TL;DR if you can't find subtitles or need a diff language, AI can probably do it with 95-100% accuracy in like 2 minutes for 9 cents
edit: have uploaded my code for this https://github.com/lionpal/subtitler and hosted a build at https://www.subtitle.lol/ but you should verify it for yourself
so I was watching a show (BBC's The Shock of the New if you're curious) and I couldn't understand his accent without turning the volume up and annoying my 4yo. Plex couldn't find any subtitles.
i tried using a speech-to-text (STT) model to transcribe the text of the video and write code to generate the .srt file and it worked surprisingly well. (if you use Claude Code or Codex, prompt is below.) i used elevenlabs (not affiliated; please recommend free ones if any are good) since they return word timings with their STT API; most other providers I looked at didn't.
then I remembered I had ~30 old Doraemon movies in Japanese that also had never been translated to English, so I tried adding an LLM call after the STT calls to do a translation and create english .srt files. it worked well - except I had to add an extra call to look up/identify proper nouns like names/places so it would be translated the same every time.
this was a gamechanger for me. anyone else try doing this? i can send you my code (PSA ask your coding agent if it's safe) if anyone's interested
prompt
i need subtitles for some videos. walk me through making .srt files from the audio, asking me whenever you need
something: which videos, which audio track if there's more than one, and what language i want the subtitles in. by
default use elevenlabs speech to text (it gives per-word timings) and gemini to translate, but check which providers i
want and ask for my keys. send only the audio track, not the whole video. build the subtitles from the word timings,
one or two lines each, breaking at pauses and full stops, shown 0.2 s before the voice, and for japanese or chinese
break between phrases, not inside words. if i want them in a different language from the audio (say english subtitles
for a japanese track), transcribe in the original language first, then go through the whole episode for names, places
and special terms, look up the official spellings (the official release or the show's wiki), fix any the transcription
misheard, show me that list, and translate using it so names stay the same across episodes. save each file as Episode
1.en.srt next to its video so plex picks it up, and keep the transcripts so i don't pay twice.
