6 Feb
2003
6 Feb
'03
6:45 a.m.
On Wed, Feb 05, 2003 at 02:41:44 -0800, Tim Hockin wrote:
I've always heard it called normailzed, and it jives with what I know. It
CAN be more than 0dB - that is one big plus of float data. You can way
exceed 0dB. If you don't lower it before the final output, you'll get a
digital clip, but you can run your whole chain REALLY hot, then gain reduce
before output, and still be OK.
"Normalised floating point" is a well know term, but normalised between
-1.0 and 1.0 is wrong.
This souds like a really bad idea, I think the intention of the plugin
reporting its RT60 (or whatever) tail size is for post roll, not silence
detection. Silence detection is pretty pointless in RT systems, and likly
to a huge source of bugs.
You cant use the "free" cycles, because youre never sure when the plugin
is going to wake up and start chewing CPU again, and in any case you dont
know how much it was really using.
Ontop of that the RT60 time is only a guideline, depending on the
processing graph it may be totally inapropraite to assert silence after
the nominal decay time.
All XAP audio data is processed in 32-bit floating
point form.
Values are normalized between -1.0 and 1.0, with 0.0 being silence.
I think "normalized" is the wrong term here, since it can't be more
than a 0 dB reference. There's no useful way to actually *normalize*
audio data. Nice. Can be
used for "optimized silence", of course - which leads to
a question: How about *outputs*? Plugins that keep track of whether
or not they're actually generating audio would need a way to mark
each output as "audible" or "silent", before returning from each
process/run() call.
Yes - we have a few options here. This is something that can save MASSIVE
CPU, and is really needed. If a chain of plugins starts with a voiced instrument,
we have a clue when
there is nothing coming down the chain (instruments need to confirm it, of
course). Each plugin in the chain might eventually be silent, with silent
input. Silence needs no processing.
"Silence" is relative. A reverb will onyl decay to mathematic silence
after a really long time, but that isnt the intention of this hint IMNSHO.
- Steve