Subject: Re: [linux-audio-dev] Sequencer Sync Woes
From: Tim Goetze (tim_AT_quitte.de)
Date: Fri Feb 09 2001 - 19:25:31 EET
Billy Biggs wrote:
> 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.
i did some more improvements to the time-based clock, and now i am
thinking about how to implement sync to external q/24. not so hard
to do with the current design, but one thing keeps bugging me, and
i'd like to know how you would (or do) handle it: in the interval
that passes between receiveing the first two 0xF8 signals, one cannot
afaik have any idea of what the tempo will be. do you say "oh well, i
don't know anything about the current tempo, so i'll do nothing til
the second signal comes in" or do you make an assumption on the tempo?
(or the third way: all MIDI messages are aligned to q/24 anyway so you
don't have to care about this at all ...)
the first, lazy assumption would mean you'd possibly delay some MIDI
events by a couple of ticks; the second could mean that if you do
too fast a tempo, you'd have to rewind the 'MIDI tape'. i'm reluctant
to apply the first, do not like the second for doing something arbitrary
and cannot do the third because it isn't appropriate for complex
patterns in time.
any ideas?
.tim
ps what is DIN sync, and on what medium is it transported?
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