How to extract and remove closed captions

Introduction

Closed captions look like subtitles but they are actually embedded inside the video stream. There is no subtitle stream assigned to them.

Extract closed captions to a SRT file

This may be helpful when a translation to another language is needed.

ffmpeg -f lavfi -i "movie=INPUT.mp4[out0+subcc]" -map s "OUTPUT.srt"

Remove closed captions in SEI

This is achieved using the filter_units video bitstream filter.

ffmpeg -i "INPUT.mp4" -c copy -map 0 -bsf:v filter_units=remove_types=6 "OUTPUT.mp4"

for AVC and remove_types=39 for HEVC. MPEG does not have SEI, so that will not work.

Type SEI can have other information there, like HDR10+ metadata, so more accurate code is needed, see #5283.