captain jack
06-09-12, 22:02
Hi,
As we all know, the Vu boxes do not provide a SNR value in dB but always in percentage. This is something to do with drivers.
Now, I have checked my friend's Dreambox 800HD receiver and compared the dB value and the percentage value to find a correlation. The correlation seems to be SNR dB = SNR% / 6.21 which gives a more or less accurate conversion.
So, if my SNR% on the Uno is 34%, which is a just about watchable picture, it converts to SNR dB of around 5.47dB which sounds about right. I *know* that this value shouldn't be taken as gospel and it's purely an indication etc. but I was wondering if it's possible for the VIX team to calculate the dB from the percentage SNR?
I have played around with OpenWebIF and edited the signal.py file like the following:
\t<e2snrdb> ''')
_v = VFFSL(SL,"snr_db",True) # u'$snr_db' on line 4, col 12
_v = round(_v/6.21,2)
if _v is not None: write(_filter(_v, rawExpr=u'$snr_db')) # from line 4, col 12.
write(u''' dB </e2snrdb>
\t<e2snr> ''')
After restarting Engima, my http://uno/web/signal changed from:
<e2frontendstatus>
<e2snrdb>42 dB</e2snrdb>
<e2snr>42 %</e2snr>
<e2ber>0</e2ber>
<e2acg>65 %</e2acg>
</e2frontendstatus>
to
<e2frontendstatus>
<e2snrdb>6.76 dB</e2snrdb>
<e2snr>42 %</e2snr>
<e2ber>0</e2ber>
<e2acg>65 %</e2acg>
</e2frontendstatus>
This helps for windows based apps which use this path to get signal levels but skins seem to take this information from somewhere else.... So, er.... where? :) skin.xml seems to look at "FrontendInfo" but I am not sure how I can use skin.xml to change values....
Any advice/ideas/criticisms?
CJ
As we all know, the Vu boxes do not provide a SNR value in dB but always in percentage. This is something to do with drivers.
Now, I have checked my friend's Dreambox 800HD receiver and compared the dB value and the percentage value to find a correlation. The correlation seems to be SNR dB = SNR% / 6.21 which gives a more or less accurate conversion.
So, if my SNR% on the Uno is 34%, which is a just about watchable picture, it converts to SNR dB of around 5.47dB which sounds about right. I *know* that this value shouldn't be taken as gospel and it's purely an indication etc. but I was wondering if it's possible for the VIX team to calculate the dB from the percentage SNR?
I have played around with OpenWebIF and edited the signal.py file like the following:
\t<e2snrdb> ''')
_v = VFFSL(SL,"snr_db",True) # u'$snr_db' on line 4, col 12
_v = round(_v/6.21,2)
if _v is not None: write(_filter(_v, rawExpr=u'$snr_db')) # from line 4, col 12.
write(u''' dB </e2snrdb>
\t<e2snr> ''')
After restarting Engima, my http://uno/web/signal changed from:
<e2frontendstatus>
<e2snrdb>42 dB</e2snrdb>
<e2snr>42 %</e2snr>
<e2ber>0</e2ber>
<e2acg>65 %</e2acg>
</e2frontendstatus>
to
<e2frontendstatus>
<e2snrdb>6.76 dB</e2snrdb>
<e2snr>42 %</e2snr>
<e2ber>0</e2ber>
<e2acg>65 %</e2acg>
</e2frontendstatus>
This helps for windows based apps which use this path to get signal levels but skins seem to take this information from somewhere else.... So, er.... where? :) skin.xml seems to look at "FrontendInfo" but I am not sure how I can use skin.xml to change values....
Any advice/ideas/criticisms?
CJ