ICH4 Sound Support?

Drew Tomlinson drew at mykitchentable.net
Mon Apr 7 16:46:02 PDT 2003

----- Original Message -----
From: "Orion Hodson" <orion at freebsd.org>
To: "Drew Tomlinson" <drew at mykitchentable.net>
Cc: "FreeBSD Questions" <freebsd-questions at freebsd.org>
Sent: Saturday, April 05, 2003 9:26 AM
Subject: Re: ICH4 Sound Support?

> Drew Tomlinson writes:
> | I've been fighting with getting sound working on FBSD 5.0-RELEASE-p7.
> | someone tell me if the pcm driver is supposed to work with ICH4
> | sound on an Intel motherboard?  I read in the 5.0 release notes that
> | is rudimentary support.  However when I attempt to play an mp3 file, the
> | quality is very bad.  Lots of static and hissing.  If I play an audio
CD, it
> | plays just fine.
> Drew, based on what you say above, there's a reasonable chance you
> have an AC97 codec attached to your ich4 sound controller that does
> not support variable rate audio.  In this case the kernel does sample
> rate conversion from mp3 rate (typ. 44.1kHz) to the fixed rate
> (48kHz).  The code on the RELENG_5_0 branch does not cope well with
> this conversion.  However, this is fixed on the HEAD branch (as of early
> February).
> In this particular case, you should be able to just copy the file
> between branches and rebuild and reinstall the kernel or kernel module
> if using it.  The appropriate fetch and inplace copy is:
> % fetch -o feeder_rate.c
> % cp feeder_rate.c ${SRC}/sys/dev/sound/pcm/
> If this doesn't work or you can't make it compile, let me know.

I tried this and was successful in getting it to compile but my sound
quality is still poor.  I was thinking of trying again after getting all the
latest pcm sources.  How can I do that using your example or is there a
better way?  I tried going to ftp.freebsd.org to see if I could find them
but did not have any luck.

Thank you again for your help.  Even if I don't resolve my problem I am
still learning a lot.


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