Massive sound changes / fix (24/32bit pcm support, new sampling rate converter, various fixes)

[Ariff Abdullah]

On Tue, 12 Jul 2005 22:44:04 +0200
Sascha Klauder <sklauder at trimind.de> wrote:
> On Thu, Jul 07, 2005 at 06:46:03AM +0800, Ariff Abdullah wrote:
> > After sometimes, I've decided to release this (massive 4k lines)
> > diff to our sound driver. This need proper review and
> > confirmation, before it can be committed.
> > 
> > Patches for both HEAD / RELENG_5 available at:
> > 
> > http://staff.mybsd.org.my/skywizard/FreeBSD/sound/
> 
> Just applied snd_RELENG_5_20050709_006.diff. 
> System is 5.4-STABLE (from 2005-06-12), tested hardware:
> 
> $ cat /dev/sndstat 
> FreeBSD Audio Driver (newpcm)
> Installed devices:
> pcm0: <Creative EMU10K1> at io 0xe000 irq 10 kld snd_emu10k1
> (4p/2r/2v channels duplex default) pcm1: <SB16 DSP 4.16> at io 0x220
> irq 5 drq 1:5 bufsz 4096d kld snd_sb16 (1p/1r/1v channels duplex)
> 
> Something's not right here.  I had some minor issues with
> crackling noise on PCM playback with pcm1 (it's an AWE64),
> which seems to be gone now, but the playback is just a bit
> too slow, which sounds pretty strange.  Playback on pcm0
> (old SB Live!) is just fine, as it was before applying the
> patch.
> 
> Recompiling mpg321 and settings vchans didn't help.  Where
> to start looking?
> 

AWE64 is actually not capable of driving sampling rate at 48k (which
is the current default value for vchan). Fortunately you can tune
default sampling rate using kernel hint by adding this to your
/boot/device.hints:

                hint.pcm.1.vchanrate="44100"

More good news is, I've already added sysctl controller to tune vchan
rate on the fly, something like sysctl hw.snd.pcm0.vchanrate=xxx. Stay
tuned. If you insist, you may try my latest (revision 8) patch from:

  http://staff.mybsd.org.my/skywizard/FreeBSD/sound/incoming/

I do have general solution to entirely eliminate noise / crackling
issues (which plagued most SBLive!), which is part of my TODO list.


Thanks for that feedback!

--

Ariff Abdullah
MyBSD

http://www.MyBSD.org.my (IPv6/IPv4)
http://staff.MyBSD.org.my (IPv6/IPv4)
http://tomoyo.MyBSD.org.my (IPv6/IPv4)