[ViX_Misc] Signal Quality Values

[abu baniaz]

Logs attached. I went into signal finder and went between the frequencies.

 

[EMJB]

…. and in the case of the new API is a number of dBs which is normally negative, not a percentage.

Now not sure that this part is correct - in spite of the name give by frontend.cpp I think the signal strength may be a percentage of a maximum, which would explain its similarity to the snr% figure. I need to trace all the signals through from API to users to follow the changing names to be sure of what is going on.

EMJB

 

[EMJB]

Logs attached. I went into signal finder and went between the frequencies.

Thanks - will try to look at them tomorrow.

EMJB

 

[EMJB]

I've had a look at the logs. The major issue seems to be the following sequence:

1. FrontendStatus.py line 25 equates the "AGC"% value to "tuner_signal_power"
2. python_helpers.cpp equates this to eDVBFrontendStatus::getSignalPower()
3. frontendparms.cpp line 84 equates this to frontend.cpp's "iFrontendInformation_ENUMS::signalPower",
4. frontend.cpp equates this to the new API relative signal strength, not the absolute signal strength in dBm (see https://linuxtv.org/downloads/v4l-d...stat-properties.html#dtv-stat-signal-strength)

as indicated in my penultimate post.

Unfortunately the new API is rather vague about how the relative signal strength is to be calculated, and I would not be surprised if drivers just equate this to the relative SNR.

In terms of specific issues arising rom the Sundtek log, I noticed that while the new API returned a value for relative (i.e. %) SNR it did not do so for the absolute (dB) value. While frontend.cpp calculates a missing relative value from the absolute value, the reverse is not true, forcing the use of the legacy API. In the absence of tuner-specific code this can produce silly answers.

The PNP log shows that frontend.cpp thinks that this tuner supports the new API, but never gets any data from it, and so always reverts to the legacy API. Aagin, in the absence of tuner-specific code this can produce silly answers.


EMJB

 

[Ojustaboo]

On my Unicable LNB, AGC is 80% on every channel I've tried, and SNR 69% to 80% depending on channel (not tried them all, but every one I've tried AGC is 80)

On my other normal LNB motorised dish, AGC varies from 72 to 82% depending on the channel



This is on my Gigablue UHD UE 4K