Description
Compositor can accept AYUV, ARGB and BGRA video streams. For each of the requested
sink pads it will compare the incoming geometry and framerate to define the
output parameters. Indeed output video frames will have the geometry of the
biggest incoming video stream and the framerate of the fastest incoming one.
Compositor will do colorspace conversion.
Individual parameters for each input stream can be configured on the
GstCompositorPad:
-
"xpos": The x-coordinate position of the top-left corner of the picture
(gint)
-
"ypos": The y-coordinate position of the top-left corner of the picture
(gint)
-
"width": The width of the picture; the input will be scaled if necessary
(gint)
-
"height": The height of the picture; the input will be scaled if necessary
(gint)
-
"alpha": The transparency of the picture; between 0.0 and 1.0. The blending
is a simple copy when fully-transparent (0.0) and fully-opaque (1.0).
(gdouble)
-
"zorder": The z-order position of the picture in the composition; between
0 and 10000. (guint)
Sample pipelines
A pipeline to demonstrate compositor used together with videobox.
This should show a 320x240 pixels video test source with some transparency
showing the background checker pattern. Another video test source with just
the snow pattern of 100x100 pixels is overlayed on top of the first one on
the left vertically centered with a small transparency showing the first
video test source behind and the checker pattern under it. Note that the
framerate of the output video is 10 frames per second.
A pipeline to demostrate bgra comping. (This does not demonstrate alpha blending).
A pipeline to test I420
A pipeline to demonstrate synchronized compositing (the second stream starts after 3 seconds)
Property Details
The “background”
property
“background” GstCompositorBackground
Background type.
Flags: Read / Write
Default value: Checker pattern