I film via a videocamera with has a microphone that unfortunatly often not loud enough. That camera stores the videos on mini DVD and at the moment I copy the videos from the camera to my computer via a batch file. Is there a command in VLC-Player that allows me to double the volume of the file that gets created?
VLC can while transcoding convert the audio codec and/or change the bitrate, but it doesn't have an option for changing the loudness. You need for that a more specialized product.
Although you haven't specified your operating system, I'll assume that it's Windows. In that case, Windows Movie Maker can do that.