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Discussion Starter · #1 ·
I know that DVDs are recorded at 480i with a YCbCr4:2:0 colorspace. So when I play them, I set my player to 480i YCbCr4:2:2 for a minimumly processed result.


When Blu-ray discs are mastered, do they use YCbCr4:2:0, YCbCr4:2:2, YCbCr4:4:4, RGB (16-235), or RGB (0-255)? When playing them, I want to set my player to perform as little processing as possible. Is 30-bit or 36-bit deep color also incorporated into mastering Blu-ray discs? If so, is it 30-bit or 36-bit? If not, I'd prefer to turn it off.
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by oztech  /t/1483517/color-space-and-deep-color-as-recorded-on-the-disc#post_23571151


I don't know of any source that uses deep color for the consumer currently .
Then I'll leave Deep Color off. What about the color space? Do Blu-ray discs use YCbCr4:2:0, YCbCr4:2:2, YCbCr4:4:4, RGB (16-235), or RGB (0-255)? Does it differ between Blu-ray discs encoded in MPEG2, MPEG4, VC1, VC2 (does that exist), and AVC?
 

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BR uses 8-bit YCbCr 4:2:0 just like DVD.


Sony has recently been marketing an extended color space that uses the levels below 16 and above 235. I haven't followed that, but put some info links in the OPPO FAQ because people ask about it: Does the player support the xvYCC color space?


-Bill
 

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Every player does different things when taking the 4:2:0 source from a Blu-ray and outputting to the display. Some always output 4:4:4, after upconverting 4:2:0. In fact, it seems, after viewing some displays/players with the Spears and Munsil HD Benchmark 2nd Edition disc, that many do really odd things with the image.


Have a look at this page for the many things that can happen, even for a simple 4:2:0 output (if the player even offers that as an option - most players I've seen only do YCbCr or RGB or RGB limited options - and you have no idea if it is 4:4:4 or 4:2:2 output for YCbCr instead of 4:2:0 that you would expect for BD):

http://www.spearsandmunsil.com/portfolio/choosing-a-color-space-2/


There is also chroma upscaling done by the player and/or the display to consider.


The above link has some good examples of how different devices screw up the output.
 

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Discussion Starter · #6 ·

Quote:
Originally Posted by maxleung  /t/1483517/color-space-and-deep-color-as-recorded-on-the-disc/0_100#post_23934401


Every player does different things when taking the 4:2:0 source from a Blu-ray and outputting to the display. Some always output 4:4:4, after upconverting 4:2:0. In fact, it seems, after viewing some displays/players with the Spears and Munsil HD Benchmark 2nd Edition disc, that many do really odd things with the image.


Have a look at this page for the many things that can happen, even for a simple 4:2:0 output (if the player even offers that as an option - most players I've seen only do YCbCr or RGB or RGB limited options - and you have no idea if it is 4:4:4 or 4:2:2 output for YCbCr instead of 4:2:0 that you would expect for BD):

http://www.spearsandmunsil.com/portfolio/choosing-a-color-space-2/


There is also chroma upscaling done by the player and/or the display to consider.


The above link has some good examples of how different devices screw up the output.
If my display and color have options for color space and deep color, I set them to do as little processing and enhancing as possible. I set my display to Auto because it matches the input source, as opposed to applying its own expansion beyond the source material. Since most Blu-ray discs are recorded at 8-bit, YCbCr4:2:0, I set my Blu-ray player to YCbCr4:2:2 (since it is the closest thing to YCbCr4:2:0), and turn Deep Color off. Then if titles are released with one of the enhanced color spaces and/or 20-bit or 36-bit deep color, I can set my player to output according to the disc I'm playing. Who knows, like some players change resolution according to the disc, maybe players will some day be able to change color space and deep color settings according to the disc as well. Then I wouldn't have to do as much manual switching every time I load a disc. I know I'm going offtopic, but it would also be cool if in addition to resolution, color space, and deep color settings, it would be convenient if the player can automaticly change aspect ratio according to a loaded disc as well to avoid stretching/squeezing so that nothing has to be manually changed every time you load a disc (if playing a disc recorded at 1920x1080, the player should be able to detect the actual aspect ratio, adding the black bars on the top and bottom if necessary, and if playing a letterbox 720x480 or 720x576 DVD, it should detect that it's letterboxed and add the black bars).
 

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Yeah that would be nice. I think a lot of players do some of what you propose already, although colorspace changing still seems to be a tricky issue, particularly on media streamers.


In an ideal world, setting colorspace to 4:2:0 should work properly for all BD players with BD content. However, as an example, my Dune Smart H1 and Pioneer 62FD (aka BDP-450) players seem to apply an extra unnecessary color conversion even when output is set to 4:2:0. The Chroma Multiburst pattern in the Spears and Munsil HD Benchmark 2nd Edition disc have one of the multiburst patterns come out completely black instead of vertical strips of 1 pixel-wide red and blue lines! The chroma upscaling (4:2:0) is horrific. I have to force the output on both players to RGB to see anything, and on the 62FD the bars are half or one quarter their brightness, which points to a double colorspace conversion error happening. And this doesn't include the error my projector (Benq W5000) introduces that also has a chroma error - double wide vertical lines for red and blue!


I strongly suggest you get the S&M 2nd Edition disc and check that there is no error being introduced. Although, you may still opt to use 4:2:0 output. You can also check out the spears and munsil website (I can't recall the exact URL right now) and see if your player has been reviewed by them - then you may not need to get the disc!


Other notes: My Pioneer BDP-62FD has dual HDMI outputs. The second output, labelled HDMI SUB, does less processing in the video. However, it does Nearest Neighbor chroma upscaling, so the chroma multiburst pattern results in double-wide blue and red vertical lines (according to the link in my previous post, this can result in contouring in some cases). But at least it doesn't add a mild edge enhancement that the other output adds. And this is with RGB output. 4:2:0 and 4:4:4 YCbCr is still incorrect on this player! ugh!
 

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Discussion Starter · #8 ·

Quote:
Originally Posted by maxleung  /t/1483517/color-space-and-deep-color-as-recorded-on-the-disc/0_100#post_23936153


Yeah that would be nice. I think a lot of players do some of what you propose already, although colorspace changing still seems to be a tricky issue, particularly on media streamers.


In an ideal world, setting colorspace to 4:2:0 should work properly for all BD players with BD content. However, as an example, my Dune Smart H1 and Pioneer 62FD (aka BDP-450) players seem to apply an extra unnecessary color conversion even when output is set to 4:2:0. The Chroma Multiburst pattern in the Spears and Munsil HD Benchmark 2nd Edition disc have one of the multiburst patterns come out completely black instead of vertical strips of 1 pixel-wide red and blue lines! The chroma upscaling (4:2:0) is horrific. I have to force the output on both players to RGB to see anything, and on the 62FD the bars are half or one quarter their brightness, which points to a double colorspace conversion error happening. And this doesn't include the error my projector (Benq W5000) introduces that also has a chroma error - double wide vertical lines for red and blue!


I strongly suggest you get the S&M 2nd Edition disc and check that there is no error being introduced. Although, you may still opt to use 4:2:0 output. You can also check out the spears and munsil website (I can't recall the exact URL right now) and see if your player has been reviewed by them - then you may not need to get the disc!


Other notes: My Pioneer BDP-62FD has dual HDMI outputs. The second output, labelled HDMI SUB, does less processing in the video. However, it does Nearest Neighbor chroma upscaling, so the chroma multiburst pattern results in double-wide blue and red vertical lines (according to the link in my previous post, this can result in contouring in some cases). But at least it doesn't add a mild edge enhancement that the other output adds. And this is with RGB output. 4:2:0 and 4:4:4 YCbCr is still incorrect on this player! ugh!
Actually, none of the players I use have a 4:2:0 option. The closest thing they have is 4:2:2. I use that setting because it is the closest thing to 4:2:0 available to me. From what I know, not many players have a true 4:2:0 setting.
 

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Quote:
Originally Posted by Big C  /t/1483517/color-space-and-deep-color-as-recorded-on-the-disc#post_23936413


From what I know, not many players have a true 4:2:0 setting.

HDMI doesn't even carry it. At least: It's not in the standard.


4:2:0 is being added in HDMI 2.0, but it is hard to know when players and displays will add that format.


-Bill
 

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yes you're right! The 62FD shows "YCbCr422" only. In theory it should be easy to go from 4:2:0 to 4:2:2, but it seems display/player manufacturers always find creative ways of screwing it up. *cynical*
 

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Quote:
Originally Posted by maxleung  /t/1483517/color-space-and-deep-color-as-recorded-on-the-disc#post_23938190


yes you're right! The 62FD shows "YCbCr422" only. In theory it should be easy to go from 4:2:0 to 4:2:2, but it seems display/player manufacturers always find creative ways of screwing it up. *cynical*

Well, to be fair, 4:2:0 is lossy storage format too embedded in the video workflow to give up. DVD and Blu-ray are both based on it; no other choices.


There hasn't been a lot of demand to transmit it as is. It has to be chroma upsampled to 4:4:4 somewhere, so why not when decoding? (Or to 4:2:2, but that also must be upsampled to 4:4:4 later).


I'm surprised 4:2:0 is in HDMI 2.0. Someone on the committee must have wanted it.


-Bill
 

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Does anyone know (or know where to find) the encoding color space specs on Ultra HD Blue Ray discs? I.e still encoded in some form of YUV and not RGB? The sampling numbers (4:4:0, 4:4:2, etc)? Guessing 10 bit instead of 8 bit?
 

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Thanks - found the official "Blu-Ray" white papers the next day.
 
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