Re: [ecasound] Bug Report: Ecasound goes silent

From: Joel Roth <joelz@email-addr-hidden>
Date: Tue Apr 03 2012 - 23:10:11 EEST

On Tue, Apr 03, 2012 at 02:20:08PM -0400, S. Massy wrote:
> On Thu, Mar 15, 2012 at 09:42:49PM +0200, Kai Vehmanen wrote:
> > Hi,
> >
> > >Symptoms:
> > >No more sound is heard, but the engine still seems to be running (clock
> > >is moving, engine-status is "running", seems to obey transport
> > >commands).
> >
> > thanks for the excellent bugreport! I managed to reproduce this with
> > your test session, and am looking for the root cause. Upon initial
> > look, this would seem to be an issue with the JACK callbacks. I also
> > got one crash while ecasound called jack_port_get_latency_range().
> > That is suspicous as the semantics of that call have changes a bit
> > (since the related ecasound code was written).
> Two more interesting facts:
> - When the bug is triggered, the clock stops updating in real-time and
> instead seems to be refreshed every 4 or 5 seconds, jumping by that
> about that amount.

Seeking can cause problems with JACK because repositioning
in multiple files can take more time than a running JACK
transport allows to its clients.

Nama deals with this by stopping the transport (if running),
issuing a seek command, allowing a short time for Ecasound
to update file positions, then restarting the transport.

Except that you found several cases where Nama was using
Ecasound setpos rather than wrapping it with this
special logic.

Will be interested to see if your problems are reduced by
these fixes to Nama.



> - Ocasionally, eeven jackd needs to be restarted in order for ecasound
> to work with jack again, suggesting some gremlins in the jack client
> code as you mention.
> Cheers,
> S.M.

Joel Roth
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Received on Wed Apr 4 00:15:02 2012

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