How to pass a Wx::Panel handle to GStreamer to render a video.

Steve_BZ has asked for the wisdom of the Perl Monks concerning the following question:

Hi Guys,

I'm having difficulty rendering a GStreamer video onto a wxPerl panel.

According to the doc it should be something like this:

my $video_panel=Wx::Panel->new($i_main_menu, wxID_ANY, wxDefaultPositi
+on, [800,600],);

(... lots of code goes here and the full executable version is here:
[download]

http://stackoverflow.com/questions/23547043/gtk-window-pointer-for-a-wxpanel-to-render-a-gstreamer-video

)

my $g_window = $video_panel->GetHandle;
$message->src->set_window_handle($g_window);
[download]

But I don't get a pointer from GetHandle just an integer as explained here (from the doc):

    vir tual WXWidget wxWindow::GetHandle()  const

        Returns the platform-specific handle of the physical window.
        Cast it to an appropriate handle, such as HWND for Windows,
        Widget for Motif or GtkWidget for GTK.
        wxPerl Note: This method will return an integer in wxPerl.
[download]

and then it errors like this:

The program 'GStreamer_test_6.pl' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadWindow (invalid Window parameter)'.
   (Details: serial 17 error_code 3 request_code 3 minor_code 0)
   (Note to programmers: normally, X errors are reported asynchronousl
+y;
    that is, you will receive the error a while after causing it.
    To debug your program, run it with the --sync command line
    option to change this behavior. You can then get a meaningful
    backtrace from your debugger if you break on the gdk_x_error() 
function.)
[download]

I guess I need to convert the integer to some sort of pointer object that GStreamer recognises.

Does anyone have any idea what the correct code should look like?

Regards

Steve.

Comment on How to pass a Wx::Panel handle to GStreamer to render a video. Select or Download Code

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Re: How to pass a Wx::Panel handle to GStreamer to render a video. by Anonymous Monk on May 10, 2014 at 06:44 UTC
I guess I need to convert the integer to some sort of pointer object that GStreamer recognises <surprised_chicken> Whaat? </surprised_chicken> There is no guessing :D what do the docs (or source) say? What type of object is this here `$message->src->set_window_handle()` what class is involved?	[reply] [d/l]
Re^2: How to pass a Wx::Panel handle to GStreamer to render a video. by Steve_BZ (Chaplain) on May 10, 2014 at 13:06 UTC
Hi Anon, Thanks for the comment. Well, as it says about the object: Cast it to an appropriate handle, such as HWND for Windows, Widget for Motif or GtkWidget for GTK. wxPerl Note: This method will return an integer in wxPerl. but I don't know what "cast it" means, nor do I know what the approriate object is. I think it is asking for the Gtk pointer of the wxWindows object, but I don't know how to "cast" an integer into a meaningful Gtk handle Id. In the c++ it says: `wxASSERT(window);` [download] But again I have no idea what that means in Perl. $message is a GstMessage from http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstMessage.html#GstMessage from which $src is derived. `GetHandle` comes from http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay I've made liberal use of `Glib::Object::Introspection;` to do the wrapping, which for the most part does a nice job (baring this unkown). If you didn't run the code, it gives you a Gtk panel running a test video, and a separate panel with buttons and a space for the video. The two panels are supposed to be superimposed. Regards Steve	[reply] [d/l] [select]
Re^3: How to pass a Wx::Panel handle to GStreamer to render a video. by Anonymous Monk on May 11, 2014 at 09:57 UTC
... wx ... In the c++ it says: ... Look at the source of the accepting end, the source of the GStreamer end :) Interesting things I found , I think they're related :) The latest GstreamerSDK and gst_x_overlay_set_window_handle (ubuntu) https://www.linuxquestions.org/questions/linux-desktop-74/how-can-i-fix-error-badwindow-invalid-window-parameter-575745/ http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-gstvideooverlay.html has stuff like static guintptr video_window_handle = 0; ... if (video_window_handle != 0) { GstVideoOverlay overlay; // GST_MESSAGE_SRC (message) will be the video sink element overlay = GST_VIDEO_OVERLAY (GST_MESSAGE_SRC (message)); gst_video_overlay_set_window_handle (overlay, video_window_handle); } else { g_warning ("Should have obtained video_window_handle by now!"); } ... #ifdef GDK_WINDOWING_X11 { gulong xid = GDK_WINDOW_XID (gtk_widget_get_window (video_window)) +; video_window_handle = xid; } #endif #ifdef GDK_WINDOWING_WIN32 { HWND wnd = GDK_WINDOW_HWND (gtk_widget_get_window (video_window)); video_window_handle = (guintptr) wnd; } #endif } [download] So the possibilities are, get newer version of gstreamer .... call set handle at different time (different signal ... do some "casting" So I think you're calling set handle at the correct time ... so get latest gstreamer if not have it? call realize something? Or try "casting" result of GetHandle into whatever "guintptr" means to Glib::Object::Introspection (or Glib) I'd also try this --sync backtrace debugging option mentioned in the error message ... could be Glib... is truncating this integer somehow or something stupid that... a better error message might be better :) last thing thing I'd try is to do the call with Inline::C :) If you didn't run the code, ....* Yup, on win32, sorry :)	[reply] [d/l]
Re^4: How to pass a Wx::Panel handle to GStreamer to render a video. by Steve_BZ (Chaplain) on May 17, 2014 at 16:06 UTC