EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Howardlong on June 08, 2017, 12:35:03 pm
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Folks
Here's a nerd question for the HTPC guys.
I have a mobo (Asrock Z270 Fatal1ty ITX/ac populated with an i7-7700k) that says it'll do up to 12bpc through the integrated graphic's HDMI 2.0b port. There is an FAQ item on setting it up for UHD BluRay which is my application, but I can't get the compatibility app to show it's HDR compatible.
My monitor (Philips BDM3275UP) is HDMI 2.0b compliant and supports 10bpc when connected to a GTX1080, but I don't get this option when connected to the integrated graphics via the HDMI 2.0 port.
I can play UHD BluRays at 4K (UHD) resolution, but I get a warning it's not HDR (as expected from the compatibility report) so you get visible banding in certain scenes.
So, is 10bpc synonymous with HDR or am I misunderstanding something?
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HDR10 is 10 bits/color. Dolby Vision is 12 bits/color and has stricter standards to comply.
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I would say it's "at least" 10 bits.
Right now HDR is a mess, a few competing standards. Just 10bpc doesn't make a video HDR, the video itself has to be encoded using another color space (bt.2020 instead of bt.709) and should be encoded accounting for the much higher range of brightness (for ex up to 1000 nits , while regular TVs and monitors have only up to 300-500nits)
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HDR10 is 10bit but 10bit isn't HDR. Your monitor doesn't support HDR - likely limited by the brightness requirements.
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HDR10 is 10bit but 10bit isn't HDR. Your monitor doesn't support HDR - likely limited by the brightness requirements.
Glorious comfusion! So the monitor supports 1.07bn colours, i.e., 2^30, or 10 bits each of R, G, B.
But that is not HDR10.
So, what is the difference between HDR10 and 10bpc, and how does the source know? Is there some meta information in the EDID or something?
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I would say it's "at least" 10 bits.
Right now HDR is a mess, a few competing standards. Just 10bpc doesn't make a video HDR, the video itself has to be encoded using another color space (bt.2020 instead of bt.709) and should be encoded accounting for the much higher range of brightness (for ex up to 1000 nits , while regular TVs and monitors have only up to 300-500nits)
Ah OK, well I guess the consumer's shafted again then. The requirements for DRM'd UHD content, and especially UHD BluRay, is hard enough as it is without adding a further complication of needing to upgrade the monitor which I *assumed* at 10bpc was HDR.
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HDR10 is 10bit but 10bit isn't HDR. Your monitor doesn't support HDR - likely limited by the brightness requirements.
Glorious comfusion! So the monitor supports 1.07bn colours, i.e., 2^30, or 10 bits each of R, G, B.
But that is not HDR10.
So, what is the difference between HDR10 and 10bpc, and how does the source know? Is there some meta information in the EDID or something?
There is some data transported along with the HDMI signal: http://www.hdmi.org/manufacturer/hdmi_2_0/hdmi_2_0a_faq.aspx (http://www.hdmi.org/manufacturer/hdmi_2_0/hdmi_2_0a_faq.aspx)
HDR is an absolute mess right now. Some stuff looks great, some stuff looks terrible. All down to the colourist, which makes it entirely subjective.
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Yeah.
If you're curious, i have some test videos here : LINK (http://ftp://helpedia.com/pub/multimedia/testvideos/)
If you have a HDR TV, you may see a difference if you play them from a usb stick or from network, between tv and monitor when it comes to colors.
Also note that your video player may ignore by default the fact that your monitor can do 10bpc ... it may actually decode the video but then convert it from 10 bits per color to 8 bits per color because that's more compatible and easier to work with. Or, it may only be able to do 10bpc in full screen mode (pretend it's a video game and reserve the whole monitor for rendering at 10bpc)
If you have your desktop configured at 10bpc, you must go in your preferred movie player and make sure it renders the video on a 10bpc "surface" and doesn't just take it down to 8bpc.
In Media Player Classic Home Cinema (https://mpc-hc.org/) you can simply press Ctrl+J to see how the video is rendered.
I'd suggest downloading Life_of_ Pi_draft_Ultra-HD_HDR.mp4 (~300 MB) and if you want, Sony_4K_HDR_Camp.mp4 (~ 1.1 GB)
Life of Pi is 4K 24fps :
Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5.1@High
Codec ID : hev1
Codec ID/Info : High Efficiency Video Coding
Duration : 54 s 375 ms
Bit rate : 44.8 Mb/s
Width : 3 840 pixels
Height : 2 160 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 24.000 FPS
Original frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0 (Type 2)
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.225
Stream size : 290 MiB (99%)
Writing library : ATEME Titan KFE 3.7.0 (4.7.0.2002)
Color range : Limited
Color primaries : BT.2020
Transfer characteristics : SMPTE ST 2084
Matrix coefficients : BT.2020 non-constant
Mastering display color primar : R: x=0.680000 y=0.320000, G: x=0.265000 y=0.690000, B: x=0.150000 y=0.060000, White point: x=0.312700 y=0.329000
Mastering display luminance : min: 0.0200 cd/m2, max: 1200.0000 cd/m2
Sony video is 4K at 60fps :
Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5.1@High
Codec ID : hvc1
Codec ID/Info : High Efficiency Video Coding
Duration : 2 min 7 s
Bit rate : 75.6 Mb/s
Maximum bit rate : 123 Mb/s
Width : 3 840 pixels
Height : 2 160 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 59.940 (60000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0 (Type 2)
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.152
Stream size : 1.12 GiB (100%)
Encoded date : UTC 2016-02-03 07:59:49
Tagged date : UTC 2016-02-03 08:01:32
Color range : Limited
Color primaries : BT.2020
Transfer characteristics : SMPTE ST 2084
Matrix coefficients : BT.2020 non-constant
Mastering display color primar : R: x=1.000000 y=1.000000, G: x=1.000000 y=1.000000, B: x=1.000000 y=1.000000, White point: x=1.000000 y=1.000000
Mastering display luminance : min: 0.1000 cd/m2, max: 0.5000 cd/m2