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Subject: berzerk peak meter? Alpha testers wanted.
From: Philipp Pertermann (philipp.pertermann_at_web.de)
Date: 2002-09-22


I still am fiddling with the volume meter. Now I've come to
a point where I have to make a decision concerning the
tradeoff
system load <-> precision.

The problem:
The MAS chip provides a 'quasi peak detector' that we can
read values from. It doesn't work very well. If a peak
happens in the music somewhen between two read outs we miss
it. Thus the more often we read values the higher ist the
probability that we actually hit a peak.
But:
Reading out the MAS often is not a good idea in two
respects:
1.) it increases the power consumption
2.) it increases the system load. If the system load becomes
too
    high stops / skips might occur.

The solutions:
I've implemented two strategies for reading out the MAS
peak.

normal mode | berzerk mode
reads once per redraw | 1 - 20 reads per redraw
--------------------------+-----------------------------
- lower precision | + higher precision
- clips undetectable | + clips detectable
+ lower power consumption | - higher power consumption
+ lower system load | - higher system load

In both modes the 'frame rate' is the same so you don't see
much difference unless you watch out for peaks.

I put an unofficial version on
www.x-phobie.de/ajbrec.ajz
In the menu General settings ->Display->Peak meter you can
switch berzerk mode on / off.

Now I want to know what you think: Do we need that berzerk
mode or is the normal mode enough? Do you encounter any
problems playing back mp3 in berzerk mode?

Phil



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