Re: [ecasound] Cannot connect to JACK Ecasound with Jack - 'Error! Cannot connect to JACK ... server!'

From: Free Lunch <freelunch@email-addr-hidden>
Date: Sat Apr 23 2005 - 17:22:57 EEST

Hi Kai,

Thank you for your response.

On 4/17/05, Kai Vehmanen <kvehmanen@email-addr-hidden> wrote:
> On Fri, 15 Apr 2005, Free Lunch wrote:
> > Something bad happened at one point.. My first WAV ended at 471707692
> > bytes. Fortunately, I ran everything under wrapper scripts to
> > automatically re-start any applications that failed (jackd, ecasound,
> > ecasignal). Unfortunately, I didn't log the output from the software
> > so there isn't really any diag info available.
> I recommend running long test runs with the same exact setup, and try
> to see if you can recreate the problem. If jackd is run with strict
> settings, the system has to be fairly well tuned so that it runs without
> glitches for long periods of time. On the bright side, once tuned, jackd
> runs does run reliably.

I haven't done any jackd tuning yet. I was running defaults. The
system config was quite stripped.

I have done some testing but need to put together a better test rig.
One challenge to accurately reproducing real world recording involves
file size limitations - limited laptop disk space. The other involves
WAV file size limitations. Both of those could be solved if ecasound
had a feature to automatically start a new recording file after a
specific file size. I don't believe it has that feature at this time?

Sure, I could send the output to /dev/null or null but that wouldn't
generate the disk I/O interrupts, etc.

> You should also watch out for system events: heavy X screensavers,
> logrotated, updatedb and etc cron runs.

All good points. I wasn't running X.

> A known design limitation of JACK is that changing connections can cause
> glitches to audio (in the same way as plugging analog mixer cables can
> cause pops ;)).

Good to know.

> > I would still like to run ecasound and ecasignalview simultaneously
> > without Jack, if that is possible. Simpler is better in these cases.
> You can use the ALSA dsnoop plugin:

I have been playing with this a bit but need to play with .asoundrc
settings a bit more. I just started working with an Edirol UA-5 so I
have a lot of testing to do.

I must say that the ecasignalview metering is *very* good. The quick
update and stats tracking catches clipping that most monitors would
miss. While I know that the update rate is adjustable, it would be
nice if there was a way to easily reset the peak value and maybe set a
'peak hold'. It might also be neat to have a 'log' of sorts:

10:18:24 Ch-01 1.0000 peak

That way, when you look over and see that you clipped, it would be
possible to check a tail'd log to see when, etc.

Thanks again,


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Received on Sat Apr 23 17:32:03 2005

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