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• Use ffmpeg to extract audio track and subtiles to a m3u8 files which can work with video.js

  12 juillet 2020, par Maxou

  I download video with multiple audio track and subtiles but I don't know the exact number and I want to convert this video to m3u8. Someone know a command which can do what i want ? Thanks

  


• How does FFMPEG copy work ?

  24 novembre 2017, par Tyler Brooks

  How can I implement the equivalent of this command :

  ffmpeg -i test.h264 -vcodec copy -hls_time 5 -hls_list_size 0 foo.m3u8

  My understanding is that you do something like this (pseudo code for clarity) :

  avformat_open_input(&ctx_in, "test.h264", NULL, NULL);
  
  avformat_find_stream_info(ctx_in, NULL);
  
  
  
  avformat_alloc_output_context2(&ctx_out, NULL, "hls", "foo.m3u8");
  
  strm_out = avformat_new_stream(ctx_out, NULL);
  
  strm_out->time_base = (AVRational){1000000, FRAMERATE};
  
  
  
  strm_out->codecpar->codec_id = AV_CODEC_ID_H264;
  
  strm_out->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
  
  strm_out->codecpar->width = width;
  
  strm_out->codecpar->height = height;
  
  strm_out->codecpar->bit_rate = bitrate;
  
  strm_out->codecpar->codec_tag = 0;
  
  
  
  avcodec_parameters_copy(ctx_out->streams[0]->codecpar,
  
    ctx_in->streams[0]->codecpar);
  
  
  
  avformat_write_header(ctx_out, NULL);
  
  
  
  while(1) {
  
    AVPacket pkt;
  
  
  
    ret = av_read_frame(ctx_in, &pkt);
  
    if (ret < 0)
  
      break;
  
  
  
    pkt.pos = -1;
  
    pkt.stream_index = 0;
  
    pkt.dts = AV_NOPTS_VALUE;
  
    pkt.pts = AV_NOPTS_VALUE;
  
    pkt.pts = SOME_DURATION;
  
  
  
    av_write_frame(ctx_out, &pkt);
  
    av_packet_unref(&pkt);
  
  }
  
  avformat_close_input(&ctx_in);
  
  av_write_trailer(ctx_out);
  
  avformat_free_context(ctx_out);

  I crash on the avformat_find_stream_info() call. I think this is the case because an H264 elemental stream is not really a container (which avformat wants).

  What is the proper way to implement the FFMPEG ’copy’ command of an elemental stream ?

• Mavericks OpenCV 2.4.9 videoWriter doesn't work

  29 septembre 2014, par Maggick

  I’m having issues writing out video files using OpenCV on Mac.

  I’m running Mavericks and have OpenCV 2.4.9 and FFMPEG 2.4.1 installed, and the newest x264 from videolan.

  But when I run even the example code from opencv website I still am not able to produce a video. http://docs.opencv.org/doc/tutorials/highgui/video-write/video-write.html

  When I run the example code I get a blank video file.

  So my code doesn’t seem to be the problem. And I don’t get any errors so I am assuming the problem is with the codec not working. But I don’t understand what I am missing.

  Has anyone else had a similar problem ? Since I’m using a Mac I cannot use the -1 flag to pick a codec.