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

[Sledgehamma]

Originally Posted by Stacey Spears

Thank you for posting. We mentioned Geoff in the stream. We also pointed out the ADL changes, which came from feedback here.

Watched the whole thing. Very informative and insightful! Your disc has that many patterns that I’m guessing you could do a 10 hour video and still haven’t covered them all
One question, though: you said that the people working on the Xbox BD player are very passionate. Yet, the Xbox can’t to 24.000 output :/ Is this a hardware limitation?
Just to add to the streaming discussion at the beginning:
Apple TV has the highest Bitrate for mainstreaming streaming, averaging about 25 Mbit.
Amazon usually has 15 Mbit or lower, but for their LOTR series they used 20 Mbit.
Bravia core actually peaks over 100mbit

[Wendell R. Breland]

Originally Posted by Sledgehamma

Apple TV has the highest Bitrate for mainstreaming streaming, averaging about 25 Mbit.

For UHD-SDR Apple bit rates are a fair amount lower as measured via my ATV4K (2nd Gen). Using a Sony VW600 UHD projector which is 8 bit. Interesting in Movies Anywhere does 25 Mbps for the same content.

[Show spoiler]

[Sledgehamma]

Thanks for pointing that out!
I was talking about DV content and also only talking about TV shows. Not sure whether it would be different for movies.

[Stacey Spears]

Spent some time looking into the ATV YCbCr levels. Turns out, RGB is also incorrect, but in a different way. Bottom line, neither are correct.

I plan to share the full results of our YCbCr and RGB Monotonicity played through ATV to someone who can then publish them.

[Stacey Spears]

Originally Posted by Sledgehamma

Watched the whole thing. Very informative and insightful! Your disc has that many patterns that I’m guessing you could do a 10 hour video and still haven’t covered them all
One question, though: you said that the people working on the Xbox BD player are very passionate. Yet, the Xbox can’t to 24.000 output :/ Is this a hardware limitation?
Just to add to the streaming discussion at the beginning:
Apple TV has the highest Bitrate for mainstreaming streaming, averaging about 25 Mbit.
Amazon usually has 15 Mbit or lower, but for their LOTR series they used 20 Mbit.
Bravia core actually peaks over 100mbit

I have never actually enquired about 24p on Xbox.

The first Xbox One had a HW limitation that prevented true YCbCr output. It had to go through RGB first due to a bug in the AMD GPU used on Xbox One.

[mrtickleuk]

Originally Posted by Geoff D

Two and a half hours?! I literally don’t have the time to watch it (though I did just leave a comment on one of Stacey’s comments ), I hope they said something nice - well, after saying “who the hell is Geoff?” first of all.

I never watch those streams at normal speed, as you say, it's just far too long. 1.2x on YouTube is my minimum, sometimes 1.5x. This one improves massively after 22 minutes.

[EddieLarkin]

It's nice to have some DV test patterns.

Comparing TV-led and player-led, the Panny 820 badly clips black level when my HZ2000 is set to player-led. Even the 2% level bar in Contrast is not visible. Switching back to TV-led, you get blacks back down to 64.

The Sony X700 doesn't have this problem in player-led (the X700 does seem to permanently shave one pixel width from the left of the screen though, was that a known thing?).

[Geoff D]

Originally Posted by EddieLarkin

It's nice to have some DV test patterns.

Comparing TV-led and player-led, the Panny 820 badly clips black level when my HZ2000 is set to player-led. Even the 2% level bar in Contrast is not visible. Switching back to TV-led, you get blacks back down to 64.

The Sony X700 doesn't have this problem in player-led (the X700 does seem to permanently shave one pixel width from the left of the screen though, was that a known thing?).

I can still see the 2% bar in player led on the ZD9, though it's definitely clipping a wee bit of black.

[Naiera]

Originally Posted by Sledgehamma

Apple TV has the highest Bitrate for mainstreaming streaming, averaging about 25 Mbit.

That is not true. The bitrate is completely dependent on which service is used. Netflix is around 10 Mbps for 4K SDR. Apple TV+, the best one, is about 20. Hulu has 4K in both 10 and 15 Mbps. Etc.

[INdetectableMAN]

However, AppleTV+ does not have the Netflix digital library hosted on its servers, therefore it does not have to transmit through its channels the amount of content that NETFLIX does, and that is something that will probably allow it to move bit rates higher. In the end everything is money and optimization of resources.

Regarding the black levels, and please correct me if I'm wrong, in DV using black clipping patterns I have always observed a sharp jump in black at about 1.8%, something that if you try to improve, using tools such as the detail in shadow of Calman, because you end up raising blacks in some critical sequences and fading to black, therefore, it is a very critical factor and adjustment, which I am not very much in favor of doing for this reason.

Also, it doesn't make a lot of sense to create a 1D LUT with a measuring device, only to end up it by eye.

What I mean is that adjusting the details near black with Calman in Dolby Vision is quite difficult to do without making the situation worse.

I also don't think there are shadow detail problems if in the black clipping pattern you are able to see between 1.8 and 1.6% with a magnifying glass. It seems that everything works differently with Dolby.

With DV everything is problems. We have already seen the explanations given regarding the DV 2.9 profile where the bluray is stuck, and whatever you do you will always end up with a darker image because of the high nit random pixels, which will cause the tone mapping to darken the image. .

That is, you can have perfect EOTF tracking in absolute mode, and still end up with a slightly darker image because of DV 2.9, since the metric algorithm is designed to work images that way. Add to that that probably in OOTB the scenario is still worse because of the Dolby predetermined configuration file.

However, it is correct because it is the intention of the creators. Congratulations Dolby on the great job you have done with Dolby Vision UHD Bluray

My order is stuck in Spanish customs.

[Sledgehamma]

Originally Posted by Naiera

That is not true. The bitrate is completely dependent on which service is used. Netflix is around 10 Mbps for 4K SDR. Apple TV+, the best one, is about 20. Hulu has 4K in both 10 and 15 Mbps. Etc.

With “Apple TV” I meant Apple TV+

[mrtickleuk]

Originally Posted by EddieLarkin

It's nice to have some DV test patterns.

Comparing TV-led and player-led, the Panny 820 badly clips black level when my HZ2000 is set to player-led. Even the 2% level bar in Contrast is not visible.

Ok, but you wouldn't ever deliberately choose player-led anyway, since it's inferior. Player-led is a last resort. Note that it's the TV, not the player, doing that clipping (see below).

Switching back to TV-led, you get blacks back down to 64.

Cool. But note that the TV is in a different mode internally for TV-led vs player-led, since it's a different signal, even though both will say "dolby vision" to the user.

[Stacey Spears]

In player-led, the player does the full decode and sends HDR12 to the display. (YCbCr 12 flagged as YCbCr 12-bit). In this scenario the image is tone mapped twice. Once by the player and again by the display. The display reports its nit capability through the EDID. The player sends in something a bit higher than the target since it knows it gets tone mapped again.

In tv-led, the DV metadata is inserted into the Cb channel (possibly Cr too) of the image. YCbCr 12-bit is flagged as RGB24 to pass through an AVR unscathed since RGB24 is the ONLY required format of HDMI. The display then does the DV processing and the image is tone mapped once. Dolby calls this mode tunneled.

In theory, they should be identical. In practice, due to a bug, they are not.

[Stacey Spears]

Originally Posted by INdetectableMAN

Also, it doesn't make a lot of sense to create a 1D LUT with a measuring device, only to end up it by eye.

What I mean is that adjusting the details near black with Calman in Dolby Vision is quite difficult to do without making the situation worse.

I also don't think there are shadow detail problems if in the black clipping pattern you are able to see between 1.8 and 1.6% with a magnifying glass. It seems that everything works differently with Dolby.

There is absolutely a problem with shadow detail due to the bottom and second to bottom/last readings Calman does. Too large of a gap between the two points. Most people don't own a meter that can measure accurately down low, so they created the manual step to fix it by using a loupe and our DR Low pattern. Works very well. You need to make several readings between those two points and if you don't own a CR meter, or Klein K10, you are not going to get accurate results.

The person who calibrates the Netflix displays adjusts shadow detail in Calman on all of them. He actually does a lot of post houses in So. Cal.

I would like to see Calman offer more points in that range to not have to do this. As I said, you would need the proper colorimeter to actually measure it with enough accuracy.

[EddieLarkin]

Originally Posted by mrtickleuk

Ok, but you wouldn't ever deliberately choose player-led anyway, since it's inferior. Player-led is a last resort.

You would if TV-led DV is broken, which it most certainly is on the HZ2000. There is a thread about it here: https://www.avforums.com/threads/is-...oleds.2364299/

Frames are constantly dropped, and fast cutting content is impossible to endure. The only way to get it to stop is disable 24p on the player and watch everything 3:2'd to 60hz, or switch to player-led.

Originally Posted by mrtickleuk

Note that it's the TV, not the player, doing that clipping (see below). Cool. But note that the TV is in a different mode internally for TV-led vs player-led, since it's a different signal, even though both will say "dolby vision" to the user.

Can you explain why the issue isn't present in player-led via the X700 then?

[Stacey Spears]

Originally Posted by EddieLarkin

Can you explain why the issue isn't present in player-led via the X700 then?

Mike will have to comment since I am not familiar with this particular issue, but it is a different path in the display and possibly a different memory. Maybe even a different baseline settings in the service menu?

I still have not had an opportunity to check out the chroma weight issue with the C3/G3 either that was mentioned earlier.

Dolby just ordered 12 copies of the disc to use internally.

[Stacey Spears]

Besides the interviews with various press, we are planning to post our own interviews with various people involved with the creation of the disc. We don't have a timeline yet, but I hope to start them this summer.

1. Audio - We will have Marc Fishman and Roger Dressler to discuss the audio side of things. If you have anything specific you would like covered around Atmos, please let me know. We also have someone from DTS for a separate discussion. Roger worked at Dolby for many, many years.

2. Montage grade - We will have Shane, the colorist, to go through the grade. We may discuss shot by shot, I am not sure how deep to go yet.

3. Peak Luminance and PCA. We will do another with two more folks from Dolby to discuss the Peak Luminance and PCA tests. Timo and Scott are the author of the paper that Peak Luminance is based on.

4. Skin Tone - We will have Phil Holland on to discuss the skin tone shoot since he was the director and DP of the shoot.

5. We will have Brandon and Bill from Colorfront on to discuss the custom pipeline Bill created for the montage to work around issues with Resolve. For those that don't know Bill, he co-founded E-Film and is now the CTO of Colorfront. Transkoder was also used to create the various versions of the skin tone content.

6. If David is up for it, I would like to spend more time with him going over the authoring.

If you have questions you would like asked of the various people, please let me know. The bugs / implementation issues with DV won't be covered since that is a different group. Timo and Scott are two of the creators of DV, but the issues are with a different team. There is a team dedicated to playback devices such as TVs is where the issues live. There is another team that is the pro team that creates the tools to used to create the content, which is what was used to master the content and create the 2000, 1000 and 600 versions.

[DisplayCalNoob]

Originally Posted by Stacey Spears

Besides the interviews with various press, we are planning to post our own interviews with various people involved with the creation of the disc. We don't have a timeline yet, but I hope to start them this summer.

1. Audio - We will have Marc Fishman and Roger Dressler to discuss the audio side of things. If you have anything specific you would like covered around Atmos, please let me know. We also have someone from DTS for a separate discussion. Roger worked at Dolby for many, many years.

2. Montage grade - We will have Shane, the colorist, to go through the grade. We may discuss shot by shot, I am not sure how deep to go yet.

3. Peak Luminance and PCA. We will do another with two more folks from Dolby to discuss the Peak Luminance and PCA tests. Timo and Scott are the author of the paper that Peak Luminance is based on.

4. Skin Tone - We will have Phil Holland on to discuss the skin tone shoot since he was the director and DP of the shoot.

5. We will have Brandon and Bill from Colorfront on to discuss the custom pipeline Bill created for the montage to work around issues with Resolve. For those that don't know Bill, he co-founded E-Film and is now the CTO of Colorfront. Transkoder was also used to create the various versions of the skin tone content.

6. If David is up for it, I would like to spend more time with him going over the authoring.

If you have questions you would like asked of the various people, please let me know. The bugs / implementation issues with DV won't be covered since that is a different group. Timo and Scott are two of the creators of DV, but the issues are with a different team. There is a team dedicated to playback devices such as TVs is where the issues live. There is another team that is the pro team that creates the tools to used to create the content, which is what was used to master the content and create the 2000, 1000 and 600 versions.

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?

[RocShemp]

For some reason, the test tones only produce sound for about three seconds each channel. The panning sounds fine. It's the individual test tones (bed and overhead layer) that have this issue. Anyone else experience this odd quirk?

[Stacey Spears]

Originally Posted by RocShemp

For some reason, the test tones only produce sound for about three seconds each channel. The panning sounds fine. It's the individual test tones (bed and overhead layer) that have this issue. Anyone else experience this odd quirk?

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.