This is the best way I've seen to do it so far but involves re-encoding. https://forum.audacityteam.org/viewtopic.php?t=63067
I also made a thread here.
https://forum.videohelp.com/threads/406495-Normalize-AC3-audio-without-re-encoding#post2663657
There are some programs that can do this without re-encoding for MP3. I haven't seen those for AC3 or MP2 yet.
Maybe try this for MP2
https://hydrogenaud.io/index.php?topic=20477.0
But it is really old and the link is dead.
You can download beSplit here: https://www.softpedia.com/get/Multimedia/Audio/Audio-Editors-Recorders/BeSplit.shtml
Actually, foobar2000 can alter mp2 files according to ReplayGain tags or fixed change.
Actually, foobar2000 can alter mp2 files according to ReplayGain tags or fixed change.
indeed, I did this just the other day with an MP2 file. Added the Replayagin tags and then "Apply gain to file content...".