Re: [linux-audio-dev] XAP and these <MEEP> timestamps...

New Message Reply About this list Date view Thread view Subject view Author view Other groups

Subject: Re: [linux-audio-dev] XAP and these timestamps...
From: Tim Hockin (thockin_AT_hockin.org)
Date: Sat Dec 14 2002 - 08:05:58 EET


> Yes - as long as the song position doesn't skip, because that won't
> (*) result in tempo events. Plugins that *lock* (rather than just
> sync) must also be informed of any discontinuities in the timeline,
> such as skips or loops.

OK, it took me a bit to grok this. We have four temporal concerns:

1) plugins that need to do things in step with the tempo
   - they have a TEMPO control
2) plugins that need to do things on tempo milestones
   - they have a TEMPO and can host callback for music-time
3) plugins that need to do things at some point in absolute time
   - they have the sample rate, no worries
4) plugins that need to do things at some point in song time
   - they have a TRANSPORT control

> (*) You *really* don't want two events with the same timestamp,
> where the first says "tempo=-Inf" and the other says
> "tempo=120 BPM". But that would be the closest to the correct

ick...

> Tempo changes
> Whenever the tempo changes, you get a sample
> accurate event with the new tempo.
>
> Unit: Ticks/sample

Before I go any further: What's a tick?

> Meter changes
> When PPQN (who would change *that* in the middle

Define PPQN in our terms? Pulses of...

Then I can digest the rest of this email :)


New Message Reply About this list Date view Thread view Subject view Author view Other groups

This archive was generated by hypermail 2b28 : Sat Dec 14 2002 - 08:11:32 EET