When trying to convert the replaygain to soundcheck values on mp4/m4a files, I first noticed that no field was written, but then I discovered that the ITUNNORM field is removed if it's already there to start with... I have been using the script below and its album gain equivalent on thousands of files before with no problem.
[#0]
T=5
F=COMMENT ITUNNORM
1=$if($eql(%_extension%,mp3),$rg2sc(%REPLAYGAIN_TRACK_GAIN%),)
[#1]
T=5
F=ITUNNORM
1=$if($eql(%_extension%,m4a|mp4),$rg2sc(%REPLAYGAIN_TRACK_GAIN%),)
Any idea of what's happening? (I should probably try an older version of mp3tag and get back, and I will do that tomorrow...)
edit: Apparently the | symbol isn't doing what it used to anymore. I separated mp4 from the second step and added one more, and now it works...
edit 2: Noooo...
if m4a extension is used, mp3tag is still not using the itunnorm field, or deleting it. Darn.