This can be reproduced/tested quickly and easily by using:
gst-launch videotestsrc pattern=blink ! video/x-raw-yuv,framerate=60/1 ! xvimagesink
This can be reproduced/tested quickly and easily by using:
gst-launch videotestsrc pattern=blink ! video/x- raw-yuv, framerate= 60/1 ! xvimagesink