Re: [LAU] Is ALSA using hrtimer?

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Paul Davis <paul@...>, Grant <emailgrant@...>
Cc: <linux-audio-user@...>
Date: Sunday, May 30, 2010 - 8:39 pm

On Sun, May 30, 2010 at 11:02 AM, Grant wrote:

I too would like to better understand these statements and the
benefits, if any, provided by loading snd-hrtimer. For example, if
snd-pcm wasn't dependent on snd_timer, why this dependency from
lsmod?::

What kinds of timing info is snd_pcm deriving from snd_timer?? What
are the benefits of using HRtimer versus system timer with ALSA?
Which results in best performance (latency and drummer-accurate MIDI
timing).
Which uses least system resources?

On Fri, May 28, 2010 at 12:11 PM, Paul Davis wrote:

Then what is the purpose of the --clocksource flag, and what are the
advantages/disadvantages of the different settings:
"c(ycle) | h(pet) | s(ystem)"??

In a different thread you mention, regarding jackd's use of snd-seq:

Would using snd-hrtimer with snd-seq change this assessment? I haven't
done any precise measurements myself, but I didn't hear anything sound
terribly "off" w/r/t my usage of ALSA midi through qjackctl/jackd (
"/usr/bin/jackd -dalsa -dhw:M66 -r44100 -p256 -n2 -Xseq -zs -H -M").
Certainly not "unusable" just using MIDI alone.

Is this issue related to timing of MIDI versus audio, or MIDI timing
itself causing the music to sound different than the musician
intended?

Thanks for all the helpful advice,

Niels
http://nielsmayer.com

PS: To get snd-hrtimer at boot in Fedora:
http://old.nabble.com/-etc-modprobe.d-dist-alsa.conf-patch-to-boot-with-...
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
[LAU] Is ALSA using hrtimer?, Grant, (Thu May 27, 9:12 pm)
Re: [LAU] Is ALSA using hrtimer?, Pedro Lopez-Cabanillas, (Fri May 28, 2:07 pm)
Re: [LAU] Is ALSA using hrtimer?, Niels Mayer, (Fri May 28, 6:13 pm)
Re: [LAU] Is ALSA using hrtimer?, Niels Mayer, (Fri May 28, 9:12 pm)
Re: [LAU] Is ALSA using hrtimer?, Pedro Lopez-Cabanillas, (Fri May 28, 10:03 pm)
Re: [LAU] Is ALSA using hrtimer?, Paul Davis, (Fri May 28, 7:11 pm)
Re: [LAU] Is ALSA using hrtimer?, Clemens Ladisch, (Fri May 28, 6:16 am)
Re: [LAU] Is ALSA using hrtimer?, Grant, (Sun May 30, 6:02 pm)
Re: [LAU] Is ALSA using hrtimer?, Niels Mayer, (Sun May 30, 8:39 pm)
Re: [LAU] Is ALSA using hrtimer?, Paul Davis, (Mon May 31, 1:19 pm)
Re: [LAU] Is ALSA using hrtimer?, Ken Restivo, (Sat Jun 5, 7:10 pm)
Re: [LAU] Is ALSA using hrtimer?, Paul Davis, (Sat Jun 5, 9:19 pm)
Re: [LAU] Is ALSA using hrtimer?, Niels Mayer, (Mon May 31, 6:56 pm)
Re: [LAU] Is ALSA using hrtimer?, Niels Mayer, (Mon May 31, 12:08 am)
Re: [LAU] Is ALSA using hrtimer?, Paul Davis, (Sun May 30, 7:55 pm)