[linux-audio-dev] XAP: cue points / looping

Tim Hockin thockin at hockin.org
Thu Dec 19 21:04:00 UTC 2002


> The "objects" I'm talking about are "Zero Latency Start Points" or 
> "Precache Points". The whole point with them is to let plugins know 
> about jump target points that the sequencer wants to be able to jump 
> to at any time, without disrupting playback.

CuePoints are absolute ticks, right?

The problem I see with PCP (I prefer to think of it as jump-point) is that
your PCPs are either global to all plugins in this timeline, or local to
each plugin.  If they are global, then absolute position does you no good.
A synth that gets a VOICE_ON at bar12:beat3 has no idea what it means to
have a PCP at tick 8675.  If you jump back in time (loop) you need to either
trigger that note again and seek to the position, or seek backwards (if it
was playing when you jumped).

The only things that can make use of this are things like disk-streaming
plugins, which start at bar1:beat1.  The idea of passing an absolute-ticks
value to a plugin is wrong, with the exception of 'automatic' starting
plugins, like a disk streamer.  We pass absolute position to POSITION aware
plugins because it is a clean way of indicating the passing of
transport-time for any that want to sync, and for things like
disk-streamers.  Are we to add this feature JUST for those plugins, also?
I'm not completely against it, I just want to make sure we're all clear that
it's not so useful to anyone else.

Or am I really missing something?

Tim



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