[PD-dev] proposal: postdsp callbacks

[Miller Puckette]

Hi Tim,

Here's another idea I'm thinking about that might be useful in this
situation... I'm thinking of having a version of switch~, which never
runs DSP except when you 'bang' it.  This way, a block of DSP analysis
or anything else could be included within a message; in fact, several of
them could, and they could be interspersed with other message processing.

My own interest in doing this is that it would allow using tilde objects
to treat video. I'd make special tilde objects to read lines out of a
pdp buffer and write them back in; then just insert any DSP chain into a
pdp chain and make computer music with the pixels...

cheers
Miller

On Fri, Jul 15, 2005 at 02:39:18PM +0200, Tim Blechmann wrote:
> hi all,
> 
> messaging functions called by dsp routines are usually implemented by
> using clocks with a delay 0.
> this only works as long as the clock callbacks are executed after each
> dsp tick.
> this causes problems for my scheduler, that uses the callback from the
> audio api (jack / portaudio) to run the dsp tick. running all the clock
> callbacks from the audio callback is not a good idea, since it's running
> from a separate thread and possibly in realtime (i.e. gem would crash).
> 
> thus i'd propose the following api extension:
> sys_postdsp_callback(t_method fn);
> 
> the function fn would be called immediately after dsp_tick() is
> executed.
> 
> this would work for both miller's synchronous and my asynchronous
> scheduler and is probably more elegant than the current solution.
> 
> drawback: external developers would have to change their externals to
> improve the dsp/message interaction granularity for my asynchronous
> scheduler...
> 
> off course, there are ugly workarounds for this (i just implemented
> one), but i'd prefer to have a clean solution ...
> 
> i would be interested in other opinions ... especially in miller's
> 
> cheers .... tim
> 
> -- 
> mailto:TimBlechmann at gmx.de    ICQ: 96771783
> http://www.mokabar.tk
> 
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