FFmpeg 简易播放器

  include_directories(/usr/local/Cellar/ffmpeg/4.2.2_3/include/ /usr/local/Cellar/sdl2/2.0.12_1/include/)
  link_directories(/usr/local/Cellar/ffmpeg/4.2.2_3/lib/ /usr/local/Cellar/sdl2/2.0.12_1/lib/)

  add_executable(simple_player simple_player.c)

  target_link_libraries(
          simple_player
          avcodec
          avdevice
          avfilter
          avformat
          avresample
          avutil
          postproc
          swresample
          swscale
          sdl2
  )

#include <libavformat/avformat.h>  
#include <libavcodec/avcodec.h>  
#include <libswscale/swscale.h>  
#include <libavutil/imgutils.h>  
#include <SDL2/SDL.h>  
#include <SDL2/SDL_thread.h>  

int main(int argc, char *argv[]) {
    if (argc < 2) {
        return -1;
    }
    int ret = -1, i = -1, v_stream_idx = -1;
    char *vf_path = argv[1];
    AVFormatContext *fmt_ctx = NULL;
    AVCodecContext *codec_ctx = NULL;
    AVCodec *codec;
    AVFrame *frame;
    AVPacket packet;

    ret = avformat_open_input(&fmt_ctx, vf_path, NULL, NULL);
    if (ret < 0) {
        printf("Open video file %s failed \n", vf_path);
        goto end;
    }
    if (avformat_find_stream_info(fmt_ctx, NULL) < 0)
        goto end;
    av_dump_format(fmt_ctx, 0, vf_path, 0);
    for (i = 0; i < fmt_ctx->nb_streams; i++) {
        if (fmt_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
            v_stream_idx = i;
            break;
        }
    }
    if (v_stream_idx == -1) {
        printf("Cannot find video stream\n");
        goto end;
    }

    codec_ctx = avcodec_alloc_context3(NULL);
    avcodec_parameters_to_context(codec_ctx, fmt_ctx->streams[v_stream_idx]->codecpar);
    codec = avcodec_find_decoder(codec_ctx->codec_id);
    if (codec == NULL) {
        printf("Unsupported codec for video file\n");
        goto end;
    }
    if (avcodec_open2(codec_ctx, codec, NULL) < 0) {
        printf("Can not open codec\n");
        goto end;
    }

    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
        printf("Could not init SDL due to %s", SDL_GetError());
        goto end;
    }
    SDL_Window *window;
    SDL_Renderer *renderer;
    SDL_Texture *texture;
    SDL_Event event;
    SDL_Rect r;
    window = SDL_CreateWindow("SDL_CreateTexture", SDL_WINDOWPOS_UNDEFINED,
                              SDL_WINDOWPOS_UNDEFINED, codec_ctx->width, codec_ctx->height,
                              SDL_WINDOW_RESIZABLE);
    r.x = 0;
    r.y = 0;
    r.w = codec_ctx->width;
    r.h = codec_ctx->height;

    renderer = SDL_CreateRenderer(window, -1, 0);
    texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_YV12, SDL_TEXTUREACCESS_STREAMING,
                                codec_ctx->width, codec_ctx->height);

    struct SwsContext *sws_ctx = NULL;
    sws_ctx = sws_getContext(codec_ctx->width, codec_ctx->height, codec_ctx->pix_fmt,
                             codec_ctx->width, codec_ctx->height, AV_PIX_FMT_YUV420P, SWS_BILINEAR, NULL, NULL, NULL);

    frame = av_frame_alloc();

    int ret1, ret2;
    AVFrame *pict;
    pict = av_frame_alloc();


    int numBytes;
    uint8_t *buffer = NULL;
    numBytes = av_image_get_buffer_size(AV_PIX_FMT_YUV420P, codec_ctx->width, codec_ctx->height, 1);
    buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
    // required, or bad dst image pointers
    av_image_fill_arrays(pict->data, pict->linesize, buffer, AV_PIX_FMT_YUV420P, codec_ctx->width, codec_ctx->height,
                         1);
    while (1) {
        SDL_PollEvent(&event);
        if (event.type == SDL_QUIT)
            break;
        ret = av_read_frame(fmt_ctx, &packet);
        if (ret < 0) {
            continue;
        }
        if (packet.stream_index == v_stream_idx) {
            ret1 = avcodec_send_packet(codec_ctx, &packet);
            if (ret1 < 0) {
                continue;
            }
            ret2 = avcodec_receive_frame(codec_ctx, frame);
            if (ret2 < 0) {
                continue;
            }
            sws_scale(sws_ctx, (uint8_t const *const *) frame->data,
                      frame->linesize, 0, codec_ctx->height,
                      pict->data, pict->linesize);
            SDL_UpdateYUVTexture(texture, &r, pict->data[0], pict->linesize[0],
                                 pict->data[1], pict->linesize[1],
                                 pict->data[2], pict->linesize[2]);
            SDL_RenderClear(renderer);
            SDL_RenderCopy(renderer, texture, NULL, NULL);
            SDL_RenderPresent(renderer);
            SDL_Delay(16);
        }
        av_packet_unref(&packet);
    }
    SDL_DestroyRenderer(renderer);
    SDL_Quit();
    av_frame_free(&frame);
    avcodec_close(codec_ctx);
    avcodec_free_context(&codec_ctx);
    end:
    avformat_close_input(&fmt_ctx);
    printf("Shutdown\n");
    return 0;
}