Re: Strange 'regression' in gtk+/gstreamer app

2016-12-12 Thread Eric Cashon via gtk-app-devel-list 

 

My guess is that it has something to do with how GTK is drawing. Look at the 
double buffered reference.

https://developer.gnome.org/gtk3/stable/GtkWidget.html#gtk-widget-set-double-buffered

For drawing transparent backgrounds GTK changed something in the drawing code 
in 3.10. When I was using 3.10 and trying to draw transparent windows they 
would work sometimes and then they wouldn't. I think that got fixed sometime in 
3.10 but then that caused the double buffering set to false not to work 
anymore. I used to be able to send an X window id to gnuplot and it would draw 
directly on the window. That doesn't work in 3.18 but did in 3.10. With 
gstreamer it still needs a X window id but it works with the updates with GTK 
but not with double buffering set to false anymore or it just ignores it. Some 
of the older gstreamer code has the double buffering always set to false. It 
isn't needed anymore. You probably don't want to set it to false if you are 
using GTK after version 3.10 on any of the drawing areas.

I don't know the internals of why this is. Just from testing some code out but 
this is my understanding of it. I will have to test a few more things out.



 



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Re: Strange 'regression' in gtk+/gstreamer app

2016-12-12 Thread Nathanael D. Noblet 
Hello Eric,

  Thanks for the reply. Yeah I forgot to mention that in the Glade file
I had set double buffered to false for both GtkDrawingAreas. I also
tried setting them to false directly in code once I finish
loading/configuring it from the glade file.

gtk_builder_connect_signals (builder, DO);

g_signal_connect (recordingArea, "realize", rec_realize_cb, DO);
g_signal_connect (viewerArea,"realize", view_realize_cb, DO );

gtk_widget_set_double_buffered (GTK_WIDGET(recordingArea), FALSE);
gtk_widget_set_double_buffered (GTK_WIDGET(viewerArea), FALSE);


One thing this did make me realized is that in my source dir I have a
copy of a tutorial/example. "basic-tutorial-5.c" (http://pastebin.com/4
gaWhCJs). It compiles and runs fine - updating the scrollbars without a
flicker. It also sets the double buffer to false. So I'm wondering if
it has to do with the notebook. That or the fact that I have two
drawing areas. One in each notebool panel that is causing the issue. It
is just so bizarre that its suddenly occurring years after it was
written.

Any other ideas?
-- 
Nathanael

On Fri, 2016-12-09 at 18:59 -0500, cecas...@aol.com wrote:
> 
> It could be a problem with the double buffering.
> 
> gtk_widget_set_double_buffered()
> 
> Try to set that to false and see if that makes any difference. This
> is on Linux? Usually you don't need this function any more and it is
> deprecated but it can sometimes still be useful. I know to get
> gnuplot pictures to redraw without flickering or a white background,
> it needs to be false.
> 
> I did a little gstreamer experimentation a little while back with the
> webcam video. It works without gtk_widget_set_double_buffered() using
> Ubuntu 16.04, GTK3.18 and gstreamer1.0. No flickering that I can see.
> I don't have a scrollbar in there though. It might be helpful.
> 
> https://github.com/cecashon/OrderedSetVelociRaptor/blob/master/Misc/S
> ound/webcam3.c 
> 
> Eric
> 
> 
> 

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Re: Strange 'regression' in gtk+/gstreamer app

2016-12-12 Thread Nathanael D. Noblet 
Hello Eric,

  Thanks for the reply. Yeah I forgot to mention that in the Glade file
I had set double buffered to false for both GtkDrawingAreas. I also
tried setting them to false directly in code once I finish
loading/configuring it from the glade file.

gtk_builder_connect_signals (builder, DO);

g_signal_connect (recordingArea, "realize", rec_realize_cb, DO);
g_signal_connect (viewerArea,"realize", view_realize_cb, DO );

gtk_widget_set_double_buffered (GTK_WIDGET(recordingArea), FALSE);
gtk_widget_set_double_buffered (GTK_WIDGET(viewerArea), FALSE);


One thing this did make me realized is that in my source dir I have a
copy of a tutorial/example. "basic-tutorial-5.c" (http://pastebin.com/4
gaWhCJs). It compiles and runs fine - updating the scrollbars without a
flicker. It also sets the double buffer to false. So I'm wondering if
it has to do with the notebook. That or the fact that I have two
drawing areas. One in each notebool panel that is causing the issue. It
is just so bizarre that its suddenly occurring years after it was
written.

Any other ideas?
-- 
Nathanael

On Fri, 2016-12-09 at 18:59 -0500, cecas...@aol.com wrote:
> 
> It could be a problem with the double buffering.
> 
> gtk_widget_set_double_buffered()
> 
> Try to set that to false and see if that makes any difference. This
> is on Linux? Usually you don't need this function any more and it is
> deprecated but it can sometimes still be useful. I know to get
> gnuplot pictures to redraw without flickering or a white background,
> it needs to be false.
> 
> I did a little gstreamer experimentation a little while back with the
> webcam video. It works without gtk_widget_set_double_buffered() using
> Ubuntu 16.04, GTK3.18 and gstreamer1.0. No flickering that I can see.
> I don't have a scrollbar in there though. It might be helpful.
> 
> https://github.com/cecashon/OrderedSetVelociRaptor/blob/master/Misc/S
> ound/webcam3.c 
> 
> Eric
> 
> 
> 

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Re: Strange 'regression' in gtk+/gstreamer app

2016-12-09 Thread Eric Cashon via gtk-app-devel-list 

It could be a problem with the double buffering.

gtk_widget_set_double_buffered()

Try to set that to false and see if that makes any difference. This is on 
Linux? Usually you don't need this function any more and it is deprecated but 
it can sometimes still be useful. I know to get gnuplot pictures to redraw 
without flickering or a white background, it needs to be false.

I did a little gstreamer experimentation a little while back with the webcam 
video. It works without gtk_widget_set_double_buffered() using Ubuntu 16.04, 
GTK3.18 and gstreamer1.0. No flickering that I can see. I don't have a 
scrollbar in there though. It might be helpful.

https://github.com/cecashon/OrderedSetVelociRaptor/blob/master/Misc/Sound/webcam3.c
 

Eric
 

 


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Strange 'regression' in gtk+/gstreamer app

2016-12-09 Thread Nathanael D. Noblet 
Hello,

  So many years ago we wrote a custom app for a client. It does video
recording from either network cameras or optionally built in webcams.
Its worked well for a long time. Originally built against gstreamer
0.10. Recently we've replaced some of the hardware and have noticed an
issue that I can't for the life of me track down.

  It was first observed on playback. When updating the position of the
scrollbar, the video would flash, as if drawn over in white if you
will. It happens each time the scrollbar position moved. For example
the callback to update it is called every 200ms, but only when it moves
does the flash occur. In digging into it some more, I also realized I
could cause it to occur while recording. We have a number of Notebooks
in the UI. Mousing over an inactive one where it then gets a little
'highlight' if you will prior to clicking also causes the video to then
flicker.

  Originally to debug this I went into the code that was updating the
scrollbar. 


if (ret && position != GST_CLOCK_TIME_NONE) {
   g_signal_handler_block (GTK_RANGE(playbackScale), updateId);

   gtk_range_set_value (GTK_RANGE(playbackScale), positionInSeconds);

   g_signal_handler_unblock (GTK_RANGE(playbackScale), updateId);
}

Simply commenting out the gtk_range_set_value stops playback on
flicker. Obviously that's less desirable. 

I wondered if part of the issue was gstreamer 0.10 as its quite old. So
started porting it to gstreamer-1.x. Made it far enough that I could
test and confirm that I still have flickering when the mouse moves over
notebook panels etc.

I'm at a complete loss. I looked at Cheese and Totem to see if I could
figure out what was going on. It seems they use clutter for quite a
bit. I don't know if I want to port it over to that as well if I don't
have to. However I would really like some pointers as to what could be
causing the issue. I can even take a screencast if anyone wants to see
the actual behaviour.

Hoping someone has some good ideas,
-- 
Nathanael


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