GTK-3 support ?

[kyrios123]

Hello,

Is there any plan for supporting gtk-3 ?
We are considering retiring wxWidgets gtk-2 build and eviacam is one of the only blocker.

Thank you !

[cmauri]

Hi!
Solus distro? Who is the maintainer of the package? Did you try building eViacam against wxWidgets gtk-3 build?

Thanks!

[kyrios123]

yes I did, that's why I made this request

[cmauri]

Added support for gtk+-3 in commit 6cd6ea9

[kyrios123]

I confirm it builds successfully with the patch.
I will do some testing during the coming days.

[kyrios123]

Hello,

I get the following error when launching the patched version (of course I did replace gtk2 libs with gtk3 libs and I used a gtk3 build of wxwidgets)

(eviacam:3978): Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported
Trace/breakpoint trap

[cmauri]

Hello,

I tried the following on a clean chrooted ubuntu artful installation:

$ dpkg -l | grep -E "gtk|opencv|wx"
(no results)

$ sudo apt-get install libopencv-dev
(this command installs around 350 packages)

$ dpkg -l | grep -E "gtk"

ii  gtk-update-icon-cache           3.22.24-0ubuntu1                  amd64       
ii  libgtk-3-0:amd64                3.22.24-0ubuntu1                  amd64 
ii  libgtk-3-bin                    3.22.24-0ubuntu1                  amd64  
ii  libgtk-3-common                 3.22.24-0ubuntu1                  all 

libopencv installs libgtk-3.0 because some modules have dependencies on it. I only had to manually install libgtk-3-dev
$ sudo apt-get install libgtk-3-dev

To install wxWidgets I used the latest stable tarball for linux. I configured it to use gtk-3 and compiled manually:

./configure --with-gtk=3
make
sudo make install
sudo ldconfig

Finally, I managed to build (from commit a598ace) and run eviacam without issues. These are the steps I followed:

./autogen.sh
./configure --prefix=/usr/local
make
sudo make install
eviacam

---

However, when installing wxWidgets from ubuntu repository, i.e.: $ sudo apt-get install libwxgtk3.0-dev eviacam build fails with:

In file included from /usr/include/gtk-3.0/gdk/gdkapplaunchcontext.h:30:0,
                 from /usr/include/gtk-3.0/gdk/gdk.h:32,
                 from /usr/include/gtk-3.0/gdk/gdkx.h:28,
                 from wxappbar.cpp:46:
/usr/include/gtk-3.0/gdk/gdktypes.h:143:39: error: conflicting declaration 'typedef struct _GdkWindow GdkWindow'
 typedef struct _GdkWindow             GdkWindow;
                                       ^~~~~~~~~
In file included from /usr/include/wx-3.0/wx/wxprec.h:12:0,
                 from wxappbar.cpp:24:
/usr/include/wx-3.0/wx/defs.h:3466:33: note: previous declaration as 'typedef struct _GdkDrawable GdkWindow'
     typedef struct _GdkDrawable GdkWindow;
                                 ^~~~~~~~~

Checking the wxWidgets version shipped with artful:

$ wx-config --selected-config 
gtk2-unicode-3.0

it is clear that has been built against gtk-2. In fact, there is an open bug in ubuntu launchpad about this:
https://bugs.launchpad.net/ubuntu/+source/wxwidgets3.0/+bug/1394031

Furthermore, when running the eviacam version shipped with artful I also get:

Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported
Trace/breakpoint trap

---

In summary, @kyrios123 make sure that both libopencv and wxWidgets are build against gtk-3 and that no other libraries add dependencies to gtk-2.

It seems also that recent versions of debian (strech) and ubuntu (artful) provide wxWidgets built against gtk-2 and libopencv against gtk-3 and thus, software that need both libraries will probably crash with the same error.

[kyrios123]

Thanks for this very useful feedback! Indeed, I see our opencv currently uses gtk-2 libraries.

[kyrios123]

We are currently testing the gtk3 vs gtk2 builds and the following issue has been reported: Takes forever getting the webcam via v4l

[JoshStrobl]

When launching from the Terminal, it starts my webcam, turns it back off, and then provides an index error. It cycles through 9 indexes until it gets to my webcam (the only video device I have), then starts the OpenCL runtime.

VIDEOIO ERROR: V4L: index 1 is not correct!
VIDEOIO ERROR: V4L: index 2 is not correct!
VIDEOIO ERROR: V4L: index 3 is not correct!
VIDEOIO ERROR: V4L: index 4 is not correct!
VIDEOIO ERROR: V4L: index 5 is not correct!
VIDEOIO ERROR: V4L: index 6 is not correct!
VIDEOIO ERROR: V4L: index 7 is not correct!
VIDEOIO ERROR: V4L: index 8 is not correct!
VIDEOIO ERROR: V4L: index 9 is not correct!
[ INFO:1] Initialize OpenCL runtime...

[cmauri]

Try applying the following patch. It basically disables multiple camera detection:
patch.diff.gz

[JoshStrobl]

@cmauri Applied patch, did a local build, same behavior as my previous comment. Here's an strace if it's any help. Webcam is a Logitech HD Pro Webcam C920.

eviacam_strace.txt (~2.6MB)

[cmauri]

output.txt
@JoshStrobl also applied the patch and, for me, this only opens the camera once. Here is the output of eviacam when running with the debug flag enabled:

./eviacam --debug

Could you please run also in debug mode and attach the output?

Remember that you should clone the devel branch and apply the patch on top of it.

[Clement-TS]

I there, I have this same issue using eviacam on a Ubuntu 18.04 desktop (was working on 16.04):

(eviacam:23589): Gtk-ERROR **: 16:01:44.053: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported
Trace/breakpoint trap

Is this fixed within the devel branch? Are there .deb available with any fix on that?
Thank you

[kyrios123]

@Clement-TS yes look at the detailed explanation here. TL;DR make sure that wxWidgets and openCV are built against the same version of GTK+ than eviacam