Re: Totaly OT

On Sun, 21 Dec 2003, Arpi wrote:

> ------------------------
> The audio codecs
> * Creative ADPCM CODEC (format 0x200)
> * Creative FastSpeech 8 and FastSpeech 10 CODEC (format 0x202 + 0x203)
>
>   form "ftp://ftp.mplayerhq.hu/MPlayer/samples/A-codecs/Creative Audio/"
>
>         and
>
> * Indeo Audio 2.5 (format 0x402)
>
>   from "ftp://ftp.mplayerhq.hu/MPlayer/samples/A-codecs/Indeo Audio/"
>
> works correctly !!!
> --------------------------
>
> so only the codecs.conf entries are missing.

	I might have missed something here: Do we have any sample media
encoded in this format? I think the core decoder algorithm in iac23_32.ax
may be @ 10012CC0, the one that starts by allocating 0x810 bytes of local
storage. One thing that jumps out at me is that it is multiplying a 32-bit
number by 1664525, adding 32,767 (0x7FFF), then shifting right by 16
(dividing by 65,536). Looks like some fixed-point math, and
1664525/65536=~25.4. I don't suppose that number stands out to anyone for
any reason? Hmm, the function trees out to several other functions, and
includes a sprinkling of FPU instructions. Perhaps not as simple as it
first appears.

--
	-Mike Melanson



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