Spears & Munsil 4K UHD HDR Benchmark (Test Discs) May 15, 2023

[Stacey Spears]

Originally Posted by DisplayCalNoob

Can you ask them, if they have done testing on lip-sync issues related to DV playback? Is it processing, is it disc authoring tools?

I have never asked them how many ms it takes to process a frame. I will ask them and see if I can get an answer.

Are you experiencing A/V sync issues with DV?

Anything processing that takes longer than the time they have to present in milliseconds (ms) will introduce delay in the video. Any video processing algorithm can do this if not fast enough.

[Stacey Spears]

We have not posted it on the website yet, so here is a link to the PCA spreadsheet that is designed to be used with the pattern set.

https://www.dropbox.com/s/rxkgd1vp1y78itd/PCA.xlsx?dl=1

Here is the pop-up help text that goes with it.

---

This set of patterns is designed for measuring “Backlight Resolution,” a term that refers to the overall ability of a display to hold black levels in one area of the screen while displaying bright objects in another area of the screen.

Any display with area backlighting or edge lighting (mostly LCD displays) will have difficulty keeping contrast high in one part of the screen when a very bright object is displayed in another part, and the effect varies relative to the bright object’s distance from the measurement location.

The patterns show a series of rings, getting further and further from the center of the screen. The total bright area of each ring is constant, thus keeping the total picture level constant. By measuring the black level in the center of the screen on successive patterns, we can get a picture of how nearby bright picture elements affect the black area in the center of the screen.

The measurement unit for Backlight Resolution is Perceptual Contrast Area (PCA). It’s represented by a number from 1 to 2048, with higher numbers being better. The measurement is a rough approximation of the number of just-noticeable gray steps the display can theoretically produce simultaneously on screen from black to white. Normal consumer displays commonly measure in the neighborhood of 1250-1550.

To perform the measurement, point a light meter at the center of the screen. If needed, use a narrow tube or other baffle between the meter and the screen to minimize reflected light, but don’t let the baffle touch the screen. Set the meter to cd/m² (nits). First measure the White Luminance (Lw) value using the “On” pattern. Then measure 9 different Black Luminance (Lk1, Lk2, … Lk9) values, using the 9 different “Off” versions of the pattern. Make sure your meter is properly centered and you’re only measuring the black area in the center of the screen.

Plug the Lw and the 9 different Lk numbers into the spreadsheet available on https://spearsandmunsil.com/ to calculate a final PCA number.

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[Wendell R. Breland]

Disclaimer - I be a projector kind of guy so mostly sit on the DV sidelines.

Below is some DV test via media players. IIRC the captures were done with a Blackmagic Design card similar to the Intensity Pro 4K and Resolve is the software used.

A few months ago I asked the folks at drastic technologies and they recommended the Decklink 4K Extreme 12G capture card for full on capture. Available here for about $1K.

[Show spoiler]

ENG voiceover. The truth about Dolby Vision on media players. Inside TV-LED and RGB tunneling. - YouTube

[RocShemp]

Originally Posted by Stacey Spears

Which player do you have? The tones are one minute each and loop, so they should stay until you press the left or right arrows.

I used the disc on my Panasonic DP-UB820 player.

[Stacey Spears]

Originally Posted by RocShemp

I used the disc on my Panasonic DP-UB820 player.

I use a 9000, which is the same chipset, so it works fine on that player.

Any chance you are pressing the right arrow by mistake?

[RocShemp]

Originally Posted by Stacey Spears

I use a 9000, which is the same chipset, so it works fine on that player.

Any chance you are pressing the right arrow by mistake?

Nope. I just let it play and hear nothing after 3 seconds. The wave graphic keeps playing onscreen but the audio from any given speaker is cut off.

I decided to try the disc on my LG UBKM9 and had the same issue.

EDIT: Whatever it is, it seems to be an eARC quirk with my LG C2. If I set the Digital Sound Output to "Pass Through" (where I read it's recommended to be to pass lossless Dolby audio to my AVR) or "Auto", the audio cuts out. If I set it to PCM, the audio plays on a constant loop but the surrounds are heard on their relative front speakers.

Chalk it up to another reason for me to get a new AVR, so I can hook my players to it instead of to my TV.

[Stacey Spears]

Originally Posted by RocShemp

Nope. I just let it play and hear nothing after 3 seconds. The wave graphic keeps playing onscreen but the audio from any given speaker is cut off.

I decided to try the disc on my LG UBKM9 and had the same issue.

EDIT: Whatever it is, it seems to be an eARC quirk with my LG C2. If I set the Digital Sound Output to "Pass Through" (where I read it's recommended to be to pass lossless Dolby audio to my AVR) or "Auto", the audio cuts out. If I set it to PCM, the audio plays on a constant loop but the surrounds are heard on their relative front speakers.

Chalk it up to another reason for me to get a new AVR, so I can hook my players to it instead of to my TV.

Which AVR are you using? What if you send audio straight to the AVR and not use eARC? The 9000 has dual HDMI outputs, one for audio, does the 820?

[RocShemp]

Originally Posted by Stacey Spears

Which AVR are you using? What if you send audio straight to the AVR and not use eARC? The 9000 has dual HDMI outputs, one for audio, does the 820?

After my Onkyo TX-NR5010 died and I could find no one in PR to fix it, due to scarcity of replacement parts that occurred after Onkyo ended all authorized repairs here some time ago, I found and cleaned a junked Denon AVR-S700W I found at work (which is now showing signs of its last days in the form of an audible buzz somewhere inside the AVR).

Yeah, the 820 has a separate audio only HDMI out. Never got around to using it.

[LordoftheRings]

The Blu-ray test disc I use to fix the picture on 4K TVs just got bigger and better - By Al Griffin

[TbeRw01]

Originally Posted by Stacey Spears

so it works fine on that player.

Hey,
why some players like the Panasonic UB820 and Zidoo/Dune are sending a BT2020 flag with the TV-LED RGB DV signal? They do that even for Profile 5 content.

while ALL these players send DV TV-LED without any BT2020 flag:
Sony X700, X800m2, Oppo bluray, LG bluray, Nvidia Shield, FireTV stick, Chromecast, AppleTV.

Comparing both, TV-LED with a bt2020 flag seem to produce slightly worse colors.

More info on the signal differences:

[Stacey Spears]

The players not sending the flag, at least X700, X800m2, OPPO nad LG are all based on MediaTek while the 820 uses a different decoder. It could be the reason.

OPPO DV levels can change, so you have to be careful with it while the Sony 800 MK2 seems stable in that deparment.

[Sledgehamma]

Originally Posted by TbeRw01

Hey,
why some players like the Panasonic UB820 and Zidoo/Dune are sending a BT2020 flag with the TV-LED RGB DV signal? They do that even for Profile 5 content.

The profile does not matter in this regard as TV led DV is just the delivery method (or do you mention profile 5 because of its ICtCp color space?). Afaik the flag does not matter for the DV processing in the display, either.

[Stacey Spears]

TV-LED uses the metadata in the RPU, not the HEVC bitstream, for its processing. Or should.

[DMDreview]

All TV boxes with DV playback support, such as amazon fire tv stick, Dune real vision, Zappiti neo, Zidoo, work only in LLDV mode, their TV-LED is fake, it is LLDV but inside an RGB tunnel. Only the Shield tv pro 2019 can work in two versions of DV, as LLDV and as tv-led.
Oppo also honestly knows how to output as tv-led

[Stacey Spears]

Originally Posted by DMDreview

All TV boxes with DV playback support, such as amazon fire tv stick, Dune real vision, Zappiti neo, Zidoo, work only in LLDV mode, their TV-LED is fake, it is LLDV but inside an RGB tunnel. Only the Shield tv pro 2019 can work in two versions of DV, as LLDV and as tv-led.
Oppo also honestly knows how to output as tv-led

TV-led lead is officially known as tunneled by Dolby. How are those devices different? TV-led is 12-bit 4:2:2 flagged as RGB24 with metadata embedded in the chroma channels.

[TbeRw01]

Originally Posted by DMDreview

All TV boxes with DV playback support, such as amazon fire tv stick, Dune real vision, Zappiti neo, Zidoo, work only in LLDV mode, their TV-LED is fake, it is LLDV but inside an RGB tunnel. Only the Shield tv pro 2019 can work in two versions of DV, as LLDV and as tv-led.
Oppo also honestly knows how to output as tv-led

You probably should have posted the youtube video explaining your point otherwise I doubt anyone will understand what you meant.

ENG voiceover. The truth about Dolby Vision on android tv box. Inside TV-LED and RGB tunneling. - YouTube

[DMDreview]

Originally Posted by Stacey Spears

TV-led lead is officially known as tunneled by Dolby. How are those devices different? TV-led is 12-bit 4:2:2 flagged as RGB24 with metadata embedded in the chroma channels.

To understand what I mean, it is easier to watch my video about tv-led, you can see what is inside the rgb tunnel, it shows the difference more clearly. the link to it posted above.

By the way, thanks for your Spears & Munsil Benchmark videos, they were very helpful in the tests

[mrtickleuk]

Originally Posted by DMDreview

To understand it is easier to watch my video about tv-led, you can see what is inside the rgb tunnel, it shows more clearly the difference. the link to it post above.

Wow! I'm sure that Stacey is very grateful that you've taken the time and trouble to kindly teach him about Dolby Vision.

[Stacey Spears]

Originally Posted by TbeRw01

You probably should have posted the youtube video explaining your point otherwise I doubt anyone will understand what you meant.

ENG voiceover. The truth about Dolby Vision on android tv box. Inside TV-LED and RGB tunneling. - YouTube

Thank you for sharing. I have forwarded the video to the vision scientists at Dolby to get their opinion. I am not sure if they will share their thoughts with me. I don't use any of those devices myself.

I am also planning to send my ATV measurements of YCbCr and RGB to Vincent in hopes he will follow-up and possibly report on the issue. Apple actually listens to Vincent. Every CE company has someone who influences them. e.g. Vizio will do what every David K. says at CNET. At least they used to, have not spoken to Vizio in a while.

[Wendell R. Breland]

Originally Posted by TbeRw01

Comparing both, TV-LED with a bt2020 flag seem to produce slightly worse colors.

More info on the signal differences:

I would like to know what software you used to generate that info. I know how to capture HDMI to a PC but have not sprung for the Blackmagic Design DeckLink 4K Extreme 12G. Do have the other HDMI device needed for capture.