Petr Vandrovec ([EMAIL PROTECTED]):

> > Sometime in the past, Gerd wrote:
> > > Another (and IMHO better) approach is to allow multiple
> > > applications queue up capture requests.  If a second application
> > > asks for a video frame while the driver is busy capturing the
> > > frame for the first application, it can simply put the request
> > > into a queue instead of returning -EBUSY.  This might need some
> > > more changes through (depending on the current driver design).
> 
> I think that it is very bad idea. You should either support delivering
> one buffer to more than one app (like current vloopback does), or you
> should return BUSY. Otherwise if you start second grabber application
> (by mistake or whatever) while one is already running, you'll start
> seeing missed frames for no apparent reason.
> 
> But of course if you have some ideas how to handle such case without
> disturbing existing grabbing/output processes...

  I agree.  Dropping frames is very bad.  Wouldn't multi-application
grabbing be handled best by some userspace library?  Similarily for
loopbacking etc?  There's too much desired functionality (colourspace
conversion, jpeg decoding, compression API, multi-apps, etc) that seems
to demand a standard userspace component.  The V4L2 API might be too
complex if you start to add too much.

-- 
Billy Biggs
[EMAIL PROTECTED]



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