#172195 - Vaati - Sun Jan 24, 2010 1:12 pm
Hello,
I am curious in how the sound files are extracted from the games. Is there something along the lines of GBA to midi that extracts gsf files from GB(C) games?
I have done some tests on roms and looked in the HEX tables to see what parts could be the music, and found lots of possible areas.
Is it also possible to extract the instruments from a ROM?
#172199 - Dwedit - Sun Jan 24, 2010 4:09 pm
Normally, you use SapTaper to extract the music from games which use Nintendo's sound engine. For other games, it's just like extracting any other game music format: You hack the game until it's a modified version of the game which only plays music when booted.
You can usually extract instruments with any decent sound editor. After hearing lots of binary data noise, you'll hear the instruments in the file. Usually they are 8-bit unsigned mono, and the frequencies will vary.
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#172210 - dantheman - Mon Jan 25, 2010 2:55 am
Like Dwedit said, from my understanding GSF files are pretty much just the actual game ROM stripped of everything but the sound data and the code that plays it, then compressed to get rid of the now-empty space. You can use the "gsfopt" program to turn a GSF file into an executable *.gba file, and sometimes you'll even see some visual graphics on screen when launching this, in addition to the audio. That's about the extent of my knowledge, but it's interesting stuff at least.