I'm trying to hardcode subtitles into a file that's in .mkv container, using one of the subtitle strams from the container. I want subtitles to have a black background on them. I'm also trying to keep 10bit encoding and preserve high quiality. Result is ok, except that all subtitles are doubled. So there is a layer of good subtitles in white on black background, and also, half of the font size down, same subtitles in black. Can someone point out the issue with my command? Thank you.
Ran this command:
ffmpeg -i movie.mkv -vf "subtitles=movie.mkv:si=0:force_style='OutlineColour=&000000000,BorderStyle=3,Outline=3,Shadow=0,MarginV=20'" -c:v libx265 -crf 23 -preset slow -x265-params profile=main10 -c:a copy movie_subs.mkv
Expected: White subtitles on black background Actual: White subtitles on black background with black subtitles half font size down
