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Comment by post_break | Hacker News Reader

My next plex server for sure.

I don’t really see the point of using this for a Plex server. Unless you’re doing massive amounts of transcoding 24/7

My Ryzen system can do 2-pass 1080p24 x264 encoding on "slower" preset in real-time. That is, both passes finish in the time it would take to play the movie. It would only make sense for streaming if you had >10 users at a time, and at that point it would probably save a lot of work if you just did the transcoding ahead of time and kept the right format on disk!

I'd do that but the amount of data I have, yeah I couldn't keep extras. Takes up too much space.

Do you actually gain anything from two-pass encoding for streaming? It helps with file sizes but not with momentary bandwidth requirements, as far as I know.

A little bit. Configured for constant bit-rates, x264 can still do a bit of jiggling on the assumption that there's a buffer, which helps with quality in general. Two-pass gives it information to do that better.

But constant-quality modes are far superior when you're not bandwidth-constrained.

Single-pass will also juggle within a seconds-long buffer. Does two-pass help on that micro level, in addition to the way it can allocate bits across an entire file?

x264 has a ton of settings for that kind of thing. This page has a good summary: https://en.wikibooks.org/wiki/MeGUI/x264_Settings#qpstep

It helps if you have a target filesize, or equivalently an average bitrate. The first pass sets the "budget" that each part of the video gets to use out of the total, and the second pass has to make the best encoding it can that fits in the budget for each part. This lets you re-allocate bits from easy parts and give harder parts a little extra.

Edit: so no, it doesn't produce any of the final video during the first pass so you're just adding a huge amount of latency for nothing.

Transcoding is what I need it for.

Maybe you have 4K source video and you happen to watch it sometimes on your mobile phone or 1080P TV. You're gonna need a good CPU.

My plex server is an rpi. What are you doing in plex that requires such horsepower?

Transcoding on the fly takes juice

That much?

Yes, it's expensive to re-encode video to a different resolution or quality.

I realize it's expensive, but does it require 12 cores/24 threads running at almost 3.5ghz. I just find that hard to believe, sorry.

Well when you've got your plex account shared with 10 or so people it adds up.

ohh, i see

He is using ~$1000 of hardware to save on ~$100 harddrive

Sounds about right.

16TB of video, actual files, not raw storage, and I need to transcode it, so you're saying just transcode that data and store duplicates? Yeah not a ~$100 hard drive.

Sorry, ~$180 (8TB storage pod, for example STEB8000100).

Whatever man, that's just a single hard drive. I've got 8 hard drives setup in a custom raid. I can't just willy nilly buy an off the shelf usb drive to add storage too it. You come off so high and mighty not knowing someones actual needs.

In an attempt to be as independent of third-party services as possible I switched from Plex to Emby and I see no reason to go back. You can even stream media outside your home network for free.

edit: https://emby.media/

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