Subject: [linux-audio-dev] Re: [Alsa-devel] XRuns and Low-Latency
From: René Rebe (rene.rebe_AT_gmx.net)
Date: Wed Aug 08 2001 - 02:50:01 EEST
Hi!
Very much thanks for sending me a such full detailed reply! ;-)
I mainly wanted to use the plug layer to get arround the sample-format
conversions. But I added support for S16_LE and S32_LE formats and
normally use hw:? devices directly. I also check if the specified ALSA-
device is a real PCM (snd_pcm_get_type or so) and if not I use hardcoded
2 channels ... (maybe the user can change this in some weeks).
My low-latency problems are a bit better when I use a ext2 fs. (Yes low-
latency was on everytime. DMA, too.)
Maybe I would have less problems when ALSA would use more periods per
buffer. My values:
format: 10
min_ch: 12
max_ch: 12
min_rate: 44100
max_rate: 44100
period_size: 2730
buffer_size: 5461
periods: 2
start_th: 1
stop_th: 1
I try to change this to 4 periods. (If possible.) Maybe someone has more
real-live approved values ??
(And thanks for the tipps to tune via sysctl. I now use:
echo " tuning linux VM subsystem ..."
# orig is: 30 64 64 256 500 3000 60 0 0
echo "8 32 64 256 500 1000 60 0 0" > /proc/sys/vm/bdflush
# orig is: 2 15 75
echo "4 15 75" > /proc/sys/vm/buffermem
# orig is: 2 15 75
echo "4 15 75" > /proc/sys/vm/pagecache
echo " enabling low-latency scheduling ..."
echo "1" > /proc/sys/kernel/lowlatency
maybe it helps a bit ...)
On Tue, 7 Aug 2001 15:22:21 -0700
Fernando Pablo Lopez-Lezcano <nando_AT_ccrma.stanford.edu> wrote:
[...]
>
> -- Fernando
>
k33p h4ck1n6 René
-- René Rebe (Registered Linux user: #127875)eMail: rene.rene_AT_gmx.net rene.rebe_AT_rocklinux.org
Homepage: http://www.rene.rebe.myokay.net/
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