[mad-user] Re: Attenuating pre-release

[David Shin]

What a cool pre-release!  We're not worthy! we're not worthy!  :D


Rob Leslie wrote:
> 
> Here's a mailing list exclusive: the following URL leads to a pre-release
> version of the MAD plug-in.
> 
>     http://www.mars.org/home/rob/proj/mpeg/mad-plugin/in_mad-0.12.3b-pre1.zip
> 
> This version includes a special "Statistics" tab in the file info dialog for
> the currently playing song.
> 
> Among other things, you'll find there an indication of how often and how much
> samples are being clipped. Furthermore, you can choose to attenuate the signal
> on-the-fly based on the amount of clipping.

It would be useful if it shows the peak clipping number (instead of the
graphical bar), or the bar and also the actual number.   With this
number, the user could then have a general idea of how to manually
change the attenuation before playback (the manual slider you
mentioned).  Right now, you can only attenuate after-the-fact, and thus
can't really listen to the samples with and without varying attenuation
to see what kind of quality difference there is easily.



> Attenuation is performed internally on high-precision pre-dithered samples, so
> it should not affect sound quality except to improve it by eliminating clipped
> samples.
> 
> Further ideas I have in this direction include:
>   - "Automatic clipping attenuation" configuration option
>   - remembering the attenuation setting on a per-file basis
>
> I'd like feedback on where this is going. Is this useful? If an automatic
> attenuation option is made available, would the manual buttons still be
> useful?

For automatic clipping attenuation, would this happen only after the
highest clipped sample?  Or would it read ahead somewhow?  

This looks like a really useful feature.  I have this one really harsh
Christina Aguilera song (most modern pop CD's sound like this though)
with bad sibilance.  I thought it was my new speakers which had too
bright treble, but after I found out the song was clipping very badly
and after I attenuated it, it played much smoother.  Verry nice.  :)


>What about amplification rather than attenuation?

Amplification at the frame level during playback sounds like a really,
really great feature!  However, wouldn't you get into the trouble of not
knowing just how much to amplify, thus inducing clipping?  So with
automatic attenuation and automatic amplification, you'd amplify to
clipping, only to attenuate again, losing the peaks of some samples. 
How can you amplify just shy of clipping at one value for the entire
song without going through the the frames before-hand?