user16320: What causes these white lines to appear in the lop left of some video recordings? I've seen them many times of the years and they always seem to look identical.


user14523: That's EIA-608 analog closed captioning data. It should be on line 21, which is within the vertical blanking interval of the SD signal. Either the line was shifted down or the VBI was captured as being active video.

16320: <p>What causes these white lines to appear in the lop left of some video recordings? I've seen them many times of the years and they always seem to look identical.</p>

<p><a href="https://i.stack.imgur.com/eQN42.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eQN42.jpg" alt="An example"></a></p>
 14523: <p>That's <a href="https://en.wikipedia.org/wiki/EIA-608" rel="nofollow">EIA-608</a> analog closed captioning data. It should be on line 21, which is within the <a href="https://en.wikipedia.org/wiki/Vertical_blanking_interval" rel="nofollow">vertical blanking interval</a> of the SD signal. Either the line was shifted down or the VBI was captured as being active video.</p>
