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post #1 of 21 Old 01-29-2012, 05:31 PM - Thread Starter
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Hi,

I just bought a TV and I have some questions:

I have an HTPC (ATI HD4350) connected through HDMI.

In the ATI Control Center I can choose between different settings: YCbCr, RGB,... Wich would be the right one? I've read somewhere that ideally it should be YCbCr since HD content is encoded that way, but I'm not sure...

Also, in the TV settings I can choose between two colorspaces: Native and Auto. Wich is the right one?

The TV is a Samsung UE32D5500.

Thanks.
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post #2 of 21 Old 01-30-2012, 06:08 AM
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YCbCr, 709 color space, 6500k color temp (or D65 white point depending how control is labled), 16-235 range, and 2.2 gamma (propper gamma depends on ambient light level, but 2.2 is the standard universal number, 2.4 if used in a dark room) are your propper settings for HD video. In some cases depending on the equipment, particularly HTPC's, it is better to use RGB instead of YCbCr.
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post #3 of 21 Old 01-30-2012, 06:19 AM
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YCbCR is compressed RGB, it will get decoded to RGB at some point in the chain, if not by the HTPC, but by the TV
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post #4 of 21 Old 01-30-2012, 06:49 AM
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Quote:


YCbCR is compressed RGB,

no it isn't
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post #5 of 21 Old 01-30-2012, 06:49 AM
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YCbCr will be decoded to ... YCbCr. Depend on rendering path it may be converted to RGB (Full or Limited) or HDCP encoded and passed through card overlay. First for players like MPC, second for TMT, PDVD.
1) MPC, Pot, KMP - FullRGB
2) TMT, PDVD - YCbCr 4:4:4

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post #6 of 21 Old 01-30-2012, 09:09 AM
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Quote:
Originally Posted by SAM64 View Post

no it isn't

Quote:


Y′CbCr is not an absolute color space, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.

http://en.wikipedia.org/wiki/YCbCr

If you want to encode RGB to YCBCR, here`s the formula :



If you want to decode it



That`s for SD content, i.e. BT 601 standard, for BT 701 (HD content) the math differs a bit.
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post #7 of 21 Old 01-30-2012, 10:16 AM - Thread Starter
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Ok, thanks guys.

When using 0-255 for the desktop (i.e. opening a .jpg pluge), I can see the whole range.

But when I open a video with MPC-HC, it automatically outputs it to 16-235. I assume this is the normal behavior, right?

When I play a video it says in the renderer info that it's outputting "NV12" (this is with YCbCr 4:4:4 in the ATI Control Center).

Also, does anyone know what the "Auto" and "Native" colorspace setting in the Samsungs mean?
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post #8 of 21 Old 01-30-2012, 11:39 AM
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Quote:


it is a way of encoding RGB information.

...so is NTSC.

In either case, component, and composite are not "compressed RGB".

Do you understand this or are you going to link to more wiki articles that you don't fully understand?
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post #9 of 21 Old 01-30-2012, 12:53 PM
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Quote:
Originally Posted by Polcius View Post

But when I open a video with MPC-HC, it automatically outputs it to 16-235. I assume this is the normal behavior, right?

Nope. MPC (EVR, VMR, madVR) outputs in RGB 0-255 by default. Note your display is also RGB device by design. So, if you don't want to screw a picture with lossy RGB > YCbCr > RGB conversions, set your driver and display to RGB 0-255.

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post #10 of 21 Old 01-30-2012, 02:22 PM
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I did a some testing on this myself as I wanted to get a consistent setting to use both with PDVD11 for BD and DVD .iso and MPC-HC for .m4v/.mkv playback. Here's what I found with my ATI 5570.

BD .iso in PDVD11 is correct using either 16-235 with RGB Full or 0-255 with YCrBr.

DVD .iso in PDVD 11 is correct using either 0-255 with RGB Studio or 0-255 with YCrBr.

MPC-HC is correct using 0-255 with YCrBr, RGB Full or RGB Studio. Setting MadVR to 16-235 washed everything out so I have MadVR set to 0-255.

So, the common denominator was 0-255 with YCrBr. It all made no sense to me but the test patterns and my eyes aren't lying.
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post #11 of 21 Old 01-31-2012, 07:30 AM - Thread Starter
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Quote:
Originally Posted by JMGNYC View Post

I did a some testing on this myself as I wanted to get a consistent setting to use both with PDVD11 for BD and DVD .iso and MPC-HC for .m4v/.mkv playback. Here's what I found with my ATI 5570.

BD .iso in PDVD11 is correct using either 16-235 with RGB Full or 0-255 with YCrBr.

DVD .iso in PDVD 11 is correct using either 0-255 with RGB Studio or 0-255 with YCrBr.

MPC-HC is correct using 0-255 with YCrBr, RGB Full or RGB Studio. Setting MadVR to 16-235 washed everything out so I have MadVR set to 0-255.

So, the common denominator was 0-255 with YCrBr. It all made no sense to me but the test patterns and my eyes aren't lying.

What do you mean by correct?

What was the diffence between RGB and YCbCr? Color primaries? Gamma? Greyscale? Black level?
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post #12 of 21 Old 01-31-2012, 08:56 AM
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Quote:
Originally Posted by Polcius View Post

What do you mean by correct?

What was the diffence between RGB and YCbCr? Color primaries? Gamma? Greyscale? Black level?

By correct, I mean pretty much everything on the calibration tests I have. The biggest differences I saw though between the different settings were the black levels.
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post #13 of 21 Old 02-01-2012, 05:33 AM - Thread Starter
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So:

Pixel format to RGB Full (0-255)
MPC-HC default settings (Renderer 0-255)

In a JPEG I can see the 0-255 but when I play a video it shows 16-235. Is this not the right way?
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post #14 of 21 Old 02-01-2012, 05:51 AM
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Check Filters while playback. Renderer? Video decoder? Check their properties if possible.

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post #15 of 21 Old 02-01-2012, 08:29 AM - Thread Starter
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Renderer is EVR-CP.

For testing I'm using a .mp4 file from this forum (AVSHDmp4), the "Basic Settings" one.

Mixer output NV12, MPC Video Decoder, using DXVA. (this I got from pressing Ctrl+J while playing the file).
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post #16 of 21 Old 02-01-2012, 01:00 PM
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Check if some shader in use. For me it seems like something wrong with rendering. Also you can try madVR renderer.
What is your Catalyst version BTW?

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post #17 of 21 Old 02-01-2012, 02:35 PM - Thread Starter
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Quote:
Originally Posted by Qaq View Post

Check if some shader in use. For me it seems like something wrong with rendering. Also you can try madVR renderer.
What is your Catalyst version BTW?

I think it is normal behavior because the same happens with VLC.

Catalyst version is 11.12.

What should be the correct behavior?

As I understand, this levels bussiness can be handled at three levels:

1. The graphics card driver
2. The video player renderer settings
3. The TV

It's really hard to figure out...
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post #18 of 21 Old 02-01-2012, 09:38 PM
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1. renderer
2. driver
3. TV
The correct behavior is: black as black, grey as grey.
Of course some sample may have less than 16-235 of DR. You can try another samples (a real movie) to compare.
Here is another important thing. Catalyst - Video: tick all "take settings from app", untick all other. Keep De-interlace on Auto. Set Dinamic Range to 0-255. Reboot and try.

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post #19 of 21 Old 02-09-2012, 04:46 PM - Thread Starter
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But what's your setting?

I mean, in a 0-255 black bars .jpeg you see the whole range; and in the video too?

Now I open a .JPEG and I see the whole range; and the video is clipped at 16-235. This way you see PC images right & videos too. Isn't this the way? I feel like I'm not understanding you...
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post #20 of 21 Old 02-09-2012, 10:38 PM
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Quote:
Originally Posted by Polcius View Post

But what's your setting?

madVR - FullRGB (0-255)
Catalyst - FullRGB (0-255)
TV - FullRGB (0-255)
Quote:


I mean, in a 0-255 black bars .jpeg you see the whole range; and in the video too?

Of course. Some pics can have compressed range, and some movies too (very rare though).
Quote:


Now I open a .JPEG and I see the whole range; and the video is clipped at 16-235. This way you see PC images right & videos too. Isn't this the way? I feel like I'm not understanding you...

Video decoder decodes compressed YUV 16-235 to uncompressed YUV 16-235
Video renderer (madVR) converts YUV 16-235 to RGB 0-255
Video driver just passes RGB 0-255 through (close to that)
TV takes RGB 0-255 signal and displays in full range.
And if your video is clipped at 16-235 somethere, you will see black as dark grey and white as light grey on 0-255 TV.

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post #21 of 21 Old 02-14-2012, 01:51 PM - Thread Starter
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Ok, now we understand each other; that's exactly how I see it right now.

BTW, something weird happens to me... When I connect the PC through VGA instead of HDMI the behavior is:

Black doesn't show 0-17 but white DOESN'T show 230-234.

If I change the renderer setting to 16-235, I see 0-17 and 230-234 (only till 234, not till 255) (this way the black level is wrong and I have to adjust it through the TV, and "not video" images/webs/etc. are displayed with the incorrect level of black).
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