Ram disk requirements

[webtron]

What are the ram disk requirements for transcoding. I'm watching a live tv stream with the app on a Chromecast with Google tv and I get a little slight pause every minute or so. It seems to go away if I pause the playback for 10 seconds so I think it's to do with a new transcoding file being created and the app not keeping much in the cache. Anyway when I look in the transcoding directory Jellyfin seems to keep the whole session of files from when I started watching. Does Jellyfin have a limit before it starts flushing the old data so I can work out how big the ram disk needs to be?

[TheDreadPirate]

From experience, it does not clean up until you stop. If you think about it, that makes sense. If you want to skip back to an earlier part it already deleted then it would need to reload that part and retranscode.

I'd say 4GB is a pretty decent size ram disk. I haven't had issues with my 4GB ram disk. My content is 1080p max, I don't transcode live TV.

[webtron]

Thanks for the reply.
How do you disable transcoding? I have tuner connected to Tvheadend and it passes through the stream untouched but Jellyfin transcodes it.
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> hevc (hevc_qsv))
Stream #0:1 -> #0:1 (mp2 (native) -> aac (libfdk_aac))

[TheDreadPirate]

In Settings > Dashboard > Users > Pick a user

Is "Force transcoding of remote media sources" checked?

My two live tv channels are H264/aac and don't transcode.

[34626]

I have a ramdisk on 24 GB, i have multiple users so sometimes it comes up on 20 GBusage.. the usage stops when amovie is stopped.

May i ask about the source of Live TV? I havent had luck using Live TV in Jellyfin yet..

[TheDreadPirate]

Some channels have IPTV streams. In my case NHK World and my local PBS station. They provide m3u/m3u8 files. In jellyfin you can't use the URL, you have to download the m3u file and save it locally. Then point Jellyfin to that m3u file (Settings > Dashboard > Live TV). TV guide data is separate and often not provided by the IPTV source. There are 3rd party TV guide providers that are not free.

[bitmap]

Isn't best practice to have the RAM disk the same size as the file you're transcoding? So if you've got massive 4K remuxes, chuck as much into the RAM disk as you can, but if it's mostly middling bitrate 1080p content, a few gigs will do fine?

[TheDreadPirate]

Isn't best practice to have the RAM disk the same size as the file you're transcoding? So if you've got massive 4K remuxes, chuck as much into the RAM disk as you can, but if it's mostly middling bitrate 1080p content, a few gigs will do fine?

Yeah.  4GB works for me, but I only have 2 people using my server at the same time, max.  My content is all 1080p and transcodes are usually to a lower bit rate and resolution and fit within my 4GB ram disk.

If you have 4K content or have a lot of users you probably need more.