Those lines are scan lines. What we are probably seeing is half a frame. Interlaced video is composed of two half frames to make one. It will first scan the odd lines (1,3,5,7, etc...) and then scan the even ones (2,4,6,8, etc...) in order to get a complete frame. You don't get that with progressive as opposed to interlace. I can also see that the capture of your video has a lot of ''blockyness''. You can see it mostly in the black parts. It's a dead giveaway for compression.
Not knowing what were the specs of the original file and what were the render parameters, that's as much as I can tell you.
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