Question

I am looking for some library or code that will allow me to convert mp4 video to mp3.
I want it to be for free and compatible with the latest .NET framework (4).

Also, if possible, I am looking for a free ffmpeg wrapper than I can have in my vb.net application without trial or messageboxes.

If there is no free ffmpeg wrapper, can someone show me how to perform the conversion from mp4 to mp3 using command line and ffmpeg ?

Answer 1

You can use the following code to process / execute ffmpeg command in vb.net.

 Dim _out As String = ""
 Dim _process As New Process()
 _process.StartInfo.UseShellExecute = False
 _process.StartInfo.RedirectStandardInput = True
 _process.StartInfo.RedirectStandardOutput = True
 _process.StartInfo.RedirectStandardError = True
 _process.StartInfo.CreateNoWindow = True
 _process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden
 _process.StartInfo.FileName = "ffmpeg";
 _process.StartInfo.Arguments = " -i input.mp4 -vn -f mp3 -ab 192k output.mp3";
 _process.Start()
 _process.StandardOutput.ReadToEnd()
 _out = _process.StandardError.ReadToEnd()
 _process.WaitForExit()
 If Not _process.HasExited Then
    _process.Kill()
 End If
 Return _out

In result you will receive ffmpeg output and mp3 audio file. For better encoding performance and parsing ffmpeg output i recommend using ffmpeg wrapper http://www.mediasoftpro.com/media-handler-pro.html