Re: [LAD] Calculate R M S

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To: <linux-audio-dev@...>
Date: Friday, February 18, 2011 - 5:53 pm

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Tnx a lot @ all for great info.

It  means block schema of Automatick Gain/Volume Control is (can
be)
Filter -- RMS_Calculator -- Volume_control 
In exact such order ?
(- For example in FFT are used Rectangular(no window) , Hann,
Hamming, Barlow ... windows. -)
What are the most common filters for ACG and "Loudness" control ?
Why not ?
So far i unterstand the best way for RMS calc would be SQRT of
integral of power2 of sound signal function.
Real signal is not sequence of sampled rectangles, but smooth
function.
Can not happen so what that rectangle inaccuracy of each sample by
freq > 10KHZ ,
in end effect will accumulate big inaccuracy ?
U mean that normally full amplitude sine wave is defined as 0dB RMS
signal ?
Can U plz gimme some examples ?
What is RMS value dB of  +/-maximum_angular signal 
_-_-_-_-_-
( such values - 4k times 0x8000 and 4k times 0x7FFF  .... ) ?
What is RMS value dB of  sine wave , peak/amplitude normalized
to 0x8000-0x7FFF  (or 1.0) ?
Tnx in Advance
Alfs Kurmis.
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Tnx a lot @ all for great info. loudness to ITU/EBU standards at the next LAC (if the p=
aper is accepted). Some filtering followed by RMS detect=
ion will provide a good approximation to subjective loudness.It  means block schema of Automatick Gain/Volume Control is=
(can be)Filter -- RMS_Calculator -- Volume_control  In ex=
act such order ?(- For example in FFT are used Rectangular(no w=
indow) , Hann, Hamming, Barlow ... windows. -)What are the most co=
mmon filters for ACG and "Loudness" control ?> How to calculate =
RMS with hi-precision for frequencies > 10 kHz ? > With inerpo=
lation or so ? Nothing special is needed for high frequencies.=
Why not ?So far i unterstand the best way for RMS calc would be SQRT of integral of power2 of=
sound signal function. Real signal is not sequence of sampled re=
ctangles, but smooth function.Can not=
happen so what that rectangle inaccuracy of each sample by freq > 10KHZ ,in end effect will accumulate big inaccuracy ? > What is reference (=
0dB ) RMS for example for 16bit PCM signal 1024 > samples ? Normally to do the calculations you convert first to floating poin=
t in the range +/- 1.0. If you read a file libsndfile will do that fo=
r you, for realtime if you use Jack all samples are already in that format. The reference for dB is what you make it. Normall=
y full scale for a sine wave is set to '0 dB' The EBU 'target' loudn=
ess is -23 dB on that scale (which is quite low for most popular musi=
c, but probably OK for general purpose use).U mean=
that normally full amplitude sine wave is defined as 0dB RMS signal ?Can U plz gimme some examples ?What is RMS value dB of  +/-maximu=
m_angular signal  _-_-_-_-_-( such values - 4k tim=
es 0x8000 and 4k times 0x7FFF  .... ) ?What is RMS value <=
span lang=3D"en" id=3D"result_box" class=3D"short_text">dB of  =
sine wave , peak/amplitude normalized to 0x8000-0x7FFF =
(or 1.0) ? Tnx in AdvanceAlfs Kurm=
is. ----

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Messages in current thread:
[LAD] Calculate R M S, Alfs Kurmis, (Wed Feb 16, 5:51 pm)
Re: [LAD] Calculate R M S, Jens M Andreasen, (Fri Feb 18, 1:16 am)
Re: [LAD] Calculate R M S, Georg Holzmann, (Thu Feb 17, 7:09 pm)
Re: [LAD] Calculate R M S, Dominique Michel, (Wed Feb 16, 8:33 pm)
Re: [LAD] Calculate R M S, Fons Adriaensen, (Wed Feb 16, 6:45 pm)
Re: [LAD] Calculate R M S, Mark Knecht, (Fri Feb 18, 7:30 pm)
Re: [LAD] Calculate R M S, Fons Adriaensen, (Fri Feb 18, 9:20 pm)
Re: [LAD] Calculate R M S, Mark Knecht, (Fri Feb 18, 10:38 pm)
Re: [LAD] Calculate R M S, Folderol, (Fri Feb 18, 9:24 pm)
Re: [LAD] Calculate R M S, Fons Adriaensen, (Fri Feb 18, 9:30 pm)
Re: [LAD] Calculate R M S, Alfs Kurmis, (Fri Feb 18, 5:53 pm)
Re: [LAD] Calculate R M S, Fons Adriaensen, (Fri Feb 18, 7:02 pm)
Re: [LAD] Calculate R M S - correction, Fons Adriaensen, (Fri Feb 18, 7:06 pm)