Re: [xougen] Re: Adding cruft to X

[Tupshin Harper]

Alan Cox wrote:

> On Llu, 2003-09-08 at 04:18, Tupshin Harper wrote:
>  
>
> > What you absolutely cannot get without awareness (at a fairly low level) 
> > of X, is synchronization. See my earlier message about that.
> >    
>
> Assuming the sound output end and display are on the same box (as would
> be normal) all you need is X properties. Prebuffer audio, send a batch
> of X events ending wiht the property change, have the audio server watch
> the change and fire when it sees it.
>
>
>  
Yes, same machine scenario is what I'm talking about, but your solution 
requires that the sound server have awareness of X events, and I was 
responding to Steve's suggestion that the sound componenent can be 
"completely oblivious" to X. That just isn't the case. I'm beginning to 
be convinced that the previously mentioned MAS 
(http://www.mediaapplicationserver.net) does almost everything required, 
but I'm absolutely *not* convinced that any of the commonly available 
sounds servers (esd, arts, nas, etc.) are sufficient because (among 
other things) their lack of awareness of X events on the X-server side.

Pre-buffering and triggering also has problems. It assumes the ability 
to pre-buffer without introducing unnecessary delays. Consider the 
scenario where an image and an audio clip need to be displayed with a 
high degree of synchronization, but a priori knowledge of the data 
involved is not available (e.g. they could be randomly selected from a 
prohibitively large set of candidates). In this case, it is necessary to 
*first* send the audio (or at least enough of it), and then send the 
graphical event. But how is it possible to know the shortest reasonable 
time to wait for the audio to get pre-buffered? There is no way to avoid 
introducing some delay (just through lack of information). Check out the 
MAS documentation for more 
info(http://www.mediaapplicationserver.net/documentation.html). The 
first slide presentation on that page (PDF format) also contains a great 
overview of the benefits.

-Tupshin