Ripping GBS by Kurausukun at 11:02 PM EDT on May 9, 2016
What's the standard way of ripping (logging?) a .gbs file from a GB ROM? I know we have the joshw repository, but I'd really like to know how to do it myself.
Like an NSF, KSS or HES, a GBS file is basically the game ROM, only everything has been stripped away except all the relevant sound data (engine, indexes, sequences, etc). Seen another way, you are "ripping" the stuff you want out of the game. After that, a header is added and you have a GBS file. Sometimes you'll want to adjust things in the GBS to do things such as putting the important engine stuff first, getting rid of unnecessary data or rearranging the order of the sequences (like music before SFX)
Depending on the game, this can range from a fairly simple process of nearly-automatic excavation all the way to seemingly impossible feats of reverse engineering every aspect of the game code. Most stuff falls somewhere in the middle of the spectrum; nearly everything that could be easily done has been done (with GB2GBS). That's not to discount the huge amount of work already done on manual ripping, but anything currently un-ripped will likely require moderate to intensive technical work.
"Logging" is when you use an emulator to log all the instructions (that concern the playing of sound) to a file, along with any samples played. Example formats include GYM, S98 and VGM (the big one, and the only one which has GB support). VGM logs can be really huge, and have to go through a number of stages of processing before they can be turned into nice and tidy VGZ files. Compared to some other chips the format supports, the Game Boy VGMs should be relatively easy to clean, but they still require a fair amount of time and effort.
While it is far easier to log a VGM than create a GBS, keep in mind that the latter (ideally) would contain all the songs already, but you have to find a way to get each song to play before you can log it. Without a sound test of some kind, this can be quite difficult, and may require intense technical work if you want to make a complete set.
Small caveat:some or all of the above may be totally wrong.
Perhaps you could tell us what games you are interested in ripping yourself? Then we could maybe give you a better idea of what you should be learning/researching.
Thanks for the info. The only games I'm really interested in ripping are the GB/GBC Pokemon games. You mentioned GB2GBS; is there somewhere I can find that? A very quick Google search turned up nothing for me.
Sorry, I got confused. The program is actually called GBgbs, but I often conflate it with GBS2GB, which is used to turn a GBS rip into a ROM with a built-in music player (such as if you want to log a VGM). GBS2GB isn't hard to find, but GBgbs is pretty rare.
It's a Windows program that requires .NET Framework 2.0 to be installed. The creator at one point put up a more advanced version (1.0f), but I don't believe anyone has ever found a copy of that.