Subject: Re: [ecasound] dbsize? (as in, -z:db,dbsize)
From: Kai Vehmanen (k_AT_eca.cx)
Date: Fri Oct 25 2002 - 21:36:59 EEST
On Fri, 25 Oct 2002, Craig Meyer wrote:
> I could use a little clarification on the dbsize
> setting. So far I've been enabling double-buffering
> with -z:db, and that's it, without specifying any
> dbsize.
It's the size of the double buffer in sample frame. So if you run ecasound
with a sample rate of 44100, -z:db would put a one second buffer between
all non-realtime inputs (= usually files) and the real-time engine.
The default is 100000 and can be fine-tuned in ecasoundrc.
> The man page says that dbsize defaults to 0, but why
> is that? Does that mean that there's no
> double-buffering going on at all?
Actually that's just my bad English: "dbzise=0 for default, otherwise
buffer size in sample frames". What I meant by that is that if you
specify -z:db,0, it will use the default (100000, or whatever you have in
your ecasoundrc).
If the double-buffer overflows/underflows, you will get errors like:
(audioio-db-client) Warning! Overrun in writing to "foo.wav". Trying to recover.
... for serious use (like recording), you should have big enough
buffer so that these never ever happen.
PS Increasing the -z:db,x value will consume memory. -z:db,100000
at cd-quality means 0.4MB of memory for every non-rt
input and output.
-- http://www.eca.cx Audio software for Linux!
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