If your playback device does not support subtitle tracks, you must permanently burn the text into the video pixels during the conversion pass. This requires slightly more bitrate to prevent pixelation around the letters. Recommended Software Tools

Highly compatible but requires larger file sizes for the same quality. Use this only if target legacy devices cannot decode modern streams.

When converting files containing English subtitles ( engsub ), you must choose how to handle the text layer:

If you can clarify: