SDL视频显示函数

SDL_Init()：初始化SDL系统
SDL_CreateWindow()：创建窗口 SDL_Window
SDL_CreateRenderer()：创建渲染器 SDL_Renderer
SDL_CreateTexture()：创建纹理 SDL_Texture
SDL_UpdateTexture()：设置纹理的数据
SDL_RenderClear()：清除渲染器的内容
SDL_RenderCopy()：将纹理的数据拷贝给渲染器
SDL_RenderPresent()：显示
SDL_Delay()：工具函数，用于延时。
SDL_Quit()：退出SDL系统

SDL数据结构

SDL_Window：代表了一个“窗口”
SDL_Renderer：代表了一个“渲染器”
SDL_Texture：代表了一个“纹理”
SDL_Rect：一个简单的矩形结构

播放视频代码

#include <QDebug>
#include <QFile>

extern "C"
{
    #include "SDL.h"
    #undef main //不能少
};

int screen_w = 640,screen_h = 360;
const int pixel_w = 640,pixel_h = 360;

uint32_t y_frame_len = pixel_w * pixel_h;
uint32_t u_frame_len = pixel_w * pixel_h / 4;
uint32_t v_frame_len = pixel_w * pixel_h / 4;
const int yuv_frame_len = y_frame_len + u_frame_len + v_frame_len;//一帧yuv数据的长度

int main(int argc, char* argv[])
{
    if(SDL_Init(SDL_INIT_VIDEO))
    {
        qDebug("无法初始化 SDL - %s\n", SDL_GetError());
        return -1;
    }

    SDL_Window *screen = SDL_CreateWindow("简单的SDL2播放窗口",
                                          SDL_WINDOWPOS_UNDEFINED,
                                          SDL_WINDOWPOS_UNDEFINED,
                                          screen_w, //窗口尺寸
                                          screen_h,
                                          SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
    if(!screen)
    {
        printf("SDL无法创建窗口 :%s\n",SDL_GetError());
        return -1;
    }
    SDL_Renderer* sdlRenderer = SDL_CreateRenderer(screen, -1, 0);

    SDL_Texture* sdlTexture = SDL_CreateTexture(sdlRenderer,
                                                SDL_PIXELFORMAT_IYUV,
                                                SDL_TEXTUREACCESS_STREAMING,
                                                pixel_w,
                                                pixel_h);

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

    QFile file("D:\\sintel_640_360.yuv");
    file.open(QIODevice::ReadOnly);

    while(1)
    {
        QByteArray array = file.read(yuv_frame_len);
        if(array.isEmpty())
        {
            file.seek(0);//游标回到起始位置（0）,然后从头读取，即重复播放
            array = file.read(yuv_frame_len);
        }

        SDL_UpdateTexture(sdlTexture, nullptr, array, pixel_w);

        SDL_RenderClear(sdlRenderer);//清除当前渲染器的内容
        SDL_RenderCopy(sdlRenderer, sdlTexture, nullptr, &sdlRect);
        SDL_RenderPresent(sdlRenderer);

        SDL_Delay(40);
    }
    file.close();

    SDL_Quit();
    return 0;
}