AVI (UT Video) files and limited-full range - problem

rgr wrote on 5/5/2025, 1:09 PM

I'm trying to render a video in xvyCC format and I'm having trouble.

According to the instructions, you have to set "32-bit floating point (video levels)" and that's what I do. I import the mts file from the camera and since it has a Y range of 16-255, I turn on the Brightness filter and lower the luminance. The luminance is within the range, and the chrominance sometimes exceeds the range. That's how it should be.

The problem starts when I want to load an AVI file (encoded UT Video). It's the same mts file, only with improved quality and adjusted Y to 16-235 range. As you can see on its histogram, the luminance is in the limited range.

 

However, after importing to Vegas on waveform I see that it is way out of range.
And here's the question -- why is this happening and what to do about it?

 

 

 

 

Comments

rgr wrote on 5/5/2025, 2:05 PM

File attached. https://files.fm/u/ca5q89zccj

RogerS wrote on 5/5/2025, 10:01 PM

Are the scopes set to studio levels?

RogerS wrote on 5/5/2025, 10:29 PM

Installing UT codecs and then opening the file in VEGAS it appears to be full range or 16-255 (looks like some values below 16 when the runner enters the scene).

Personally I used a levels filter to bring everything into full range (so I can see what I'm doing for editing) and then added a levels Fx on the output/preview Fx back to 16-235 before rendering.

These days I let VEGAS do it automatically using either 8-bit full or 32-bit full mode (view transform off). The 32-bit mode is helpful for when you have 10-bit+ footage and do log-REC709 conversions.

Last changed by RogerS on 5/5/2025, 10:33 PM, changed a total of 1 times.

Custom PC (2022) Intel i5-13600K with UHD 770 iGPU with latest driver, MSI z690 Tomahawk motherboard, 64GB Corsair DDR5 5200 ram, NVIDIA 2080 Super (8GB) with latest studio driver, 2TB Hynix P41 SSD and 2TB Samsung 980 Pro cache drive, Windows 11 Pro 64 bit https://pcpartpicker.com/b/rZ9NnQ

ASUS Zenbook Pro 14 Intel i9-13900H with Intel graphics iGPU with latest ASUS driver, NVIDIA 4060 (8GB) with latest studio driver, 48GB system ram, Windows 11 Home, 1TB Samsung SSD.

VEGAS Pro 21.208
VEGAS Pro 22.239

Try the
VEGAS 4K "sample project" benchmark (works with VP 16+): https://forms.gle/ypyrrbUghEiaf2aC7
VEGAS Pro 20 "Ad" benchmark (works with VP 20+): https://forms.gle/eErJTR87K2bbJc4Q7

RogerS wrote on 5/5/2025, 10:44 PM

Reading about this format, https://en.wikipedia.org/wiki/XvYCC https://www.vegascreativesoftware.info/us/forum/x-v-color-and-the-future--78777/ I'm not sure any of this is possible to edit in VEGAS (color adjusments to keep luminance to 16-235 while chroma goes from 0-255).

Help just says

32-bit floating point (video levels) is recommended when working with 10-bit YUV input/output or when using xvYCC/x.v.Color media.

Does your display support such color modes?