Summary:ASTERISK-05610: chan_oss no audio path - one way audio path
Reporter:Tracy Carlton (carltont)Labels:
Date Opened:2005-11-15 09:43:18.000-0600Date Closed:2011-06-07 14:03:27
Versions:Frequency of
Description:When using a half-duplex sound card (for paging app) there is no audio in either direction (to sound card output or from mic input).Using a full-duplex sound card produces a one-way audio path - from mic input to originating extension (backwards from the desired function :) ).  I have confirmed this now with three different MBs with onboard soundcards (all half-duplex) and using two different models of SoundBlaster full-duplex cards (SB Live and SB 512 PCI).  Renaming and recompiling with the old chan_oss works as expected - No support of half-duplex, working correctly with either SB card.  
Comments:By: Kevin P. Fleming (kpfleming) 2005-11-15 21:03:04.000-0600

Luigi, can you try to help this user figure out what the problem is? It appears to be caused by your re-written chan_oss module.

By: Luigi Rizzo (rizzo) 2005-11-16 01:22:29.000-0600

if you can contact me by email (rizzo@icir.org) we can try to sort out
the details - basically i need to know what options are you using in
oss.conf and how are you activating the channel from the dialplan.
Also, knowing which OS you are using would help.

By: Tracy Carlton (carltont) 2005-11-21 09:04:49.000-0600

I emailed rizzo on 11/16/05 with the requested info.  Have not had a response since.

By: Luigi Rizzo (rizzo) 2005-11-21 09:15:25.000-0600

carltont: i am sorry but i probably missed that... or my spamfilter killed i
(see http://info.iet.unipi.it/~luigi/ to see why i need a very
aggressive one!).
Could you resend it or post your email so i can contact you ? ?

By: Tracy Carlton (carltont) 2005-11-21 10:59:15.000-0600

rizzo you can contact me at tracy at ycic dot net.

I'll also resend the email as well.


By: Luigi Rizzo (rizzo) 2005-11-24 10:57:33.000-0600

sorry but i cannot reproduce the problem locally.
With "autoanswer = yes" in oss.conf, an incoming call routed to chan_oss e.g.
with this in your dialplan:

   exten => s,1,Dial(Console/dsp) ;

will be answered immediately and incoming sound routed to the speaker
as expected.

Make sure you are using at least rev.1.61 of chan_oss.c because that
version might fix a potentially related bug.
Other than that, I don't know, it does not seem that there is a problem here.

If your concern is half duplex support, that's another story - it unsupported
at the moment. What the previous version did was "one way audio", not
really "half duplex" (meant as a channel where you can switch between
one direction and the other). If there is demand i can try to restore
one-way audio operation.

By: Tracy Carlton (carltont) 2005-12-02 00:34:24.000-0600


I'm using the 1.63 version that is included in the asterisk 1.2 release tarball and have now tried 4 different models of Soundblaster full-duplex sound cards on 3 widely different PCs - P3 Aopen, P4 - Intel, P4 Abit, SB Live(2 sub models), SB 512, SB Live 24bit sound cards.  I've also spoken with two other people having the same issue.

Perhaps if you sent me your working chan_oss.c file and oss.conf files I can try them on my systems and see what I can see.

By: Tracy Carlton (carltont) 2005-12-08 09:15:37.000-0600

This issue has been solved.

It related to Centos 4.x's sound card driver support and its interactions with chan_oss.  It is correctable using the alsa utilities (not installed by default). SORRY!