I did something similar for myself using mpv's scripting interface (for Japanese immersion).
I can press a button and have the current subtitle analyzed for words with mecab, or press another button and have audio + screenshot + text sent to Anki for review.
mpv allows to seek previous/next subtitle, so even relistening a particular phrase is really convenient.
Indeed, you get high quality in context cards, something that is still missing from most Anki decks.
The code is here https://github.com/pigoz/mpv-nihongo, keep in mind that a lot of stuff is hardcoded, poorly documented, and it requires an mpv patch to work.
If there's enough interest, I can try and make it simple for someone that's not me to use.
I can press a button and have the current subtitle analyzed for words with mecab, or press another button and have audio + screenshot + text sent to Anki for review.
mpv allows to seek previous/next subtitle, so even relistening a particular phrase is really convenient.
It makes language learning really fun.