Rockbox Technical Forums

Rockbox Development => Feature Ideas => Topic started by: Strife89 on September 04, 2008, 12:47:31 PM

Title: Request for a "codec": GSF format
Post by: Strife89 on September 04, 2008, 12:47:31 PM
Here's an audio format I would like to see for Rockbox: GSF (Gameboy Sound Format, if I'm not mistaken). The format is used in Game Boy Advance games. The way the format works is, it relies on one large file as a sort of "instrument database"; and it uses several small files - often less than 512 bytes - as the "sheet music".

The format appears to be very similar to the PSF (Playstation Sound Format) file type. With that said, I was only able to find one player for which the source is available, and said player is a Winamp plugin. The author's website for the plugin is GSF Central (http://www.caitsith2.com/gsf/) , and the source is here: http://www.caitsith2.com/gsf/player/in_gsf_src_0.11.rar .

So, if anyone has any interest in this format, please say so. I am a big fan of GBA music and I'd love to see this one go through. :)
Title: Re: Request for a "codec": GSF format
Post by: LambdaCalculus on September 04, 2008, 12:57:37 PM
Here's a description of how the GSF codec works, according to Wikipedia (http://en.wikipedia.org/wiki/GBA_Sound_Format):

Quote
The players convert the files internally into a Game Boy Advance ROM that is then run through a cut down emulator with no support for graphics hardware. Even without support for graphics, though, emulation of the Game Boy Advance can be quite processor intensive, and neither program works well on machines under 500 MHz.

Like PSF, which is a single PS executable (according to Wikipedia), GSF appears to emulate the ARM7TDMI core in the GBA, meaning that playback may be terribly slow on some targets. (I'm looking at you, PortalPlayer!)

But still, it doesn't hurt to look at the codec and see how much optimization can be done. ;)
Title: Re: Request for a "codec": GSF format
Post by: delt on September 08, 2008, 02:16:27 PM
SPC and NSF(E) formats would be great too (snes and nes music) and much less cpu intensive. We might be able to hack the mikmod plugin to load them.....
Title: Re: Request for a "codec": GSF format
Post by: LambdaCalculus on September 08, 2008, 02:19:50 PM
We already have SPC and NSF codecs in Rockbox. They're listed in the manual (see Appendix A).
Title: Re: Request for a "codec": GSF format
Post by: delt on September 08, 2008, 02:23:34 PM
Really? cool :D didn't notice them, sorry!