Libav和网络摄像头捕获

Question

尝试使用ffmpeg打开网络摄像头（ffplay -f video4linux2 / dev / video0正常工作

    pFormatCtx = NULL;
    av_register_all();
    avcodec_register_all();
    avformat_network_init();


    const char      device[]     = "/dev/video0";
    const char      formatName[] = "video4linux";

if (!(pFormat = av_find_input_format(formatName))) {
     printf("can't find input format %s\n", formatName);
     return ;
}

if (avformat_open_input(&pFormatCtx, device, pFormat,  NULL)!=0) {
     printf("can't find open input file %s\n", device);
     return ;
}

但pFormat始终为0;

更新：如何从网络摄像头获取mjpeg？

Answer 1

你应该在开头调用avdevice_register_all（）。

pFormatCtx = NULL;
av_register_all();
avdevice_register_all();
avcodec_register_all();
avformat_network_init();

const char      device[]     = "/dev/video0";
const char      formatName[] = "video4linux";

if (!(pFormat = av_find_input_format(formatName))) {
  printf("can't find input format %s\n", formatName);
  return ;
}

if (avformat_open_input(&pFormatCtx, device, pFormat,  NULL)!=0) {
  printf("can't find open input file %s\n", device);
  return ;
}