Normalize audio on mp4

I have a bunch of mp4 videos where I need to adjust the gain, but I don’t want to recode the video. Can I create a profile that would accomplish this.

Yes you can create a custom profile by combining say a MP4 Normal (for audio) with a MP4 Unprocessed profile (for video) and then have the audio slider process the gain.

ok where would I look for more information on creating that kind of profile?

ok I’m still looking for audio slider… can you point me to it?