I self-host Jellyfin on my homelab and got frustrated opening a laptop every time there was a football match just to deal with popup-infested streaming sites. The actual video underneath is just a standard HLS stream, but getting it into Jellyfin turned out to be harder than expected.

Three problems: (1) the m3u8 URL is buried behind iframes and obfuscated JS, (2) tokens expire every few hours, and (3) the upstream server checks User-Agent and Referer headers on both the playlist and .ts segments — Jellyfin doesn't send these, so you get 403.

I ended up writing three scripts:

- detect-headers.sh: give it a page URL, it follows the iframe chain, extracts the m3u8, then brute-forces header combinations on both .m3u8 and .ts requests. Tells you exactly what the stream needs.

- hls-proxy.py: single-file Python reverse proxy (stdlib only, zero pip dependencies). Injects the required headers and rewrites the m3u8 so segment requests also go through the proxy.

- refresh-m3u.sh: extracts fresh URLs before tokens expire, outputs a Jellyfin-ready M3U with logos and channel groups. Runs on a systemd timer.

~200 lines of Python, ~100 lines of bash. The proxy is the interesting part technically — it has to handle relative and absolute segment URLs, rewrite URI= in EXT tags (for encryption keys), and add CORS headers since Jellyfin's web client makes cross-origin requests.

Happy to answer questions about the approach or implementation.