HDTV Forum

Y Cb Cr 4:2:2, 4:4:4, or RGB?

Which of these should I use with a hdmi cable for the best picture quality on my tv?

spanky167 ...

Obviously, none! .... HDMI cable must have their own, specific port, labeled "HDMI"!

That first & last are strictly for 'RCA' Component-type video connections ...

Coming from WHAT source? Local Cable / Satellite or Blu Ray Player & what IS the HDTV?

eli

p.s - akirby - - - "IF" this is another 'SPAM' - so, it's the Season to be charitable?

I believe he is not talking about the connector type but the color space to use. I'm not an expert in this area but in general RGB is best for computer use. 4:2:2 or 4:4:4 usually works best for Blu-Ray. You often have to experiment to find what works best for your equipment. For most devices that have color space choices, I would start with the Auto setting. That may be all you need.

Jazzguyy - -

NOW, the .. Lightbulb .. finally comes "ON!"

Thanks!

eli

I would like to know what product is giving you these options (especially YCbCr since that is 480i and rarely supported via HDMI)? Gotta model number?

The source is a Panasonic Home Theater system/dvd player. SC-PT770 is the model number. And the option is which color space to use, no auto choice. Going to a Phillips HDTV 1080p.

When you take a new HDMI source product out of the box and connect it to the display it will query the EDID of the display and (typically) select the highest scan rate the display can accept along with RGB versus YCbCr settings. If you have a true native 720p and expect or want a 720p output from the source you will have to set that manually as well because the EDID will say the display supports 1080i (or 1080p) and that will be the automated setting.

I am left with the impression that you are looking through your settings, inspecting what you expect, or seeing if you can get a better image by manually changing a setting.

On page 29, at the bottom, it talks about the HDMI Menu and a setting called Video Priority and this appears to be for HDMI connections only. The description does not jive with the available settings documented on page 23. It appears that if you have this option turned off the source will go by the display EDID for output settings (the opposite of page 29) and what I suggest you try. If you want to change those settings then you turn Video Priority on and manually make your selection.

If you prefer manual settings and are connecting this via HDMI to a TV made in the last 3 years I think the answer will be...

HD Enhancer: turn it off, no matter what, for a natural response. Heck, this eye candy may be the automated setting which would require going to manual settings to turn it off.

Video Format: I can't find a manual scan rate setting and it appears these choices along with your display EDID determines the output scan rate. The player will select the highest progressive scan rate or the highest interlaced scan rate.

Using HDMI you would go with 480p/720p/1080p.

If you had an older HDMI or DVI capable 1080p display that does not accept 1080p you might have to use the other setting, 480i/1080i (480p or higher preferred for DVD, many displays won't accept a 480i HDMI signal so I'm not sure what is going on here).

The product does have analog outputs and if you use those you can't get better than 480p and you will also have to set the output for progressive to get 480p rather than 480i (page 28). It appears analog settings are in a different menu.

Color Space:
YCbCr 4:2:2 - Use this setting for an HDMI connection since that is the color format you are getting from DVD and blu-ray. In most cases this setting will give you the correct response and is what your HDMI ready display expects. It represents 16-235 video levels.

YCbCr 4:4:4 - Trying real hard to recall a real world reason for this setting but can't. It changes the video levels to PC, 0-255, and this would be a very uncommon setting to use but is there to compensate for some display design quirk. You won't get more color using this.

RGB - RGB and YCbCr is not interchangeable. The HDMI spec requires the display to process both. The DVI spec does not.

If your display has a digital video DVI connection and the EDID is not set right the product may not select RGB in which case you have to set it manually via this adjustment (you may get no picture or a poor image with really bad color). DVI is an RGB 4:4:4 color format used for PC and was thrown in HDTVs in the early days as a digital video input with copy protection. Note that the 4:4:4 color of this setting does not create anymore color than the 4:4:4 color setting for YCbCr. It does use the same video levels of 0-255.

Like the YCbCr 4:4:4, this setting might be used to compensate for some display design quirk or matching video levels in your system.

Yea, figured that out at the last minute...

Now the YCbCr 4:4:4 setting makes no sense at all.

On the other hand maybe that is why YCbCr labeling is all over this manual; that is the specification created by DVD 480i component video. Change the output to 480p and you are using YPbPr video specifications.

Yes the manual was very confusing to me too. I screwed around with the settings some more after reading your posts and it seems to give me the best picture with video priority on, enhanced hdmi on 3, RGB (set to enhanced also). I guess if it looks better then thats all that matters. Thanks for your help.

Spanky167,

Some of the responses might have assumed that YCbCr was limited to 480i (such as S-video), or that RGB and component were only analog formats.

YCbCr is the digital version of component analog YPbPr (typically transported by the red-blue-green joined wires).

YCbCr can be transmitted over DVI and HDMI since version 1.0. HDMI carries also RGB and, depending on the version, HDMI can carry more than the typical 8 bits per pixel, and I quote from an article below:

“HDMI 1.0 can carry up to 8 bits/component in RGB 4:4:4 and YCbCr 4:4:4 but can actually carry up to 12-bits/component in YCbCr 4:2:2, so even in 1.0, there was some support for greater color depth, but at the expense of horizontal chroma bandwidth/resolution.

In other words, versions 1.0, 1.1, 1.2 all support 24-bit pixels. For RGB and YCbCr 4:4:4 this means 8-bits per component, but for YCbCr 4:2:2 this means up to 12-bits per component.”

HDMI 1.3 extended that capacity.

http://www.hdtvmagazine.com/articles/20 ... lution.php

http://www.hdtvmagazine.com/articles/20 ... ion_xz.php

A 4:2:2 signal version discards the color resolution information from a 4:4:4 RGB original for compression purposes. A less compressed signal is always better for image quality, and it is better that the connected equipment maintains the signal in the digital domain without any conversions/compression to YCbCr 4:2:2 or 4:2:0 (such as MPEG-2 19Mbps HDTV) unless is needed. Once the color resolution is discarded from an original RGB 4:4:4 signal it can only be interpolated, but converting back to RGB cannot restore the lost of resolution.

The first Sony Blu-ray player BDP-S1 released in 2006 has the option of output YCbCr or RGB (16-235 or 0-255).

Follow the instruction manual of your player and of the display device to select the option that is best for the pair and perfoms less conversions, and is better for your eyes.

Best Regards,

Rodolfo La Maestra