Firefox doesn't like (f)MP4 output from TVHeadend?

Ratchanan

So I want to watch TV from TVHeadend with Firefox. Amongst all containers TVHeadend offers, MKV, MPEG-TS and MPEG-PS doesn't work outright. WebM works, but it can't contain H.264 from TV stations/IPTV providers, so it requires transcoding which I would like to avoid if possible.

So MP4 is the preferred option. But on my machine, video plays for less than a second, and then freeze. If I re-hit play, it replay that playable segment over and over, but can't get pass that point. I tried this both with webtv-h264-vorbis-mp4 built-in profile, and a profile which use MP4 as container but copy both video and audio.

So I'm not sure if it's the fault of Firefox, libavformat, or my own setup. Any help in looking into this is appreciated.

TVHeadend server runs inside a Docker container; the image used is ghcr.io/tvheadend/tvheadend:master (i.e. the Alpine-based one). The client is Firefox 135 on Ubuntu 24.10.

DaveH

The first obvious step would be to try another browser, such as a chrome-based one or a webkit-based one. That would help to narrow down where the problem is.

Ratchanan

I've tried both Chromium and Gnome Web (Webkit-based). Both browsers play both (f)MP4 and MKV fine. Gnome Web even plays MPEG-TS (pass profile), but that's beside the point.

It's actually known that Firefox doesn't support MKV, but it claims to support fMP4 outside of Media Source Extension API. So it should work, but I'm not sure why it doesn't.