Sub-surface protocol

[Kai-Uwe Behrmann]

> On Tue, Dec 18, 2012 at 10:45 AM, Kai-Uwe Behrmann <ku.b at gmx.de> wrote:
>> Am 17.12.2012 16:47, schrieb Richard Hughes:
>>> On 5 December 2012 14:32, Pekka Paalanen <ppaalanen at gmail.com> wrote:
>>>>
>>>> One of the most important use cases is a video player in a window. It
>>>> has XRGB or ARGB window decorations, usually the video content in YUV,
>>>> and possibly an ARGB overlay for subtitles etc. Currently, the client
>>>> has to color-convert the video, and merge it with the decorations and
>>>> subtitles, before sending the grand ARGB buffer to the compositor.
>>>
>>>
>>> A subsurface idea was what Øyvind and I
>>> were discussing at the OpenICC hackfest when we were talking about
>>> tagging a surface with a known ICC profile. This would allow a toolkit
>>> to declare a window area to be AdobeRGB or some home-created camera
>>> profile from a jpeg that has been tagged with an embedded color
>>> profile.
>>
>>
>> Sounds natural to help with CM compositing needs and was therefore discussed
>> [1] for OpenICC's Color Management Near X project in 2008.
>>
>> However, we had seen quite some objections around subwindows at that time.
>> Did something substancial change on that matter?
> I don't see anything there that applies to Wayland. The link to the
> original proposal is also dead.

the old thread starter from Tomas for reference: 
http://www.spinics.net/lists/xorg/msg35268.html

>> To put the question in other words, do Qt and Gtk developers now or soon
>> play with the idea to use wayland as the internal compositing core?

> I believe both have paths to use subwindows/subsurfaces for video and
> OpenGL. These can probably be used for clients with special needs,
> such as image viewers and editors which would simply attach an ICC
> profile to the subsurface. For compositing they could use subsurfaces
> to optimize scrolling performance. I expect that to happen with
> browsers first and I believe Android already does that.

Reads encouraging.

>> [1] https://mail.gnome.org/archives/gtk-devel-list/2008-June/msg00150.html