Psub.mp4 Guide
: To use these subtitles in an MP4, they must be hardcoded (burned directly into the video frames) using tools like HandBrake .
: The build volume is limited to 9.8″ L x 8.2″ W x 8.6″ H (250mm x 210mm x 220mm). Psub.mp4
: MP4 files do not support bitmap-based subtitles like PGS (from Blu-ray) or VobSub (from DVD) as "soft" (toggleable) tracks. : To use these subtitles in an MP4,

