逍遙文工作室

#include <SDL2/SDL.h>

extern "C" {
  #include <libavformat/avformat.h>
  #include <libavcodec/avcodec.h>
  #include <libavutil/imgutils.h>
  #include <libswscale/swscale.h>
}

int screen_width = 1280;
int screen_height = 720;

int main(int argc, char *argv[]) {
    // Initialize SDL
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        fprintf(stderr, "SDL initialization failed: %s\n", SDL_GetError());
        return -1;
    }

    // Open the video file
    const char *filename = "/Users/happyman/Work/TestSDL/TestSDL/sample.264";
    AVFormatContext *formatContext = avformat_alloc_context();
    if (avformat_open_input(&formatContext, filename, NULL, NULL) != 0) {
        fprintf(stderr, "Failed to open video file\n");
        return -1;
    }

    // Find the video stream information
    if (avformat_find_stream_info(formatContext, NULL) < 0) {
        fprintf(stderr, "Failed to find stream information\n");
        return -1;
    }

    // Find the video stream
    int videoStream = -1;
    for (int i = 0; i < formatContext->nb_streams; i++) {
        if (formatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
            videoStream = i;
            break;
        }
    }

    if (videoStream == -1) {
        fprintf(stderr, "No video stream found\n");
        return -1;
    }

    // Get the codec parameters
    AVCodecParameters *codecParameters = formatContext->streams[videoStream]->codecpar;

    // Find the decoder
    AVCodec *codec = (AVCodec *)avcodec_find_decoder(codecParameters->codec_id);
    if (codec == NULL) {
        fprintf(stderr, "Unsupported codec\n");
        return -1;
    }

    // Create a codec context
    AVCodecContext *codecContext = avcodec_alloc_context3(codec);
    if (avcodec_parameters_to_context(codecContext, codecParameters) < 0) {
        fprintf(stderr, "Failed to copy codec parameters to codec context\n");
        return -1;
    }

    // Open the codec
    if (avcodec_open2(codecContext, codec, NULL) < 0) {
        fprintf(stderr, "Failed to open codec\n");
        return -1;
    }

    // Create an SDL window
    SDL_Window *window = SDL_CreateWindow("Video Player", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, screen_width, screen_height, SDL_WINDOW_SHOWN);
    if (window == NULL) {
        fprintf(stderr, "Failed to create SDL window: %s\n", SDL_GetError());
        return -1;
    }

    // Create an SDL renderer
    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
    if (renderer == NULL) {
        fprintf(stderr, "Failed to create SDL renderer: %s\n", SDL_GetError());
        return -1;
    }

    // Create an SDL texture
    SDL_Texture *texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, codecContext->width, codecContext->height);
    if (texture == NULL) {
        fprintf(stderr, "Failed to create SDL texture: %s\n", SDL_GetError());
        return -1;
    }

    // Allocate video frame
    AVFrame *frame = av_frame_alloc();
    if (frame == NULL) {
        fprintf(stderr, "Failed to allocate video frame\n");
        return -1;
    }

    // Allocate an AVPacket
    AVPacket *packet = av_packet_alloc();
    if (packet == NULL) {
        fprintf(stderr, "Failed to allocate packet\n");
        return -1;
    }

    // Initialize SWS context for software scaling
    struct SwsContext *swsContext = sws_getContext(codecContext->width, codecContext->height, codecContext->pix_fmt, codecContext->width, codecContext->height, AV_PIX_FMT_YUV420P, SWS_BILINEAR, NULL, NULL, NULL);

    // 顯示位置與大小
    int width = 1000;
    SDL_Rect sdl_rect;
    sdl_rect.x = 0;
    sdl_rect.y = 0;
    sdl_rect.w = width;
    sdl_rect.h = codecContext->height*width/codecContext->width;
    
    // Event loop
    SDL_Event event;
    Uint32 targetFramerate = 30;
    Uint32 frameDelay = 1000 / targetFramerate; // Delay between frames in milliseconds
    Uint32 frameStart, frameTime;
    
    while (1) {
        frameStart = SDL_GetTicks();
        // Read frame
        if (av_read_frame(formatContext, packet) >= 0) {
            
            if (SDL_PollEvent(&event)) {
                if (event.type == SDL_MOUSEBUTTONDOWN) {
                    
                }
                if (event.type == SDL_QUIT) {
                    break;
                }
            }

            if (packet->stream_index == videoStream) {
                // Send packet to decoder
                if (avcodec_send_packet(codecContext, packet) == 0) {
                    // Receive frame from decoder
                    if (avcodec_receive_frame(codecContext, frame) == 0) {
                        // Convert the image from its native format to YUV420
                        sws_scale(swsContext, frame->data, frame->linesize, 0, codecContext->height,
                                  frame->data, frame->linesize);

                        // Update texture
                        SDL_UpdateYUVTexture(texture,                   // sdl texture
                                             NULL,                 // sdl rect
                                             frame->data[0],            // y plane
                                             frame->linesize[0],        // y pitch
                                             frame->data[1],            // u plane
                                             frame->linesize[1],        // u pitch
                                             frame->data[2],            // v plane
                                             frame->linesize[2]         // v pitch
                                             );
                        
                        // Clear the screen
                        SDL_RenderClear(renderer);

                        // Copy the texture to the renderer
                        SDL_RenderCopy(renderer, texture, NULL, &sdl_rect);

                        // Render the frame
                        SDL_RenderPresent(renderer);
                        
                        // Delay to control frame rate
                        frameTime = SDL_GetTicks() - frameStart;
                        if (frameDelay > frameTime) {
                            SDL_Delay(frameDelay - frameTime);
                        }
                    }
                }
            }

            // Free the packet that was allocated by av_read_frame
            av_packet_unref(packet);
        }
    }

    // Clean up
    SDL_DestroyTexture(texture);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);

    sws_freeContext(swsContext);

    av_frame_free(&frame);
    av_packet_free(&packet);
    avcodec_free_context(&codecContext);
    avformat_close_input(&formatContext);

    SDL_Quit();

    return 0;
}