V-Log clip render output looks different to preview

Andrew-Stevenson wrote on 6/7/2024, 11:00 AM

Hi,

I have a Panasonic HC-X2 which I normally use in Cinema mode with no issues. However I am learning how to use V-Log profile and have some problems - possibly caused by my own ignorance of HDR10 and HLG work-flows.

I imported a clip and used the Track Colour Grading function to quickly dial in reasonable looking colours. However when I render the clip it doesn't look the same as that I see in the Preview window.

Wen I play the rendered video in Media Player the video is darker than Vegas preview. When I play the same clip in VLC the video is lighter than Vegas preview.

Are the settings I have chosen correct for Vegas?

Why do the video players render the same clip differently?

When the video is being rendered, why does the preview window change to P3D65 ST2084 (1000 nits)?

 

Windows 11.

Vegas 21(Build 315).

Monitor: MSI 321UP DsplayHDR 600 DCI-P3 (95%)

Video card: NVIDIA GeForce RTX 3060

 

Project Settings:

HDR Mode: Off

Pixel format: 32 but floating point (full range)

Compositing gamma: 2.222 (Video)

ACES version: 1.2

ACES color space: Default (ACES2065-1)

View transform: P3D65 (ACES)

 

Preview window states it is using P3D65 (ACES). Changes to 'P3D65 ST2084 (1000 nits)' when rendering, then reverts back.

 

Render Profile:

HDR10 UHD 2160p 50fps (Mainconcept HEVC)

 

General
Complete name                            : C:\Users\Andrew\Videos\VLog Test\A061C001_240602_S2WK.MOV
Format                                   : MPEG-4
Format profile                           : QuickTime
Codec ID                                 : qt   2011.07 (qt  /pana)
File size                                : 779 MiB
Duration                                 : 33 s 600 ms
Overall bit rate                         : 195 Mb/s
Frame rate                               : 50.000 FPS
Encoded date                             : 2024-06-02 17:01:46 UTC
Tagged date                              : 2024-06-02 17:01:46 UTC
com.panasonic.Semi-Pro.metadata.xml      : <?xml version="1.0" encoding="UTF-8" standalone="no" ?> / <ClipMain xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:schemas-Professional-Plug-in:Semi-Pro:ClipMetadata:v1.0"> /   <ClipContent> /     <GlobalClipID>060A2B340101010501010D4313000000705266AF630406ED0000000000000000</GlobalClipID> /     <Duration>1680</Duration> /     <EditUnit>1/50</EditUnit> /     <EssenceList> /       <Video> /         <Codec BitRate="200">H265_420_LongGOP</Codec> /         <ActiveLine>2160</ActiveLine> /         <ActivePixel>3840</ActivePixel> /         <BitDepth>10</BitDepth> /         <FrameRate>50p</FrameRate> /         <TimecodeType>NonDrop</TimecodeType> /         <StartTimecode>09:07:32:04</StartTimecode> /         <EndTimecode>09:08:05:18</EndTimecode> /         <StartBinaryGroup>00000000</StartBinaryGroup> /       </Video> /       <Audio> /         <Channel>2</Channel> /         <SamplingRate>48000</SamplingRate> /         <BitsPerSample>24</BitsPerSample> /       </Audio> /     </EssenceList> /     <ClipMetadata> /       <UserClipName>A061C001_240602_S2WK</UserClipName> /       <DataSource>SHOOTING</DataSource> /       <Access> /         <CreationDate>2024-06-02T17:01:46+00:00</CreationDate> /         <LastUpdateDate>2024-06-02T17:02:20+00:00</LastUpdateDate> /       </Access> /       <Device> /         <Manufacturer>Panasonic</Manufacturer> /         <SerialNo.>WP2SA002913</SerialNo.> /         <ModelName>HC-X2</ModelName> /       </Device> /       <Shoot> /         <StartDate>2024-06-02T17:01:46+00:00</StartDate> /         <EndDate>2024-06-02T17:02:20+00:00</EndDate> /       </Shoot> /     </ClipMetadata> /   </ClipContent> /   <UserArea> /     <AcquisitionMetadata xmlns="urn:schemas-Professional-Plug-in:P2:CameraMetadata:v1.2"> /       <CameraUnitMetadata> /         <Gamma> /           <CaptureGamma>V-Log</CaptureGamma> /         </Gamma> /         <Gamut> /           <CaptureGamut>V-Gamut</CaptureGamut> /         </Gamut> /       </CameraUnitMetadata> /     </AcquisitionMetadata> /   </UserArea> / </ClipMain>

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5.2@High
Codec ID                                 : hvc1
Codec ID/Info                            : High Efficiency Video Coding
Duration                                 : 33 s 600 ms
Bit rate                                 : 192 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 50.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.464
Stream size                              : 770 MiB (99%)
Language                                 : English
Encoded date                             : 2024-06-02 17:01:46 UTC
Tagged date                              : 2024-06-02 17:01:46 UTC
Color range                              : Full
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709
Codec configuration box                  : hvcC

Audio
ID                                       : 2
Format                                   : PCM
Format settings                          : Big / Signed
Codec ID                                 : lpcm
Duration                                 : 33 s 600 ms
Bit rate mode                            : Constant
Bit rate                                 : 2 304 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 kHz
Bit depth                                : 24 bits
Stream size                              : 9.23 MiB (1%)
Language                                 : English
Encoded date                             : 2024-06-02 17:01:46 UTC
Tagged date                              : 2024-06-02 17:01:46 UTC

Other
ID                                       : 3
Type                                     : Time code
Format                                   : QuickTime TC
Duration                                 : 33 s 600 ms
Bit rate mode                            : Constant
Frame rate                               : 50.000 FPS
Time code of first frame                 : 09:07:32:08
Time code of last frame                  : 09:08:05:37
Time code, stripped                      : No
Title                                    : A061
Language                                 : English
Encoded date                             : 2024-06-02 17:01:46 UTC
Tagged date                              : 2024-06-02 17:01:46 UTC

Comments

Howard-Vigorita wrote on 6/7/2024, 12:57 PM

When you use Vegas in either one of the full-range modes, the preview is in full-range too. When you render it, however, Vegas defaults to limited-range in its render presets. VLC displays those renders the way the metadata tells it to... which is limited range and looks different from the full-range preview. I don't know if there's a way to get VLC to display a limited-range clip in full range.

One workaround is to tell Vegas to render full-range which should make the VLC display of the render match the Vegas preview. That's done in Vegas on the render preset's "Customize Template/Project" tab.

A 2nd workaround is to let the render remain default limited-range but use a viewer app that can be told to employ a limited to full-range view transform. When my render target is going to be YouTube, I view with MPC-HC which has a Shader setting (16-235 to 0-255) for limited-range viewing which replicates YouTube upload processing. That way my Vegas preview, MPC-HC view, and YouTube upload all look the same.

Andrew-Stevenson wrote on 6/7/2024, 3:26 PM

Thanks for the reply.

I did not know about the 'Color space' and 'Color range' settings in the 'Custom Settings' 'Project' tab.

The preview is saying 'Rec. 2020 HLG 1000 nits (ACES)' so I tried rendering with the following:

1) Color space: Rec. 2020 ST2084 (1000 nits)

Color range: Full

2) Color space: Rec. 2020 ST2084 (1000 nits)

Color range: Limited

Neither setting gets close to how the video looks in preview but full is further out than limited. Am I wrong to think setting the preview and render settings to the same colour space would render an accurate reproduction?

I've done a lot of reading around using V-Log and HLG and understand the theory but can't translate that into the correct settings for Vegas.

The manual states "VEGAS provides the simplest workflow in mastering HDR10 or HLG content. VEGAS supports HDR preview when in HDR mode, if the system connected to an HDR monitor and the graphics card supports HDR output. NOTE VEGAS HDR preview is based on HDR10 format. HLG format in preview is not supported yet (why does preview window say HLG then?)."

I have tried HLG and HDR10 with clips in HLG and V-Log and cannot find the magic formula for rendering what I see in preview. Is this just not possible in Vegas? When using SDR, it's never been a problem rendering what I see in preview...

Howard-Vigorita wrote on 6/7/2024, 3:59 PM

Sorry, didn't realize you were using Aces. Don't use that myself so my recommendations may not apply. Fwiw, I didn't think you were supposed to change Compositing Gama for Aces but someone who uses Aces here would be more up on that than myself.

fr0sty wrote on 6/7/2024, 4:01 PM

If you want to render HDR, it is best to start with VLOG, so you're on the right path. However, you don't have your project configured properly. Follow these steps:

1. First, you need an HDR compatible display, preferably a secondary monitor so you can see it full screen. You don't want a cheap one, either, as many cheaper HDR displays do not hit the 1000 nits (750 nits for OLED as they hit purer color and deeper blacks) required for true HDR. I recommend a good OLED TV, or professional grade HDR monitor that you then calibrate using a device like a Datacolor Spyder X.

2. From here, make sure Windows has HDR mode enabled on that monitor. Open display settings, select the correct monitor in display settings, then enable windows HDR mode from there.

3. Now you're ready to go into VEGAS. Start a new project with your resolution set where you want it (likely UHD 4K) and the frame rate where you want it, and enable HDR10 mode. Windows doesn't support HLG output at this time, so I use HDR10 primarily. It's better anyway, from a technical standpoint. I also sometimes will enable the "enable blue light fix" under look modification, if I'm editing an event where blue LED lights are used. It helps keep them from washing out.

4. Once you have your project created, import your media, and then right click on it. Go into properties, and set the color space to "VLOG-VGamut" (make sure it's that and not one of the other VLOG options).

5. Now enable full screen preview on your HDR monitor. You can verify it is working by going into display settings (right click on the preview monitor in VEGAS to access them) and make sure the "enable HDR output" check box is checked.

At this point, you're ready to open the color grading panel and do some adjustments.

Unfortunately, HDR mode is currently kinda broken in VEGAS, you can only adjust saturation, levels, exposure, and curves so much before you start to see strange artifacts and over-exposing of the color... but if you don't push it too hard, you can still get a decent looking HDR output. I'm currently bugging the hell out of the team to get that fixed, because I too produce a lot of HDR content, and it's been a thorn in my side for some time now.

When making adjustments in the color grading panel to levels, exposure, or saturation, go very easy, hold CRTL while making adjustments to not push it too far, and back off if you start seeing artifacts. I usually start with a slight boost to exposure (and I mean VERY slight), then use color curves and just a touch of saturation boost from there.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

Andrew-Stevenson wrote on 6/7/2024, 6:10 PM

Thanks for the steps, I've made much progress! The HDR preview is now working and I can render a video and the colours now look the same in the preview window and in VLC.

I have a couple of small follow up questions I hope you can help me with, if it helps I summarised my changes beneath the questions.

Q1: When I click on the 'HDR' button above the preview window, the video within ceases being constrained to the aspect ratio of the clip and leaps to fill the full preview window distorting the aspect ratio unless I resize the window to match. Is this a bug, or is there another setting I need to change to keep the aspect ratio? I am viewing with the preview window docked in Vegas (don't have another separate HDR monitor just for full screen playback).

Q2: I notice when setting the color space for the input and output transforms there is a 'color range' option with 'limited' and 'full'. How should this be used? In the context of the render project tab, is 'limited' for when outputting constrained to the display referred colour space and 'full' for when outputting the scene referred full floating point ACES 2065-1?

Q3: What does the color range setting do in the context of the media properties (presumably this is the input transform to go from display referred to scene referred)?

Q4: Acknowledged that I am currently using a consumer level monitor that only goes up to 600 nits. I can confused as to whether the Rec.2020 ST2084 1000 nits setting is the best to use. Since the monitor states 95% DCI-P3 which is a lower gamut, should I be choosing a 'View transform' something like P3-D65 ST2048 1000 nits instead?

To fix the previous issues I now have the following settings:

HDR in Windows 11 was turned off. After turning it on I needed to restart Vegas to make the 'Enable HDR' checkbox appear in the 'Preview Device' tab. I started a new project with properties:

HDR Mode: HDR10

Pixel format: 32-bit floating point (full range)

Compositing gamma: 1.000 (Linear)

ACES version: 1.2

ACES color space: ACEScct

View transform: Rec.2020 ST2084 1000 nits (ACES)

I imported the clip and set it to:

Color space: Panasonic - V-Log - V-Gamut

Color range: Undefined

I clicked on the 'HDR' button above the preview window so it turned blue. That video in the window transformed into something that looked HDR instead of washed out SDR.

I rendered the timeline using

HDR10 UHD 2160p 50fps (NVENC)

Color space: Rec 2020 ST2084 (1000 nits)

Color range (YCbCr output): Limited (default).

 

fr0sty wrote on 6/7/2024, 7:56 PM

1. Another of the bugs I've been bugging the team to fix... HDR in VEGAS works, but it needs a lot of work.

2. You want full range all the way through. Make sure even your camera is set to record full range if there is an option.

3. Color range specifies if it is using 0-1023 levels for 10 bit video, or 0-255 for 8 bit. With 8 bit video, most levels are set to limited (16-235), and most players expect this, so in order to keep consistent levels from one playback device to another, it's recommended to use that... but with HDR, you want full range to get as much of the dynamic range your camera produces as possible.

4. HDR requires the 1k nits transform, so you'll have to just do your best and understand that you're not seeing the video the same as someone with a better screen will. Get a better reference monitor as soon as you can.

As far as your settings go, I typically use default ACES color space, I'm not sure if using ACEScct will have any detrimental effects, so I'd recommend sticking with default. Also, you want full range on render output.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

Andrew-Stevenson wrote on 6/8/2024, 3:22 PM

When you wrote about artifacts in the HDR output, were you talking about slight graduations in colour turning blocky and making very distinct jumps? This is what I see. It's also 4 times slower to render with colour grading.

Also noticed some more bugs in the last 24 hour.

1) After rendering has finished, the HDR preview is turned off and it takes two clicks of the HDR button to turn it back on again.

2) The Vectorscope, Waveform and Histogram views stop working regularly and I have to restart Vegas.

I

fr0sty wrote on 6/8/2024, 11:45 PM

Yeah, something like that... Here's an example of what I notice. Note that this is a photo of my screen taking from my cell phone, so the moire effect is a by product of that, but you can see color noise in the clouds, pixelation... and if you look at the Tennessee on the back of the guy's blue shirt, you'll notice it is clipped to pure white, when it's actually supposed to be blue. Also, the exposure slider is WAY too sensitive, just barely moving it overexposes the image a lot.

Last changed by fr0sty on 6/8/2024, 11:46 PM, changed a total of 1 times.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

Wolfgang S. wrote on 6/9/2024, 3:03 PM

For your v-log footage, use the ACES transformation ACEScc, what is great for log footage. ACEScct is fine too, but adds a „toe“ to encoding. See here: https://blog.frame.io/2019/09/09/guide-to-aces/

I tend to use ACEScc for my v-log footage of my EVA1, especially since the default ACES settings are broken in Vegas today

And yes, if you use for color space „v-log, v-Gamut“ as IDT, the capture referred data are transfered back to scene referred data (what takes out the backed in camera specific color science bias theoretically, and shows you the Colors as they were during the shoot).

The monitor should be calibrated and be able to show 1000 nits, what is the standard for HDR today. But those monitors are still expensive.
 

 

Desktop: PC AMD 3960X, 24x3,8 Mhz * GTX 3080 Ti * Blackmagic Extreme 4K 12G * QNAP Max8 10 Gb Lan * Blackmagic Pocket 6K/6K Pro, EVA1, FS7

Laptop: ProArt Studiobook 16 OLED (ProArt Studiobook 16 OLED (i9 12900H with i-GPU Iris XE, 32 GB Ram. Geforce RTX 3070 TI 8GB) with internal HDR preview on the laptop monitor. Blackmagic Ultrastudio 4K mini

HDR monitor: ProArt Monitor PA32 UCG, Atomos Sumo

fr0sty wrote on 6/10/2024, 1:07 AM

If you can get an OLED monitor that can do 1k or higher nits (not all can), that will be your best bet, as OLED can hit perfect black, unlike LED, LCD, etc. The only better display tech is Mini LED, and those cost tens of thousands of dollars. Just make sure to get a 3 year warranty on it, as I've had two of my OLED displays show dead pixels around the edges of the screen (both LG model, so consider that) within a few years.

Last changed by fr0sty on 6/10/2024, 1:08 AM, changed a total of 1 times.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

mark-y wrote on 6/10/2024, 2:27 PM

The MediaInfo you posted (your camera source?) is neither V-LOG nor HDR. It is generic 10 bit 4:2:0 BT709 Full.

  <Codec BitRate="200">H265_420_LongGOP</Codec> /         <ActiveLine>2160</ActiveLine> /         <ActivePixel>3840</ActivePixel> /         <BitDepth>10</BitDepth> / 

Unfortunately, there is no physical way to upconvert the 709 color space to 2084 HDR. The range of available colors is what it is, and putting that color palette inside a bigger balloon is called "adding air."

Even the latest AI Imaging tech can't do that yet, even with still images; however, some progress has been made for upfilling 8 bit still images to 16 bit float space (Topaz Gigapixel). It's wonderful.

https://www.vegascreativesoftware.info/us/forum/feature-request-ai-bit-depth-expansion-like-topaz-remarkable--144903/

You can see from this CIE image where the 709/sRGB color palette fits inside the larger ACES space you would need for your camera source to comfortably adapt for true HDR10 output.

Regarding your monitor, being able to view a reasonable approximation of your output range, at least 1000 nits for HDR, is certainly an advantage. There is a hidden Windows utility to "fake" the output dynamics of HDR even on a 709/sRGB monitor, which look kinda ok. When you have HDR-worthy camera source and want to send HDR10 to Youtube, encode at 2000 nits, which is their served format.

@Andrew-Stevenson

Howard-Vigorita wrote on 6/10/2024, 3:27 PM

Feature request: SDR to HDR AI Upscale for vp22...

Wolfgang S. wrote on 6/10/2024, 3:56 PM

The MediaInfo you posted (your camera source?) is neither V-LOG nor HDR. It is generic 10 bit 4:2:0 BT709 Full.
 

Not true very likely. Only, because the Panasonic camera does not write the correct metadata in the file does not mean, that it is not v-log v-gamut.

Desktop: PC AMD 3960X, 24x3,8 Mhz * GTX 3080 Ti * Blackmagic Extreme 4K 12G * QNAP Max8 10 Gb Lan * Blackmagic Pocket 6K/6K Pro, EVA1, FS7

Laptop: ProArt Studiobook 16 OLED (ProArt Studiobook 16 OLED (i9 12900H with i-GPU Iris XE, 32 GB Ram. Geforce RTX 3070 TI 8GB) with internal HDR preview on the laptop monitor. Blackmagic Ultrastudio 4K mini

HDR monitor: ProArt Monitor PA32 UCG, Atomos Sumo

fr0sty wrote on 6/10/2024, 6:31 PM

For your v-log footage, use the ACES transformation ACEScc, what is great for log footage. ACEScct is fine too, but adds a „toe“ to encoding. See here: https://blog.frame.io/2019/09/09/guide-to-aces/

I tend to use ACEScc for my v-log footage of my EVA1, especially since the default ACES settings are broken in Vegas today

And yes, if you use for color space „v-log, v-Gamut“ as IDT, the capture referred data are transfered back to scene referred data (what takes out the backed in camera specific color science bias theoretically, and shows you the Colors as they were during the shoot).

The monitor should be calibrated and be able to show 1000 nits, what is the standard for HDR today. But those monitors are still expensive.
 

 

Unfortunately, ACEScc and ACEScct both still exhibit the artifacts I was talking about, but they aren't anywhere near as bad about it. I actually thought I'd got a good render out of it last night, but if you watch until the very end, look at the sunglasses on the guy with the blue "Tennessee" shirt that walks up near the end, you can see the artifacts I'm talking about on his sunglasses.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

mark-y wrote on 6/10/2024, 7:17 PM

Feature request: SDR to HDR AI Upscale for vp22...

Interesting! I wonder how long it takes to render a ten-minute clip.

Howard-Vigorita wrote on 6/11/2024, 9:36 AM

@mark-y Apparently it's implemented as a real-time display converter:

https://www.msi.com/blog/how-to-turn-sdr-content-into-hdr

I get the hdr checkbox if I'm plugged into Nvidia hdmi but it's grayed out because I don't have an hdr monitor. I suppose with all the right hardware one could convert sdr video clips using screen capture. It's also apparently possible to do it manually in Resolve without Nvidia ai which I don't know is any better or worse or if there is a similar Vegas workflow.