Sub-surface protocol

[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.

Sorry to be late to the party. 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.

The use case are image viewers like EOG or editors like GIMP. Gimp
wants to color correct the main preview window converting from source
ICC profile to monitor ICC profile, but we really don't want to "turn
off" the sRGB->monitor profile for the selector widgets. By using a
subsurface we get the behaviour we want without adding tons of code.
At the moment Oyranos has some kind of xatom protocol to let the
compositor know an opt-out-region and this isn't ideal or suited at
all to wayland.

Anyway, I just wanted to say "rock on" and maybe to keep ICC color
correction at the back of your mind for the sub-surface. :)

Thanks,

Richard