Archiving large avi files - best settings?

[Full of Eyes]

Hi there, I have a few large avi files that I made back in the early 2000's. I'm saving all of my old stuff to the Arweave permaweb and I'd like to turn these bulky (and out of date) files into more managable and 'future proofed' files types. Any thoughts on best settings to use for this?

I was using an edited form of the 'Match Source Adaptive High Bitrate' preset, using a target br of 8mbps and a max of 12mbps (these are all SD files). 

Any thoughts from those of you who know more about this sort of thing? Thanks!

[David Arbor]

AVI doesn't tell you what codec was used, so I don't know if you're moving from a lightly compressed or highly compressed file, but H.264 will likely be futureproof for some time. That being said, it's not an archiving format as it is highly compressed. For standard definition material, I would give ProRes LT a try and see how the file sizes compare.

[Full of Eyes]

Excellent - thank you for the suggestion, I'll look into that!

[Warren Heaton]

That's part of what ProRes 422 Proxy is for.

The idea is that we transcode to ProRes 422 Proxy for archiving and if we ever need it again later, bump that back up to ProRes 422 HQ.  

ProRes 422 Proxy has a shallow peak signal noise ratio, but will work well for a first generation transcode.  

You can also use ProRes 422 LT, but it will be about double the file size. 

[Full of Eyes]

See - I didn't even know that such a thing existed. So....you could take a ProRes 422 Proxy file and later somehow *up* its quality?

[Warren Heaton]

Think of it in terms of qualty preservation and visible differences in first generation transcodes.

You're dropping to a format with lesser quality preservation for archiving and bumping back up for higher quality preservation for later use.

Of course, picture quality is important.  Going from uncompressed AVI to ProRes 422 Proxy might have a subtle difference for high-detail images.  A first generation ProRes 422 Proxy is most likely going to look great, but you would not want to keep using it as ProRes 422 Proxy afterward.  Bumping it up to ProRes 422 HQ brings back higher quality presrevation based on whatever the ProRes 422 Proxy picture looks like.

To test it for archival purposes, transocde one minute (pick a minute of high-detaile picture) of your AVI to ProRes 422 Proxy then transcode the ProRes 422 Proxy to ProRes 422 HQ.  Then, do a before/after or side-by-side comparison between the AVI and ProRes 422 HQ.  You could also use ProRes 422 LT.

For more on ProRes: Apple ProRes White Paper 2022

[Full of Eyes]

Cool. I'll try that test and see how it looks.