(SDL)一個簡單的SDL視頻文件播放程序

時間 2020-06-03

標籤 sdl 一個簡單視頻文件播放程序简体版

原文原文鏈接

須要說明的是，對於新手須要在ubuntu系統安裝SDL庫安裝包和開發安裝包，能夠參考官網的文章：ios

https://wiki.libsdl.org/Installationubuntu

SDL是跨平臺的，下面的代碼更改下#include路徑，指引下鏈接lib庫，就能夠在windows上編譯運行。windows

文章旨在快速運行一個example，具體SDL API需查看官方文檔。ide

 1 #include "iostream"
 2 #include "SDL2/SDL.h"
 3 
 4 #define PIXEL_W 352
 5 #define PIXEL_H 288
 6 #define IMAGE_SIZE 152064 // 352 * 288 * 1.5
 7 
 8 #define REFRESH_EVENT (SDL_USEREVENT + 1) // 自定義事件，每40毫秒觸發圖像幀更新
 9 
 10 bool thread_exit = false;  11 // 每40毫秒出發圖像幀更新
 12 int refresh_video(void *opaque)  13 {  14     while (thread_exit == false)  15  {  16         SDL_Event event;  17         event.type = REFRESH_EVENT;  18         SDL_PushEvent(&event);  19         std::cout << "push REFRESH_EVENT" << std::endl;  20         SDL_Delay(40);  21  }  22 
 23     return 0;  24 }  25 
 26 int main(int argc, char **argv)  27 {  28     if (SDL_Init(SDL_INIT_VIDEO) == -1)  29  {  30         std::cout << SDL_GetError() << std::endl;  31         return -1;  32  }  33 
 34     SDL_Window *sdlWindow = NULL;  35     sdlWindow= SDL_CreateWindow("SDL example", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, PIXEL_W, PIXEL_H, SDL_WINDOW_OPENGL);  36     if (sdlWindow == NULL)  37  {  38         std::cout << SDL_GetError() << std::endl;  39         return -1;  40  }  41 
 42     SDL_Renderer *sdlRenderer = NULL;  43     sdlRenderer = SDL_CreateRenderer(sdlWindow, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);  44     if (sdlRenderer == NULL)  45  {  46         std::cout << SDL_GetError() << std::endl;  47         return -1;  48  }  49 
 50     SDL_Texture *sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, PIXEL_W, PIXEL_H);  51 
 52     FILE *fp = fopen("352_288_example.IYUV", "r");  53     if (fp == NULL)  54  {  55         std::cout << "open file error" << std::endl;  56         return -1;  57  }  58 
 59     char *pImageBuffer = (char *)malloc(IMAGE_SIZE);  60     if (pImageBuffer == NULL)  61  {  62         std::cout << "malloc image buffer error" << std::endl;  63         return -1;  64  }  65 
 66     memset(pImageBuffer, 0x00, IMAGE_SIZE);  67 
 68  SDL_Rect sdlRect;  69     sdlRect.x = 0;  70     sdlRect.y = 0;  71     sdlRect.w = PIXEL_W;  72     sdlRect.h = PIXEL_H;  73 
 74     SDL_Event event;  75     SDL_Thread *refresh_thread = SDL_CreateThread(refresh_video, NULL, NULL);  76 
 77     while(1)  78  {  79         std::cout << "waiting event..." << std::endl;  80         SDL_WaitEvent(&event);  81         if (event.type == REFRESH_EVENT)  82  {  83             std::cout << "get REFRESH_EVENT." << std::endl;  84             if (fread(pImageBuffer, 1, IMAGE_SIZE, fp) != IMAGE_SIZE)  85  {  86                 fseek(fp, 0, SEEK_SET);  87                 fread(pImageBuffer, 1, IMAGE_SIZE, fp);  88  }  89 
 90  SDL_UpdateTexture(sdlTexture, NULL, pImageBuffer, PIXEL_W);  91  SDL_RenderClear(sdlRenderer);  92             SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, &sdlRect);  93  SDL_RenderPresent(sdlRenderer);  94  }  95         else if (event.type == SDL_QUIT)  96  {  97             std::cout << "get QUIT." << std::endl;  98             break;  99  } 100         else
101  { 102             std::cout << event.type << std::endl; 103  } 104  } 105 
106     thread_exit = true; 107     return 0; 108 }