Re: [ecasound] dither

From: Joel Roth <joelz@email-addr-hidden>
Date: Thu Aug 13 2015 - 01:21:21 EEST

rtaylor wrote:
> Hi all,
>
> What is the status of dither (if any) in ecasound? I'm looking at
> implementing this myself, or I could help if someone is already working
> on this.
>
> I've been using ecasound to build crossovers with equalization for
> active loudspeakers, but also as a general signal-processing toolbox.
> See e.g. here:
>
> http://rtaylor.sites.tru.ca/2013/06/25/digital-crossovereq-with-open-source-software-howto/
>
> Lack of dither is a problem for me, though I have a workaround that
> pipes output from ecasound to sox for dithered re-quantization. I have
> a post here that shows the problems with ecasound's undithered output,
> plus my current workaround:
 
> http://rtaylor.sites.tru.ca/2015/08/12/dither-and-ecasound/

Hi Richard,

Nice articles, both.

I didn't find any match for 'dither' in the
Ecasound git history. Grepping through the
sources I found only this mention. If there
is not "dither" in comments anywhere.

(edi-37): Porting Steve Harris' dither code from JACK to ecasound
         - submitted: jhall, 17.03.2003
         - migrated to sf.net -> sffeat:2134188

Looking further:

git:master ~/build/ecasound $ grep -ri dither `ls`
Binary file ecasound/ecasound matches
Binary file libecasound/plugins/.libs/audioio_sndfile.o matches
Binary file libecasound/plugins/.libs/libecasound_plugins.a matches
Binary file libecasound/plugins/audioio_sndfile.o matches
Binary file libecasound/.libs/libecasound.a matches

Does this suggest that dithering, such as ecasound has, is
from libndfile?

From man ecasound:

  Libsndfile - ’sndfile’
              If libsndfile support was enabled at compile-time, this option
              allows you to force Ecasound to use libsndfile for reading/writing
              a certain audio file. Option syntax is -i:sndfile,foobar.ext[,.for‐
              mat-ext] (same for -o). The optional third parameter "format" can
              be used to override the audio format (for example you can create an
              AIFF file with filename "foo.wav").

So, maybe try using

-o,sndfile,output.wav ?

cheers, Joel

 
> Richard
>
>
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-- 
Joel Roth
  
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Received on Thu Aug 13 04:15:01 2015

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