I downloaded L4.1.15 x11 demo image for MCIMX6SX-SDB and I tested overlay display as following.
gst-launch-1.0 videotestsrc ! imxv4l2sink
gst-launch-1.0 videotestsrc ! overlaysink overlay-width=640 overlay-height=480
gst-launch-1.0 imxv4l2src device=/dev/video3 ! overlaysink overlay-width=640 overlay-height=480 //uvc camera
It seems matchbox-window-manager installed and only one window can activate at once.
(Q) Is there any other window managers which supported i.MX6SX?
(Q) Is there any Gstreamer plugin like mfw_isink to display two videos on the matchbox desktop?
As far as I know I can display two mixed videos as following but too slow and desktop was lost.
videomixer name=mix ! imxvideoconvert_g2d ! imxv4l2sink \
videotestsrc pattern="snow" ! "video/x-raw,width=640,height=480" ! alpha alpha=1.0 ! mix. \
videotestsrc ! "video/x-raw,width=320,height=240" ! alpha alpha=0.3 ! videobox top=-80 left=-80 border-alpha=0.7 ! mix.