Answers.Body: <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>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-08-04T02:22:53.740Z
Answers.LastActivityDate: 2016-08-04T02:22:53.740Z
Answers.UserDisplayName: Michael Liebman
Answers.Body: <p>Very likely you're seeing either VITC (vertical interval time code) or closed captions encoded on line 21 of the vertical interval. Those are both part of analog video only, though they may remain after being digitized.</p>
  
  <p>If we could see the video in motion it would be easier to tell.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-08-04T02:23:52.793Z
Answers.Text: The pulses are too wide for it to be VITC, plus there is only one line.
Answers.UserDisplayName: Michael Liebman
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-08-04T02:19:44.567Z
Answers.LastActivityDate: 2016-08-04T02:19:44.567Z
Answers.UserDisplayName: Jim Mack
Body: <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.sstatic.net/eQN42.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/eQN42.jpg" alt="An example"></a></p>
  
Tags: <recording><closed-captioning>
Title: What causes these lines in the top left of some video recordings?
UserDisplayName: cannaelogin
ThreadText: # What causes these lines in the top left of some video recordings?
  
  (Asked by: username_0 on 2016-08-03)
  
  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.
  
  [![An example](https://i.sstatic.net/eQN42.jpg)](https://i.sstatic.net/eQN42.jpg)
  
  **Tags:** recording, closed-captioning
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2016-08-04. Score: 3
  
  That's [EIA-608](https://en.wikipedia.org/wiki/EIA-608) analog closed captioning data. It should be on line 21, which is within the [vertical blanking interval](https://en.wikipedia.org/wiki/Vertical_blanking_interval) of the SD signal. Either the line was shifted down or the VBI was captured as being active video.
  
  
  ---
  
  ### Answer by username_2 on 2016-08-04. Score: 0
  
  Very likely you're seeing either VITC (vertical interval time code) or closed captions encoded on line 21 of the vertical interval. Those are both part of analog video only, though they may remain after being digitized.
  
  If we could see the video in motion it would be easier to tell.
  
  > **Comments:**
  > **username_1**: The pulses are too wide for it to be VITC, plus there is only one line.  
  
  ---
  
  