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Rockbox mail archiveSubject: Re: Fwd: iRiver Codec - RT encoding and Fixed point libraryRe: Fwd: iRiver Codec - RT encoding and Fixed point library
From: <dave_at_beermex.com>
Date: Wed, 13 Jul 2005 21:32:29 +0100 (BST) There may well be some sort of fixed point instructions in certain versions of the coldfire. However, not on the CF5249 that H1xx/H3xx use, (other than the more simple fractional mode of the EMAC unit, which we are already using in all of our codecs). If there is a fixed-point version of Shine MP3 encoder already optimised for ARM then that is probably a good starting point. I'm not sure of the merits of 'emulating' floating point using a fixed-point CPU, however (it will either require major rewrites of the code or would just run suboptimally - in either case, rewriting to use fixed-point data would probably be a necessity) d > Hello, > > I follow the rockbox porting effort to iriver from the very beginning > and I'm quite impressed by the work done so far. > > My freetime is limited and maybe I won't be able to write any line of > C (but who knows), but I was curious about the "Real Time encoding" > subject. > > There are comments in the wiki about ShineMP3 encoder and fixed point. > Is there anybody here interested by the subject? > > Quote from the wiki: > What about a fixed point library ? Can't we use a floating point > algorithm with a fixed point library ? Furthermore, it seems that > there is some sort of fixed point instructions in certain versions of > the coldfire. > > http://www.mactech.com/articles/mactech/Vol.13/13.11/Fixed-PointMathSpeed/ > http://www.freescale.com/files/32bit/doc/reports_presentations/V4PRES.html#mac > > Does someone here know if we could use floating point code with a > fixed point (mainly inlined) library ? Is lame too complicated for > this use ? (maybe it is). > > Furthermore, such a library could be used by other modules of rockbox... > > What do you think about this ? > > Robin > > _______________________________________________ > http://cool.haxx.se/mailman/listinfo/rockbox > _______________________________________________ http://cool.haxx.se/mailman/listinfo/rockbox Received on 2005-07-13 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |