Overlay Video on Wayland

[Scott Talbert]

On Thu, 19 Apr 2018, Nicolas Dufresne wrote:

>>>>>> Is it possible to use video overlays (either with GstPlayer
>>>>>> or playbin) on
>>>>>> Wayland surfaces?  And if so, what is the recommended
>>>>>> approach?  I saw
>>>>>> there was 'waylandsink' but it doesn't seem to be public.
>>>>>
>>>>> waylansink is part of gst-plugins-bad (unstable), and can be
>>>>> used with
>>>>> GstVideoOverlay interface on wayland. Run "gst-inspect-1.0
>>>>> waylandsink"
>>>>> for details. An example application can be found here:
>>>>>
>>>>> https://cgit.freedesktop.org/gstreamer/gst-plugins-bad/tree/tes
>>>>> ts/examples/waylandsink
>>>>
>>>> The problem, though, is that gst/wayland/wayland.h header is not
>>>> public.
>>>>
>>>> See
>>>> https://cgit.freedesktop.org/gstreamer/gst-plugins-bad/tree/gst-l
>>>> ibs/gst/wayland/Makefile.am#n26
>>>
>>> You don't really need that library. The geometry stuff can be
>>> ignored,
>>> and then the rest is just helpers around string comparison:
>>>
>>> https://cgit.freedesktop.org/gstreamer/gst-plugins-bad/tree/gst-lib
>>> s/gst/wayland/wayland.c
>>>
>>> If you really want these helpers, you can copy them in your app.
>>
>> OK.  I'm seeing a few issues with the sample application.
>>
>> First, these warnings are issued during startup (on Fedora 27):
>>
>> ** (gst-wayland-gtk-demo:11908): WARNING **: Wayland compositor is
>> missing
>> the ability to scale, video display may not work properly.
>
> Yes, I've added that warning to try and convince people that a GL
> compositer should support scaling. waylandsink without that in the
> compositor is pretty useless, and that's why waylandsink is pretty
> useless on Gnome Shell.

So does the fact that I'm on Gnome Shell explain the offset by 100 pixels 
problem too?  If waylandsink won't work on Gnome Shell, are there any 
other alternatives?

>> ** (gst-wayland-gtk-demo:11908): WARNING **: Could not bind to
>> zwp_linux_dmabuf_v1
>>
>> On Debian Unstable, I see the first warning only.
>
> I have go the example builds, do you also get that warning in:
>
>  gst-launch-1.0 videotestsrc ! waylandsink
>
> I have Fedora 27, and on Gnome Shell I don't get this warning (maybe
> I'll get this problem tomorrow when I update ...).

Yes, I get both warnings when I run that command.

Scott