[FFmpeg-user] Insert black frames -- How?

[Mark Filipak (ffmpeg)]

I want to insert black frames into a stream on a regular basis.
#1, Is that an input device? I think so. Or,
#2, is it better/easier to repeat an input frame and blacken the repeated frame? Maybe.

I seek guidance. I've read everything I could find. Methinks #1 would be best. But if #2, would a 
'pad' filter that covers the entire frame be best/easiest?

Thanks Folks!
Mark.
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