodec         *pCodec;
    AVFrame *pFrame, *pFrameYUV;
    uint8_t *out_buffer;
    AVPacket *packet;
    int y_size;
    int ret, got_picture;
    struct SwsContext *img_convert_ctx;

创建这些变量,结构体

    //注册ffmpeg编解码器
    av_register_all();
    avformat_network_init();
    pFormatCtx = avformat_alloc_context();

if (avformat_open_input(&pFormatCtx, filepath, NULL, NULL) != 0) {
        printf("Couldn't open input stream.\n"); //打开h264文件
        return -1;
    }
    if (avformat_find_stream_info(pFormatCtx, NULL)<0) {
        printf("Couldn't find stream information.\n"); //检测流
        return -1;
    }
    videoindex = -1;
    for (i = 0; inb_streams; i++)//找到视频流
        if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
            videoindex = i;
            break;
        }
    if (videoindex == -1) {
        printf("Didn't find a video stream.\n");
        return -1;
    }

    pFrame = av_frame_alloc(); //初始化
    pFrameYUV = av_frame_alloc();//初始化
    out_buffer = (uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));//分配内存空间
    avpicture_fill((AVPicture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);//分配内存空间
    packet = (AVPacket *)av_malloc(sizeof(AVPacket));//
    //Output Info-----------------------------
    printf("--------------- File Information ----------------\n");
    av_dump_format(pFormatCtx, 0, filepath, 0);
    printf("-------------------------------------------------\n");
    img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
        pCodecCtx->width, pCodecCtx->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);//转码的信息

while (av_read_frame(pFormatCtx, packet) >= 0) {
        if (packet->stream_index == videoindex) {
            ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
            if (ret < 0) {
                printf("Decode Error.\n");
                return -1;
            }
            if (got_picture) {
                sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height,
                    pFrameYUV->data, pFrameYUV->linesize);//转码一帧数据

---

SDL

初始化SDL

if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
        printf("Could not initialize SDL - %s\n", SDL_GetError());
        return -1;
    }

    screen_w = pCodecCtx->width;
    screen_h = pCodecCtx->height;
    //SDL 2.0 Support for multiple windows
    screen = SDL_CreateWindow("Simplest ffmpeg player's Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
        screen_w, screen_h,
        SDL_WINDOW_OPENGL);

    if (!screen) {
        printf("SDL: could not create window - exiting:%s\n", SDL_GetError());
        return -1;
    }

    sdlRenderer = SDL_CreateRenderer(screen, -1, 0);
    //IYUV: Y + U + V  (3 planes)
    //YV12: Y + V + U  (3 planes)
    sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, pCodecCtx->width, pCodecCtx->height);

    sdlRect.x = 0;
    sdlRect.y = 0;
    sdlRect.w = screen_w;
    sdlRect.h = screen_h;

SDL_UpdateYUVTexture(sdlTexture, &sdlRect,
                    pFrameYUV->data[0], pFrameYUV->linesize[0],
                    pFrameYUV->data[1], pFrameYUV->linesize[1],
                    pFrameYUV->data[2], pFrameYUV->linesize[2]);

                SDL_RenderClear(sdlRenderer);
                SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, &sdlRect);
                SDL_RenderPresent(sdlRenderer);
                //SDL End-----------------------
                //Delay 40ms
                SDL_Delay(40);

 //最后将所有的资源释放掉
SDL_Quit();

    av_frame_free(&pFrameYUV);
    av_frame_free(&pFrame);
    avcodec_close(pCodecCtx);
    avformat_close_input(&pFormatCtx);

tips

在编译完成后，我点击运行，没有什么反应，但是我点击生成的exe却可以执行
当时我觉得很奇怪，在试错之后明白了，是filepath[]的问题，编译的是cpp的路径，
执行的exe在Debug下面，它们不一样.
感觉这是不人性化的设置