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Need help choosing an HDMI Color Space

post #1 of 14
Thread Starter 
I recently bought the Panasonic BDT230 player, and I don't know which HDMI Color Mode to choose. My display is the Mitsubishi HC3800 DLP projector. I have the Spears and Munsil 1st edition disc, and read the article on their website, but it's way too complicated for me. Is there 1 test I can use to choose one? I also have the AVS709 test patterns if that would be easier. Thanks
post #2 of 14
I would use YCbCr 4:2:2.
post #3 of 14
Quote:
Originally Posted by rahzel View Post

I would use YCbCr 4:2:2.

Me too.
post #4 of 14
Why?
post #5 of 14
Quote:
I have the Spears and Munsil 1st edition disc, and read the article on their website, but it's way too complicated for me.

There is a PDF that has check boxes to mark off after looking at each pattern.

I would start with the chroma alignment pattern and look at the red stripe on yellow background. Does the pink blur on either side of the red stripe look symmetrical? Or is one side dark red and the other pink? You want to select the mode where it is symmetrical.

If you don't see a difference on the above pattern, then look at the chroma multiburst. Does the last burst on the 2nd and fourth row look brighter in one vs. the other? Go with the brighter burst.

The Panasonic player has advanced chroma processing, so if you let it convert to 4:4:4, then the 2nd row burst will probably be brighter than sending 4:2:2. If you disable the processing then they might be the same.
post #6 of 14
Quote:
Originally Posted by JimP View Post

Why?
Doug can explain it better than I can.

HTPCs is a different story.
post #7 of 14
USUALLY YCbCr 4:2:2 is the best choice... I'd say 90%-95% of the time that's what you want to use.

The exceptions are random models that for some reason, sending them RGB produces better-looking images. So you always want to do a check with your particular display Watch something familiar in YCbCr 4:2:2 then repeat the same scene in RGB mode (16-235 or limited or Standard, different manufacturers use different conventions for naming). If the images look the same, just use 4:2:2 and forget about it. But if RGB looks better, switch all your sources to RGB mode if they have an option to do that.

If you are doing the comparison between the 2 modes and you don't notice either one being obviously better (or worse) than the other mode, don't fret over it. Most of the time there's not going to be a difference. Don't spend more than 10 minutes looking for differences either. If you see a difference, it should be fairly obvious and you won't need anthing close to 10 minutes to decide that one of the connections looks better.

In even more-rare cases, RGB looks worse than YCbCr... doesn't happen very often, but I have seen it 2 times on 2 different brands of displays more than a couple of years apart.

You never want to assume 1 mode is the right mode all the time. You really have to check each brand/model display you use and if you ever change displays, you should check again with the new display. I've never detected a way to determine what mode is going to work best, it has always come down to a visual check. Fairly close to 95% of the time, you'll see no difference between RGB and YCbCr 4:2:2 mode so don't be surprised if that's what you experience.
post #8 of 14
Thread Starter 
Thanks guys.
post #9 of 14
I've read rgb is better because ycc is more compressed,(although I thought setting it to hdmi black level low would compress it too)..i would think less compression would mean smoother gradation(gradation more an issue on plasma)? I use rgb black level low.
Edited by Vic12345 - 7/17/13 at 1:24am
post #10 of 14
Quote:
Originally Posted by sspears View Post

There is a PDF that has check boxes to mark off after looking at each pattern.

I would start with the chroma alignment pattern and look at the red stripe on yellow background. Does the pink blur on either side of the red stripe look symmetrical? Or is one side dark red and the other pink? You want to select the mode where it is symmetrical.

If you don't see a difference on the above pattern, then look at the chroma multiburst. Does the last burst on the 2nd and fourth row look brighter in one vs. the other? Go with the brighter burst.

The Panasonic player has advanced chroma processing, so if you let it convert to 4:4:4, then the 2nd row burst will probably be brighter than sending 4:2:2. If you disable the processing then they might be the same.

Where is this PDF file located?

I've looked at the both disks on S and M calibration disk (edition 2) and on your website as well. Nowhere to be found. confused.gif
post #11 of 14
Quote:
Originally Posted by Iain- View Post

Where is this PDF file located?

I've looked at the both disks on S and M calibration disk (edition 2) and on your website as well. Nowhere to be found. confused.gif

Here's the PDF.......and here's the walk-through on how to use it.....LINK.
post #12 of 14
Quote:
Originally Posted by Vic12345 View Post

I've read rgb is better because ycc is more compressed,(although I thought setting it to hdmi black level low would compress it too)..i would think less compression would mean smoother gradation(gradation more an issue on plasma)? I use rgb black level low.
Almost all video is encoded using YCbCr 4:2:0 and uses a range of 16-235, so outputting RGB would require a conversion. No compression is being done regardless of what color space you use when it comes to Blu-Ray. You may be thinking of gaming consoles or PCs that output native RGB 0-255. It's usually best to avoid conversions, so for video, YCbCr is usually the best option. As Doug said, there are rare times that RGB will look better.

HTPCs are different because unlike Blu-Ray players, they can't output native YCbCr so they need to get converted to RGB before it reaches the display anyway. So with PCs, IMO it's best to output RGB 0-255 whenever possible, or RGB 16-235 if your HDMI port is shared and you need to match your other devices.
Edited by rahzel - 7/17/13 at 11:42am
post #13 of 14
8-bit RGB carries more color information than humans can see. There is ZERO reason to use RGB unless it happens to be the mode that produces the best looking images on your particular display.

Blu-ray discs are encoded in YCbCr 4:2:0 But you NEVER get that out of a Blu-ray disc player.

The 4 refers to the luminance data, the 2 and the 0 refer to how much color decimation is done (this is NOT the same thing as compression). Color decimation removes the "excess" color information that we can't benefit from because our vision system can't see it. 4:4:4 indicates no color decimation and YCbCr 4:4:4 has the same amount of data in the datastream as RGB... which means way more data than needed for human vision as related to color resolution. The data on the Blu-ray disc is always 4:2:0 but disc players always output 4:2:2 or 4:4:4 when you select a YCBCr mode so the player already restores some of the decimated color information. Doing MORE "un-decimation" accomplishes nothing though which is why 4:2:2 is the best output option. Most displays process video in YCbCr mode anyway (where color and tint can be fairly easily manipulated). It is much more difficult for a TV to process RGB and in fact, most TVs receiving RGB actually convert the incoming RGB to YCbCr before processing it. By sending YCbCr, you avoid that extra conversion step. You can tell if a TV is converting RGB to YCbCr this way: If you send RGB to the display and the COLOR and TINT controls still work, the TV is converting RGB to YCbCr. If the COLOR and TINT controls become unavailable in RGB mode, the TV is staying in RGB mode when you send RGB.

But none of that tells you whether RGB or YCbCr looks better. You still have to view familiar content in both modes in order to see if one mode is obviously better than the other.
post #14 of 14
I have too use gamma+1 for reasons i wont repeat again,but it makes the shiny whites too Shiny bright and midtones washed out on bright screens.

I read ycc makes things shinier/brighter/more luminance in the bright areas.Is this true?
If true,is it still true when you use a low contrast setting?


Edit I've gone back to gamma 0,as 1 washes out the brighter shades too much with the lower contrast I'm using.
Edited by Vic12345 - 7/19/13 at 4:14am
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