Hi,
 
You are wrong here, the davinci drivers only support stereo operation.
 
If you record a .wav file and set the number of channels to Mono (via OSS) you 
will get a stereo file regardless. If you attempt to play this file back on 
another machine (with known working mono audio), the audio will play out 'slow' 
as the file is marked as mono in the .wav header but you have actually captured 
stereo input. If you play the file out on the davinci, the switch to mono does 
not work and thus masks the fact that the device is stereo and the file should 
play out.
 
You can confirm this is the case if you capture a raw data file, time say 10 
seconds & then get the calculator out and check the number of bytes you have 
written is what it should be. You will find the value will be similar for both 
a stereo & mono file which is not correct as the stereo file should be twice 
the size.
 
What is broken on the davinci is the OSS mixer. It does not set a value for the 
right channel, so if you read the mixer it appears that only the left channel 
has gain. Although this is 'cosmetic', a side effect of this is you cannot set 
'balance' for left/right as the left value is actually used for the right 
channel as well.
 
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: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of amr ali
Sent: 03 October 2008 19:14
To: [email protected]
Subject: RE: Query : Audio Related (Dhaval Vadhar)


Hi,
I think all davinci drivers captures audio as mono & plays back audio as stereo 
only.
BR,
Amr Ali.
Embedded Systems Developer.
+20123600207.


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