EXR in DWAA or DWAB compressions

Hi to all,

I was wondering if anyone tried to use the DWAA or DWAB compressions for EXRs?

I'm wondering if these could be used with ACES. I know that ACES recommends uncompressed. But, uncompressed is just not viable...

Any takes on this?

There both lossy compressions but visually lossless. SO far I was unable to find any difference with the ARRIRAW 65 files i'm testing them with.

Thanks!

Charles B.

Maybe you can use one of the lossless ones?
Any method is hit with CPU quite strong.
Is it not easier to up storage/bandwidth and stay with uncompressed EXR?

I also seen reports that Resolve is not very good with decoding DWAA or DWAB.

Why not piz compression? Or zip?

Those are lossless so you're gaining around 2x space only.
DWAX are lossy, so you can gain 6x if desired

Those are lossless so you're gaining around 2x space only.
DWAX are lossy, so you can gain 6x if desired

Yes, but, what's the point to go exr of you compress it and lose data?

Isn't better just stick with dpx then?

Hmmm...DWAA is only mild compression. You don't loose bit depth precision with DWAA, but only some high frequencies. At 3:1 you unlikely will be able to tell the difference and you gain 3x the space. Event at higher compression ratio you just getting grain/noise softened a bit, which in some cases actually not a bad thing. If you tarts with 6K files and going to 4K this is probably not going change much end look at all.
It will hit your CPU a lot though.

Ok so a strong CPU would be the key!

The reason I'm wanting to use EXR if for ACES deliveries to VFX. I know we're supposed to use uncompressed but some have been using it successfully in ACES VFX workflows.

A 4K uncompressed file is 53 megs a frame. That 1.2GB/sec. I'd need to hit 1.5 to have a little bit of overhead... That's a pretty massive storage!

But I guess I could build a SSD raid just to handle those shots!

Thanks!

1.5GB/sec is fairly easy these days. 3xSSDs will do (single NVMe) or 8 good HDDs. It all depends how much storage you need and how much space.
It's fairly easy to build storage up to e.g. 5GB/sec- pass this is bit more tricky (specially when you want it safe).

I don't think that e.g. 3x compression is any issue. Bigger issue is actual fact that any compression hits EXR quite a lot on CPU needs.

1.5GB/sec is fairly easy these days. 3xSSDs will do (single NVMe) or 8 good HDDs. It all depends how much storage you need and how much space.
It's fairly easy to build storage up to e.g. 5GB/sec- pass this is bit more tricky (specially when you want it safe).

I don't think that e.g. 3x compression is any issue. Bigger issue is actual fact that any compression hits EXR quite a lot on CPU needs.

Good to know! Thanks!

At that point, use zip/ piz compression: you have half of the storage abs bandwidth needed, and lossless.

Keep in mind that 4k exr compress files require a ton of CPU abs GPU to work in realtime.

A TON.

At that point, use zip/ piz compression: you have half of the storage abs bandwidth needed, and lossless.

Keep in mind that 4k exr compress files require a ton of CPU abs GPU to work in realtime.

A TON.

But piz or zip also uses CPU right?

Yes, but probably about 25% less than DWA based on info from people's tests.
You just don't know ho much it will save you as it's lossless compression. It can be anywhere from 1.2x only to above 2x. If you have typical camera source it should be around 2x. Try on your source as it can really vary.
When it comes to storage speed you can't really say- I need 2x less compared to uncompressed EXR. You pretty much still need to have as fast storage as for uncompressed EXR for 100% reliable playback as some frames may not compress much at all.
PIZ sounds like a best lossless option (if you have good CPU). It's wavelet based and good for typical/real camera noisy/grainy sources.

Yes, but probably about 25% less than DWA based on info from people's tests.
You just don't know ho much it will save you as it's lossless compression. It can be anywhere from 1.2x only to above 2x. If you have typical camera source it should be around 2x. Try on your source as it can really vary.
When it comes to storage speed you can't really say- I need 2x less compared to uncompressed EXR. You pretty much still need to have as fast storage as for uncompressed EXR for 100% reliable playback as some frames may not compress much at all.
PIZ sounds like a best lossless option (if you have good CPU). It's wavelet based and good for typical/real camera noisy/grainy sources.

Sounds good! Thanks again for all the help!

Yes i will pic piz too.

You never have enough space: plan for a lot then double that.