[vdr] Low volume on Pro7 ?

Rainer Zocholl UseNet-Posting-Nospam-74308- at zocki.toppoint.de
Sat Jun 11 14:14:00 CEST 2005


prakashp at arcor.de(Prakash Punnoor)  11.06.05 12:21


>Rainer Zocholl schrieb:
>> hm at seneca.muc.de(Harald Milz)  10.06.05 22:24
>>
>>>Dr. Werner Fink <werner at suse.de> wrote:
>>>
>>>>Most AC3 channels do have a lower volume due to the fact that
>>>>the dynanic range of AC3 is much more than 100dB. This is much
>>>>more than you can do with Mpeg Audio and raw PCM at 16bit[1].
>>
>>>Hmmm - I'm missing the logic here. If the average level of an AC3
>>>channel is below the other (PCM) channels, I turn the receiver up
>>>anyway. The next explosion - well, you get the idea.
>>
>> The trick must be not to increase the volume of ac3 but to reduce
>> the volume of other channels.

>Nope, in fact the correct way to do it, would be if a *correct* value
>for dialog normalization in the ac3 header would be sent and then the
>receiver amplifies the whole track relative to this and the volume
>setting you chose so that it matches "non-ac3" streams. Unfortunately
>no broadcaster really does this. Otherwise eg commercial breaks in
>movies with 5.1 wouldn't be this horrible load. So you have to
>complain to the broadcasting station to learn to transmit correctly
>filled ac3 headers...

Or is it done by (stupid) intention to "emphesis" the commerical
break, to wakeup the already sleeping viewers?

IIRC that are simple SCART-Plugs which reduces the volume
during commericial breaks. 
OTOH: 
As the commecial are not always ac3(are they at all?), the 
"dialog normalization value" must be changed on evey break.
Add-dropping software would be lucky to have such an exact signal to detect 
"commericals" ends and beginns!


>If dynamics are too much for you, simply enable DRC, which every
>receiver should be able to handle. Then your ac3 5.1 sounds like every
>other compressed source, if you select heavy DRC. (Yes, every standard
>2ch downmix is heavily compressed.)

A, i see thanks.

>I like to have dynamics. I agree that even 100db would probably enough
>for giving that, but I don't mind that at least 5.1 ac3 does actually
>provide dynamics in sound.

>> 1. Marketing, bigger number looks better (see PPMO)

>I guess you are refering to PMPO? ;-)

Yes, what else? ;)


>> We already had this disussion with "CD" and the "giant" 90dB
>> they claimed to give.

>IIRC, CD gives something like 114db with dithering...and 96db without.

The absoulte Value does not matter. The point was that even 90dB would 
hard to use in normal home environment, or are you able to turn your 
heart beat (reversibel) off to reduce the ground noise?
(At aprox. 1kHz a healthy ear (in the youth) is almost able to hear the
noise the blood flow causes and the brown's movements of air molecules..)
I don't think that any real hifi enthuiast will kill his ears with
sound levels above 100dB(A), but if you already have 20dB
in your -very- silent listning room, so you have to gerate 120DB(A) 
in the peaks to get 100dB range!
I know that most musicians(incl. classics "unpluged"!) to uses
"In-Ear-Monitors" Not only because that works MUCH better
(allowing Stage InterCom etc.), too their ears will be protected.
Sorry, i don't think that you will have fun with such a
dynamic range in the long term. Be cautious! (Have a look
for "Tinitus" etc. in the Web).


Rainer---<=====>                         Vertraulich
             //
           //                              
         <=====>--------------ocholl, Kiel, Germany ------------




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