[v 0.10] Gst::init() is slow

[José Alburquerque]

On Sun, 2012-09-09 at 07:01 -0400, José Alburquerque wrote:
> On Sep 9, 2012, at 4:19 AM, José Alburquerque <jaalburquerque at cox.net> wrote:
> 
> > On Sun, 2012-09-09 at 09:46 +0300, Jiergir Ogoerg wrote:
> >> Thanks,
> >> To my desktop app startup time is critical, so, if I switch to the Gst
> >> C interface do you think the gst_init() would never take longer than
> >> say 200 milliseconds? Or is it nonetheless possible for it to take
> >> much longer like over 1-2 seconds in some cases?
> > 
> > Actually, I think I spoke too soon in my last post.
> > 
> > I was just thinking things through more thoroughly and since plug-in
> > types are not accessible in C.  It may be possible to register the
> > wrapping functions for these plug-in types later (when they are
> > constructed) and not at startup (in Gst::init()) since it is not
> > possible to have these plug-in types from some C code and then try to
> > wrap them in a C++ wrapper which is why we go through the process of
> > loading the plug-ins and registering the wrapping functions in the first
> > place.  It may not even be necessary to register wrapping functions for
> > these plug-in types.
> 
> Sorry, I'm just wrong here.  Though the C types are not available, having one from C code is possible because the plug-ins are created using the GType system.  Registering the wrapping functions for plug-ins is thus still vital upon initialization.
> 
> You're better off using C.  I hope I didn't give you false hopes.

Okay.  I'm going back and forth because the issue is more complicated
than what I thought.  Could you please ignore this last post.  I'll look
at this during the week and not rush.  If it's possible it will be in
the release.  If not it wont.  Sorry.

> 
> -Jose
> 
> > 
> > If the above is so, startup time (Gst::init()) will probably never be
> > more than the 100ms you mentioned.
> > 
> > I'll be looking into this this week at the end of which a new release
> > should be out.  If it this is doable, I'll include it in that release.
> > 
> > In the meanwhile, however, I'm sure that using C will never have such a
> > slow start-up time.  gst_init() does not load all the possible plug-ins
> > as gstreamermm does right now.
> >> 
> >> 
> >> On Sun, Sep 9, 2012 at 7:37 AM, José Alburquerque
> >> <jaalburquerque at cox.net> wrote:
> >>       On Sat, 2012-09-08 at 13:19 +0300, Jiergir Ogoerg wrote:
> >>> Hi,
> >>> Gst::init() takes like 100+ ms, on rare occasions it takes
> >>       even
> >>> longer, like over 2-4 seconds. Is it normal?
> >> 
> >> 
> >>       Probably.  The reason is that Gst::init() not only initializes
> >>       GStreamer, it also initializes glibmm (which it relies on) and
> >>       registers
> >>       methods that wrap C types to correct C++ types for all the
> >>       GStreamer
> >>       GObject and GstMiniObject derived types and all the GStreamer
> >>       plug-in
> >>       types that gstreamermm makes available to be used in a C++
> >>       way.  In the
> >>       process, it must load all the plug-ins that gstreamermm makes
> >>       available
> >>       (this is probably the most time consuming part though only for
> >>       the
> >>       execution for which the plug-ins have not been loaded; the
> >>       rest of the
> >>       executions wont experience so much a delay).  We know of no
> >>       other way to
> >>       ensure that the C objects handled are correctly differentiated
> >>       and
> >>       treated as appropriate C++ classes.
> >> 
> >>> 
> >>> To combat this I do Gst::init() in another pthread for my
> >>       gui app to
> >>> show up instantly as usually.
> >>> 
> >>> Using Ubuntu 12.04 amd64.
> >>> Intel Core i5.
> >> 
> >>> _______________________________________________
> >>> gstreamer-devel mailing list
> >>> gstreamer-devel at lists.freedesktop.org
> >>> 
> >>       http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
> >> 
> >> 
> >>       --
> >>       José
> >> 
> >>       _______________________________________________
> >>       gstreamer-devel mailing list
> >>       gstreamer-devel at lists.freedesktop.org
> >>       http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
> >> 
> >> 
> >> _______________________________________________
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> >> gstreamer-devel at lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
> > 
> > -- 
> > José
> > 
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> > http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
> 
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-- 
José