Subject: Re: NetBSD plays .wav ultra fast
To: Andreas Gustafsson <gson@nominum.com>
From: Greywolf <greywolf@starwolf.com>
List: current-users
Date: 07/19/2001 13:30:14
On Thu, 19 Jul 2001, Andreas Gustafsson wrote:

# There is a problem with using these instructions in the NetBSD kernel:
# they use the floating point registers, and the floating point context
# switch code of the NetBSD i386 port does not maintain floating point
# state for the kernel, only for user processes.  I have some patches to
# deal with this, but they are scary. Followups about this issue should
# go to port-i386, of course.
# 
# None of this matters if we only need to deal with the specific case of
# 8 kHz -> 48 kHz - that's simple enough that you should be able to get
# decent quality using a reasonable amount of CPU with a filter based on
# integer multiplies, adds and shifts, and/or lookup tables.  As you
# say, handling arbitrary frequency ratios is the hard part.

You mean like the standard 11025/22050/44100 Hz -> 48000 Hz that
mp3 conversion is wont to use on these chips?

# Andreas Gustafsson, gson@nominum.com

				--*greywolf;
--
non-adjustable PC97 hardware should be shot.