[jingai]

Just for confirmation, this in a nutshell means we should target sRGB when calibrating/characterizing our displays and video cards, correct?

edit: I guess just calibrating. IIRC XBMC doesn't use the OS color profile, right?

[DerekCuster]

Just for confirmation, this in a nutshell means we should target sRGB when calibrating/characterizing our displays and video cards, correct?

edit: I guess just calibrating. IIRC XBMC doesn't use the OS color profile, right?

I'm not sure, I think we should still (or best practice) need to calibrate to 709 as that's what the card will most likely be converting any video to if it's connected to a HDTV via HDMI. Most HDTVs expect that, I'm pretty sure none expect full RGB 0-255 via hdmi... Afaik it's only part of the HDMI spec for backward compat and is not a requirement, so some tvs don't support it at all.

Currently, I calibrate to 709 using calman/chromapure and my i1Dpro. My results with a bluray playing the AVS disc for example, are completely different from when xbmc displays the same test samples even on the same hdmi. Xbmc does manipulate the video, it's not a million miles off, but either way it's not ideal in any world.

@Martijn,
I only asked if frodo would support the HDVideo standard? No need to be so grumpy. I never created the HDMI/Bluray/Digital video standards... But I also didn't create xbmc... But if I did... My video player would play video standards... Not pc standards... Just Sayin

Ohh... And in this universe 2 is considered a lot in many ways..
Can you find me 2 planets that are as habitable as our earth for humans to exist and live on now? I'd consider 2 a lot if I could chose where to live

I read the other day that 2 people are hurt every single day from lighting their own farts, I'd consider that a lot... A lot of douche bags!

The list goes on

[jingai]

Just for confirmation, this in a nutshell means we should target sRGB when calibrating/characterizing our displays and video cards, correct?

edit: I guess just calibrating. IIRC XBMC doesn't use the OS color profile, right?

I'm not sure, I think we should still (or best practice) need to calibrate to 709 as that's what the card will most likely be converting any video to if it's connected to a HDTV via HDMI. Most HDTVs expect that, I'm pretty sure none expect full RGB 0-255 via hdmi... Afaik it's only part of the HDMI spec for backward compat and is not a requirement, so some tvs don't support it at all.

Mine does support full-range RGB. And XBMC outputs only full-range (expanding 16-235 to 0-255), from what I can tell. So it seems to me that calibrating to sRGB is the right thing to do, but honestly the confusion over this is exactly why I was asking here.

Currently, I calibrate to 709 using calman/chromapure and my i1Dpro. My results with a bluray playing the AVS disc for example, are completely different from when xbmc displays the same test samples even on the same hdmi. Xbmc does manipulate the video, it's not a million miles off, but either way it's not ideal in any world.

My results with dispcal and a DataColor Spyder3 "appear" correct. I put that in quotes because obviously I can't tell for certain by eye alone, which is why I bought a colorimeter in the first place.

I can say with absolute certainty that my photos when viewed in XBMC are spot on. I know this because my editing display is also calibrated. Both displays support >95% of sRGB color space and they look identical. From what I understand, XBMC plays videos in the same color space as its GUI, so I assume photos are also in the same color space.

I will also say that I did at one point calibrate to Rec.709 and was not at all happy with the results. It was definitely flattening the image.

[DerekCuster]

Yea, I'm not sure then in your case. If you are using full RGB conversion on your media player and your GFX Card, and sending Full RGB to your tv (and expecting it on your TV) then I assume you should still calibrate your display around that and still calibrate to 709 (for video at least on 1 preset) as all the test images are created in this format, then maybe set up another preset for pictures etc as they don't share the same color space.

Afaik though spyder3 dont calibrate HDTVs correctly (only profile monitors or CCFL) as they can't accommodate for RGB LED or White LED as it throws them off. To my knowledge the i1DPro and Munki can can correctly identify and calibrate around these display types as its part of their profile.

Perhaps that's why the rec709 didn't look correct? Is your display LED back lit, if so you may need a different calibration device.

Sending a video raw through other media players (looking at the graph) sent to the display in their native format gives me relatively good chroma/delta results (delta less than 2)... Via xbmc, I get a whole different set of result.

It's doing something to the video (converting to RGB then expanding the range) before sending it to my GFX card to convert back to how it was in the first place, and then for my display to display it, which seems like an old redundant step IMO.

I can get close with xbmc but not perfect as my pallet is shifted slightly when using the inbuilt xbmc media player over an external player.

I'll just hope xbmc Gives us more options in the future and allows native bluray, ycbcr 4:4:4 (4:2:2) standards etc.

@ the devs,
Just out of curiosity, when xbmc plays a bluray iso (when it gets support) is it really gonna convert that beautiful video, from it's native format to RGB 0-255? I hope not

[jingai]

Yea, I'm not sure then in your case. If you are using full RGB conversion on your media player and your GFX Card, and sending Full RGB to your tv (and expecting it on your TV) then I assume you should still calibrate your display around that and still calibrate to 709 (for video at least on 1 preset) as all the test images are created in this format, then maybe set up another preset for pictures etc as they don't share the same color space.

XBMC expands 16-235 to 0-255. I'm not sure I understand why you think I should calibrate for 16-235 if that's not what it's sending to the display?

In other words, XBMC is doing this for me, AFAIK. And that's my question to the devs here.

Afaik though spyder3 dont calibrate HDTVs correctly (only profile monitors or CCFL) as they can't accommodate for RGB LED or White LED as it throws them off. To my knowledge the i1DPro and Munki can can correctly identify and calibrate around these display types as its part of their profile.

Perhaps that's why the rec709 didn't look correct? Is your display LED back lit, if so you may need a different calibration device.

My LED-backlit IPS TV is no different than my LED-backlit IPS computer monitor. They're both just monitors, at least when I tell the TV to expect a full-range source.

The Spyder3 does work with LED-backlit LCD monitors -- the fact that my photos are identical between both displays means it's working.

I think what you're thinking of is displays with wide color gamuts (Adobe RGB).

Sending a video raw through other media players (looking at the graph) sent to the display in their native format gives me relatively good chroma/delta results (delta less than 2)... Via xbmc, I get a whole different set of result.

I assume this is because XBMC is expanding it for you because it expects it's hooked up to a "computer" monitor, whereas the other devices expect to be hooked up to a "TV". Bear in mind that these days there is very little difference, and in the case of my TV, no difference at all since I can explicitly tell it to behave like a standard "computer" monitor.

It's doing something to the video (converting to RGB then expanding the range) before sending it to my GFX card to convert back to how it was in the first place, and then for my display to display it, which seems like an old redundant step IMO.

I can get close with xbmc but not perfect as my pallet is shifted slightly when using the inbuilt xbmc media player over an external player.

From what I understand, that's exactly what it's doing. Which would mean you need to calibrate to sRGB and ensure your TV is configured to accept a full-range RGB source.

Hopefully one of the devs can correct me if I'm wrong, because I am very interested in getting this right.

Anecdotally though, I can definitely say that the output I see from XBMC very, very closely matches what I see on a bluray from my PS3. So I'm thinking I'm probably right here, but confirmation would be awesome.

@ the devs,
Just out of curiosity, when xbmc plays a bluray iso (when it gets support) is it really gonna convert that beautiful video, from it's native format to RGB 0-255? I hope not

I'm not sure I understand why you think this is a bad thing, unless your display can't be configured to expect a full-range source. Although I think calibrating to Rec.709 in that case might give roughly the same results? I suppose some information might be lost since it's essentially expanding and then squashing it back down, not sure..

[azaze1]

I love and respect XBMC despite the team's stubborn attitude towards this feature. I've also been hoping for a 16-235 setting to be added especially as it is seems to be described as something simple mathematically. If for nothing else it would make the UI and fanart show up properly since brightness and contrast don't work until you launch dvdplayer. This leaves me wondering if it's a principal thing preventing the project from adopting the standard (kind of like how Varnish cache server developers refuse to support SSL).

All the justifications for supporting 16-235 have been made already, and the only thing I read are invitations to become a developer and submit a patch. I know that open-source projects have a different DNA compared to customer focused businesses, but in the end the features are usually driven by user requests or customer demands.

XBMC has certainly listened to users when developing its feature road map and this has proven very successful with each major release. That leads me to believe that it's a matter of stubborn principal that prevents a fully recognized standard from making it's way into the road map.

[Martijn]

Or perhaps better things to do than spending valuable time on a feature for a small group..

[jmarshall]

I can say with absolute certainty that my photos when viewed in XBMC are spot on. I know this because my editing display is also calibrated. Both displays support >95% of sRGB color space and they look identical. From what I understand, XBMC plays videos in the same color space as its GUI, so I assume photos are also in the same color space.

100% correct.

[jingai]

Jonathan,

So it's also to correct to assume we should be targeting sRGB for display calibrations if the TV supports full range RGB, and Rec.709 if not?

If so, I think it is the latter that folks are complaining about because they perceive some quality loss mapping to RGB color space and back (on the GPU).

[jmarshall]

I would think so, yes.

I'm not sure whether or not there's a way to tell the GPU that the framebuffer should be interpreted as YUV (assuming that the UI was converted appropriately). Assuming there isn't, then there's no advantage to restricting the range of the RGB space on the way through - you have to go from a YUV space to RGB and back again, so you mayaswell at least make the RGB space fullrange to preserve as much range as possible. Ofcourse, this is assuming that the GPU correct does conversion from fullrange RGB back to the YUV space correctly.

[azaze1]

Or perhaps better things to do than spending valuable time on a feature for a small group..

HD audio made it in, is that a small group? Unless all the people wanting that feature have 24" dell LCDs connected to 7.1 receivers and preamps.

[lrusak]

Why not just adjust colorspace in your OS? I'm not sure about windows but you can do this in linux via xorg.conf for both AMD and Nvidia GPUs.

Also, XBMC use to have a setting called VDPAU studio level color conversion, but I think it was removed as Fernetmenta said it didn't work properly.

[jingai]

Of course, this is assuming that the GPU correct does conversion from fullrange RGB back to the YUV space correctly.

And this may be where the issue lies. I assume it should be able to mathematically speaking but maybe some GPUs do wonky things here.

---

Why not just adjust colorspace in your OS? I'm not sure about windows but you can do this in linux via xorg.conf for both AMD and Nvidia GPUs.

I could be wrong, but I think the problem with that is that XBMC always assumes RGB no matter what -- I know that it doesn't use the OS color profile, at least. If it did it would solve the problem for him, but I imagine it's not as simple to implement as people are thinking.

[azaze1]

Why not just adjust colorspace in your OS? I'm not sure about windows but you can do this in linux via xorg.conf for both AMD and Nvidia GPUs.

Also, XBMC use to have a setting called VDPAU studio level color conversion, but I think it was removed as Fernetmenta said it didn't work properly.

The AMD drivers support studio limited RGB which would be great if I never exited XBMC to the windows desktop to download updates or browse or do anything other than view video. Being it's a PC with a PC video card, I configure the system as a whole to full 0-255 and rely on applications configuration to make adjustments according to their purpose. With external players the renderers can accommodate PC monitors and TV displays where you might expect a 10-foot interface to control media.

[DerekCuster]

I think we're all signing from the same hymn sheet here, but from different rooms
Which is good, but confusing

The reason I don't think the spyder3 does HDTV (LED) is because their website says only the 4 can do LED HDTVs correctly, and the Spyder 3s spec says it won't do LED HDTVs (only ccfl HDTVs and monitors).
http://spyder.datacolor.com/tv-calibration/

It's not just data color though, even the display2 and other Meters were not able to do White LED correctly until recently (without spending the bug bucks).

As for Full RGB my tv doesn't accept it. It's a 2012 3D LED HDTV and it only accepts 16/235 Ycbcr 4:4:4 and sRGB 16-235...
So for me this it just seems insane that a video player doesn't play the actual video standard, that it is encoded in, back untouched?

It's the equivalent to taking DTS master audio, unpacking it, manipulating it, changing its bit rate and then re-encoding it back to MA or HR for payback ...

It's just seems such a strange process for a video player to point blank refuse to play back video in its native format?

While I agree that the differences are minor, My deltas are off when using xbmc and hard to correct as my co,our
Pallet has shifter... From the 709 pallet the video was encoded in, to the RGB pallet.

My tv gives me deltas of 1/2 when I use a bluray player and an almost perfect gamma of 2.2 ... The same hdmi using my external player on my HTPC gives the same results (using ffdshow) ... But xbmc... Wow... Xbmc makes me have to recalibrate my HDTV completely as reds are shifted, gamma is shifted (quite dramatically) and green is squed (as is cyan)... My point is, while xbmc does a great job, it categorically does readjust the video, and therefore displays it in a "fine" format, but it's not how the film was intended to be... It's not displaying the colours as the director intended.. It's faffing about doing conversions on HD content that is unnessecary, maybe years ago with old avi files this was a good feature... But to manipulate bluray quality video? Really... Why... It's perfect as is.. Just pass it straight through in it's native format.

The other thing is, when my old LG tv was used in full RGB mode, it was stated as a "supported" but the chroma errors were incredible as the tv was not really capable of handleing it correctly, in sRGB (limited) it was fine, but when switching the black point in the tv menu, the tv was unable to reproduce this space effectively, as it produced serious issues with the colour reproduction. Some samsungs were known for producing orange reds when in full RGB mode as they too were not great at dealing with the full RGB range (without errors) effectively.

Doing what xbmc is doing, Reminds me of that old woman who touched up that Jesus painting

Point is though, it looks like there not going to add it and are just getting angry when users ask for it and then become quite tetchy/petty and childish by telling us to code it etc.. It's the most common response from a dev on here

I know changing the video code will be a huge undertaking (much like audio is) but if xbmc doesn't do something about it (other than smart arse responses), will people still be around using this relic in a few years when 4k comes along...

It's 2012 and so far xbmc can not do any of the following in its current official state:
Does not play bluray or bluray menu.
Does not play 3d iso
Does not fully support HD video standards
Does not fully support HD Audio (until frodo is released)
No forced subs
No dual audio out (like ps3 etc)
Etc
Etc

My initial post wasn't "having a go"
I only asked a simple question regrading the 2013 version of frodo.
A simple no would have sufficed, instead of the "code it yourself" response.

Such an attitude toward a simple question is kinda uncalled and all to common in the forums from devs, particularly when xbmc hasn't been coded by the current lot to do some of the most basic movie playback functions.

Just Sayin guys... Maybe you should stop with the smart responses and just say, "we hope to one day" or something similar. I'd understand your grumpy attitude if this player was all singing all dancing and you guys were on it with bleeding edge features... But didn't xbmc just get DVD support in the last 12 months or so bit late to the party.

Anyway, it's to going to happen.
Everyone's tv etc is different, we will have to work around xbmc, no matter how deteremtnal it is to our video, if we wish to use it as a player (I use it as a front end and play in external player)
Thanks for letting me know it won't happen.
Hope you guys sort out your calibration issues, I'll Stick with REC.709 and calman via ffdshow players with a delta of less than 2.
Here's hoping...