Subject: Re: [linux-audio-dev] XAP and these
On Thursday 12 December 2002 13.32, Steve Harris wrote:
Right. So, what we need to do now is agree on a sensible time struct.
I'm trying to find out whether or not it makes sense to say anything
For example, if you're delaying events by musical time, you're not
Anyway, the *real* reason why I'm worrying about this is that such a
//David Olofson - Programmer, Composer, Open Source Advocate
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: Thu Dec 12 2002 - 15:06:23 EET
From: David Olofson (david_AT_olofson.net)
Date: Thu Dec 12 2002 - 15:01:45 EET
> On Thu, Dec 12, 2002 at 12:16:09 +0100, David Olofson wrote:
> > I (still) don't think musical time belongs in timestamps of your
> > average event in XAP. Those events are meant to act as an
> > alternative to audio rate controls or blockless processing. The
> > host gives you a time frame to work with (expressed as a number
> > of audio frames), and that's the timeframe you're meant to work
> > with. This applies to audio as well as events.
>
> I agree. For efficiect reasons if nothing else, having musical
> events mixed in with your data events would make it very hard to
> parse.
>
> Musical time can be expressed in the same way it is in VST (as I
> understand it) or jack and friends.
>
> It does need to be part of the API, but not mixed in with the (very
> low level) event system.
That is, basically copying that of VST or JACK.
more than "in the past" or "in the future" about timestamps that are
outside the buffer... Do you ever have a *valid* reason to query the
musical time of an audio time that is outside the time frame you're
supposed to work within?
*allowed* to keep the audio time of a future musical times, since it
may be invalid by the time you get there. (Timeline edits or
transport manipulation.) So, you only really have to know that the
event *is* in the future, so you can put it in your internal queue
for processing later on.
rule could make life a lot easier for hosts. You can cache time
structs for the current buffer, but never have to even generate them
for timestamps that fall outside. (The call would just return one of
two error codes or something.)
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