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post #31 of 45 Old 09-23-2015, 06:13 PM
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Originally Posted by virtualrain View Post
I didn't have an auto start either. Just cd to .config then and create it there. I'll double check the path later... Maybe I'm missing a dot or something.
Any help you can provide would be great. Is <i> a ctrl function or is it actually a <, i, and >?

How do I paste in putty? When I tried ctrl-V it didn't work right.

Hitting ESC did not seem to exit out of anything. Is it supposed to?

I must not be doing something right...

B.
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post #32 of 45 Old 09-24-2015, 01:28 PM
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Hmm. The conversion chains you've suggested would be highly suboptimal due to the lossy steps, but such steps shouldn't be required unless you're choosing poorly with your filter stages?

If you're running in windowed mode, then video might be converted from YCbCr 4:2:0 directly to RGB 0-255 via video hardware (ie, see nppiYCbCr420ToRGB_8u_P3C3R from the nVidia CUDA docs, or similar for ATI), or it might be chroma upsampled from YCbCr 4:2:0 to YCbCr 4:4:4 via madVR or whichever. If your output is set to RGB limited, then yes, you'll get the lossy RGB 0-255 -> RGB 16-235 compression; but otherwise you'd be sending either RGB 0-255 or YCbCr 4:4:4 to the display depending on which output format you set.
So you say the same i said. If you set GPU output to YCbCr there will be with films double color space conversion, YCbCr -> RGB (with chroma upsampling) and then RGB -> YCbCr, and double levels range conversion, 16-235 -> 0-255 and then 0-255 -> 16-235.
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post #33 of 45 Old 09-24-2015, 08:31 PM
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Originally Posted by HDANDMORE View Post
So you say the same i said. If you set GPU output to YCbCr there will be with films double color space conversion, YCbCr -> RGB (with chroma upsampling) and then RGB -> YCbCr, and double levels range conversion, 16-235 -> 0-255 and then 0-255 -> 16-235.
Well, maybe so...?

I had thought that one of the points of paying for the fancier BluRay PC software players (PowerDVD, Nero, etc) was to get an optimized set of codecs which could stream the video directly from the disk rather than needing to rip and re-encode the video. I had also thought that when such video players were running in full screen exclusive mode, they could passthrough YCbCr 4:2:0 with nothing more than maybe chroma/luma upsampling to 4:2:2 or 4:4:4 depending on what the display can do.

Evidently not. So I suppose there's still an argument to be made for blowing $80 for a decided external BluRay player....

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post #34 of 45 Old 09-25-2015, 10:52 AM
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Originally Posted by cswiger View Post
Well, maybe so...?

I had thought that one of the points of paying for the fancier BluRay PC software players (PowerDVD, Nero, etc) was to get an optimized set of codecs which could stream the video directly from the disk rather than needing to rip and re-encode the video. I had also thought that when such video players were running in full screen exclusive mode, they could passthrough YCbCr 4:2:0 with nothing more than maybe chroma/luma upsampling to 4:2:2 or 4:4:4 depending on what the display can do.
Ok, i understand.

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Originally Posted by cswiger View Post
Evidently not. So I suppose there's still an argument to be made for blowing $80 for a decided external BluRay player....
If someone watch only 1080p film in a 1080p screen and wants just one YCbCr -> RGB conversion and doesn't care about how it is done and is sure TV doesn't do multiple YCbCr-RGB conversions and doesn't care how all this is dithered to native bitdepth (or just like how his TV does all this) then i think maybe there is a valid argument when speaking only about PQ.

If someone doesn't care about RGB->YCbCr conversion because his TV does in a good way but cares about range level's conversion because WTW then a HTPC can properly configured send 16-235 without conversion. Plus more control on things like YCbCr->RGB conversion, dithering, deinterlacing, debanding if needed, etc.

If someone is a PQ maniac then a TV configured as a monitor and a HTPC give him full control in all the chain YCbCr->RGB conversion in 16 bits, customizable chroma upsampling, customizable deinterlacing, customizable dithering to the native bitdepth, color calibration, frame interpolation, etc.

And there are 4k displays so customizable image upscaling is a plus, some people like sharpening and you have customizable options (finesharp, lumasharpen, super xbr, etc.) ... well, you know.

And if you don't watch only 1080p films the list of PQ improvements go on.

What i mean is PQ speaking is not a valid argument in most cases. PlugandPlay is the argument, and may be price.
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post #35 of 45 Old 09-25-2015, 12:11 PM
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Originally Posted by HDANDMORE View Post

If someone doesn't care about RGB->YCbCr conversion because his TV does in a good way but cares about range level's conversion because WTW then a HTPC can properly configured send 16-235 without conversion. Plus more control on things like YCbCr->RGB conversion, dithering, deinterlacing, debanding if needed, etc.
I can't edit. YCbCr->RGB conversion should be deleted.
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post #36 of 45 Old 09-27-2015, 11:17 PM - Thread Starter
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Originally Posted by Brian B View Post
Any help you can provide would be great. Is <i> a ctrl function or is it actually a <, i, and >?

How do I paste in putty? When I tried ctrl-V it didn't work right.

Hitting ESC did not seem to exit out of anything. Is it supposed to?

I must not be doing something right...

B.

Hey. I'm not likely going to be a lot of help, as I use a Mac and I'm hardly a guru at the command line. So Google is likely to be more helpful than I am. I don't use Putty as the Mac has its own terminal app.

However, when I say <i> that means type the letter "i" on the keyboard... using VI, You need to type <i> on the keyboard to activate insert mode, then paste the lines into the editor, then type <esc> <w> <q> to exit edit mode, write the file, and quit respectively.

Navigating around directories is a lot like on any other computer ... Use "cd .." to go up a level and "cd <name>" to go into a directory.

Hope that helps. Google using VI in Linux if you're still struggling.

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post #37 of 45 Old 09-27-2015, 11:23 PM - Thread Starter
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Quote:
Originally Posted by HDANDMORE View Post
It is not so easy. With windows OS if you set YCbCr as the output the flow with films will be:



YCbCr 4:2:0 -> YCbCr 4:2:2 -> YCbCr 4:4:4 -> RGB 16-235 -> RGB 0-255 -> RGB 16-235 -> YCbCr 4:4:4 (-> YCbCr 4:2:2)



If you set RGB 0-255 as output in the GPU and the renderer in RGB 16-235 the flow will be:



YCbCr 4:2:0 -> YCbCr 4:2:2 -> YCbCr 4:4:4 -> RGB 16-235



I don't know if this is true with linux.



sawfish has explained perfectly all the RGB levels - TV black levels configuration.

What a mess. I don't know what Linux is doing either, but I can't imagine it's any worse than this. Perhaps it's worth looking into? What advantage does Windows offer over something like OpenElec?

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post #38 of 45 Old 09-27-2015, 11:37 PM - Thread Starter
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Originally Posted by HDANDMORE View Post
Ok, i understand.







If someone watch only 1080p film in a 1080p screen and wants just one YCbCr -> RGB conversion and doesn't care about how it is done and is sure TV doesn't do multiple YCbCr-RGB conversions and doesn't care how all this is dithered to native bitdepth (or just like how his TV does all this) then i think maybe there is a valid argument when speaking only about PQ.



If someone doesn't care about RGB->YCbCr conversion because his TV does in a good way but cares about range level's conversion because WTW then a HTPC can properly configured send 16-235 without conversion. Plus more control on things like YCbCr->RGB conversion, dithering, deinterlacing, debanding if needed, etc.



If someone is a PQ maniac then a TV configured as a monitor and a HTPC give him full control in all the chain YCbCr->RGB conversion in 16 bits, customizable chroma upsampling, customizable deinterlacing, customizable dithering to the native bitdepth, color calibration, frame interpolation, etc.



And there are 4k displays so customizable image upscaling is a plus, some people like sharpening and you have customizable options (finesharp, lumasharpen, super xbr, etc.) ... well, you know.



And if you don't watch only 1080p films the list of PQ improvements go on.



What i mean is PQ speaking is not a valid argument in most cases. PlugandPlay is the argument, and may be price.

I suspect we all care. I certainly do, which is why I've wasted countless hours of my life just trying to get the f'n levels matched in my signal chain. It's another thing completely to know WTF you need to do, and how to do it. HTPCs are a total pain in the ass... They offer plenty of flexibility but no end of frustration and suck people's valuable time. But we're not here to debate the TCO of HTPCs. That's a lost cause.

Hopefully this thread is helping some folks like me make some progress in at least understanding the issues, if not addressing them.

So now that you've brought up the whole color space conversion thing, how about explaining the PQ downsides to not addressing it, the upsides to getting it right, and some guidance on how to optimize it?

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post #39 of 45 Old 09-29-2015, 04:31 AM
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What a mess. I don't know what Linux is doing either, but I can't imagine it's any worse than this. Perhaps it's worth looking into? What advantage does Windows offer over something like OpenElec?
madvr
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post #40 of 45 Old 09-29-2015, 04:34 AM
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Originally Posted by virtualrain View Post
I suspect we all care. I certainly do, which is why I've wasted countless hours of my life just trying to get the f'n levels matched in my signal chain. It's another thing completely to know WTF you need to do, and how to do it. HTPCs are a total pain in the ass... They offer plenty of flexibility but no end of frustration and suck people's valuable time. But we're not here to debate the TCO of HTPCs. That's a lost cause.

Hopefully this thread is helping some folks like me make some progress in at least understanding the issues, if not addressing them.

So now that you've brought up the whole color space conversion thing, how about explaining the PQ downsides to not addressing it, the upsides to getting it right, and some guidance on how to optimize it?
[URL="http://www.spearsandmunsil.com/portfolio/choosing-a-color-space-2/"Choosing a Color Space[/URL]
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post #41 of 45 Old 09-29-2015, 04:39 AM
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I can't edit. The edited link:

Choosing a Color Space
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post #42 of 45 Unread Today, 07:41 AM
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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!

I know this post is old but I just picked up the new Apple TV and wanted to say thanks and to reaffirm what you said here. I am setting up the Apple TV on a calibrated display (i1 display pro) and running numerous black level tests on all devices to compare with Apple TV as I am seeing EVERYWERE else people on forums saying Apple TV high rgb = full pc levels (0-255) and low = tv limited 16-235) and that's just simply not right.

I hate it when I see people say it's a preference , there's no right or wrong. When it comes to hdmi black level there's a right and a wrong. Both sources need to match or it's wrong. Simple.

Apple TV really should put in brackets alongside rgb high (16-235) and rgb low (0-255) cos as it is the way they have it is backwards to what Samsung are doing as far as I know, and hey should really change it as well to say the numbers alongside.

STOP THIS HDMI BLACK LEVEL MADNESS!! lol.

Anyway just wanted to reiterate that on Apple TV rgb high is actually 16-235 and rgb low is 0-255. Their thinking must of been 16 is a higher number than 0 so let's go with that? I dunno. Either way they should put the numbers alongside it so people can set it right, cos I think the majority are getting it wrong on the Apple TV cos it's backwards to what most devices name them.
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post #43 of 45 Unread Today, 09:42 AM
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Apple TV uses the term "RGB High" to mean the full 0-255 range. If you have a Samsung, the equivalent setting is "HDMI Black Level" and that should be set to "Normal" to match up.

Or use "RGB Low" on the Apple TV, meaning the 16-235 range, and use "HDMI Black Level" of "Low" on a Samsung to match.

References:
Is the labeling correct? "Samsung mislabeling HDMI Black Level setting "Normal" and "Low"
https://forums.plex.tv/discussion/21...xelated-grainy

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post #44 of 45 Unread Today, 09:49 AM
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Originally Posted by cswiger View Post
Apple TV uses the term "RGB High" to mean the full 0-255 range. If you have a Samsung, the equivalent setting is "HDMI Black Level" and that should be set to "Normal" to match up.

Or use "RGB Low" on the Apple TV, meaning the 16-235 range, and use "HDMI Black Level" of "Low" on a Samsung to match.

References:
Is the labeling correct? "Samsung mislabeling HDMI Black Level setting "Normal" and "Low"
https://forums.plex.tv/discussion/21...xelated-grainy

Incorrect. That's the way most do it but with Apple TV high is indeed 16-235 and low is 0-255. I will post some photos of some testing I have done with various settings if you like. I welcome you to do the same. You will see what sawfish and I am saying is correct .
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post #45 of 45 Unread Today, 06:46 PM
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Link where I get into it a little bit more..


https://www.reddit.com/r/appletv/com...i_black_level/
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