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• Selected png images to gif using ffmpeg or imagemagick

  28 avril 2021, par Ghajik

  I want to convert png to gif and i want to mention which are the frames i want to combine
eg : frame1.png and frame2.png.
I've tried using ffmpeg -i frames/%03d.png -vf fps=20 logo.gif but it is considering all the images in that directory, but i want only two images in that directory to be included in the gif i want to create. Thank you in advance.

  


• Parsing x264 to LibAV in C

  26 mai 2018, par Stephan Pich

  For a Project in School I have to encode and mux a Yuv File to mp4 using the Libav and lib x264 explicitly. I’ve already managed to encode the File to h264 using the libx264 but now i’m stuck muxing them into mp4.

  I know that I’ve to write the NALU Packages into the file but I’ve no Idea how to turn the NALU to AVFrame or AVPacket.

  Thanks for your help in advance.

• ffmpeg file read permission denied in application but not in debug

  25 novembre 2019, par Purgitoria

  My application has a function of taking captured images and using an ffmpeg background worker to stitch these into a time lapse video. The GUI has some simple options for video quality and for the source folder and output file. I had an older version of my application written in VB.NET and that worked without issue but i am rewriting in C# as it supports additional capture and filter capability in the image processing but am having real trouble figuring out what is wrong with this function.

  I have tried relocating ffmpeg to different locations just in case it was a permissions issue but that had no effect and i also tried to put the function in a "try" with a message box to output any exceptions but i got different errors that prevented me from compiling the code. When i run the application from within VS 2015 in the debugging tool the function works just fine and it will create a video from a collection of still images and create a log but when i build and install the application it does not work at all and i cannot see what is causing it to fail. In the options for ffmpeg i used the -report to output a log of what happens in the background worker and in debug it creates this log but from the application it does not so i presumed it was not even running ffmpeg and going straight to the completed stage of the function.

  Function startConversion()
  
  
  
      CheckForIllegalCrossThreadCalls = False
  
      Dim quality As Integer = trbQuality.Value
  
      Dim input As String = tbFolderOpen.Text
  
      Dim output As String = tbFolderSave.Text
  
      Dim exepath As String = Application.StartupPath + "\\bin\ffmpeg.exe"
  
      input = input & "\SCAImg_%1d.bmp"
  
      input = Chr(34) & input & Chr(34)
  
      output = Chr(34) & output & Chr(34)
  
  
  
      Dim sr As StreamReader
  
      Dim ffmpegOutput As String
  
  
  
      ' all parameters required to run the process
  
      proc.StartInfo.UseShellExecute = False
  
      proc.StartInfo.CreateNoWindow = True
  
      proc.StartInfo.RedirectStandardError = True
  
      proc.StartInfo.FileName = exepath
  
      proc.StartInfo.Arguments = "-framerate 25 -start_number 0 -pattern_type sequence -framerate 10 -i " & input & " -r 10 -c:v libx264 -preset slow -crf " & quality & " " & output
  
      proc.Start()
  
  
  
      lblInfo.Text = "Conversion in progress... Please wait..."
  
      sr = proc.StandardError 'standard error is used by ffmpeg
  
      btnMakeVideo.Enabled = False
  
      Do
  
          ffmpegOutput = sr.ReadLine
  
          tbProgress.Text = ffmpegOutput
  
      Loop Until proc.HasExited And ffmpegOutput = Nothing Or ffmpegOutput = ""
  
  
  
      tbProgress.Text = "Finished !"
  
      lblInfo.Text = "Completed!"
  
      MsgBox("Completed!", MsgBoxStyle.Exclamation)
  
      btnMakeVideo.Enabled = True
  
      Return 0
  
  
  
  End Function

  I checked the application folder and it does contain a sub folder \bin with the ffmpeg.exe located within the folder so i then used cmd to run an instance of the installed ffmpeg from the application folder and it seemed to be throwing out permissions errors :

  Failed to open report "ffmpeg-20191101-191452.log" : Permission denied Failed to set value ’1’ for option ’report’ : Permission denied Error parsing global options : Permission denied

  This seems then like it is certainly a permissions problem but where i am not sure. I did not run in to this error when using VB.NET so i am wondering where i am going wrong now. I thought perhaps it would just be a write permission in the application folder so i the removed the -report and ran ffmpeg again using cmd from my application folder and it then gave the error

  C :\Users\CEAstro\Pictures\AnytimeCap : Permission denied

  Am i missing something really obvious in my code or is there something more fundamental i have wrong in my setup ?

  I should also add that i tried running ffmpeg via cmd from a copy that was manually placed elsewhere (i used the same file) and that actually created the report but again i got a permission denied when trying to read the input files, considering it was from the user "my pictures" folder which should not have restrictions on read/write access i am at a rael loss.