Back in the ancient SD days, we would place a wipe on the footage that killed the first 25 lines or so, and record that to another source, then use the wiped footage in the production. This eliminated the lines with the closed caption encoding. I would think this would work for HD as well.
But that is if you are talking about closed captions. If you really are talking about subtitles, they are baked into the video, and you can only mask them or blur them.
Dell Precision T7600 (x2)
Win 7 64-bit
Adobe CC 2014 (as of 7/2015)
256GB SSD system drive
4 internal media drives RAID 5
Typically cutting short form from HD MP4 and P2 MXF.