make_it_cool: kdelibs/kdemm

[Marco Lohse]

Matthias Kretz wrote:
> So you can actually decide for every node whether you want to share it?
> 

yes

> We probably need to take care with kdemm then, that we don't create a big mess 
> of available NMM sessions. How would you suggest to use NMM on a desktop 
> computer - or even on a multiuser desktop computer (user1 logs in, locks the 
> desktop, user2 starts a second X session - both sessions use kdemm/NMM for 
> multimedia).
> 

no problem: every application simply requests its own exclusive NMM flow 
graph; no need to share anything. E.g. if you want to play back a file, 
you usually do not need to share any part of your NMM flow graph.

In contrast: assume that you only have a single TV board available 
within your system (or within the network in general, since NMM is 
network transparent). If an application requests an NMM plug-in 
representing that TV board, it might want to share it (because it is a 
'nice' application). Now, another application can try to request a TV 
board, too. Since only a single board is available, NMM allows to share 
this single device between different applications.

This is all handled automatically within NMM. The application developer 
simply can specify an optional 'sharing attribute' for each plug-in node 
within the flow graph. (If you are interested in the more technical 
aspects of the NMM session sharing service, there is a research paper 
available online.)

> Would every NMM app have its own PlaybackNode or would you start one central 
> NMM session per user (or per computer) that only handles the audio output, 
> but then for all NMM apps (kind of like a soundserver).
> 

NMM is not a sound server. Every application will have its own 
PlaybackNode. The PlaybackNode will then 'speak' with the sound server.

> On Monday 21 March 2005 13:05, Marco Lohse wrote:
> 
>>If an application decides to share parts of its NMM flow graph, then,
>>yes, other applications can access these parts (if they pass the
>>security mechanisms of NMM, e.g. passwords). This means that, for
>>example, two applications can share a single TV board. We call this
>>feature 'session sharing'.
>