How to Set Subtitle Font Size

The size of soft subtitles cannot be adjusted; it is controlled by the player. Hard subtitles can be adjusted by modifying the Hard subtitle font pixels size in Menu -- Tools/Options - Advanced Options. The default is 14.

Controlling the Number of Characters per Line in Subtitles

By default, Chinese, Japanese, and Korean subtitles have 30 characters per line, while other languages have 60 characters per line. This can be adjusted by modifying Characters per line for CJK subtitles and Characters per line for other subtitles in Menu -- Tools/Options - Advanced Options.