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• FFMPEG Process not ending when encoding libx264

  17 janvier 2015, par Jamie Hartnoll

  Well, I’m very new and inexperienced with using Process and using FFMPEG, and command line processes in ASP.NET in general... but, have something working, nearly !

  I’m trying to convert AVI files to MP4 files which can be streamed to an HTML5 player.

  After a lot of messing around, I have found that for this to work it has to be encoded with X264, but, for some reason, when I do this the FFMPEG process does not close/end.

  The code I am using is below and works perfectly if I use -vcodec mpeg4, but when I use -vcodec libx264, whilst it works and produces the file I need to Process never ends.

  To get round this, I am temporarily adding 5 second time out to WaitForExit in the Process, but this is definitely a hack and whilst is OK with what I am doing at the moment is not a robust solution.

  Can anyone point me in the direction of why this is happening ?!

  Public Shared Sub AviToMP4(VideoFileName As String, Optional DeleteSource As Boolean = True)
  
  
  
      Dim SourceFile As String = VideoFileName.Replace(".avi", "")
  
      Dim DestinationFile As String = SourceFile
  
  
  
      Dim FFMPEG_EXE_PATH As String = """" & System.AppDomain.CurrentDomain.BaseDirectory() & "ffMPEG.exe"""
  
      Dim Codec = "libx264" ' libx264 || mpeg4
  
      Dim cdml = " -i """ & SourceFile & ".avi"" -acodec aac -strict -2 -b:a 128k -vcodec " & Codec & " -b:v 1200k -flags +aic+mv4 """ & DestinationFile & ".mp4"""
  
  
  
      Dim ProcessorLocation As String = FFMPEG_EXE_PATH
  
      Dim CommandLines As String = cdml
  
  
  
      Try
  
          Dim ProcessingResponse As String = ""
  
          Using myProcess As New Process()
  
              myProcess.StartInfo.UseShellExecute = False
  
              myProcess.StartInfo.RedirectStandardInput = True
  
              myProcess.StartInfo.RedirectStandardOutput = True
  
              myProcess.StartInfo.RedirectStandardError = True
  
              myProcess.StartInfo.CreateNoWindow = True
  
              myProcess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden
  
              myProcess.StartInfo.FileName = ProcessorLocation
  
              myProcess.StartInfo.Arguments = CommandLines
  
              myProcess.Start()
  
              ProcessingResponse = myProcess.StandardError.ReadToEnd()
  
              myProcess.WaitForExit(5000) ' <<< Have to put a timeout here for libx264 or it will never end!!
  
          End Using
  
          HttpContext.Current.Response.Write("<pre>" &amp; ProcessingResponse &amp; "</pre><hr />")
  
          If File.Exists(SourceFile) AndAlso DeleteSource Then
  
              File.Delete(SourceFile)
  
          End If
  
      Catch ex As Exception
  
          HttpContext.Current.Response.Write(ex.ToString &amp; "<p>")
  
      End Try
  
  
  
  End Sub
  
  </p>

• Streaming x264 with packet loss

  6 octobre 2014, par user2629511

  I write the program where I use x264 as the coder.
  I use the following parameters :

  av_opt_set (codecContextH264[numberCoder]-> priv_data, "profile", "baseline", 0);
  
  av_opt_set (codecContextH264[numberCoder]-> priv_data, "preset", "ultrafast", 0);
  
  av_opt_set (codecContextH264[numberCoder]-> priv_data, "tune", "zerolatency", 0);
  
  codecContextH264[numberCoder]-> bit_rate =bitrate;
  
  codecContextH264[numberCoder]-> bit_rate_tolerance=bitrate-5000;
  
  codecContextH264[numberCoder]-> width = w;
  
  codecContextH264[numberCoder]-> height = h;
  
  codecContextH264[numberCoder]-> time_base.den = fps;
  
  codecContextH264[numberCoder]-> time_base.num = 1;
  
  codecContextH264[numberCoder]-> pix_fmt = PIX_FMT_YUV420P;
  
  codecContextH264[numberCoder]-> gop_size = fps*3;
  
  codecContextH264[numberCoder]-> keyint_min = fps*3;
  
  codecContextH264[numberCoder]-> max_b_frames = 0; 
  
  codecContextH264[numberCoder]-> slices = (int) (w*h)/1500+1;

  I use only I and P frames.
  What x264 settings I shall use that could lose P frames ?
  Perhaps x264 has no such opportunity ?!
  I read that if to use a "base" profile, it is possible to lose P frames...
  Help please.

• Streaming x264 with packet loss

  6 octobre 2014, par user2629511

  I write the program where I use x264 as the coder.
  I use the following parameters :

  av_opt_set (codecContextH264[numberCoder]-> priv_data, "profile", "baseline", 0);
  
  av_opt_set (codecContextH264[numberCoder]-> priv_data, "preset", "ultrafast", 0);
  
  av_opt_set (codecContextH264[numberCoder]-> priv_data, "tune", "zerolatency", 0);
  
  codecContextH264[numberCoder]-> bit_rate =bitrate;
  
  codecContextH264[numberCoder]-> bit_rate_tolerance=bitrate-5000;
  
  codecContextH264[numberCoder]-> width = w;
  
  codecContextH264[numberCoder]-> height = h;
  
  codecContextH264[numberCoder]-> time_base.den = fps;
  
  codecContextH264[numberCoder]-> time_base.num = 1;
  
  codecContextH264[numberCoder]-> pix_fmt = PIX_FMT_YUV420P;
  
  codecContextH264[numberCoder]-> gop_size = fps*3;
  
  codecContextH264[numberCoder]-> keyint_min = fps*3;
  
  codecContextH264[numberCoder]-> max_b_frames = 0; 
  
  codecContextH264[numberCoder]-> slices = (int) (w*h)/1500+1;

  I use only I and P frames.
  What x264 settings I shall use that could lose P frames ?
  Perhaps x264 has no such opportunity ?!
  I read that if to use a "base" profile, it is possible to lose P frames...
  Help please.