OSS Device Driver

Phil Quiney PQuiney at trinityconvergence.com
Mon Sep 22 04:36:03 CDT 2008


Please keep the list in the thread.
 
You would need to ask TI.
 
My guess is that depending on how the audio device is 'plumbed in' to the EVM it will either be a lot of work or a 30 second fix. 
 
The fact that is hasn't been done suggests to me that it is a lot of work ;-)
 
Regards
 
Phil Q
 
Phil Quiney, Senior Software Engineer
Trinity Convergence
Cambridge Business Park
Cowley Road
Cambridge CB4 0WZ, UK
T: +44(0)1223-435536
F: +44(0)1223-435560
www.trinityconvergence.com <http://www.trinityconvergence.com/> 

 

________________________________

From: amr ali [mailto:amraldo at hotmail.com] 
Sent: 22 September 2008 10:25
To: Phil Quiney
Subject: RE: OSS Device Driver


Hi,
Can the Device Driver be edited to support mono operation? 
BR,
Amr.





________________________________


Subject: RE: OSS Device Driver
Date: Mon, 22 Sep 2008 10:20:20 +0100
From: PQuiney at trinityconvergence.com
To: amraldo at hotmail.com



It must be doing a mono->stereo conversion internally. 
 
This is what we have to do to get mono playback to work on the DM6446 in our application that directly accesses /dev/dsp. If you are running full duplex you need to do a stareo->mono conversion on the input as well.
 
The same application will happily work on other targets that do support mono so it is not an application thing.
 
Regards
 
Phil Q
 
Phil Quiney, Senior Software Engineer
Trinity Convergence
Cambridge Business Park
Cowley Road
Cambridge CB4 0WZ, UK
T: +44(0)1223-435536
F: +44(0)1223-435560
www.trinityconvergence.com <http://www.trinityconvergence.com/> 

 

________________________________

From: amr ali [mailto:amraldo at hotmail.com] 
Sent: 22 September 2008 10:07
To: Phil Quiney
Subject: RE: OSS Device Driver



Hi,
But how does mpg123 player plays mono files?!!!
BR,
Amr.




________________________________


Subject: RE: OSS Device Driver
Date: Mon, 22 Sep 2008 10:04:45 +0100
From: PQuiney at trinityconvergence.com
To: amraldo at hotmail.com; davinci-linux-open-source at linux.davincidsp.com



Hi,
 
The driver does not do mono. If you attempt to play a mono stream it will go 'clicky' as the driver will 'use up' the input in half the time as it is expecting stereo data.
 
The 'set channels' ioctl used to set mono appears to succeed - it is ignored, the driver is still stereo ;-)
 
Regards
 
Phil Q
 
Phil Quiney, Senior Software Engineer
Trinity Convergence
Cambridge Business Park
Cowley Road
Cambridge CB4 0WZ, UK
T: +44(0)1223-435536
F: +44(0)1223-435560
www.trinityconvergence.com <http://www.trinityconvergence.com/> 

 

________________________________

From: davinci-linux-open-source-bounces at linux.davincidsp.com [mailto:davinci-linux-open-source-bounces at linux.davincidsp.com] On Behalf Of amr ali
Sent: 22 September 2008 09:56
To: davinci-linux-open-source at linux.davincidsp.com
Subject: RE: OSS Device Driver



Hi,
I did a lot of tests. I used the mp3 player mpg123 and VLCfor mp3 playback. mpg123 never failed, while VLC fails on mono only. You have any clue?
BR,
Amr Ali.



 


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