On 14.06.2014 20:20, Arthur Konovalov wrote:
14.06.2014 17:52, Klaus Schmidinger kirjutas:
On 14.06.2014 16:40, Arthur Konovalov wrote:
I've noticed strange effect with the SNR bar. Every time when UNC
counter increased SNR bar becomes more and more red. In the same time
hex and percent values are fine. Combined screenshot from femon
plugin: http://www.pictureshack.ru/images/95487_unc.jpg
It's not plugin depended. The same behavior can be observed on
standard VDR's channel LCARS skin info bar.

Why UNC occurred, it's a different story. Currently I can't explain
why viewing some (not all!) HD channels lead to the UNC (disturbance
are visible too). Is it bitrate or something else, I don't know. It
seems only 1080i suffer, not 720p and BER stays always on zero. If
somebody have any method to
debug and find reason of this, I will be thankful for sharing.

It would appear that UNC is a static counter that is simply counted up with
every uncorrected error, and is only reset to 0 on a channel switch.

I don't know about femon, but the way VDR uses this counter to produce its
"signal quality" measure is

   int b = 100 - (Unc * 10 + (Ber / 256) * 5);

So if the value of Unc increases, the signal quality decreases.
Maybe we should only take Unc into account if it has been counted up
within the past few seconds?

If anybody can suggest a proper way of doing this, please speak up.

Why just don't use values from device without additional calculation?

Because when I introduced cDevice::SignalQuality() it was agreed upon
that SNR, BER and UNC should be taken into account.
If the general opinion is now that we should leave UNC (and BER?) out
of the calculation, that's fine with me.

Any opinions?

Klaus

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