Moved your thread to 'AV Talk' since it doesn't seem to be related to Hybrid.
That is a video with hardcoded subtitles, so it doesn't contain a subtitle stream you would have to use some tool which uses OCR to extract the subtitles.
ffmpeg does have a filter (ocr) which uses tesseract to extract subtitles, but I have never tried that.
Tools like Subtitle Edit, SupRip and similar also can ocr subtitles from video files (depending on the tool you will have to install some other tools and filters for this).
There should be guides for all this throughout the Internet.