SDL2播放显示yuv视频

SDL2播放显示yuv视频

配置请参照前面的笔记https://www.cnblogs.com/zzr-stdio/p/14514043.html

如果没有yuv的视频，可以使用ffmpeg将一段avi等视频转为yuv的视频。简易命令如下：

ffmpeg.exe -i 1.avi test_1280x720.yuv

这里1.avi视频的分辨率就是1280x720.记住这个分辨率，对后面读取yuv文件很重要。

示例代码：

#include <iostream>
#include<Windows.h>
#include<fstream>
#include<string>
#include<SDL.h>
#include<SDL_filesystem.h>
using namespace std;

int main(int argc, char* argv[])
{
	int cx = ::GetSystemMetrics(SM_CXSCREEN);//获取屏幕的宽度 1920
	int cy = ::GetSystemMetrics(SM_CYSCREEN);//获取屏幕的高度 1080
	
	int const SCREEN_W = cx;
	int const SCREEN_H = cy;
	int const SCREEN_X = 0;
	int const SCREEN_Y = 0;
	char info[100] = { 0 };
	sprintf_s(info, "屏幕分辨率：%dx%d", cx, cy);
	cout << info << endl;
	char* ch = SDL_GetBasePath();//获取运行目录
	string outfilename = string(ch) + string("test_1280x720.yuv");//拼接视频文件路径，该文件是yuv420。
	
	int width = 1280;//yuv视频分辨率，宽度，注意此处一定要填写正确的.yuv文件的分辨率宽度
	int height = 720;//yuv视频分辨率，高度，注意此处一定要填写正确的.yuv文件的分辨率高度
	int size = width * height * 3 / 2;//这是每帧画面的字节数量
	FILE* fs;
	::fopen_s(&fs, outfilename.c_str(), "rb+");
	if (fs == nullptr)
	{
		cout << "打开文件失败！" << endl;
		return 1;
	}
	::SDL_Init(SDL_INIT_VIDEO);//日常初始化SDL
	
	SDL_Window* window = SDL_CreateWindow("h", SCREEN_X, SCREEN_Y, SCREEN_W, SCREEN_H, SDL_WINDOW_SHOWN);
	SDL_SetWindowOpacity(window, 1);//设置透明度
	SDL_Renderer* rend = SDL_CreateRenderer(window, -1, 0);
	Uint32 pixformat = SDL_PIXELFORMAT_IYUV;//该文件的格式
	SDL_Texture* sdlTexture = SDL_CreateTexture(rend, pixformat, SDL_TEXTUREACCESS_STREAMING, width, height);//创建对应纹理
	SDL_Event event;
	unsigned char* buffer = new unsigned char[size];//每帧存储缓存
	int count = 1;
	SDL_Rect rect = { 0, 0, SCREEN_W, SCREEN_H };
	bool quit = false;
	while (quit == false)
	{
		while (SDL_PollEvent(&event))//事件循环
		{
			if (event.type == SDL_QUIT) //响应退出
            {
				quit = true;
			}
		}
		 memset(buffer, 0, size);//清零，实际也可以不清零，因为后一个画面数据会全部覆盖前一个画面的数据。
		 size_t len = ::fread(buffer, 1, size, fs);//从文件读取一帧画面
		 //cout << "第" << count++ << "帧" << endl;
		 if (len != size)
		 {
			 count = 1;
			 ::fseek(fs, 0, 0);//循环播放
			 continue;
		 }
		 SDL_UpdateTexture(sdlTexture, nullptr, buffer, width);//更新纹理画面
		 SDL_RenderClear(rend);
		 SDL_RenderCopy(rend, sdlTexture, nullptr, &rect);//显示画面
		 SDL_RenderPresent(rend);
		 ::SDL_Delay(1000 / 25);//控制显示帧速度
	}
    fclose(fs);//关闭文件
	::SDL_DestroyTexture(sdlTexture);
	::SDL_DestroyRenderer(rend);
	::SDL_DestroyWindow(window);
	::SDL_Quit();
    std::cout << "Hello World!
";
	getchar();
	return 0;
}