[gst-devel] simultaneous OSS playback/record

Wilson, Diego dwilson at ti.com
Wed Jun 14 17:26:46 CEST 2006


Here's my problem. I am very aware my OSS driver does not allow two
opens. What's more I even know the person who wrote this OSS driver. And
I contacted him regarding the "full duplex" issue. 

The driver writer (say that three times fast) is arguing you should not
open a /dev/dsp device twice using OSS to begin with. And the "Open
Sound System Programmer's Guide" supports his argument. The guide says
you should open the device once, turn on a full duplex mode and then
read and write like there was no tomorrow. The guide *is* the golden
standard for OSS Audio isn't it? Cuz maybe I'm looking in the wrong

Now IMHO there's only two possible solutions to my problem:

1. Convince the writer of the OSS driver that you *should* be able to
open the /dev/dsp device twice.
2. Find a way of doing OSS full duplex in GStreamer by opening the
/dev/dsp device once.

For now, I'm making a plea to the GStreamer gods for an answer. C'mon, I
know your watching.


Diego Wilson

-----Original Message-----
From: Thomas Vander Stichele [mailto:thomas at apestaart.org] 
Sent: Wednesday, June 14, 2006 4:11 AM
To: Wilson, Diego
Cc: Edgard Lima; gstreamer-devel at lists.sourceforge.net
Subject: Re: [gst-devel] simultaneous OSS playback/record

On Tue, 2006-06-13 at 13:20 -0500, Wilson, Diego wrote:
> Edgard,
> None of them work. I'm getting the following error on all of them:
> ERROR: from element /pipeline0/osssrc0: Unable to open device /dev/dsp
> for recording: Device or resource busy

Well, then your oss driver really *does not* allow two opens, even from
the same process.

I have the same for my ac97 intel sound card.  alsasrc ! alsasink works
fine on it, so it's not the hardware's fault.


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