Re: [ecasound] 'circular' use of loop devices?

From: James Mckernon <jmckernon@email-addr-hidden>
Date: Sat Apr 14 2012 - 18:37:17 EEST

Beautiful. This works just as I'd hoped. I'm actually not too bothered
about the ~23ms delay, as it's actually mostly delay-based effects that I
wanted to investigate with this, so that's easy enough to compensate for -
I'll just subtract 23 from the time parameter for the delay I use. (In any
case, I suspect that it's not really possible to do what I'm asking for
without *some* inherent delay, whether that's a few samples or a few

Thanks so much!

On Sat, Apr 14, 2012 at 2:52 PM, Kai Vehmanen <kvehmanen@email-addr-hidden> wrote:

> Hi,
> On Sat, 14 Apr 2012, James Mckernon wrote:
> I'm trying to experiment with some experimental effects paths within
>> ecasound - in particular, ones that involve 'circular' chains, whose input
>> and output are the same loop device. I'm thinking something along the lines
>> of the following:
>> ecasound -a:1 -i:input.mp3 -o:loop,1 -a:2 -i:loop,1 -o:alsa -a:3
>> -i:loop,1 [some_effects_here] -o:loop,1
> When ecasound processes this, when it reaches "-a:3 -i:loop,1", it
> connects "loop,1" only to chain 3 and not anymore to 1, and this causes the
> error messages below (no input for chain 1).
> So when you want to connect an input/output to multiple chains, you have
> to do it like this:
> ecasound -a:1 -i input.mp3 -a:1,3 -o:loop,1 -a:2,3 -i:loop,1 -a:2 -o:alsa
> -a:3 [some_effects_here]
> But this is probably not quite what you are looking for, as each hop from
> a loop output to its input, causes an additional delay of one engine
> iteration (equivalent to -b:size, e.g. -b:1024@email-addr-hidden -> delay of
> ~23.2ms). You can modify the delay by setting -b:xxx to different values,
> but this is a bit clumsy and may have side-effects to e.g. overall
> performance (low buffersize values increase engine overhead).
> Funnily enough, the closely related setup,
>> ecasound -a:1 -i:input.mp3 -o:loop,1 -a:2 -i:loop,1 -o:alsa -a:3
>> -i:loop,2 [some_effects_here] -o:loop,2
>> seems to instantiate without any problems.
> Yep, so here "loop,1" and "loop,2" are considered separate objects, so the
> above error doesn't happen (each chain has an input and an output defined
> above).

For Developers, A Lot Can Happen In A Second.
Boundary is the first to Know...and Tell You.
Monitor Your Applications in Ultra-Fine Resolution. Try it FREE!

Ecasound-list mailing list
Received on Sat Apr 14 20:15:01 2012

This archive was generated by hypermail 2.1.8 : Sat Apr 14 2012 - 20:15:01 EEST