I have an MKV wrapped 1920x800 video and a sidecar .srt subtitle file. I want to convert the video to 1920 x 1080 and add black border on top and bottom while keeping the original aspect ratio. I also want to insert the subtitles on the black border.
I have an idea on how to insert the subtitles, but I'm not sure how to add the border. I'd appreciate any suggestions on how to do this all in one pass so that I lose at little quality as possible.