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Reverse stereo

Posted: Fri Dec 10, 2010 4:32 pm
by natirips
Is there a way to reverse stereo (system-wide) using OSS4 (preferably connector-wise)?

[Long and boring story]
My left and right headphones are reversed (yes, I put the one marked "L" on my left ear and the one marked "R" on my right ear). My speakers (connected at the back of the computer) are playing just fine, but my headphones (connected to the front panel) are playing reversed stereo. It is most likely my motherboard's fault because I used the same headset and the same speakers before on my old computer also using OSS4 and everything was fine.
[/Long and boring story]

I'm using OSS4 v4.2 under Debian GNU/Linux (squeeze) on amd64.

Re: Reverse stereo

Posted: Sat Dec 11, 2010 1:15 pm
by cesium
Yes, you can using vmix.

Get and build the version from mercurial repo (see instructions here), and use "vmixctl remap" command. IIRC, "sudo vmixctl remap /dev/dsp 2 1" should do it for everything that uses vmix.

Re: Reverse stereo

Posted: Sat Dec 11, 2010 4:21 pm
by natirips
Edit:
I compiled the one from mercurial repository, and everything considering this post is done using that version.
/edit.

I am now using some of the back-panel jacks and everything is fine. The front-panel jacks are still stereo-reversed, and the command had no effect whatsoever.

So neither of the following has any effect whatsoever (all ran as root, tested using "osstest"):

Code: Select all

vmixctl remap /dev/dsp 0 0 0 0 6 5

Code: Select all

vmixctl remap /dev/dsp 0 0 0 0 5 6

Code: Select all

vmixctl remap /dev/dsp 1 2

Code: Select all

vmixctl remap /dev/dsp 2 1
. :roll:



Oh, and by the way, the wiki forgets to mention "libtool" under dependencies. It's needed for "make build" part, I had to install it to build. (hypothetically libtool may only be needed for configure --enable-midi=YES)

Re: Reverse stereo

Posted: Sat Dec 11, 2010 6:02 pm
by cesium
osstest by default bypasses vmix, so you won't get any difference (including if you mute vmix or any other setting change). Try testing with "osstest -V" and I think you'll find out "sudo vmixctl remap /dev/dsp 2 1" line works. [99.99% of software don't try to bypass vmix (only other exception I recall is JACK), and you can add a parameter to osscore.conf to disable said bypass, so I don't expect this to become a problem].

As for libtool, yea, I'll add it to the wiki (I think it's only used for libsalsa. libsalsa is only built under Linux when some ALSA headers are found, and building it can be disabled with --enable-libsalsa=NO switch to configure).

Re: Reverse stereo

Posted: Sat Dec 11, 2010 8:48 pm
by natirips
Ah, now it works. Thanks.

Re: Reverse stereo

Posted: Thu Dec 01, 2011 10:40 am
by ojin11
I too had been recently wondering whether there was an easy way out there by which I could reverse the stereo headphones. Anyway, it is good to learn that we can indeed use Vmix. However, is there any recent version of Vmix available for download which includes this feature?

Re: Reverse stereo

Posted: Thu Aug 04, 2016 9:42 am
by natirips
@adibitar69: Your problem may be unrelated to mine. See if you're using the correct type of jack (see a poor quality attached image, sorry for the quality, I don't have a proper camera at hand).
jacks.jpg


Be sure the colors are matched because mobile phone/tablet/... headphones (usually black or white) have 4 connections (left, right, mic, ground) while traditional computer headphones (usually green) have 3 connectors (left, right, ground). Count the shiny sections divided by black lines.

Sometimes you may be lucky to get mobile phone headphones to work on a desktop by not plugging them all the way in but a millimeter or two short.



Also, this thread was dead for five years. As I just discovered, OSS' forums even changed their web address in the mean time.

Re: Reverse stereo

Posted: Thu Feb 14, 2019 10:16 am
by WilliamGrant
Thank You for this information its perfectly working fine.