FFV1 non Intra

Hello
Since FFV1 is part of Resolve 18.5 I decide to have a look.

FFV1 options

SCR-20240428-mwek.png (30.68 KiB) Viewed 740 times

In the Type menu there is "Intra" choices and "non Intra" with Keyframes
"non Intra" give access to Keyframes (GOP size?)
I've never found any article about those use cases

I tried both and gave me same result in MediaInfo
What is the difference ?
Thanks

Intra doesn't need keyframes because there's no GOP. Every frame is independently encoded.

Intra doesn't need keyframes because there's no GOP. Every frame is independently encoded.

What "keyframe" parameter is for , then ?
This parameter disappears when Intra type is selected
So What is non Intra ??

Intra doesn't need keyframes because there's no GOP. Every frame is independently encoded.

What "keyframe" parameter is for , then ?
This parameter disappears when Intra type is selected
So What is non Intra ??

From the specification: https://datatracker.ietf.org/doc/rfc9043/

"intra" indicates the constraint on "keyframe" in each instance of Frame.
Inferred to be 0 if not present.
+=======+=======================================================+ | value | relationship +=======+=======================================================+
| 0 | "keyframe" can be 0 or 1 (non keyframes or keyframes) |
+-------+-------------------------------------------------------+
| 1 | "keyframe" MUST be 1 (keyframes only) |
+-------+-------------------------------------------------------+
| Other | reserved for future use |
+-------+-------------------------------------------------------+

That means that non-intra is Group of Pictures (that's why it's available then).
Intra is every frame is keyframe (that is a forced GoP of 1, and thus the setting to change it is not available)

In the real world, using Intra drastically speeds up encoding: As an example I have a 2160p 4 minute 30 second clip. Intra took 7 minutes, Non intra took both 20 minutes.
Size difference is:
Intra: 38 588 023 KB
Non intra auto keyrames: 38 544 034 KB (saving 43 989 KB)
Non intra 120 GoP: 38 550 750 (saving 37 273 KB)

Big Thank you Mads

This is a bit confusing, since the doc clearly states:
"This document defines FFV1, a lossless, intra-frame video encoding format."
I don't see keyframes offered in Deliver in 18.6.6, so this might just have been a mistake by BM, and corrected by now.

I don't see keyframes offered in Deliver in 18.6.6, so this might just have been a mistake by BM, and corrected by now.

Have you seen my screenshot in the OP? You can see keyframe
You must select a non Intra Type first.
I would say BlackMagicDesign did a pretty good job with the UI. It only shows what’s and when necessary !!

Thanks for the heads up, so the linked doc is a bit misleading.
I tried your settings now. It doesn't only encode forever, but can't even play realtime at 25 fps in HD from a NVMe drive, connected by Thunderbolt! I have yet to find another format that doesn't on my hardware.
I'd consider that pretty much useless, until that codec version get's hardware support. The Intra version should be good for high-end archival, though.
Interestingly, TVAI, where I often use FFV1 for archival, doesn't even offer the GOP version.

I agree that GOP encoding seems to be a no-go