Re: Creative ADPCM?

Hi everyone!

I subscribed to this list a while back but apparently the messages were 
being filtered out with the spam since then :(

>From: Jim Leonard <[email protected]>
>Reply-To: [email protected]
>To: [email protected]
>Subject: Re: [codec-devel] Creative ADPCM?
>Date: Sun, 17 Oct 2004 14:54:41 -0500
>
>
>Let me know what you find as I'm always in the market for an 8-bit
>audio compression technique that has low decoding requirements, such
>as:
>
>- John Ratcliff's ACOMP (variable bit-depth per frame ADPCM)
>- Michael J. Mahon's 4-bit ADPCM adapted for 8-bit input (uses
>regular DVI values table but ends at the last value below 127)
>- 8svx fibonacci deltas (good for voice, bad for music)
>- Dumb raw convert from 8-bit to 6-bit (RealSound did this)

Where can I find details on these? I like to play around with audio and 
video codecs (the not-so processor intensive, non-FPU kind which my brain 
can more easily comprehend). I'm sure most if not all my ideas were 
reinventing the wheel so I always like to check out what has been done 
before. I wrote a couple programs for audio which stored the sign of the 
difference and log base 2 of the magnitude. So I went from 16-bit PCM to 
5-bits per sample and the quality was good at high sample rates.

>
>I'd love to add Creative's methods to this list, and any others you
>know of!
>--
>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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