12 replies to this topic

[sky2]

Hello,

What is the reason why all OpenPLI images show an absolute maximum of signale 16.2 db and 99%? I noticed that even with an antenna over 200 centimeters, the signal is always 16.2db, while the operator's receiver is above 20 dB.

 

Thanks!

[athoik]

Because the manufacturer doesn't provide DVB API 5.10 where dB controlled directly from drivers.

What you see is an aproximation estimation.

Ask for DVB API 5.10 and driver support.

Edited by athoik, 2 September 2017 - 20:41.

[ian1095]

Well it used to work correctly. Up until about March this year when it started doing what the Original Poster stated its now doing.

 

Ian.

[Erik Slagter]

It is determined by the manufacturer, not by the image.

[Robinson]

Well it used to work correctly. Up until about March this year when it started doing what the Original Poster stated its now doing.

 

Ian.

On which box was it correct?

I have used ET9000 for several years and it never went above 16.17dB (which is indeed 16.2dB after rounding the value off).

[WanWizard]

On the HD2400 I have 18.5 on the Astra UHD demo feed. If I can recall correctly the ET10K also stopped at 16.2.

[betacentauri]

I still don't understand why the value is so important for so many people...
I never look at it.

[ian1095]

 

Well it used to work correctly. Up until about March this year when it started doing what the Original Poster stated its now doing.

 

Ian.

On which box was it correct?

I have used ET9000 for several years and it never went above 16.17dB (which is indeed 16.2dB after rounding the value off).

 

VU+ Solo2

 

But as stated its been incorrect for over 6 months now.

 

Ian.

[Erik Slagter]

I still don't understand why the value is so important for so many people...
I never look at it.

I can understand, but it is misguided. The value has such an enormous margin that it's useless.

[Dimitrij]

Because the manufacturer doesn't provide DVB API 5.10 where dB controlled directly from drivers.

What you see is an aproximation estimation.

Ask for DVB API 5.10 and driver support.

DVB API 5.10 just a nightmare .
Constant mistakes snr/db from manufacturers.

Edited by Dimitrij, 3 September 2017 - 21:09.

[athoik]

Because the manufacturer doesn't provide DVB API 5.10 where dB controlled directly from drivers.

What you see is an aproximation estimation.

Ask for DVB API 5.10 and driver support.

DVB API 5.10 just a nightmare .
Constant mistakes snr/db from manufacturers.

Yeah, that's what manufacturer provide for E2, shitty driver. Wake up

[athoik]

Well it used to work correctly. Up until about March this year when it started doing what the Original Poster stated its now doing.
 
Ian.

On which box was it correct?
I have used ET9000 for several years and it never went above 16.17dB (which is indeed 16.2dB after rounding the value off).

VU+ Solo2
 
But as stated its been incorrect for over 6 months now.
 
Ian.

Vu+, generally speaking doesn't provide dB on their driver, it just uses dvb api 3 with values scaled as percentage. 0 to 65535, 0 to 100% quality not dB.

Everyone can monitor what the driver return by simply installing femon (opkg install dvb-femon).

Then execute femon to get values DIRECTLY FROM DRIVERS......
 

# femon -h
femon: invalid option -- 'h'

usage: femon [options]
     -H        : human readable output
     -A        : Acoustical mode. A sound indicates the signal quality.
     -r        : If 'Acoustical mode' is active it tells the application
                 is called remotely via ssh. The sound is heard on the 'real'
                 machine but. The user has to be root.
     -a number : use given adapter (default 0)
     -f number : use given frontend (default 0)
     -c number : samples to take (default 0 = infinite)

# femon -f 2 -c 3
FE: FTM-4862 (Availink AVL6862) (DVBS)
Problem retrieving frontend information: Operation not supported
status SCVYL | signal 003a | snr 39a8 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
Problem retrieving frontend information: Operation not supported
status SCVYL | signal 003a | snr 3926 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
Problem retrieving frontend information: Operation not supported
status SCVYL | signal 003a | snr 39a8 | ber 00000000 | unc 00000000 | FE_HAS_LOCK

As you can see above I used frontend 2 (identified as C under E2) and 3 samples. The interensting part is snr 3926. What is the value for VU+?


If the receiver supports also DVB API 5.10 you can use dvb-fe-tool (opkg install v4l-utils) and get the values return by newer API.
 

# dvb-fe-tool -m -f 2
Lock   (0x1f) Signal= 59.00% C/N= 14.72dB postBER= 0
       Layer A: C/N= 92.00%
Lock   (0x1f) Signal= 58.00% C/N= 14.72dB postBER= 0
       Layer A: C/N= 92.00%
Lock   (0x1f) Signal= 58.00% C/N= 14.75dB postBER= 0
       Layer A: C/N= 92.00%
Lock   (0x1f) Signal= 58.00% C/N= 14.73dB postBER= 0
       Layer A: C/N= 92.00%

So the question is what VU+ returns on femon?

Give me the output to tell you how calculation on DVB API 3 works (foolling you thinking that receiver show dB....).

Edited by athoik, 3 September 2017 - 21:42.

[Robinson]

I still don't understand why the value is so important for so many people...
I never look at it.

I am a big fan of numbers and statistics.