Hi friends,

I have mp4 files with closed captions which I would like to extract, edit and then remux back to the mp4 file.

"MediaTab" shows me this:

Id: 1-CC1
Format: EIA-608
Muxing mode: SCTE 128 / DTVCC Transport
Muxing mode, more info: Muxed in Video #1

I would be happy to know of a free software for windows that could do this. I've tried using handbreak, according to this page it's suppose to do it somehow but I didn't see the closed captions/subtitle anywhere. I also have davinci resolve if it helps.

and another newbie question, if I'll manage do all that, will muxing the CC back to the mp4 take a long time? I'm hoping it wont take long like encoding as I'm not burning subtitles frame by frame, just packing another text file in the mp4 container right?

Thanks so much for your help!