Ecasound newbie - convert 4 channel to twin stereo
Andrew Ferguson <[email protected]> Sat, 28 Jul 2018 17:30:58 +0100
| Newsgroups | gmane.comp.audio.ecasound.general |
|---|---|
| Message-ID | <[email protected]> |
This is a multi-part message in MIME format.
--===============5389243848842138721==
Content-Type: multipart/alternative;
boundary="------------FA7941CA3C17A1D6A831C627"
Content-Language: en-US
This is a multi-part message in MIME format.
--------------FA7941CA3C17A1D6A831C627
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
So I had never used Ecasound before until yesterday, but I found a
project on GitHub <https://github.com/markmerz/ladspa-sq-sv> where
someone had written a SQ Quadraphonic decoder as a LADSPA plugin, and so
I installed the plugin and ecasound, and tried to make it work in the
way that I needed.
The example command on the plugin page was:
ecasound -x -i sq-test-tones.m4a -el:hilbert_stereo_200taps
-el:sq_decoder_shadow_vector -f:,4 -o test.wav
This takes a two-channel input file with some SQ quadraphonic test tones
and produces a single 4-channel discrete quadraphonic file. However, my
goal is to have ecasound take a realtime input from an ALSA device,
decode the SQ signal using the plugin, then output to two 2-chanel
devices, one for the front set of speakers, and one for the rear set of
speakers. I currently don't have the ALSA devices setup with the system
I will be using (an original Raspberry Pi Model B), so I'm using files
as placeholders for the input and output devices.
I tried the following command, based upon the original command from the
plugin page and the ecasound documentation for multitrack usage:
ecasound -a:1,2 -x -i sq-test-tones.m4a -el:hilbert_stereo_200taps
-el:sq_decoder_shadow_vector -a:1 -f:16,2,44100 -o front.wav -a:2
-f:16,2,44100 -o back.wav -chcopy:3,1 -chcopy:4,2
unfortunately, this gives the error "Exactly one chain should be
selected when adding chain operators". I can get this to work
individually, by using this command to get the front set of speakers:
ecasound -x -i sq-test-tones.m4a -el:hilbert_stereo_200taps
-el:sq_decoder_shadow_vector -f:,4 -a:1 -f:16,2,44100 -o front.wav
and this one for the rear set of speakers:
ecasound -x -i sq-test-tones.m4a -el:hilbert_stereo_200taps
-el:sq_decoder_shadow_vector -f:,4 -a:1 -f:16,2,44100 -chcopy:3,1
-chcopy:4,2 -o back.wav
but I really need to to be all in one command.
Would someone with more experience with ecasound be able to guide me
towards a solution to this?
Thanks,
Andrew
--------------FA7941CA3C17A1D6A831C627
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: 7bit
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>So I had never used Ecasound before until yesterday, but I found
a <a moz-do-not-send="true"
href="https://github.com/markmerz/ladspa-sq-sv">project on
GitHub</a> where someone had written a SQ Quadraphonic decoder
as a LADSPA plugin, and so I installed the plugin and ecasound,
and tried to make it work in the way that I needed.</p>
<p><br>
</p>
<p>The example command on the plugin page was:</p>
<blockquote>
<p>ecasound -x -i sq-test-tones.m4a -el:hilbert_stereo_200taps
-el:sq_decoder_shadow_vector -f:,4 -o test.wav<br>
</p>
</blockquote>
<p>This takes a two-channel input file with some SQ quadraphonic
test tones and produces a single 4-channel discrete quadraphonic
file. However, my goal is to have ecasound take a realtime input
from an ALSA device, decode the SQ signal using the plugin, then
output to two 2-chanel devices, one for the front set of speakers,
and one for the rear set of speakers. I currently don't have the
ALSA devices setup with the system I will be using (an original
Raspberry Pi Model B), so I'm using files as placeholders for the
input and output devices.</p>
<p>I tried the following command, based upon the original command
from the plugin page and the ecasound documentation for multitrack
usage:</p>
<blockquote>
<p>ecasound -a:1,2 -x -i sq-test-tones.m4a
-el:hilbert_stereo_200taps -el:sq_decoder_shadow_vector -a:1
-f:16,2,44100 -o front.wav -a:2 -f:16,2,44100 -o back.wav
-chcopy:3,1 -chcopy:4,2<br>
</p>
</blockquote>
<p>unfortunately, this gives the error "Exactly one chain should be
selected when adding chain operators". I can get this to work
individually, by using this command to get the front set of
speakers:</p>
<blockquote>
<p>ecasound -x -i sq-test-tones.m4a -el:hilbert_stereo_200taps
-el:sq_decoder_shadow_vector -f:,4 -a:1 -f:16,2,44100 -o
front.wav<br>
</p>
</blockquote>
<p>and this one for the rear set of speakers:</p>
<blockquote>
<p>ecasound -x -i sq-test-tones.m4a -el:hilbert_stereo_200taps
-el:sq_decoder_shadow_vector -f:,4 -a:1 -f:16,2,44100
-chcopy:3,1 -chcopy:4,2 -o back.wav<br>
</p>
</blockquote>
<p>but I really need to to be all in one command.</p>
<p><br>
</p>
<p>Would someone with more experience with ecasound be able to guide
me towards a solution to this?</p>
<p>Thanks,</p>
<p>Andrew<br>
</p>
</body>
</html>
--------------FA7941CA3C17A1D6A831C627--
--===============5389243848842138721==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
--===============5389243848842138721==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
Ecasound-list mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/ecasound-list
--===============5389243848842138721==--