Dolby Vision

[JosephTocco]

I got movie in HDR described as Atmos DV. When I play it I have violet Elephants and green sky I'm using madVR.



MediaInfo:

HDR format: Dolby Vision, Version 1.0, dvhe.05.06, BL+
Bit depth: 10 bits
Codec configuration box: hvcC+dvcC

What is this and how to get valid colors?

[Selur]

What is this and how to get valid colors?

Afaik there is no software decoder which can decode Dolby Vision (Atmos is probably related to the audio not the video) outside of Dolby Vision authoring software.
To your questions:
a. it's HDR content not properly decoded
b. use a hardware player that supports Dolby Vision
(c. find and sponsor someone to reverse engineer Dolby Vision and write a patch for libav for it)

[JosephTocco]

Now I see in description:

mixed dolby vision file. There is a very limited amount of devices that can play dv muxed this way

On Dolby wensite is some sample, but there is nothing special in this, just brighter.
https://www.dolby.com/technologies/dolby-vision/

Need dedicated hardware to watch movies, so I don't find it useful.

But maybe this is only for cinemas? Is it better than other hdr?

[Selur]

But maybe this is only for cinemas?

nope, it's meant for consumer hardware.

Is it better than other hdr?

(when I write HDR10 this includes HDR10+)
potentially: yes
in praxis: not really
https://www.heimkinoraum.de/tests/dolby-vision-vs-uhd-premium-hdr10-166 (<- nice, rough overview in german)
-> I would recommend to use HDR10+ instead

Cu Selur

[netmask56]

Zidoo UHD3000 does Dolby Vision DV assuming your TV also supports Dolby Vision.

[Selur]

@netmask56: So that does mean the 'Zidoo UHD3000' is able to passthrough DV to the display, right? It doesn't come with a DV decoder chip or similar.

[netmask56]

@netmask56: So that does mean the 'Zidoo UHD3000' is able to passthrough DV to the display, right? It doesn't come with a DV decoder chip or similar.

Model UHD3000
Front Display LED
Chassis Aviation aluminum alloy
OS Android 9.0
CPU Realtek RTD1619DR ARM Cortex-A55(hexa-core)
GPU ARM Mali-G51 MP3
RAM 4GB DDR4
Internal Storage 32GB eMMC
Bluetooth BT 4.2
WiFi 2.4G+5G dual band WiFi, 802.11 a/b/g/n/AC 2T2R MIMO 867Mbps
Ethernet 1*RJ-45(10/100/1000Mbps)
HDMI Output 2.0a (4K@60fps/12Bit/HDR/BT2020/YCbCr 4:4：4 output) + 1.4 (Audio Only passthrough) separate audio and video output
Video Decoding 4K@60p,HEVC/H.265 12Bit,HDR10,HDR10+,Dolby Vision
Audio Decoding Support HD audio passthrough and decode 2 channels
Built-in XMOS+ESS 9068 DAC,supporting DSD、MQA decoding
USB Audio Input USB audio input supports Windows 7, Windows 10, Mac and Android
Up to two channels DSD512, PCM 768KHz@32bit PCM, MQA decoding
Other Audio Port 1*Optical,1*Coaxial,1*RCA L/R,XLR L/R balanced
Analog Audio Characteristics Frequency range: 20Hz-20KHz +/-0.35dB
SNR: > 128dBrA
THD+N: < 0.00026%
Output level: (XLR) 4.0±0.4Vrms. (RCA) 2.0±0.2Vrms.
DNR: > 125dB
Crosstalk: > 135dBrA
Power Supply AC 110~120/220~240V 50/60Hz (built-in switching power supply + linear power supply)
USB 2*USB3.0,2*USB2.0
SATA 2*SATA3.0 and 3.5" HDD bay (HDD is not included)
Other Ports 1*IR input,1*RCA composite video connector,1*RS232
Dimensions 312mm*430mm*72mm
Accessories 1*remote control,1*power cable,2*antennas,1*user manual

[betwixt]

Presumably it should look more like this. I captured the image from this web page, loaded it into Gimp and hue shifted it by +75.
From that I would assume the problem is a chroma phase shift which should be easy to correct with standard editing tools.

Brian.


[Attachment 59164 - Click to enlarge]

[Selur]

@betwixt: Sure, but like HDR10+, DolbyVision has hdr data per frame, so adjusting the hue etc might work on one frame, but you would potentially have to adjust hue&co differently for each frame.

[JosephTocco]

Another question on DV. I have got mopic in DV, Image colors are not correct in player, but some short parts are displayed correctly, in others they are more to correct than incorrect. Why?

ID                             : 1
Format                         : HEVC
Format/Info                    : High Efficiency Video Coding
Format profile                 : Main 10@L4@Main
HDR format                     : Dolby Vision, Version 1.0, dvhe.05.03, BL+RPU
Codec ID                       : V_MPEGH/ISO/HEVC
Duration                       : 59 min 42 s
Bit rate                       : 5 581 kb/s
Width                          : 1 920 pixels
Height                         : 1 080 pixels
Display aspect ratio           : 16:9
Frame rate mode                : Constant
Frame rate                     : 23.976 (24000/1001) FPS
Color space                    : YUV
Chroma subsampling             : 4:2:0
Bit depth                      : 10 bits
Bits/(Pixel*Frame)             : 0.112
Stream size                    : 2.33 GiB (36%)
Default                        : Yes
Forced                         : No
Color range                    : Full

[Selur]

Wild guess is that the player does not support the Dolby Vision profile (dvhe.05.03).
You might want to read
https://www.diversifiedvideosolutions.com/Dolby_Vision/Dolby_Vision_profiles_and_level...boratories.pdf
in regard to profiles compatibility together with th description of your player in regard to which profiles it supports.

Cu Selur

[netmask56]

I got movie in HDR described as Atmos DV. When I play it I have violet Elephants and green sky I'm using madVR.



MediaInfo:

HDR format: Dolby Vision, Version 1.0, dvhe.05.06, BL+
Bit depth: 10 bits
Codec configuration box: hvcC+dvcC

What is this and how to get valid colors?

An obvious question but maybe? Does your TV support Dolby Vision ? I had a client who had quite a few DV UHD discs and files and kept complaining he couldn't get DV to work even tho' his media player did. It turned out his TV whilst new, a Samsung, didn't support DV

[JosephTocco]

Player = MPC-HC I know DV requires special decoder that is not supported by most devices, but strange in this mopic is that some short scenes has correctly decoded colors

I have Samsung (definitely non-)smart TV, 3yo, and I have already got used to that it is good for television only, for movies and so on it is completely not suitable - does not support most A/V codecs, do you believe that? It even doesn't support full specification of Matroska...

[Selur]

There is no DolbyVision software decoder, especially not in libav so MPC-HC can't decode the dv data, but only passthrough the dv data to the display (assuming it's configured to do so).
If your display does not support dv then you can't properly play the file.
Seeing some scenes that seem 'correct' only means that the dv data in these scenes does not alter the appearance much.

-> If you want DolbyVision you need either a display which supports it (comes with it's own DV decoder) or a software player which does HDR-DV to SDR, since there isn't such a player available and it doesn't seem like Dolby is creating one you can't playback the file properly.

Cu Selur

[usually_quiet]

I have Samsung (definitely non-)smart TV, 3yo, and I have already got used to that it is good for television only, for movies and so on it is completely not suitable - does not support most A/V codecs, do you believe that? It even doesn't support full specification of Matroska...

Under those circumstances, you can only play files with HDR10 and even then you must use software players that can perform tone mapping in some way.

[Ennio]

...So that does mean the 'Zidoo UHD3000' is able to passthrough DV to the display, right? It doesn't come with a DV decoder chip or similar.

Zidoo RDT1619DR based mediaplayers have the Dolby Vison VS10 engine onboard, which is hardware. This engine can perform DV content tonemapping and put it out as LLDV, or put DV out as "TV-led", in which case the TV will do the tone-mapping. Eventhough these players are able to playback DV content that carry a Full Enhancement Layer (FEL), they do lack a second HEVC decoder for it. So you'll miss out on the FEL's 10 to 12 bit differential data. There is of course discussion going on whether or how much this extra data would add to a better picture.

Having such a player, I must say it performs well with all kinds of video-content. Next to the Dolby Vision capabilities, Zidoo has also made big leaps forward with HDR/DV to SDR conversion quality. Which is still important to a lot of non-4K/HDR/DV display owners.