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Re: Using normalize from another program [was Re: ITP: normalize]

On Wed, Jan 03, 2001 at 05:33:41PM -0200, Eduardo Marcel Macan wrote:
> On Wed, Jan 03, 2001 at 10:59:18AM -0800, idalton@ferret.phonewave.net wrote:
> > Hey, this looks spiffy. I have something of a usage question though, in
> > regards to the 'gender' (distributed ripper/encoder) program I'm
> > scripting. I'd LIKE to add audio normalisation as an option, but since
> > ripping and encoding tasks happen concurrently and asynchronously (but
> > with file locking) I'm not at all sure how to handle a sane
> > normalisation default, or even if there IS such a beast.
> 	Normalization has to take into account the maximum amplitude each 
> wave reaches before scaling each value down or up to the desired level.
> 	normalize computes the power of each small block of the the sound file
> in RMS (Richard Matthew Stallmans , sorry, I couldn't resist :) :) :) )
> looking for the highest value so all blocks can be proportionally scaled.
> 	So, there is no way to have normalization ocurring concurrently
> to acquisition of the sound and encoding. You'll have to record everything
> first, then normalize everything and then encode the normalized file.
> 	It is not possible to do normalization through a pipe, for an
> example.

Hehe. 'everything' is a slippery word here. I grok you to mean 'the
whole track' and not 'every possible track to be recorded'. ;)
Anyway, I could still have normalisation and acquisition processes
running concurrently; just not on the same track.

> 	You can normalize each file to a predefined aplitude value so you can
> do it once each file was "ripped" instead of doing normalization in batch
> mode. The author of normalize chose from his experience 0.25 dB to be a
> good power default.
> I use this default to record my CDs (made out of my own midi files and 
> mods mostly) and I am glad with it.

I'll do this then. I read his examples and was a bit confused how to
apply them to my project. Thanks.

-- Ferret

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