[LAU] Simple loop playing from command line

Ken Restivo ken at restivo.org
Tue Jan 11 07:18:03 UTC 2011


I'm trying to figure out a way to play a simple loop from the command line. It doesn't need to be synchronized with anything (our drummer will be talking over it).

I found this archive:

 http://comments.gmane.org/gmane.comp.audio.ecasound.general/3843

 But there seems to be no "audioloop" in ecasound (I have  2.4.6.1-2 ).

The man page I have on my system mentions "-tl", so I tried that, and it zombified jack (not good).

Here is what I tried;

$ ecasound -f:f32_le,2,48000 -t:3600 -a:1 -i:audioloop,johnloop48.wav  -a:all -o jack_auto
 does nothing, just tells me three tims that it is using realtime-scheduling:
 - [ Engine init - Driver start ] 
(eca-engine) Using realtime-scheduling (SCHED_FIFO:50).
(eca-engine) Using realtime-scheduling (SCHED_FIFO:50).
(eca-engine) Using realtime-scheduling (SCHED_FIFO:50).

Hmm. Goole says try "notransport". So I do.

$  ecasound -f:f32_le,2,48000 -G:jack,ecasound,notransport -tl -a:1 -i:audioloop,johnloop48.wav  -a:all -o jack_auto
	does nothing, just goes:
	- [ Engine init - Driver start ] 
(eca-engine) Using realtime-scheduling (SCHED_FIFO:50).
and then hangs, but at least that tells me only once that it's realtime-scheduling

OK, how about doing what the docs say?

$ ecasound -f:f32_le,2,48000 -G:jack,ecasound,notransport -tl -a:1 -i:johnloop48.wav  -a:all -o jack_auto
  plays the loop once, then zombifies
  (eca-engine) Using realtime-scheduling (SCHED_FIFO:50).
zombified - calling shutdown handler
(eca-engine) WARNING: Engine has raised an error! Possible causes: connection 
... lost to system services, unable to adapt to changes in operating environment, etc.
- [ Controller/Batch processing finished (-3) ] --------------------------------
ecasound: Warning! Errors detected during processing.
(eca-control-objects) Disconnecting chainsetup: "command-line-setup".

At least I got sound out of it though.

Are there any other command-line tools I could use to loop a wav file, possibly simpler and less weird than ecasound?

I guess I could write one, just read the bytes out of a wav file in a loop, and dump it into the jack process callback, wouldn't be too hard. But if something already exists, then I'd rather use that.

Thanks!
 
-ken


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