add source code

CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(sdl-yuv LANGUAGES C)
+find_package(SDL2 REQUIRED)
+
+add_executable(sdl-yuv main.c)
+
+include(GNUInstallDirs)
+install(TARGETS sdl-yuv
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+)
+
+target_link_libraries(${PROJECT_NAME} PRIVATE SDL2::SDL2)

main.c

@@ -0,0 +1,141 @@
+#include <stdio.h>
+#include <SDL2/SDL.h>
+
+#define REFRESH_EVENT (SDL_USEREVENT + 1)
+#define QUIT_EVENT (SDL_USEREVENT + 1)
+
+#define YUV_WIDTH 320
+#define YUV_HEIGHT 240
+
+// SDL_PIXELFORMAT_IYUV =      /**< Planar mode: Y + U + V  (3 planes) */
+#define YUV_FORMAT SDL_PIXELFORMAT_IYUV
+
+int nThreadExitFlag = 0;
+
+int refreshVideoThread(void *data) {
+    while (!nThreadExitFlag)
+    {
+        SDL_Event event;
+        event.type = REFRESH_EVENT;
+        SDL_PushEvent(&event);
+        SDL_Delay(40);
+    }
+    nThreadExitFlag = 0;
+    SDL_Event eq;
+    eq.type = QUIT_EVENT;
+    SDL_PushEvent(&eq);
+
+    return 0;
+}
+
+int main()
+{
+    if (SDL_Init(SDL_INIT_VIDEO)) {
+        fprintf(stderr, "SDL_Init(SDL_INIT_VIDEO) failed: %s\n", SDL_GetError());
+        return -1;
+    }
+
+    SDL_Event event;
+    SDL_Rect rect;
+    SDL_Window *window;
+    SDL_Renderer *renderer = NULL;
+    SDL_Texture  *texture = NULL;
+    SDL_Thread *t = NULL;
+    uint32_t pixformat = YUV_FORMAT;
+    int video_width = YUV_WIDTH;
+    int video_height = YUV_HEIGHT;
+    int win_width = YUV_WIDTH;
+    int win_height = YUV_HEIGHT;
+
+    FILE *video_fd = NULL;
+    const char* yuv_path = "yuv420p_320x240.yuv";
+    size_t video_buff_len = 0;
+    uint8_t *video_buf = NULL;
+
+    uint32_t y_frame_len = video_width * video_height;
+    uint32_t u_frame_len = video_width * video_height / 4;
+    uint32_t v_frame_len = video_width * video_height / 4;
+    uint32_t yuv_frame_size = y_frame_len + u_frame_len + v_frame_len;
+
+    window = SDL_CreateWindow("YUV", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
+        win_width, win_height, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
+
+    if (!window) {
+        printf("SDL_CreateWindow() failed: %s\n", SDL_GetError());
+        goto fail;
+    }
+    // 基于窗口创建渲染器
+    renderer = SDL_CreateRenderer(window, -1, 0);
+    // 基于渲染器创建纹理
+    texture = SDL_CreateTexture(renderer, pixformat, SDL_TEXTUREACCESS_STREAMING,
+        video_width, video_height);
+    video_buf = (uint8_t*)malloc(yuv_frame_size);
+    if (!video_buf) {
+        fprintf(stderr, "malloc video_buf failed\n");
+    }
+
+    video_fd = fopen(yuv_path, "rb");
+    if (!video_fd) {
+        fprintf(stderr, "fopen failed\n");
+    }
+
+    t = SDL_CreateThread(refreshVideoThread, "refresh_video_thread", NULL);
+
+    while (1) {
+        SDL_WaitEvent(&event);
+
+        if (event.type == REFRESH_EVENT) {
+            video_buff_len = fread(video_buf, 1, yuv_frame_size, video_fd);
+            if (video_buff_len <= 0) {
+                fprintf(stderr, "fread from yuv file failed\n");
+                goto fail;
+            }
+            SDL_UpdateTexture(texture, NULL, video_buf, video_width);
+
+            rect.x = 0;
+            rect.y = 0;
+            float w_ratio = win_width * 1.0 / video_width;
+            float h_ratio = win_height * 1.0 / video_height;
+
+            // 保持宽高比
+            rect.w = video_width * w_ratio;
+            rect.h = video_height * h_ratio;
+            // 清楚渲染器中的缓存
+            SDL_RenderClear(renderer);
+            SDL_RenderCopy(renderer, texture, NULL, &rect);
+            SDL_RenderPresent(renderer);
+        }
+        else if (event.type == SDL_WINDOWEVENT) {
+            SDL_GetWindowSize(window, &win_width, &win_height);
+        }
+        else if (event.type == SDL_QUIT) {
+            nThreadExitFlag = 1;
+        }
+        else if (event.type == QUIT_EVENT) {
+            break;
+        }
+    }
+fail:
+    nThreadExitFlag = 1;
+    if (t) {
+        SDL_WaitThread(t, NULL);
+    }
+    if (video_buf) {
+        free(video_buf);
+    }
+    if (video_fd) {
+        fclose(video_fd);
+    }
+    if (texture) {
+        SDL_DestroyTexture(texture);
+    }
+    if (renderer) {
+        SDL_DestroyRenderer(renderer);
+    }
+    if (window) {
+        SDL_DestroyWindow(window);
+    }
+
+    SDL_Quit();
+    return 0;
+}