10 Dec
2002
10 Dec
'02
5:55 p.m.
On Tuesday 10 December 2002 20.31, Paul Davis wrote:
no, but there are a *lot* of things that plugins, particularly
instrument plugins, might want to do that are based on musical time
or even just transport time.
Yes - I'm not suggesting that there should not be transport and
musical time; just that stopping musical time does not imply stopping
audio/event time.
I assume that if the host loops, or the user jumps
back in
song-position, time does not jump with it, it just keeps on
ticking?
Yes. You can't rewind *time*, can you? ;-)
Seriously though, the reason to do it this way is that timestamp
time is directly related to "audio time" (ie sample count) - and
in a real time system, it just keeps running all the time. I
don't see a reason to stop time, kill the audio, stop all plugins
etc etc, just because you stop the *sequencer*! the free-running sample count time is
irrelevant for many things. when you ask a plugin to start the
release phase of a note off at a certain time, its often not based
on the sample count but on musical time.
That's a sequencer implementation issue. Event timestamps are always
based on audio time. (Or ticks, if you don't have audio. Doesn't
matter, as long as all plugins use the same unit.)
if you stretch the tempo
while the note sounds, it should still start the release phase when
it reaches the correct musical time, not some arbitrary sample
count.
Of course. But since *everything* is processed one buffer at a time -
events as well as audio, this automatically Just Works(TM). You're
not allowed to queue ahead, so as long as you can get the musical
time for any sample frame within the current buffer, there's no
problem.
//David Olofson - Programmer, Composer, Open Source Advocate
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