Dolby Vision "bt2020"- realtek 1619 bug??

That will be different on each TV. On my Philips, I don't have many settings, I just reduced the saturation till the reds were ok with me.

 

Hi Mark, I can confirm on my LG C1 that this extra BT.2020 flag does affect color reproduction in Dolby Vision. This flag can be found on the C1's HDMI diagnostics screen under AVI Info Frame. I can upload comparison photos later if that will help.

I tested one of Le Labo de Jay's DV demo (Let's talk about HDR - DOLBY VISION iOS) on both the Z9X and C1's internal player. I can't link that here because of the spam filter, but it's easy enough to find on his website.

The difference is very noticeable at 2:04 with the red model car:
- C1 internal player: red looks... red and vibrant
- Z9X TV-led DV: red looks more muted, pink-ish, and unnatural

I don't have any professional camera equipment to capture the difference (I can try later in the day with my iPhone when there's less glare), but given the reports here and from @Reset_9999 on the main ZIDOO Z9X thread, I believe it's a real bug.

I also don't have an HDFury to remove this extra flag. Considering that the Z9X seems to be working as intended otherwise, I was hoping that the devs could address this instead of me having to purchase an HDFury 4K scaler, which costs more than the Z9X itself. Is there any chance you could help raise this with them again? I happen to speak Mandarin as well, so if there's anyone at Zidoo I can directly reach out to, could you let me know?

Thanks!

 

Been talking to the devs about this again and again there is no reason for this flag to make any difference.

As I said previously the colours are defined by primaries in the Dolby Block in the EDID and each TV is different.

The Dolby Block for your C1 decodes like this:

LG C1
EB:01:46: D0:00:48:03:76:82:5E:6D:95
DV Version: 2
DV DM Version: reserved
DV Interface: standard and low latency 422 12bit
2160p60: supported
YUV422 12bit: not supported
Global Dimming: not supported
Backlight Control: not supported, default 100 nits
RED Primary: 0.676, 0.320
GREEN Primary: 0.254, 0.684
BLUE Primary: 0.145, 0.051
MAX/MIN Luminance: 775 / 0.000 nits

So those are the primaries it will use with Dolby Vision - closer to DCI-P3 than BT.2020.

Comparing different sources isn't really valid because each will have its own way of handling the output - particularly internal players, and probably nothing to do with DV handling.

What I can tell you is that I have a Sony UHD BluRay player and the picture looks exactly the same as the Zidoo in DV.

You say above that "Z9X TV-led DV: red looks more muted, pink-ish, and unnatural" - can you check it's the same in Player Led.

 

Thanks, Mark!

I went back and tested further by flipping back and forth between the Z9X and the C1 internal player. This time I didn't feel like I was seeing as much difference in color (if any at all).

Something kinda interesting: I think there was once when I flipped between the sources a few times in a row, and the color on the same source shifted between two viewings, producing some of the "muted, pink-ish" red I was seeing before. I guess I can chalk that up to either HDMI shenanigans, untimely ABL / ASBL, or maybe it was just placebo.

In any case, thank you again for helping, especially for clarifying the inherent issue with comparing different sources!

 

I can confirm on my LG C2 and both Zidoo UHD3000 and Z1000 Pro, I get a BT2020 flag on the LG’s info bar when playing Dolby Vision content. I have it set to player led and HDR on auto. I could be crazy but I also felt like the colors seemed slightly more muted and less vibrant playing 4K UHD disc backups with Dolby Vision on the Zidoo, as opposed to playing the disc itself in my Panasonic. According to others, it sounds like there shouldn’t be any difference and I also thought it was weird since they’re essentially the same file. It was enough for me to notice though, and this was before I found this thread. The BT2020 tag aside, is there any chance that the Zidoo handles and outputs DV file content differently than a disc and other player would? Should there be any difference with color at all??

 

Hmm. Well fun fact, I just double checked and my Panasonic UB9000 player also displays the BT2020 flag when playing back UHD discs that have Dolby Vision. It’s not just the Zidoo that does this after all. I do still seem to think the colors and overall presentation looks more vibrant and pleasing playing from the disc on the Panasonic. I wonder if that’s a placebo effect or if the Zidoo’s Dolby Vision playback from these rips could somehow be inferior to the actual disc. They are Remux MKV’s, not transcodes or compressed FYI. Any thoughts on this? Am I just crazy?

 

You’re right. I just tested my UB820 and it too sets BT.2020 for DV. Comparing it against my Z9X on the C1’s HDMI diagnostics screen under AVI Info Frame (playing different source files as I don’t have any 1:1 rips), here are the fields with different values:

• UB820 playing DV disc:
  • Active Info: VALID
  • Content Type: CINEMA
  • Extended Colorimetry: BT2020_RGBORYCBCR
    
  • VIC: 93
  • YCC Quantization Range: LIMITED

• Z9X playing DV demo file:
  • Active Info: INVALID
  • Content Type: GRAPHICS
  • Extended Colorimetry: BT2020_RGBORYCBCR
    
  • VIC: 94
  • YCC Quantization Range: LIMITED

• Apple TV 4K 2021 streaming DV content on ATV+ (for comparison):
  • Active Info: VALID
  • Content Type: GRAPHICS
  • Extended Colorimetry: XVYCC601
  • VIC: 0
  • YCC Quantization Range: FULL

There are also some differences under Video(LINK)’s Total res and PHY. Although I’m not sure they would make a difference in color.

In your case: Is your Blu-ray in FEL DV? The Zidoo discards the EL video stream, while the UB9000 merges the EL with BL to create a full 12-bit image, so that could be one of the reasons for the slight difference.

 

That’s all very interesting. Yes I was playing a FEL DV disc. For some reason I thought I read somewhere that using MakeMKV preserves the FEL information and that the Zidoo could play this back without any loss as well. I admit I am no expert on this stuff, and don’t know a lot of the inter workings regarding FEL and MEL. That’s a shame the Zidoo can’t play them back the same way a disc player can though, as the primary reason for me purchasing the UHD3000 was to hopefully play a virtually identical backup without needing to mess with changing discs all the time. It’s not a night and day difference, so I will continue using the Zidoo most of the time but a shame that there is any difference at all. Is this even something that could be implemented in the Zidoo going forward? The implementation of the EL layer and producing a full 12 bit image like you mention the disc players are doing?

 

I think it’s been mentioned in other threads here. Playing back the EL and BL at the same time requires two HEVC hardware decoders, which the Zidoo’s chipset doesn’t provide. So, it’s likely not going to happen, unless I guess if someone were to crack the proprietary DV magic and figure out how to software-decode DV.

There are a handful of devices that can do this, but when I did the research recently, none of the stable ones can pass lossless audio like DTS-HD MA through HDMI. (You can go on the makemkv forum and search for the user RESET_9999. In his signature there’s a spreadsheet comparing many playback devices. Very informative.)

So, you really got to pick and choose. My own interest in this messy situation is just injecting DV metadata from streaming services to plain HDR10 Blu-rays, so there’s no EL involved, and the Z9X is just fine.

 

Dolby will tell you that if you play a Dolby Vision file on any Dolby Vision source device to any Dolby Vision display device, you will have exactly the same experience for the same environment.

I can tell you from experience that's utter horse s**t.

Every source/display combination is going to have its own idiosyncrasies regardless of what is decreed from ivory towers.

 

I have done a LOT of A/B evaluation with mkv's sourced from BD's, HDR10 4kBD's and DV 4kBD's against the same discs played on my Panasonic 9000. With the picture controls (or whatever they are called in the Zidoo) set to ...

Brightness 33 (+1)
Contrast 34 (+2)
Hue 32 (no change)
Saturation 33 (+1)

... the MKV and the disc playback are very, very, very close. Casual comparison of the 2 sources will not show a difference - it requires repeated A/Bing and a practiced eye to detect the difference. The reason the brightness is up 1 tick is because the contrast needed +2 to match the perceived contrast of the disc but the blacks were slighted crushed so the brightness adjustment fixed that without killing the contrast improvement. This on a professionally calibrated Sony 85X95K (done by one of the calibrators that preps the TV's for the annual Value Electronics TV Shootout, not some hack at BB). The saturation tweak is required across all source formats (SDR BD, HDR UHD & DV UHD) so the very slight color difference is a result of the Panasonic's chroma processing. The DV mkv's don't seem to require any different chroma tweak in the Z9X than the HDR10 or SDR BD content so I'm pretty sure the 10 bit -> 12 bit DV chroma expansion is all but invisible in most circumstances.

While it would be great if the video was indistinguishable with no adjustments, I doubt this is achievable without actually using the Panasonic HCX processor.

It may be that there is some LG-specific DV glitch, but the DV video out of the Zidoo certainly is rendered by my Sony consistently and accurately.

 

The thing with the above settings is that it throws the white point out (235 reference white scale), on my setup anyway (using an APL clipping test file, so granted, technically, not tested for perceived differences with real world content)

 

Yeah I can’t imagine adjusting the picture settings on the player itself would maintain a calibrated image. If the Zidoo is not displaying content correctly or accurately it should be fixed internally because boosting brightness, contrast, and saturation is going to alter the calibration for all content.

Also this question was originally about Dolby Vision content and I’m pretty sure you can’t even adjust those settings for Dolby Vision. Only SDR and HDR content allows picture parameters.

 

Would it be fair to assume that the quality of MEL discs would show even less difference than comparing the Zidoos with a FEL disc?

 

MEL presentation on a Zidoo is exactly the same as MEL presentation on any UHD BluRay player.