Originally Posted by steve6933
I recently watched a couple of movies on 7.2 (This TV) and noticed that when I watch the signal with 1:1 pixel mapping, I can see the dotted lines at the top few pixels of the screen. I think this is digital data for closed captioning. Is this something that the network needs to fix? Is anyone else seeing this?
What you are seeing is signal within the "vertical blanking interval". The VBI signal is a data signal contained within the regions of Line 21 & 22 analog.
A lot of times, when a program is "upconverted" from an older analog tape, the device which does the upconversion, won't mask this, and with the higher resolution, it's much more obvious. Typically what i've seen isn't CC data (Line 21 field 1), but rather time code. Back in the ancient days of analog broadcasting, (wait that was only a couple years ago, right?), anyways, we used to stuff other things in the VBI too, including color bars, test pulses, etc., in the lines below 21.