I think you problem may be the way MAME/MESS/MENU work. When I set up Advmenu it was “grabbing” a file from somewhere (Either an mp3 on my memory stick, or a sample from ./advance folder, but it was so scratchy and garbled I couldn’t make out what it was! With HD/CD/Laserdisc images MAME uses .chd files where the standard is pretty much .bin and .cue or .m2v .ogg etc. you have to use the CHDMAN tools (Which come with the binaries) to convert them for use in MAME. They do work though, I converted my Killer Instinct CHD (Avdmame couldn’t see it) from another version of MAME I run (Mame 0.136) for Mame 0.106 and it worked! But, for anybody reading this DON’T waste your time trying it, it WON’T RUN acceptably on RPi, I was using it as a test! I did previously note this in a forum which may assist (.mng files are for movie clips) -
The .mp3 files are compressed with the LAME 3.91 utility with the command
line : lame -v -V 6 -k -h --resample 22.05 source.wav dest.mp3
The .mng files are compressed with the ZMNG utility with the command line :
zmng -s 4x4 source.mng dest.mng
The LAME utility can be download at http://lame.sourceforge.net
The ZMNG utility is included in the contrib directory of AdvanceMAME
Obviously you will have to use Command Prompt in windows for the above, (I’m not sure the tools are available in the Linux binaries, but I don’t use Linux for my general Emulator usage due to the proliferation of DOS/Windows EMU’s in contrast to Linux). However, I do believe if you use the “snapshot” and “record” functions in MAME/MESS they output in the correct format for use in MENU.
Hope that helps!