M3U Playlist feature ... i got questions!

[Z3R0B4NG]

Currently i got Redump and No-Intro compliant files only, archived as zip rar or 7z on sitting on my unRAID server, LaunchBox extracts those into a local folder and RetroArch takes it from there.  

For Multidisk games, this does obviously not work.  

There is no M3U, the different Disks are automatically compressed into their own zip files by Clrmamepro when rebuilding, so the 2nd Disk doesn't even end up in the Temp folder for RetroArch to find.  
I would have to extract all multidisk games, manually create M3U files, compress both disks+m3u in one zip file and then re-import to LaunchBox, that is a crap ton of fiddly work that i have not bothered with so far... also updating the No-Intro / Redump sets might break that work again because those M3U files are not part of the .dat and it might even complain about 2 images being in one zip... not sure, have not tried yet.  

 

SO...  

LaunchBox 10.10 now automatically creates M3U files. Set a checkmark in the Emulator options and DONE.  
...ok, but HOW EXACTLY does it work? Is it foolproof enough already for the setup i explained above to "just work"?  

I want to know exactly how this functions, how does it determine that a game is multi disk, just by the filename Disk 1 Disk 2? What about C64 games that have Side 1, Side 2 in the name instead (because a Floppy has sides)... or something entirely else?
Is it intelligent enough to understand when multiple disks are in different zip archives and extracts all of them AND throws the on the fly created .M3U into the temp folder for RetroArch to see?

...that just sounds to good to be true. Just flick the switch and it magically works? For real?

 

//edit:

sad face, flicked the switch, didn't work, Retro Arch does not see Disk 2.
extracted both zip archives, added the .cue files to LaunchBox, did not work again... 
uuuuh... OK, i need documentation or a guide for this. (maybe a wild EtaPrime will appear and make a video on it?)

Edited January 21, 2020 by Z3R0B4NG

[C-Beats]

This feature will automatically create and send to your emulator a M3U file under ALL of the following conditions:

1. The application path launched is associated to an additional application of the game you are playing
2. The additional application associated has a disc number associated to it (found in the "Edit Addtional Application" form found in the "Edit Game" form of LaunchBox)
3. The application path launched is not already a M3U
4. The emulator is marked that is supports M3U

If all the above is TRUE then the M3U is made with the application you selected to launch as first track, followed by all other additional applications under that game that also have a disc number, in disc order (numerical).

To directly answer some of your above questions.

NO at this time archived paths will NOT play nice with this feature and the M3U will point the emulator to the archive and not the .CUE contained within.
NO at this time the only data point used in this process is "Disc" located in the additional application. Side is not used at all.

For this process to play nicely with your set up, the roms would need to be extracted and the raw files added to Launchbox (typically you want to add the .CUE files NOT .BIN, or .GDI for Dreamcast). Each file should be brought in as an additional application of the game (some people think of these as versions) with the disc marked. The emulator in question will need marked as being able to support this feature as well. Once those steps are complete the process should do the rest for you.

[Z3R0B4NG]

OK, i tried again and now it worked :) Not sure what i have done wrong the first time.  

For science i imported a 2 disc game as euro and france version to see what happens with the .m3u if i check merge games with matching names into one game.  

see attached picture for result.  

In RetroArch you of course see these numbered as Disc 1 2 3 4 so you wouldn't know that Disc 2 is Disc 1 of the france version.  

hmmm...