H.264-movie too quiet (how normalize)

I encoded a h.264-movie with Nero Recode. My Audiosettings was:

High Complecity Nero Digital Audio

The file is okay (playable in MediaPlayer, ShowTime), but the sound is really quiet. How can I normalize it (but I don’t want to change the codec!)?

I tried NeroWaveEditor (extracted mp4-Audio-File from the mp4-Container & also the hole .mp4 file inclusive video and subtitles). I see the frequency of all 5 streams, but can’t play the file. And when I try to save, the program crashs down.

Well, I’ve had the same issue for quite some time now. :confused: