how do I normalize too silent audio

[Aivc]

So that's the problem: I got a video file (AVI) and the audio track contains sound that is quite to low. What program do you use to normalize audio and raise the volume? Do you extract the audio track first and edit it or is there any solution to do it while working on the video?

[AlanHK]

Demux the audio (use eg VirtualDub, Avidemux).
If the audio is MP3, you can normalise it without recompressing using using MP3Gain or MP3DirectCut and then mux it back.
If any other format, use an audio editor like Audacity.