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Re-encoding a media library

· 3 min read · Tech

Some quick notes on considering re-encoding a media library. My Plex movie library is around 1 TB right now. I recently learned about AV1, a next-generation encoder for video files.

I tested locally with Handbrake and saw great results:

“AV1 encoding is awesome. Default preset with Handbrake takes a 6.78GB file and outputs at 1.22GB. 18% the file size. Totally indistinguishable to my eyes. My Mac Studio can re-encode at 120fps, so going to work my whole Plex library through this in the next couple weeks.” (tweet)

Napkin math: 1 TB library, we could conservatively guess 50% of the library is worth re-encoding1. That’s 500 GB of media, which could, at an average 80% filesize reduction, be reduced to 100 GB. That’s about 40% savings in total on my media library. Pretty impressive!

But I decided not to do it. Here’s why.

Space isn’t at a premium

I future-proofed my NAS that this media library is hosted on. It’s a 32 TB TrueNAS Mini X, and I’m only using about 20% of the available storage. I’m not constrained at the moment. Not even close! If I save 400 GB of space re-encoding this media, I’ve basically freed up 1% of my hard drive. Sure, it’s cool, but it’s not exactly a priority at the moment.

Encoding takes forever

At 120 FPS, I can re-encode a 2-hour movie in about 20 minutes. That’s not bad, but if I want to re-encode 500 GB of media, that’s going to take a while. I have better things to do with my time.

My Mac Studio is powerful, but I don’t want to dedicate it to encoding for days on end. And I don’t want to run it 24/7 to get through the backlog.

Client compatibility

Not all devices support AV1 yet. My Apple TV does, my iPad does, my Mac does. But my Roku doesn’t. And I have a few older devices that don’t support it either. So if I re-encode everything to AV1, I’m going to have compatibility issues.

Plex can transcode on the fly, but that’s not ideal. It uses CPU on my server, and it can introduce latency. I’d rather just have files that work everywhere.

Conclusion

AV1 is cool, and I’m excited about it. But for my use case, it’s not worth the effort right now. Maybe in a few years, when storage is more expensive, or when I’m running out of space, or when all my devices support AV1, I’ll revisit this. But for now, I’m going to keep my library as-is.

Footnotes

  1. Some files are already highly compressed, so they won’t benefit much from re-encoding. ↩