[LAU] ebur128 batch processing

[Gene Heskett]

On Friday 07 March 2014 17:34:15 Jaromír Mikeš did opine:

> 2014-03-07 14:28 GMT+01:00 Jِrn Nettingsmeier
> <nettings at stackingdwarves.net>
> 
> > On 03/07/2014 01:48 AM, Jaromيr Mike¹ wrote:
> >> Hi,
> >> 
> >> I will got about 100 stereo wav files mixed hopefully in similar way
> >> (loudness).
> >> I need them process to meet ebur128 specification.
> >> True peaks -3dB
> >> RMS -23dB
> > 
> > can i ask which broadcaster mandates -3dB true peak? that seems quite
> > conservative.
> 
> Czech TV ;)
> 
> mira

Humm, that peak is 7db below the average vu meter reading here, and we 
won't even look at a board that will not handle 20-24db peaks, preferable a 
solid +30dbm.

But now, with everything digital, it seems the producers are all living by 
the old AM motto, the louder the better, and I can quite easily hear 
digital clipping that is less than 6 db above the average.  That makes it 
pretty darned obvious, particularly when their excrement production gear 
does a sign inversion in an add/mix stage to go with the peak.

How then do they handle the noise floor when they are running rms 27db 
below a lot of the rest of the planet?

That means their broadcast gear has to have a -83db noise floor to hold the 
mandated noise floor over here of -60db or better.  Best I ever saw was -66 
and that was with the video modulation removed on a UHF transmitter.  We 
could do that to get thru a Proof of Performance on UHF because the UHF 
amplifiers in those days were all klystrons, which if the video was on had 
so much Incidental Carrier Phase Modulation that the true intercarrier 
measured noise was usually in the high -40's, to very low -50's if the 
visual wasn't tuned for best efficiency.

That was not often done because it had a very noticeable effect on the 
monthly power bill, which at best was in the $10,000 USD/month range for 
most stations.

Cheers, Gene
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