Unifab AI 2.0.3.7 (HDR Upconverter malfunction: excessive pixelization, etc.)

Mandalorian1

Currently using (fresh install) Unifab AI, version 2.0.3.7. There are noticeable issues with the output from the HDR Upconverter. I am upconverting a 4K source (H265 at about 3.5GB size). It ends up creating an HDR 4K H265 output copy that is only 1.7GB in size. It seems to me that there must be excessive compression applied during the HDR upconvert. Every setting for the video HDR upconvert is at max quality/bitrate as well which doesn't make sense. The size of the file in the outcome of the HDR upconvert should be at least the same and not half the size of the original, especially when both are H265 codec. The outcome of all this is excessive pixelization noted in the HDR output video file. Additionally noted is unexplained strobing/flashing of lighting effect in certain scenes (especially those with brighter lighting in the background than in the foreground). Neither of these two noted issues exist in playback of the original 4K source in the same scenes where they are noted in the HDR output video playback.

All this renders the HDR Upconverter as "broke" and not even reliable useable at this point. Please fix.

knighter

For compress problem：please send the UniFab_log for check.
For flashing problem: We're testing the new model, which solves the flicker problem.

Mandalorian1

Looks like both the flickering/flashing issue as well as the compression issue have been addressed in new 3.0.0.0 version. However, the upscale to 4K produces now inferior quality to previous versions of software. Did side-by-side comparison and details are not as crisp and clear in video output following upscale event from 1080p to 4K. This may be explained by removal of granular functionality to adjust bit rate and other settings by more advanced users to enhance output quality. Now selecting "High Quality" produces a "mystery" quality of output that is any user's guess as to what bit rate is used and other granular settings available in previous versions that could be used to enhance outcome of an upscale.

Screenshots attached (better noticeable when watching videos). You can see differences in attached output especially in areas of finer details (clothing patterns; facial features, etc.)

The one on the top is from a version prior to 3.0.0.0; bottom from version 3.0.0.0 4K upscale. Snapshots taken 9 seconds in each (within milliseconds variance).

Facial features of the boy are noticeably sharper with crisper more noted detail from the earlier version while the one from 3.0.0.0 is lacking in sharpness and detail.

knighter

Which version is the old version？

Please tell us the bitrate you've set for this conversion.

knighter

I found your ticket，we've reported this problem.

Mandalorian1

I investigated, tested, and reviewed this further, especially given that I could not recollect the exact 2.0.3.x version I used (nor the exact settings).

The original source video I used for this test has a resolution of 1920 x 800, or an aspect ratio of 2:40. When I select to upscale to 4K in version 3.0.0.1 (and 3.0.0.0) it doubles the resolution to 3840 x 1600 in order to maintain the original 2:40 aspect ratio with a bit rate of 28339kbps.

I installed UniFab 2.0.3.7 and for the same video source file I enlarged the video to 4K using the following settings:

Version 2.0.3.7, contrary to 3.0.0.1, with the settings noted produces an output file with a 5184 x 2160 resolution (still maintaining a 2:40 aspect ratio) and with a resulting bit rate of 64745kbps. This would help explain the superior video quality with greater detail above the output produced using version 3.0.0.1.

To conclude, it appears that both are maintaining a 4K minimum resolution and the original 2:40 aspect ratio. However, the earlier version of Unifab (version 2.0.3.7) maintains a true 2160 vertical pixel height as a minimum while expanding the horizontal pixel width to 5184 (approaching 5K resolution). Version 3.0.0.x (3.0.0.1 version used here), on the other hand, maintains a 3840 horizontal pixel width while sacrificing height (only 1600 pixels instead of 2160). While the output produced using 3.0.0.1 technically meets 4K standards, the quality and detail (with 3840 x 1600 resolution @ 28339kbps) will be less than what was produced using version 2.0.3.7 (with a 5184 x 2160 resolution @ 64745kbps).

In my estimation, I would suggest that the software maintain a 2160p vertical pixel height (or 5184 x 2160 resolution @ 64745kbps) that meets what most might consider a desirable minimum vertical pixel height for 4K UHD when the user selects "4K" for the upscale option. At the same time, keep the resolution doubling limited to the "2x" option that is also available in 3.0.0.x version for a user to choose (creating a 3840 x 1600 resolution per this test case) while retaining the typical 4K horizontal pixel width of 3840 if that is what the user wishes(reducing to 1600 the vertical pixel height to maintain the 2:40 aspect ratio in this case while sacrificing output quality and detail from the "4K" option). It makes no sense to have a "2x" option and "4k" option that essentially do the same thing. In my opinion, the "4K" option should mostly yield superior results to the "2x" option wherever and whenever possible, especially when upscaling from HD (1080p) as was the case per my testing.

raven-au

@Mandalorian1 it sounds like the above is a bit of a problem.

Presumably this is to be played on a TV which means a limited number of native resolutions.
I'd wonder which of the two looks better on a TV, the 3840 x 1600 (the equivalent of the original cropped 1080p) or the TV scaled 5184 x 2160?
In fact I'm not even sure what the TV would do with the later resolution ...
Unless you maybe have an 8k TV which I don't so I have no idea what would happen with that.
Or maybe a real 4k TV (4196 horizontal instead of the common 3840 resolution).

IMHO the 3840 x 1600 to maintain the original UHD crop and allow a native TV resolution (of 3840 x 2160) to be used is probably the better choice unless it's to be displayed on some other output device that doesn't have the same limitations as a TV (at least a 4k TV anyway).

Mandalorian1

@raven-au the PC hardware I have for my media PC will downscale it to 4K. It is not an issue. Even downscaling 8K to a 4K TV is not usually an issue. A lot depends on source and hardware capability used to display the signal. All I know is the 5184 x 2160 resolution of the two examples I shared displays without issue on my LG G4 OLED using my AMD Ryzen 7 8700G APU-based Home Theatre PC that I built. I personally prefer how 2037 version handles rendering when I select 4K resolution. I'm not asking it to merely double the resolution (that's what the "2x" option should be there for). I want to retain the 2160p (pixel height). The 3840 x 1600 is not as sharp and detailed. Version 3.0.0.x of this software should remain consistent with previous versions as I noted. What's the point to having a "2x" option and "4K" option for upscaling if both do exactly the same thing as the other? I realize there may be some instances where sameness between the two would exist, but I am deliberately selecting "4K" or "2x" expecting a higher quality outcome.

raven-au

@Mandalorian1 I do think that the current HDR conversion produces softer output in some cases (I don't know why, and I don't know why it doesn't appear to be uniform, at least for me) and based on this discussion it might well be independent of resolution.

Mandalorian1

@Mandalorian1 I do think that the current HDR conversion produces softer output in some cases (I don't know why, and I don't know why it doesn't appear to be uniform, at least for me) and based on this discussion it might well be independent of resolution.
raven-au

That's a good point and I agree. There's likely a number of other influencing factors. Just purchased a Topaz license and am learning that there are a variety of elements associated with upscaling (including the model and other associated parameters used) that could influence the quality of the output.