Re: Creative ADPCM?

Mike Melanson wrote:

> 	I don't have any info. What are the technical details? 8:4
> compression? Are you able to generate samples?

I can indeed, and I even have a DOS program that loads a .VOC file, lets you 
edit it graphically if desired, then perform "compression" on the block and 
save the result...

...HOWEVER, unless you want the challenge, I no longer have a need for it as I 
found the holy grail I'd been looking for:  Some Apple II enthusiast took IMA 
ADPCM and adapted it for 8-bit data.  (It turns out to look pretty much like 
I'd expect, with only the deltas table modified -- I probably could have 
experimented with this myself but it is nice to have a third party verify your 
hypothesis.)  I have no quality samples to test, but his decompression 
implementation is in about 30 lines of 6502 assembly and will obviously fit my 
needs (Apples are 1MHz, my target is ~5MHz).

For those curious, it's here:  http://members.aol.com/MJMahon/adpcm.zip
-- 
Jim Leonard ([email protected])                    http://www.oldskool.org/
Want to help an ambitious games project?             http://www.mobygames.com/
Or check out some trippy MindCandy at             http://www.mindcandydvd.com/


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