Finally one I can help with.
CBC Gem (prevously watch.cbc.ca) uses the 608 closed caption format in their streams instead of subtitles. (Closed captions being part of ATSC for TV streams).
FFmpeg can extract closed captions and convert them to SRT (subrip) or ASS (Substation Alpha) formats (the latter also converting colors and positions better).
Command is as follows
ffmpeg -f lavfi -i "movie='input.mp4'[out0+subcc]" -map s "output.ssa"
Replace the input and output correspondingly.
(Edit: this assumes you used yt-dip or youtube-dl to do the download)
You can also mux it into the same file if you prefer embedding it into the same file (in FFmpeg, add an extra -i before the lavfi, do -c:v copy -c:a copy, -map 0, -map 1:s). I can post a more complete command if you’re interested.