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• Can't find preset files

  1er juin 2012, par Bilthon

  this is a ffmpeg issue. I've got this error saying it could not find the hq preset file, then I read in the documentation that it looks for the preset files at 'PREFIX/share/ffmpeg' and also at '$HOME/.ffmpeg'. The thing is I'm calling ffmpeg from whithin a php file that calls a python script that finally executes the command something like 'commands.getstatusoutput(command)' so I was not sure who the user was.

  The solution ? I just used -fpre and my call now looks like this :

  /usr/local/bin/ffmpeg -i ../files/tmpvideos/myStream.flv -y -acodec libfaac -ab 96k -b 800k -maxrate 800k -minrate 600k -bufsize 800k -s 720x640 -vcodec libx264 -g 300 -r 20 -fpre /home/admin/.ffmpeg/libx264-hq.ffpreset -threads 0 ../files/tmpvideos/4647-60.mp4

  I created that directory under /home/admin and am 100% sure that there the file is there now, but still ffmpeg says :

  File for preset '/home/admin/.ffmpeg/libx264-hq.ffpreset' not found

  So I'm not sure why is it not working since I'm specifying the complete path now. Any ideas ?

  One reason that I'm thinking of, is that it maybe was not compiled correctly, like with all the flags and stuff. What I mean is that while some outputs out there looked like this :

  FFmpeg version SVN-r22976, Copyright (c) 2000-2010 the FFmpeg developers
  
    built on Apr 30 2010 12:03:12 with gcc 4.2.1-sjlj (mingw32-2)
  
    configuration: --enable-shared --enable-static --enable-memalign-hack
  
  --enable
  
  -libmp3lame --enable-libx264 --enable-gpl
  
    libavutil     50.14. 0 / 50.14. 0
  
    libavcodec    52.66. 0 / 52.66. 0
  
    libavformat   52.61. 0 / 52.61. 0
  
    libavdevice   52. 2. 0 / 52. 2. 0
  
    libswscale     0.10. 0 /  0.10. 0

  mine looks more like this :

  Output: FFmpeg version 0.6.1, Copyright (c) 2000-2010 the FFmpeg developers
  
    built on Nov 12 2010 16:32:38 with gcc 4.1.2 20080704 (Red Hat 4.1.2-48)
  
    configuration:
  
    libavutil     50.15. 1 / 50.15. 1
  
    libavcodec    52.72. 2 / 52.72. 2
  
    libavformat   52.64. 2 / 52.64. 2
  
    libavdevice   52. 2. 0 / 52. 2. 0
  
    libswscale     0.11. 0 /  0.11. 0

  No configuration stuff. What do u think ? could be that this ffmpeg was not compiled correctly so it will never find the presets ? I didn't compile it, so can't be sure.

  Thanks and sorry for the verbosity of the question.

  Nelson

• 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>

• lavfi : add a libplacebo filter

  26 juillet 2021, par Niklas Haas

  lavfi : add a libplacebo filter
  This filter conceptually maps the libplacebo `pl_renderer` API into
  
  libavfilter, which is a high-level image rendering API designed to work
  
  with an RGB pipeline internally. As such, there's no way to avoid e.g.
  
  chroma interpolation with this filter, although new versions of
  
  libplacebo support outputting back to subsampled YCbCr after processing
  
  is done.
  That being said, `pl_renderer` supports automatic integration of the
  
  majority of libplacebo's shaders, ranging from debanding to tone
  
  mapping, and also supports loading custom mpv-style user shaders, making
  
  this API a natural candidate for getting a lot of functionality out of
  
  relatively little code.
  In the future, I may approach this problem either by rewriting this
  
  filter to also support a non-renderer codepath, or by upgrading
  
  libplacebo's renderer to support a full YCbCr pipeline.
  This unfortunately requires a very new version of libplacebo (unreleased
  
  at time of writing) for timeline semaphore support. But the amount of
  
  boilerplate needed to hack in backwards compatibility would have been
  
  very unreasonable.
  

  • [DH] configure
  • [DH] libavfilter/Makefile
  • [DH] libavfilter/allfilters.c
  • [DH] libavfilter/vf_libplacebo.c