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Discussion Starter · #1 · (Edited)
I'm a bit confused. If I play the AVS black level test pattern in Plex on my TV and adjust black levels so 17+ is flashing (which happens to be Sonys default setting for "Cinema Pro" or 50)... It looks like you would expect...

ImageUploadedByTapatalk1441691740.892690.jpg

If I then quit Plex to my Mac Mini desktop (don't change TV settings at all) and load the test pattern in Preview, it looks like this... The full range is visible...

ImageUploadedByTapatalk1441691751.078743.jpg

What is going on here? I would have expected my desktop to show 1-16 as pitch black.

Without changing anything on the TV, why is 16 black in Plex, but the same test pattern on my Mac desktop indicates 0 is black? Is this right? Can someone make sense of it for me?
 

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That's the way it works.

Video content has black at 16, PCs use 0 as black.

Depending on how you view the content (video player, jpg viewer, ect..) you'll get different results.
 

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Discussion Starter · #3 ·
That's the way it works.

Video content has black at 16, PCs use 0 as black.

Depending on how you view the content (video player, jpg viewer, ect..) you'll get different results.
Thanks... so my TV is set correctly?

Also, I notice that Kodi has a setting for using 16-235... that is currently off and Kodi produces the same result at Plex (first attached image above). What will enabling that setting do? Should I turn it on or leave it off?
 

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Discussion Starter · #4 ·
I came across this great post by member sawfish that may help my situation... but I have a few questions...

I agree, but I think it's potentially confusing to say the GPU should output "limited color range". Unless the TV doesn't support it, the GPU should output RGB 0-255, the PC default. As I understand it, the only alternative is for it to compress everything to 16-235, either as RGB or YCbCr. For this to work for video, video must first be expanded to RGB 0-255, causing the dreaded levels round trip of 16-235 to 0-255 to 16-235. I'm going to assume below the card is outputting RGB 0-255, which means it can pass through whatever is presented to it.

As for the video player and TV, the main consideration is, do you want consistency between desktop and video? If so, the video player should expand Video Levels to PC Levels, i.e. 16-235 to 0-255, and the TV should be set to PC Levels ("Non-standard" for my ST60). For video, this discards BTB and WTW and scales all the values in between into 0-255, which is necessary for Black = 0 and White = 255 to work for video as well as the desktop. If you don't care about this, then your video player can leave the video untouched and output Video Levels, and your TV should be set accordingly ("Standard" for my ST60). This is the WMC default and Kodi's "Use limited range" option. This is passthrough for video and preserves BTB and WTW, but the TV will crush black and probably at least some white on the desktop, as it should be calibrated for Black = 16 and White = 235 (overshoots allowed). This is not a problem unless you use the PC for gaming, critical picture viewing, and whatnot. It won't interfere in the least with using WMC or Kodi, nor will it interfere with maintaining the PC and even writing letters and such. This choice provides consistency with video devices like streamers, BD players, etc, some of which may not have RGB 0-255 output options, e.g. my Sony S5100 BD player only has RGB 16-235 (however, unlike a PC, it doesn't appear to do a levels round trip). This consistency would let you hook everything up to an AVR and use a single AVR HDMI output.

Agree completely with using the TV for all calibration. I use the second of the two approaches just above, and my PC and BD player measure the same under the same calibration, which is all done with the TV. This was not the case when I had the video player output PC Levels; then, I had to make some tweaks to Brightness in the Nvidia Control Panel to get Bar 17 to show up in AVS HD 709 Black Clipping.
Can someone confirm or correct my understanding?

- My Mac is outputting 0-255 full range on the desktop?
- Video playback in Kodi/Plex has limited output from 16-235?
- My current TV black level is correct (black at 16 for video and 0 on the computer desktop)?

Now what I don't understand is what Kodi's "use limited range" does? It already seems to output a limited range... even without enabling this option? What am I missing? It sounds like Kodi's "use limited range" does the opposite and passes through full 0-255? I'm very confused about this.
 
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I came across this great post by member sawfish that may help my situation... but I have a few questions...

Can someone confirm or correct my understanding?

- My Mac is outputting 0-255 full range on the desktop?
- Video playback in Kodi/Plex has limited output from 16-235?
- My current TV black level is correct (black at 16 for video and 0 on the computer desktop)?
Going by your first post, your video card is outputting 0-255, Kodi/Plex are expanding video from 16-235 to 0-255, and your TV is set for 0-255. Unlike Kodi/Plex, your paint program is just displaying the image without any alteration. This is all fine if you want the desktop/video consistency I talked about in the message you quoted. You can verify by playing Black Clipping in Kodi/Plex, then raising Brightness on the TV and failing to see bars below 17 light up. They won't, because that information was lost in the 16-235 to 0-255 expansion.

Now what I don't understand is what Kodi's "use limited range" does? It already seems to output a limited range... even without enabling this option? What am I missing? It sounds like Kodi's "use limited range" does the opposite and passes through full 0-255? I'm very confused about this.
Kodi's "Limited Range" option is the passthrough for video I talked about in that message. It doesn't touch video, but unlike WMC, it does alter its UI so that the UI won't be crushed, not that it really matters that much.
 

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Discussion Starter · #6 ·
Going by your first post, your video card is outputting 0-255, Kodi/Plex are expanding video from 16-235 to 0-255, and your TV is set for 0-255. Unlike Kodi/Plex, your paint program is just displaying the image without any alteration. This is all fine if you want the desktop/video consistency I talked about in the message you quoted. You can verify by playing Black Clipping in Kodi/Plex, then raising Brightness on the TV and failing to see bars below 17 light up. They won't, because that information was lost in the 16-235 to 0-255 expansion.
Ok thanks, this makes sense. I was a bit confused that raising black level while playing the pattern didn't reveal more bars on the test pattern... I thought they were left off. Now I see they were clipped off.

Is there anything I can do to preserve the WTW? I'm not sure I should care about BTB... right?

Kodi's "Limited Range" option is the passthrough for video I talked about in that message. It doesn't touch video, but unlike WMC, it does alter its UI so that the UI won't be crushed, not that it really matters that much.
Sorry, but do you recommend using this option or not? Will this preserve the WTW? Would I need to re-adjust my black levels?
 

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Is there anything I can do to preserve the WTW?
No.

I'm not sure I should care about BTB... right?
It does help one set Brightness.

Sorry, but do you recommend using this option or not?
See my post that you quoted. I can't really "recommend" anything so instead I described the trade-offs. As I said, I personally use the passthrough approach, because the calibration is better, and I don't care about desktop/video consistency or the desktop being crushed, because it doesn't matter for my usage of WMC and Kodi.

Will this preserve the WTW? Would I need to re-adjust my black levels?
The passthrough approach should preserve both WTW and BTB. You would need to set your TV to "Standard" or whatever it calls Video Levels, and then check all the settings.
 

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Discussion Starter · #8 · (Edited)
No.

It does help one set Brightness.

See my post that you quoted. I can't really "recommend" anything so instead I described the trade-offs. As I said, I personally use the passthrough approach, because the calibration is better, and I don't care about desktop/video consistency or the desktop being crushed, because it doesn't matter for my usage of WMC and Kodi.

The passthrough approach should preserve both WTW and BTB. You would need to set your TV to "Standard" or whatever it calls Video Levels, and then check all the settings.
Thank you very much, I'll try some things this evening. I don't care about desktop crush as my Mac is exclusive to Plex/Kodi (I'm still trying to figure out which player is better).

My TV has the following settings...

The HDMI® Dynamic Range feature helps produce natural color by changing the luminance tone reproduction of HDMI input color signals. The dynamic range of the image is reproduced properly by selecting the desired dynamic range for signal type being used.
Use the Auto setting during normal operation. The Auto setting automatically selects the dynamic range Full or Limited based on dynamic range information coming from connected device.
The Full setting should be used when you would like the signal range fixed to full range. An example may be a high-definition signal from a device connected using an HDMI cable.
Limited: The signal range is fixed to limited range. This should be used when less color is desired.
If I want to go the passthrough route to preserver WTW and BTB, should I be using Full or Limited?

EDIT: Never mind... I found this, which explains the TV settings more clearly...

http://forum.kodi.tv/showthread.php?tid=225712&pid=1995501#pid1995501
 

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It does help one set Brightness.

See my post that you quoted. I can't really "recommend" anything so instead I described the trade-offs. As I said, I personally use the passthrough approach, because the calibration is better, and I don't care about desktop/video consistency or the desktop being crushed, because it doesn't matter for my usage of WMC and Kodi.

The passthrough approach should preserve both WTW and BTB. You would need to set your TV to "Standard" or whatever it calls Video Levels, and then check all the settings.
Thanks for clarifying full range vs limited range. While the definitions are well known and seemingly straightforward, sometimes things may seem to be working "backwards" if one doesn't think it through carefully.

Not that I have anything against passthrough, but personally I haven't found BTB to be essential for setting contrast. I just posted my view in a different thread earlier today:

http://www.avsforum.com/forum/139-d...ernal-displays-can-really-3.html#post37137466
 

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Thank you very much, I'll try some things this evening. I don't care about desktop crush as my Mac is exclusive to Plex/Kodi (I'm still trying to figure out which player is better).

My TV has the following settings...

The HDMI® Dynamic Range feature helps produce natural color by changing the luminance tone reproduction of HDMI input color signals. The dynamic range of the image is reproduced properly by selecting the desired dynamic range for signal type being used.
Use the Auto setting during normal operation. The Auto setting automatically selects the dynamic range Full or Limited based on dynamic range information coming from connected device.
The Full setting should be used when you would like the signal range fixed to full range. An example may be a high-definition signal from a device connected using an HDMI cable.
Limited: The signal range is fixed to limited range. This should be used when less color is desired.
Wow. I doubt those instructions have anything to do with reality. Per google, Thanks Sony. Below, I'm going to assume Full/Limited have their usual meaning.

If I want to go the passthrough route to preserver WTW and BTB, should I be using Full or Limited?
For the passthrough option I talked about, you would choose Limited, because that's what your player is outputting. If your player were outputting Full Range, it would have already discarded BTB/WTW in the expansion from Limited Range aka Video Levels to Full Range aka PC Levels. Only when the player is outputting Video Levels can there be BTB/WTW. Again, the video card must be outputting Full Range RGB 0-255 for this to work, and I'm talking about the setting that affects all output. If there is a separate "Video" section, ideally it would be left at "Let the player decide" or whatever they call it. In summary, the idea for passthrough is to set the player up to decode the video without altering the pixel values and for the card to output those pixels without altering them. This means Limited Range for the player and Full Range for the card.

EDIT: Never mind... I found this, which explains the TV settings more clearly...

http://forum.kodi.tv/showthread.php?tid=225712&pid=1995501#pid1995501
And crawfish even rhymes with sawfish. Hmmmm. :D
 

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Discussion Starter · #12 · (Edited)
For the passthrough option I talked about, you would choose Limited, because that's what your player is outputting. If your player were outputting Full Range, it would have already discarded BTB/WTW in the expansion from Limited Range aka Video Levels to Full Range aka PC Levels. Only when the player is outputting Video Levels can there be BTB/WTW. Again, the video card must be outputting Full Range RGB 0-255 for this to work, and I'm talking about the setting that affects all output. If there is a separate "Video" section, ideally it would be left at "Let the player decide" or whatever they call it. In summary, the idea for passthrough is to set the player up to decode the video without altering the pixel values and for the card to output those pixels without altering them. This means Limited Range for the player and Full Range for the card.
Thanks again for your help.

This evening I set Kodi (running on OpenELEC on my Mac Mini) to limited range, and the TV to limited range and was dismayed to find I still wasn't getting WTW and BTB on the test patterns. They were still getting clipped. So I thought I would look into ensuring the OpenELEC GPU driver was set for full RGB colour range and came across this thread (last post) which pointed out another setting in Kodi that needs to be disabled (VAAPI Render Method). Sure enough, toggling that did the trick. I've now calibrated my TV's black point properly and get full WTW on max contrast.

I suspect 99% of people using HTPCs are probably running with non-ideal settings as a result of all this nonsense that's very poorly documented anywhere.

Now that I have my TV setup properly for Kodi. What am I likely going to run into when running my PS4 through the AVR to the same TV input? Any advice on how to setup my PS4 to use the same TV settings on the same TV input? I believe the PS4 has both a Limited and Full color range option as well. Will the TV set to limited mean games won't look good? Unfortunately, the Limited/Full range setting on the TV is a per input setting, not a picture mode setting.
 

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I suspect 99% of people using HTPCs are probably running with non-ideal settings as a result of all this nonsense that's very poorly documented anywhere.
I don't doubt it. The terminology is confusing at best and often used ambiguously, which doesn't help.

Now that I have my TV setup properly for Kodi. What am I likely going to run into when running my PS4 through the AVR to the same TV input? Any advice on how to setup my PS4 to use the same TV settings on the same TV input? I believe the PS4 has both a Limited and Full color range option as well. Will the TV set to limited mean games won't look good? Unfortunately, the Limited/Full range setting on the TV is a per input setting, not a picture mode setting.
I don't do PS4 so can't really advise on that. The holy grail is an AVR with two HDMI outputs, one you can use for Video Levels and the other for PC Levels, like my Pioneer VSX-1124. OTOH, if everything has to go to a single TV input, and one or more devices do best outputting PC Levels (black = 0, white = 255), the compromise approach for the HTPC may be the best bet, that is, having the video player expand Video Levels to PC Levels. Lots of people do just that.
 

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Now that I have my TV setup properly for Kodi. What am I likely going to run into when running my PS4 through the AVR to the same TV input?
The default setting on the PS4 is "automatic", it would be best to set it manually to "Limited".
 

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Discussion Starter · #15 · (Edited)
The default setting on the PS4 is "automatic", it would be best to set it manually to "Limited".
Why do you suggest this? (not disagreeing, just trying to understand what's going on when you set it one way or the other)

Edit: I use the PS4 for gaming, not watching movies. I would expect games to use the full RGB range... No?
 

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Discussion Starter · #16 ·
I don't doubt it. The terminology is confusing at best and often used ambiguously, which doesn't help.

I don't do PS4 so can't really advise on that. The holy grail is an AVR with two HDMI outputs, one you can use for Video Levels and the other for PC Levels, like my Pioneer VSX-1124. OTOH, if everything has to go to a single TV input, and one or more devices do best outputting PC Levels (black = 0, white = 255), the compromise approach for the HTPC may be the best bet, that is, having the video player expand Video Levels to PC Levels. Lots of people do just that.
Great idea. I have two HDMI outputs on my new Yamaha AVR. I can use the existing one for video levels with Kodi and the other with full RGB for gaming. :D
 

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Discussion Starter · #17 ·
I came across this article about levels and gaming consoles, which I thought was good until I read this, which seems out of date... Most modern TVs work just fine in full RGB mode, and have no trouble reproducing the full range... No?

http://referencehometheater.com/2014/commentary/rgb-full-vs-limited/

Q: My TV supports Full mode, shouldn’t I use this?

A: No. TVs support Full to make them easier to calibrate. Most TVs will not display a black level below 16 because video content should never have it. By letting you see Black 15 or 14, it can make it easier to calibrate the display and get the black level correct. However, you really should not use this as your main setting as most displays are not designed to display levels below 16, and often introduce color tints when doing white levels past 240 or so. Additionally, if you restrict yourself to levels 16-235 you wind up with a brighter image with a better contrast ratio, as you can turn up the contrast level higher. Contrast Ratio is the thing your eye notices most, and so it will produce a more pleasing image.

Also, since any non-video game content will only use 16-235, these picture settings will work for all inputs and sources, not just a single source.
 

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I came across this article about levels and gaming consoles, which I thought was good until I read this, which seems out of date... Most modern TVs work just fine in full RGB mode, and have no trouble reproducing the full range... No?
IMHO, that article actually contains some errors:

TVs support Full to make them easier to calibrate...By letting you see Black 15 or 14, it can make it easier to calibrate the display
Full mode does not display BTB; Limited mode does. Some people find it easier to set the Brightness control if they can see BTB during calibration.

Additionally, if you restrict yourself to levels 16-235 you wind up with a brighter image with a better contrast ratio, as you can turn up the contrast level higher.
Limited mode actually produces a dimmer image, hence worse (lower) contrast ratio, if you follow the usual calibration approach, which reserves some headroom to allow for WTW. White the contrast level setting may indeed by higher, it's not receiving the "full" signal which more than negates the higher setting.
 

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IMHO, that article actually contains some errors...

Full mode does not display BTB; Limited mode does.
It's pretty unfortunate terminology, isn't it? When talking about video, "Limited Range" is the default and passthrough, or lossless, or whatever synonym you prefer, while "Full Range" discards information and scales values as it expands 16-235 to 0-255, the discarded values being BTB (< 16) and WTW (> 235). The word "Full" sounds better than and thus preferable to "Limited", but it isn't here. I think it's clearer to use "Video Levels" and "PC Levels" in this context, where "Levels" means the values considered to be reference black and white.

When talking about video card output, it's the other way around. The default is "Full Range RGB", 0-255, or passthrough, or lossless, or whatever synonym you prefer, while "Limited Range RGB" is 16-235 and implies that 0-255 is compressed to the range 16-235. So for video card output, "Full" really is better than "Limited".

When talking about TVs and other devices, each manufacturer is its own universe. For example, my Panasonic ST60 uses "Standard" and "Non-standard" for Video Levels and PC Levels, respectively, which is pretty good. OTOH, the Apple TV uses "RGB High" to mean Video Levels and "RGB Low" to mean PC Levels. Argggh!
 
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