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• Creating Thumbnail Image from Video using FFMPEG is not working in ASP.NET Core

  17 août 2020, par TanvirArjel

  I am trying to create thumbnail image for uploaded video with FFMPEG in ASP.NET Core as follows :

  



  private void GetThumbnail(IFormFile file)
{
        var fileName = CreateEmployeeViewModel.Video.FileName;
        var webRootPath = _webHostEnvironment.WebRootPath;
        var filePath = Path.Combine(webRootPath, "videos", fileName);

        var fileExtension = Path.GetExtension(filePath);
        var thumbnailImageName = fileName.Replace(fileExtension, ".jpg");
        var thumbnailImagePath = Path.Combine(webRootPath, "thumbnails", thumbnailImageName);

        ProcessStartInfo startInfo = new ProcessStartInfo();

        string arguments = $"-i {filePath} -ss 00:00:14.435 -vframes 1 {thumbnailImagePath}";

        startInfo.FileName = Path.Combine(Directory.GetCurrentDirectory(), "Ffmpeg\\ffmpeg.exe");
        startInfo.CreateNoWindow = false;
        startInfo.UseShellExecute = false;
        startInfo.RedirectStandardError = true;
        startInfo.RedirectStandardOutput = true;
        startInfo.WindowStyle = ProcessWindowStyle.Hidden;
        startInfo.Arguments = arguments;

        try
        {
            Process process = Process.Start(startInfo);
            process.WaitForExit(5000);
            process.Close();
        }
        catch
        {
            // Log error.
        }

}


  



  It's not showing any error but it's also not generating the thumbnail image. am I missing anything please ?

  



  Note : if I execute the above configuration from command line its works !

  


• How to run the set of commands in windows command line

  24 février 2020, par robert.little

  x264-preset is used in the second command (Cmd 2). Is it substitution or ?

  Cmd 1 :

  x264-preset:
  
  vcodec=libx264
  
  thread_type=slice
  
  slices=1
  
  profile=baseline
  
  level=32
  
  preset=superfast
  
  tune=zerolatency
  
  intra-refresh=1
  
  crf=15
  
  x264-params=vbv-maxrate=5000:vbv-bufsize=1:slice-max-size=1500:keyint=60

  Cmd 2

  $ ffmpeg -r 30 -f dshow -i video="devicename" -pix_fmt yuv420p -an -vpre
  
  x264-preset -f mpegts udp://127.0.0.1:8888

  When I run the Cmd 1 it doesn’t work. Even with the SET like :

  x264-preset:
  
  SET vcodec=libx264
  
  SET thread_type=slice
  
  SET slices=1
  
  SET profile=baseline
  
  SET level=32
  
  SET preset=superfast
  
  SET tune=zerolatency
  
  SET intra-refresh=1
  
  SET crf=15
  
  SET x264-params=vbv-maxrate=5000:vbv-bufsize=1:slice-max-size=1500:keyint=60

  Source :
  https://lists.ffmpeg.org/pipermail/ffmpeg-user/2016-January/030127.html

• how to fix nvidia hevc transcoding problem

  25 novembre 2019, par Dlniya Dlzar

  we are using FFmpeg for media broadcasting DVB-T2
  the structure is like that :

  [ source h264 (multicast) >> FFmpeg h265 >> scrambler ]

  we are using Nvidia GPU for transcoding

  the problem is, when we transcode to H265 there is an issue when we play the video.
  it is like cc error or maybe muxing issue, we don’t know, what we know is, the stream has lagging every few mins.
  we played the output stream by FFmpeg again

  /root/bin/ffmpeg -v error -i udp://lo@127.0.0.1:5000 -f null - 2>error.log

  we got this

  [hevc @ 0x2610b40] PPS id out of range: 0
  
      Last message repeated 35 times
  
  [hevc @ 0x2604a80] Could not find ref with POC 21

  and here is our FFmpeg command line example for transcoding

  /root/bin/ffmpeg -re -y -vsync 0 -hwaccel cuvid -c:v h264_cuvid  -deint 2  -drop_second_field 1 -surfaces 10 -fflags discardcorrupt+genpts+nobuffer -i   "udp://227.30.40.4:1234?localaddr=192.168.2.55&overrun_nonfatal=1&&fifo_size=50000000" -map 0:p:352 -af aresample=async=1  -acodec aac -ac 1 -strict -2  -vcodec hevc_nvenc  -g 40  -b:v 2300k -minrate 2300k -maxrate 2300k -bufsize 2300k -preset hq -metadata service_provider="ISTAR MEDIA" -metadata service_name="KURDMAX" -flags cgop -sc_threshold 500  -f mpegts -muxrate 2700k  -y  "udp://227.2.2.6:1234?localaddr=192.168.2.55&fifo_buffer=50000000&overrun_nonfatal_option=1&bitrate=2700000&burst_bits=2700000&pkt_size=1316" 2> /var/log/ffmpeg/kurdmax.txt