devaru
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 Posted:
Tue Dec 21, 2004 8:03 am Post subject:
how to convert frame energy into "dBov" |
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In G711-appendix-2,
The noise level is expressed in –dBov, with values from 0 to 127
representing 0 to –127 dBov.
I know dBov is the level relative to the overload of the
system.(Representation relative to the overload point of a system is
particularly useful for digital implementations, since one does not need
to know the relative calibration of the analog circuitry.)
For example, in the case of a u-law system, the reference would be a
square wave with values +/-8192, and this square wave represents 0dBov.
Some where in the internet I found that
dBov = 10 log(p/Pref);
For example, consider the signal with minimal enargy say 1 (other than 0).
then dBov = 10*log(1/8192) = -39.13389
0dBov is the maximum value and -39.13389 dBov is the minimal value. But
the standard says, the energy is expressed in dBov in the range 0 to 127.
Please let me know what is the exact procedure to represent the energy in
"dBov"
thanks
-Lingadevaru |
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