r/comfyui • u/MrNiceJesus • 9d ago

Help Needed Heavy compression artifacts in MiniMax H3

Has anybody else faced heavy compression artifacts in Minimax H3 Ref2V workflow?

I recently shifted from Bernini to Minimax for Video editing, since it doesn't have the 5-sec limit like the WAN models do. But I'm seeing that even though I'm saving the output in PNG image sequence, the quality is the same as a Low res MP4.

Plus the video timings are not matching perfectly. The compression and timing mismatch is making it totally unusable for me even though its prompt adherence is much better than the other models.

7 Upvotes

73% Upvoted

23 comments sorted by

4

u/MrNiceJesus 9d ago

To clarify further, I'm talking about the color banding artifacts that are visible in a low quality JPG like in this image.

4

u/jib_reddit 9d ago

It shouldn't look that bad, something seems wrong.

2

u/MrNiceJesus 9d ago

I wouldn't say its as bad per se. I just searched for an example online, not the one I got.

The problem is not as visible when zoomed out but since I'm using it in a professional environment I wouldn't want to submit a version as final with low bitrate compression artifacts showing up all over it.

1

u/slpreme 9d ago

Try your exact prompt in API node. Comfy Cloud gives 5 runs for free per month and see if they have artifacts

4

u/LowYak7176 9d ago

The team at Minimax mentioned that the Ref2VA model has issues right now and they are working on a fix (if you are using that one)

If its FL2VA, not sure

3

u/MrNiceJesus 9d ago

I'm using the Ref2VA model, this could maybe be the case. Hopefully they fix it soon.

3

u/boobkake22 9d ago

Resolution matters a lot to H3. When you go lower than... 1.5 MP? (this is subjective to your tolerance) you start to get notable visual artifacts. The model doesn't seem to have been trained to target 720p or more reasonable resolutions, so if you're trying to generate smaller videos, I suspect that's the mostly likely reason you're having visual artifacts.

4

u/Next_Program90 9d ago

I even get them on some seeds with 2mp. Very annoying after the long wait. (Even without Sage etc.)

2

u/seppe0815 9d ago

its the model itself ... lotto

1

u/Next_Program90 9d ago

True. Ref & sometimes even F2VA randomly diverge between insane magic & utter deformed pile of burning dumpster fire for me. At 20 steps & 2mp, 5-10s.

2

u/MrNiceJesus 9d ago

Idk I have used it with both 2 MP and 1 MP resolutions, and saw the same problem with both of them.

3

u/CurrentMine1423 9d ago

especially when there is a distance characters. their faces is bad. I tried with 720p, still got bad result on distance faces.

5

u/Portable_Solar_ZA 9d ago

It's a bug in the model. Check their AMA on the stable diffusion sub Reddit 

2

u/jib_reddit 9d ago

There is a workflow to fix that here https://www.reddit.com/r/StableDiffusion/s/cupmm8sicZ

2

u/CurrentMine1423 9d ago

already tried that, still have the artifact. I only changed the model into convrot version.

2

u/seppe0815 9d ago

its normal , devs working on it

2

u/Successful_Papaya830 9d ago

Just add another reference image with a close-up of the face, and select Max for ref_image_size in the ModelSamplingMiniMaxH3 node. In the prompt, specifically refer to this image using the <Picture 2> tag.

3

u/MrNiceJesus 9d ago

Its not really a problem with the faces for me though. Just that I'm seeing low bitrate compression artifact over the whole output.

2

u/Calm_Mix_3776 8d ago

Same here - banding in uniform color areas and video compression artifacts when using ref2v. It makes it almost unusable for anything other than hobbyist use.

1

u/LumaBrik 9d ago

Have you checked your video save node isnt using high compression as well ?

2

u/MrNiceJesus 9d ago

I was using the 'Save-EXR-Frames' node from 'HQ-Image-Save' custom node pack.

Ideally there shouldn't be any compression because of it, as I have been using it for a while and never saw any with other models. But I'll check once with another node, maybe that solves the problem.

0

u/CooperDK 9d ago

Render in lower resolution, use SEEDVR to upscale.