Re: audio dropouts still
On 1/11/14, Ralf Mardorf <ralf.mardorf@alice-dsl.net> wrote:
> Klaus you are mistaken.
>
> On Fri, 2014-01-10 at 14:09 +0000, Klaus wrote:
>> correlation between absolute CPU power and drop-outs
>
> The issues Zenaan does experience are likely related to jackd, a sound
> server that cares about sample accuracy [1].
Could be, but before jackd, I was running pulseaudio, and had the same
problems. So then I installed jackd and others, and went on my war of
stopping pulseaudio (succeeded),
but now, the exact same problem (at least audibly as far as I can tell)!
So this problem (to my ears) sounds identical with pulseaudio, as with jackd.
Perhaps I could test alsaplayer, direct to hardware, from command line
(even no X running), no jackd (don't start it, and check to make sure
it's not running), no pulseaudio (got this one handled now :)
I shall try when I can afford the workstation downtime - but an hour
is usually heaps of time, so I can put on some peaceful reading music,
easy to hear glitches in :)
> When using jackd, CPU frequency scaling does matter a lot!
Well if it matters for jackd, it would probably effect other things
(eg pulseaudio, or mpd) too yes?
> If you don't believe a professional audio engineer using Linux audio
> since around 10 years, perhaps a Linux audio link is able to enlighten
> you.
>
> "CPU frequency scaling daemons that scale the frequency of the CPU
> depending on the CPU load could cause xruns in some cases. More recent
Again, no xruns here.
> versions of Jack1 (>= 0.118.0) are suffering less from xruns or run xrun
> free with a CPU frequency scaling daemon enabled that's set to a scaling
> governor like ondemand. A specialized CPU scaling daemon is in the works
> that depends on the DSP-load instead of the CPU load: jackfreqd" -
> http://wiki.linuxaudio.org/wiki/system_configuration
A custom cpu governor, just for jackd. Wow! Hard core audio! How far
in the "works" part of "in the works" is this jackfreqd ?
> JFTR some users might find setting up jackd to complicated, but jackd
> provides advantages, e.g. "Within software, jackd provides
> sample-accurate synchronization between all JACK applications." -
> http://manual.ardour.org/synchronization/on-clock-and-time/
> This does mean, that signals are not out-of-phase, so there won't be
> unwanted filtering effects.
> The easiness of other sound servers comes at a price.
I am happy to learn, how to set up a pro-audio type system with Linux kernel.
Right now, I am driven by merely (very) audible and random but
consistently occurring, audio drop outs. For a modern machine,
something is really wrong if I can't play my music collection!
Thanks for all the pointers,
Zenaan
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