Re: femon patch for dB

[Antti Palosaari <crope@xxxxxx>]

On 10/29/2011 02:01 AM, James wrote:
> I added a switch to femon so it displays signal and snr in dB.
>
> The cx23885 driver for my Hauppauge WinTV-HVR1250 reports signal and snr
> in dB.
>
> http://lockie.ca/test/femon.patch.bz2

from patch:
human readable output: (signal: 0-65335, snr: 1/256 increments)\n"
human readable output: (signal and snr in .1 dB increments)\n"

You should take look to demod drivers and check what those are 
returning. I have strong feeling that most drivers returns SNR as 10xdB. 
And SS as 0-0xffff. I think there is good consensus of SNR unit, but for 
SS it is not so clear. For my drivers I have used SNR 10xdB and SS 
0-0xffff. That's why, giving only those two alternatives is not 
suitable. Maybe it is better to set own param for SNR and SS?

Devin did some research about SNR long time back:
http://www.devinheitmueller.com/snr.txt

regards
Antti
--
http://palosaari.fi/
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