MP Colorspace? Can it be changed? (1 Viewer)

[bobn4burton]

Just got my MP installation up and running. Everything is working great so far. I have one question...what colorspace does MP use? It appears to be using the smaller 'AV colorspace' of 16-235 (or something close to those numbers) instead of the full 'PC colorspace' of 0-255. I have my HTPC connected to my LCDTV via HDMI. My LCDTV is a Sceptre 37" and you can use the HDMI port with 3 settings (DVI, HDCP, HDMI). When using HDMI my blacks are darker and colors more vibrant. Same with HDCP. When I switch to DVI mode, the blacks are washed out as well as colors.

The Sceptre TV excpects a PC colorspace of 0-255 in DVI mode and an AV colorspace of 16-235 in HDMI/HDCP mode. I am assuming that MP must be outputting in AV colorspace...hence the washed out picture when I'm in DVI mode.

I'd really prefer to use the DVI setting on my TV because there is no overscan and perfect 1:1 pixel mapping. HDMI/HDCP modes both overscan and scale the video signal.

Is there anyway to change which colorspace MP uses? TIA

My specs:

MediaPortal Version: 0.2.1.0
MediaPortal Skin: Mepo Green
Windows Version: MCE2005
CPU Type: AMD Athlon64 @ 2.4Ghz
Memory: 1 GB
Motherboard: Asus A8N-E
Motherboard Chipset: Nforce 4
Video Card: 7600GT
Video Card Driver: Nvidia 93.71
Sound Card: Onboard Digital
1. TV Card: VBox 150
1. TV Card Type: ATSC
MPEG2 Video Codec: Nvidia PureVideo
MPEG2 Audio Codec: Nvidia PureVideo

 

[Taipan]

Is there anyway to change which colorspace MP uses?

No, there is no way - MP uses the VMR9 mode which otputs in the range 16-235 - you must adjust your monitor/TV/display/projector accordingly.

 

[bobn4burton]

Hmmm...that's a bummer. I didn't realize this. My TV doesn't have any settings to compensate for this unfortunately. The only thing I can do on my TV side, is to switch to either HDMI/HDCP mode, but the problem with this is that the TV will overscan and scale the image. I'd really prefer to keep my image 1:1 from the PC.

So is there anything I can do? Is it possible to get good results by adjusting the gamma on the video card settings? Anyone used CoreAVC...they claim a 'VMR9 color fix'...?

 

[Taipan]

Is it possible to get good results by adjusting the gamma on the video card settings?

You can make the adjustments at the video card, but don't touch the gamma.

You just need to decrease the Brightness to get the correct black level and increase the contrast to get the correct white level. I am not familiar with your particular card, so I cannot be more specific than that - but you do need to find the adjustments that apply to VMR9 - I think it is referred to as "3D" mode?

 

[bobn4burton]

I found the settings that work while MP is running. Does anyone have any tips for adjusting the brightness contrast?

1. It's hard because you can't have the adjustments window open the same time as MP...so you have to go back and forth. Is there a better way?

2. Is this really the only way to fix this colorspace problem???

I'm tempted to go out and buy the Sony V2500 46" lcd because its a pretty good HDTV with good 1:1 pixel mapping, but it also has a colorspace setting. You can choose which colorspace to use for each input which would be very nice.

It sure would be nice if you could somehow set which color space VMR9 used...

 

[zswman]

I found the settings that work while MP is running.
I'm tempted to go out and buy the Sony V2500 46" lcd because its a pretty good HDTV with good 1:1 pixel mapping, but it also has a colorspace setting. You can choose which colorspace to use for each input which would be very nice.

Go to avsforum.com and search on "cloudy XBR2" and read-up on the Sony LCDs before you buy (this issue I speak of also affects the V2500). I run MP on a 46XBR2 and it looks fantastic, but dark scenes have real issues w/ uneven backlighting.

 

[tourettes]

I remember reading from somewhere that there is aregistry setting for nvidia drivers that can be used to select the colorspace.

 

[bobn4burton]

I remember reading from somewhere that there is aregistry setting for nvidia drivers that can be used to select the colorspace.

If this is true, it would be REALLY cool. Anybody know anything about this?

 

[bobn4burton]

OK...I found the registry hack and it seems to be working great for me! Here is how you do it for anyone interested:

Launch regedit and determine the current primary display
looking in HKey_Local_Machine\Hardware\DeviceMap\Video
and note the GUID (global unique identifier assigned by
which is the long string in brackets { } at the end of the entry
device\video0ʺ.
Look in
HKey_Local_Machine\SYSTEM\CurrentControlSet\Contro l\
GUID}\0000
where {GUID} is the number derived from the previous step.
Open the ʺ0000ʺ directory and create a new DWORD called
VMRCCCSStatus and give it a value of
0x1 - to force use of the standard YUV range of 16-235
0x3 - to force use of the extended YUV range of 0-255



So I made the DWORD VMRCCCStatus in the following registry folder:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Video\{GUID}\0000
and gave it a HEX value of 3. I rebooted and seems to work great.

 

[Marcusb]

great that it works and thanks for posting the results for the benefit of others