[linux-audio-dev] XAP and Event Outputs

[Tim Goetze]

David Olofson wrote:

>And normal plugins don't generate and "output" audio or control data 
>an arbitrary number of buffers ahead. Why should they do that with 
>events?

you may have an algorithm written in a scripting (non-rt
capable) language to generate events for example. or you
don't wan't to iterate a lot of stored events at every
sample to find out which to process, and still offer sample-
accurate timing. 

>Think about an event processor, and it becomes really rather obvious 
>that you *cannot* produce output beyond the end of the "buffer time 
>frame" you're supposed to work with. You don't have the *input* yet.

i don't see how this touches the workings of an event
processor, rt or not. and a 'musical' event processor
is more likely to be rooted in musical time than in 
audio time.

>> in general, it makes
>> all timing calculations (quantization, arpeggiators etc)
>> one level easier, and they do tend to get hairy quickly
>> enough.
>
>And it's better to have an event system that needs host calls to even 
>*look* at an event?

host calls only to convert the timestamp on the event, i 
understand. you need the reverse if your events are all
audio-timestamped instead.

if you keep a table or other cache mapping audio frame to 
musical time for the current block of audio, you're just 
fine.

>I believe controlling synths with timestamped events can be hairy 
>enough without having to check the type of every timestamp as well.

i think it's sane to keep timestamps within one domain.

>That's it! Why do you want to force complexity that belongs in the 
>sequencer upon every damn plugin in the system, as well as the host? 

on average, this is not complex if done right i think. and
if i use a system to produce music, to me it seems natural 
for the system to understand the concept of musical time.

tim