[linux-dvb] [Proposal] Meaningful reporting of SNR
abraham.manu at gmail.com
Wed Apr 12 18:32:46 CEST 2006
Rusty Scott wrote:
> On Wed, 2006-04-12 at 16:57 +0200, Robert Schlabbach wrote:
>> From: "Rusty Scott" <rustys at ieee.org>
>>> 1) That it be encouraged to report SNR in dB whenever possible.
>> I'm afraid most hardware is incapable of producing such measurements.
>> Instead, I'd propose scaling all signal measurements to _percentages_.
> Currently done. Causes confusion. Percentage is meaningless.
> Why penalize the cards that are capable? If SNR cannot be reported by a
> card then it shouldn't be throwing out a number that isn't
> representative of SNR. If it is representative of SNR in some form, the
> manufacturers I've dealt with provide the formula to compute SNR in dB.
> SNR as a percentage is a useless number (Percentage of what? Largest
> possible value a card can produce?). Given the number of questions
> concerning "What should I be seeing for SNR from XXX?" where the reply
> is it should be "big", there are a number of people looking for a
> meaningful, consistent, method to provide this information. For ATSC
> and QAM there is an SNR point where errors begin to degrade the quality
> of what you see; the same applies to every transmission coding scheme.
Yeah, i agree with you, we are working on it such that we can do some
standardization. We are in fact working on a proof of concept thing
right now. Hopefully, many will like it when it is done.
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