Subject: Re: [linux-audio-dev] Sequencer Sync Woes
From: Billy Biggs (bbiggs_AT_DIV8.NET)
Date: Wed Feb 07 2001 - 20:14:43 EET
Tim Goetze (tim_AT_quitte.de):
> i must be missing something or do both of you assume the song tempo is
> constant?
Of course not :) Every time the tempo changes, I change
usec_per_tick. That's the only thing that needs to change. You keep
track of your current position, the time of the last beat (24ppq pulse,
and only the last pulse), and that's it.
Do you calculate your position in the song based on the current time?
That's no good for me. In my app, you need to be able to turn looping
on and off, and move the loop mid-song. Otherwise, how can you play
live?
I usually have to sync to an external source: I have a TR-707 which
can output DIN sync to my TR-606, but only if it's the sync master. So,
I usually don't care too much about keeping track of the tempo myself.
Thanks for the code, I'm going to think about it some more.
> i use double as the type of real time mostly out of laziness; do you
> think there is too much computational overhead? one could switch to
> uint.uint then. i don't even have an idea how many cycles a double /
> takes ...
I don't think it's significant to worry about.
-- Billy Biggs bbiggs_AT_dumbterm.net http://www.billybiggs.com/ wbiggs_AT_uwaterloo.ca
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