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• pyav / ffmpeg / libav receiving too many keyframe

  26 mai 2021, par user1315621

  I am streaming from an rtsp source. It looks like half of the frames received are key frames. Is there a way to reduce this percentage and have an higher number of P-frames and B-frames ? If possible, I would like to increase the number of P-frames (not the one of B-frames).
I am using pyav which is a Python wrapper for libav (ffmpeg)

  


  Code :

  


  container = av.open(
    url, 'r',
    options={
        'rtsp_transport': 'tcp',
        'stimeout': '5000000',
        'max_delay': '5000000',
    }
)
stream = container.streams.video[0]
codec_context = stream.codec_context
codec_context.export_mvs = True
codec_context.gop_size = 25  

for packet in self.container.demux(video=0):
    for video_frame in packet.decode():
        print(video_frame.is_key_frame)


  


  Output :

  


  True
False
True
False
...


  


  Note 1 : I can't edit the source. I can just edit the code used to stream the video.

  


  Note 2 : same solution should apply to pyav, libavi and ffmpeg.

  


  Edit : it seems that B-frames are disabled : codec_context.has_b_frames is False

  


• how to provide login username and password to ffmpeg ?

  11 septembre 2012, par Lynx

  how can i provide username and password to ffmpeg to enable it to write data to some folder in ftp server ?
  the folder is protected by password and if possible i dont want to remove that password. so, can i simply just pass the password to ffmpeg ? or is there any other solutions ?

  example of ffmpeg process to create thumbnail from video file

  string thumbpath, thumbname, videofile;
  
  videofile = "Video Source path";
  
  thumbpath = "thumbnail path";
  
  thumbname = thumbpath + "20120910160600.mjpeg";
  
  
  
  string thumbargs = "-i \"" + videofile + "\" -vframes 1 -s 60*30 -ss 00:00:00 -f image2 \"" + thumbname + "\"";
  
  
  
  Process process = new Process();
  
  
  
  process.StartInfo.FileName = Server.MapPath("~\\ffmpeg\\bin\\ffmpeg.exe");
  
  process.StartInfo.Arguments = thumbargs;
  
  
  
  process.StartInfo.UseShellExecute = false;
  
  process.StartInfo.RedirectStandardOutput = true;
  
  process.StartInfo.RedirectStandardInput = false;
  
  process.StartInfo.RedirectStandardError = true;
  
  process.StartInfo.CreateNoWindow = false;
  
  process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;

  New Learner,
  Please guide me....

• How to extract Images from MP4 video on upload - FFMPEG

  11 février 2015, par michael hanon

  I am putting together a training site for my company and we need to extract an image from each mp4 video we upload. I have searched lots and decided to try FFMPEG.

  Here is what I have so far. I’m not getting errors, but no image in the specified folder.

  Any help would be appreciated.

             string inputfile = Server.MapPath("/Report/TrainingLibrary/Material/Videos/RMSIMAILSignature.mp4");
           //string withouttext;
           string thumbpath;
           string thumbname;
           string thumbargs;
           //string thumbre;
          thumbpath = AppDomain.CurrentDomain.BaseDirectory + "Reports\\ TrainingLibrary\\Material\\Videos\\";
           thumbname = thumbpath + "Image" + "%d" + ".jpg";
           thumbargs = "-i " + inputfile + " -vframes 1 -ss 00:00:07 -s 150x150 " + thumbname;
           Process thumbproc = new Process();
           thumbproc = new Process();
           thumbproc.StartInfo.FileName = "C:\\FFMPEG\\Bin\\ffmpeg.exe";
           thumbproc.StartInfo.Arguments = thumbargs;
           thumbproc.StartInfo.UseShellExecute = false;
           thumbproc.StartInfo.CreateNoWindow = false;
           thumbproc.StartInfo.RedirectStandardOutput = false;
           try
           {
               thumbproc.Start();
           }
           catch (Exception ex)
           {
               Response.Write(ex.Message);
           }
           thumbproc.WaitForExit();
           thumbproc.Close();