[vlc-devel] Chroma-key plugin for VLC as class broadcast client

[jpd at m2x.nl]

On Sun, May 3, 2009 18:39, Juan Fernando Herrera J. wrote:
> Greetings. I wondered if someone could be interested in this idea.
> It's about a player mode in which the player image would be
> chroma-keyed against the computer desktop, so that the image would
> overlap the windows contents.

EG the compiz window manager with the "fakeARGB" plugin (unsupported)
or perhaps providing an OpenGL fragment program to the "colorfilter"
plugin, (supported) allows you to do exactly that, on an X server with
the compositing and rendering extentions (requires OpenGL-supported
graphics hardware).

Another way could be to use the shape extention, requiring vlc to provide
its own mask and telling the system to only paint what isn't masked out,
provided updating can be done fast enough (also on the server side).

The thing is more or less that it's not something the application does,
but the windowing system (in X11's case, the window- or compositing
manager), though of course a vlc plugin could be made to specifically
support steering the component that actually does it.

This then leaves the problem of taking the picture output and re-forming
it into some form that can be encoded and broadcast. A vlc screen capture
plugin and an accompanying masking/chroma keying plugin might be worth
investigating.