[ecasound] Bug Report: Ecasound goes silent

From: S. Massy <lists@email-addr-hidden>
Date: Sat Mar 10 2012 - 23:02:54 EET

Bug report:

No more sound is heard, but the engine still seems to be running (clock
is moving, engine-status is "running", seems to obey transport

Temporary solution:
cs-disconnect/cs-connect restores sound.

- Transport commands: fw/rw/setpos, occasionally start/stop
- On copp-set, especially multiple ones.
  (In nama terms, mostly on solo and mute/unmute, which means multiple
  copp-set on eadb ops)
- More rarely, it happens for no obvious reason while playing back.

- The more complex a chainsetup is, the more likely it is to happen.
- Th shorter the JACK period (-p) is, the more likely it is to happen.
- Nama manages to mitigate this problem by introducing a sleep period
  between operations, though this does not entirely eliminate the
  (e.g stop, sleep, fw, sleep, start)

Usability is affected on complex chainsetups using the IAM or ECI.
Usability might also be affected on very large chainsetups in batch
mode. For a DAW like nama using ecasound as its backend, it means
rearming 1-5 times an hour on a modest project (5-10 tracks) while

Software info:
- Ecasound 2.8.1 (also observed on 2.8.0)
- jackdmp version 1.9.7 (also observed on jackd1 0.118)
- JACK cmdline: "jackd -R -P65 -t1000 -dalsa -d hw:1,0 -r48000 -p128 -n3
                       -M -H -Xseq"
- kernel SMP PREEMPT RT x86_64
- Debian Squeeze with some custom software

Case study:
I have put together a downloadable project for debugging purposes.
Thanks go to the packet-in band[1] for allowing me to use the material
from a song[2] I helped mix.
Link: http://wolfdream.ca/files/bugreport_smassy.tar.bz2
After untarring, you'll find in the bugreport_smassy directory:
- bugreport_smassy.ecs (The chainsetup)
- bugreport_smassy.log (A log of the bug being reproduced as described
- wav (A subdir with the audio material)
(NOTE: The audio material is flac compressed for convenience, so you
need to do:
$ cd wav;flac -d *flac;rm *flac;cd ..
...to make it ready for testing.)
(NOTE: The following ladspa plugins should be installed for the project
to work as expected: swh-plugins, tap-plugins,
invada-studio-plugins-ladspa, fil-plugins)

Reproducing the bug:
The simplest but by no means the only way to reproduce this bug is to
do (with jackd running):
$ ecasound -s bugreport_smassy.ecs -c
(In IAM)
> cs-connect
> setpos 10
> start
> fw 20

Please, let me know if I can be of any further assistance with this.

1. http://packet-in.org
2. http://packet-in.org/repo/RPM12/Marianas_Trench/attribution.txt


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Received on Sun Mar 11 00:15:03 2012

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