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post #1 of 49 Old 04-17-2012, 05:16 PM - Thread Starter
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This may be stupid but:

Can I use the newest Disney WOW calibrate disk in a standard DVD player? I have a nice new LCD but no bluray. Thanks.
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post #2 of 49 Old 04-17-2012, 05:22 PM
 
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It will not be the same, but yes you could use the DVD. BD's are not that expensive these days. Plus side is, you have a brand new HD tv, and you should be showing it in all its glory, even if you are just watching DVD's. Our Sony BDP-S370 does a good job in upscaling DVD's, and all I used to calibrate both of our sets, was the old Circuit City Calibration DVD that I found, that we got when we bought our Panny Plasma back in 2007.
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post #3 of 49 Old 04-17-2012, 05:44 PM
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Quote:
Originally Posted by Pirateghost View Post

This may be stupid but:

Can I use the newest Disney WOW calibrate disk in a standard DVD player? I have a nice new LCD but no bluray. Thanks.

if you buy the DVD version of Disney WOW, yes

if you buy the BD version, not without a BD player
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post #4 of 49 Old 04-21-2012, 01:10 PM
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In my experience, consumer BD (and DVD, for that matter) players are notorious for putting out incorrect colors and video levels. So if you're planning to use either type of device to do an accurate general display calibration, I would research well before you buy.

For example, almost all of the recent Sony BD players I've tested have a noticeable green push in both YCbCr and RGB mode, and clip green detail above ~92-93% stimulus in the RGB mode. This includes the S380, S185, S580 - 2011 models and S390 -2012 model. The one possible exception was the S580 in RGB mode.

I did not test the S370. You can use the pattern below though to check for green clipping in the RGB mode. If the player clips the green values in RGB mode, chances are pretty good that it's also pushing green, because the mapping of the RGB values is off.

If you have advanced decoder controls on your TV, then you might be able to work around these kinds of issues and still get reasonably good results. On many (most?) TV's though, I suspect those controls are global, and can't be adjusted differently for each input. And the patterns needed to make such tweaks probably aren't readily available.

Other brands may not be much better than the Sonys. Some lower-end Panny players I've tested seemed even more problematic to configure than the Sonys.


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post #5 of 49 Old 04-21-2012, 03:41 PM
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post #6 of 49 Old 04-21-2012, 08:56 PM
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Quote:
Originally Posted by ADU View Post

In my experience, consumer BD (and DVD, for that matter) players are notorious for putting out incorrect colors and video levels. So if you're planning to use either type of device to do an accurate general display calibration, I would research well before you buy.

For example, almost all of the recent Sony BD players I've tested have a noticeable green push in both YCbCr and RGB mode, and clip green detail above ~92% stimulus in the RGB mode. This includes the S380, S185, S580 - 2011 models and S390 -2012 model. The one exception was the S580 in RGB mode.

I did not test the S370. You can use the pattern below though to check for green clipping in the RGB mode. If the player clips the green values in RGB mode, chances are pretty good that it's also pushing green, because the mapping of the RGB values is off.

If you have advanced decoder controls on your TV, then you might be able to work around these kinds of issues and still get reasonably good results. On many (most?) TV's though, I suspect those controls are global, and can't be adjusted differently for each input. And the patterns needed to make such tweaks probably aren't readily available.

Other brands may not be much better than the Sonys. Some lower-end Panny players I've tested seemed even more problematic to configure than the Sonys.

Since this is similar to the testing that I do for HDMI Color Space conversion testing, I have a few questions about this then:

- What test pattern are you using? It looks like it is using % (so 16-235/240) and not the full 0-255 range.
- How have you verified the pattern to make sure it's accurate?
- What are you using to test this on? If it's on a display, how are you sure that the display handles this correctly?
- What firmware versions were tested for the players? Were there different picture modes that could be selected, and which one was used?

I haven't tested a 2012 Sony model yet (I should have the 590 soon and will test it), but getting different performance on the Sony 580 when moving between YCbCr and RGB seems quite strange. When I tested it, the performance was identical, and the green clipping issue is actually caused by it lowering the Luma value it reads off the disc, but green appears clipped since Green makes up most of the visible spectrum, so to lower light output (or luma) you reduce green. That said, when moving between YCbCr and RGB the performance was the same, in that if I took corresponding YCbCr values for the RGB values and did the math on my own, I got the matching RGB coordinates.

The Panasonic 210, as mentioned, is perfect. So are the Oppo players, and the Cambridge 751BD, and most players are now really, really close unless you accidentally implement a picture mode. Getting two different results from the Sony makes me think that either a picture mode was enabled, or the target device isn't handing the colorspaces correctly. I'm mostly wondering how you verify the disc data and the display device (or whatever you are reading the values from), as that can introduce errors as well potentially.

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post #7 of 49 Old 04-21-2012, 09:26 PM
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OK, so I went through the Sony 185 Blu-ray player thread and found that you seem to be using this clip test JPEG/PNG for seeing how a Blu-ray player does with clipping colors, and here's the quick reasons off why this won't work right:

- You're using material stored in RGB format to test this, whereas all Blu-ray content is stored in YCbCr 4:2:0 format. This is introducing an additional RGB -> YCbCr step that won't occur with any Blu-ray disc, and therefore will have no bearing at all on how a player will perform with actual content.
- You're explicitly testing the range of 229 and above for values. Only values 90-92 should contain encoded video content. Some material does contain things above 235 (92 on your pattern is 235) but it shouldn't. The important material is between 16-235 (240 for Cb and Cr values, which aren't in here) and so if something crops 250 then that's not ideal, but the real world implications are practically nil.
- You're verifying this pattern based on how it looks on a display. Some displays can never display content past a certain value, no matter how you set it up. It could just as easily be that the Blu-ray player that isn't cropping is the only one that's improperly moving values too low on the scale, so instead of 255 that's actually 240, so now it's visible.
- The PNG size (at least as posted) isn't 1920x1080, so you're asking the player to scale, which can cause the colors to be slightly changed potentially.

Really, using that test image in the way that you are just tells us nothing about how a Blu-ray player performs with clipping colors with Blu-ray material. You could easily pick up a Panasonic 210 or Oppo player, and they could fail this test, and yet they still are perfect Blu-ray players, and I have the testing to back that up. It's a good thought, but is just doesn't apply here.

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post #8 of 49 Old 04-21-2012, 09:37 PM
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Did you ever test the Samsung c6900 or comparable models?

I think my Samsung Bluray player is also mildly changing the image somehow, I didn't do enough tests to see exaclty what it's doing though. Just curious because this is the bluray player I am using on my JVC projector ATM...


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post #9 of 49 Old 04-21-2012, 09:40 PM
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Quote:
Originally Posted by coderguy View Post

Did you ever test the Samsung c6900 or comparable models?

I think my Samsung Bluray player is also mildly changing the image somehow, I didn't do enough tests to see exaclty what it's doing though. Just curious because this is the bluray player I am using on my JVC projector ATM...

I did the Samsung D6500 and D5500 models, and we have reviews on the site of those. How recent is the 6900? I can really only keep track of so many company model numbers in my head at once. If it's current, I'll email Samsung this weekend and try to get one for testing, as I haven't tested anything from CES this year yet (Panasonic, Sony, and Samsung included).

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post #10 of 49 Old 04-21-2012, 10:38 PM
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It's about a year old or so. It's a pretty common model because it was sold a lot both online and at retailers as a common 3d player. There are a few other models which are basically the same player with minor differences (mostly aesthetic). It's just ok IMHO, I personally will replace it soon. The Hulu and Netflix interface are not that good on it, and the player's reading ability seems to be too sensitive to scratches (although no idea which bluray player deals with scratches the best).

It is one of those players that likes to freeze for multiple seconds when it hits a scratch and not respond to user input, since I use a lot of redbox (scratch box) movies, it gets to be a pain sometimes. A lot of power on/off, cleaning disc, trying again.


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post #11 of 49 Old 04-26-2012, 02:21 PM
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Quote:
Originally Posted by Smackrabbit View Post

Since this is similar to the testing that I do for HDMI Color Space conversion testing, I have a few questions about this then:...

You raise some very good questions, Chris. I hadn't really planned on publishing my results on all the players, but hopefully the graph below will begin to answer a few of your questions, and maybe give you something to compare with your own tests. Most of the info was gathered just for my own personal use in selecting a new BD player, which is why some of it is incomplete.

Brand: Sony Sony Sony Sony Sony
Model #: DVP-NS77H BDP-S580 BDP-S380 BDP-S185 BDP-S390
Player Type: Upscaling DVD Blu-ray Blu-ray Blu-ray Blu-ray
Model Year: 2007 2011 2011 2011 2012
Hardware Mfr. Code:
(2-digit code on back of player)
7D ? (late rev. purchased 12-11, so probably 1C or 1D) ? ? (late rev. purchased 3-12, so probably 1C or 1D) 1D
Mfr. Date:
(based on hardware mfr. code)
Q4 2007 ? (probably Q3 or Q4 2011) ? ? (probably Q3 or Q4 2011) Q4 2011
Software Revision:
(in system info)
n/a M07.R.0263
(default)
? M09.R.0036
(update)
M11.R.0060
(default)
HDMI Color Mode: RGB
(Tested on Gateway FHD2400 LCD & Sony 34XBR800 CRT)
Green Push:
File Type: MPEG2
(16-235 YCbCr DVD-Video)
No No Yes Yes Yes
File Type: PNG
(0-255 RGB)
- - Yes Yes Yes
Green Clip Point in % Stimulus:
(100% stimulus = no visible clipping in normal color range)
File Type: MPEG2
(16-235 YCbCr DVD-Video)
100% - 92-93% 92-93% 92-93%
File Type: PNG
(0-255 RGB)
- - 92-93% 92-93% 92-93%
HDMI Color Mode: YCbCr 4:2:2 & 4:4:4
(Tested on Gateway FHD2400 LCD only)
Green Push:
File Type: MPEG2
(16-235 YCbCr DVD-Video)
Yes(?)* Yes(?)* Yes(?)* Yes(?)* Yes(?)*
File Type: PNG
(0-255 RGB)
- - Yes(?)* Yes(?)* Yes(?)*
Green Clip Point in % Stimulus:
(100% stimulus = no visible clipping in normal color range)
File Type: MPEG2
(16-235 YCbCr DVD-Video)
100% - 100% 100% 100%
File Type: PNG
(0-255 RGB)
- - 100% 100% 100%

* Edit 5/3/12: Results shown in red above are now in doubt due to a possible error in my testing on the YCbCr HDMI modes on these players.

The S580 is the first player I tested, so I don't have as complete info on that unit as the others. I created the PNG green push and clip tests and DVD clip test patterns after I encountered decoding errors on other players, to better help me analyze and correct (as much as possible) the problems on my TV.

Unlike the other BD players though, the color output on the S580 appeared to be the same on DVD tests as on my older Sony NS77H upscaling DVD player. As you can see from the tests above, both players appear to push green in the YCbCr HDMI color modes, but not in the RGB HDMI color mode.

I'll try to lay may hands on another late rev. S580 so I can do a more thorough series of tests though. It is conceivable that some S580's may "fail" the tests, while others may not depending on the hardware and software revisions on the players.

I'm also going to create a set of JPEG patterns as well, so I have a third file type for comparison. (My older NS77H DVD player does not support PNG, so I could not perform those tests on it.)

The PNG clip test patterns that I used on the S185, S380 and S390 are basically the same as the one posted earlier, except that the resolution was 1920x1080. When I tried to upload/attach the 1080p file here, the AVS image attachment handler converted the file to JPEG introducing some unwanted compression errors in the pattern. So I had to crop and slightly scale the PNG file down to 800x600 for posting here. I have tested the 800x600 pattern above on the players as well, and it gives the same result as the 1080p patterns, even though it's scaled by the player to fit the screen. As indicated on the graph, the values on the PNG tests range from 0-255. To "avoid confusion" though, I've treated them as a "% stimulus". So, for example a 90% color swatch in the PNG test is basically 255 * .90, which equals 229 in RGB levels.

Interestingly, the clip point on the S185, S380, and S390 players I tested is the same on the DVD patterns, despite the fact that the color palette is compressed to a 16-235 range.

The Green Push/Decoding patterns look something like this...



...though I created add'l patterns with approximately 25%, 50%, 75% and 100% "bars" at 1080p resolution to test decoding performance at different stimulus levels. I also created a 2nd set of decoder patterns that were limited to approx. 10% to 90% stimulus range to better correct the player's decoding problems on my own TV, because the clipping errors on the player were causing unreliable results with standard 0% to 100% stimulus color bars.

(Last time we talked, I had some questions about the accuracy of my MPEG encoder, but I have performed some tests on that as well, which confirm it's reliability to my satisfaction. In my tests, the captured RGB values after MPEG compression/encoding are only off the original "pre-encoded" RGB values by about 1 or 2 RGB codes at most, which is less than the errors I've encountered on at least one commercial calibration disc.)

The HDMI RGB color mode tests were performed using 2 different displays, a 34" Sony 34XBR800 CRT via DVI at 1080i, and also a 24" Gateway FHD2400 1920x1200 resolution computer/video monitor via HDMI at 1080p, mapped 1:1 with no overscan/scaling. Since the Sony TV does not support YCbCr via DVI, the HDMI YCbCr color mode tests were performed only on the 24" Gateway display.

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post #12 of 49 Old 04-26-2012, 03:17 PM
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I have the Sony S590 here now, and should know over the weekend if the output is perfect or not for both RGB and YCbCr, but some other questions this raised with me (I'm admittedly reading quickly right now):

- With the evaluations being done on two different displays, one or both could have an issue, and is adding an extra variable to the testing
- Using DVDs here, or DVD content, could be a bad idea. Since DVD uses Rec 601 and Blu-ray uses Rec 709 for encoding, the formula to get from YCbCr to RGB is slightly different. Typically a player will apply a matrix twist to this to get the correct values for HD from an SD DVD, but what if it doesn't? Then the displays are seeing a 1080p signal and assuming it's HD and using Rec 709 to display it, but really it should be using different values to convert YCbCr to RGB. That's yet another variable introduced that you can't account for in the results.
- Since RGB is just converted from YCbCr, if you have an issue in YCbCr then you should have an issue in RGB. If you don't then the issue to me is more likely that a display is handing the two colorspaces differently, but since you are using two different displays for two different colorspaces, I'd say there's a 99% chance it's the display that is causing the issue. Especially with the results being exactly the same across all the players. That leads me to think its more of a methodology issue than a player issue.

The different things that would have to be eliminated in my mind would be:

- The test content needs to be 4:2:0 encoded onto a Blu-ray, just like actual Blu-ray content is
- The display has to be the same for all of them
- You'd need separate test patterns for YCbCr and RGB, to make sure if the issue is in the conversion or something else

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post #13 of 49 Old 04-26-2012, 05:29 PM
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Quote:
Originally Posted by Smackrabbit View Post

Were there different picture modes that could be selected, and which one was used?

Forgot to mention above that the picture quality mode was set to "Standard" in all cases during my tests. I did not use either the "Bright Room" or "Theater Room" modes.

Quote:


I haven't tested a 2012 Sony model yet (I should have the 590 soon and will test it), but getting different performance on the Sony 580 when moving between YCbCr and RGB seems quite strange. When I tested it, the performance was identical, and the green clipping issue is actually caused by it lowering the Luma value it reads off the disc, but green appears clipped since Green makes up most of the visible spectrum, so to lower light output (or luma) you reduce green. That said, when moving between YCbCr and RGB the performance was the same, in that if I took corresponding YCbCr values for the RGB values and did the math on my own, I got the matching RGB coordinates.

There are alot of things which could explain the different result I got on the S580 in the RGB versus YCbCr HDMI color modes, which is why I'd like to retest another unit to confirm the results with some other file formats.

My suspicion is that Sony may have fixed the decoding in the RGB HDMI color mode in a subsequent software or hardware revision of the S580, after your less than stellar review. But that's pure speculation, and I see no evidence of them making similar adjustments on other models so far.

I suppose it's also conceivable that the S580 performs more "correctly" with DVDs in the HDMI RGB color mode than Blu-rays, but that seems a bit unlikely to me. It'll be interesting to see your results on the S590 though (which I haven't tested yet).

Quote:
Originally Posted by Smackrabbit View Post

OK, so I went through the Sony 185 Blu-ray player thread and found that you seem to be using this clip test JPEG/PNG for seeing how a Blu-ray player does with clipping colors, and here's the quick reasons off why this won't work right:

- You're using material stored in RGB format to test this, whereas all Blu-ray content is stored in YCbCr 4:2:0 format. This is introducing an additional RGB -> YCbCr step that won't occur with any Blu-ray disc, and therefore will have no bearing at all on how a player will perform with actual content.

It has bearing on how the player performs with still files and potentially any web-based content as well, since PNG is a standard format for the web.

As indicated above though, I also performed tests using YCbCr format MPEG-2 DVD-Video.

Quote:


- You're explicitly testing the range of 229 and above for values. Only values 90-92 should contain encoded video content. Some material does contain things above 235 (92 on your pattern is 235) but it shouldn't. The important material is between 16-235 (240 for Cb and Cr values, which aren't in here) and so if something crops 250 then that's not ideal, but the real world implications are practically nil.

Just to clarify a bit more on this... In my tests, the green clipping in the HDMI RGB color mode on the S185, S380 and S390 is noticeable whether the file format is RGB (0-255), or YCbCr (16-235). The clipping is not occuring above the standard 16-235 video range on the DVD tests (where it would be invisible on many displays), as you suggest above. It's occurring at about 92-93% stimulus within the standard 16-235 DVD video range.

The fact that the clipping is consistent across two different file/video types (PNG stills and MPEG2 video), and different color file formats (RGB and YCbCr) suggests to me that the clipping problem in the players' HDMI RGB color modes are likely "across the board", and will probably be evident on other kinds of media as well, including potentially Blu-ray discs. IMO, the same theory applies to the green push on the S185, S380 and S390 in both the RGB and YCbCr HDMI color modes.

I haven't actually done any tests with Blu-ray format video files yet though, as you point out. So my tests are only "circumstantial" as far as Blu-ray performance is concerned at this point. (I'll get to the BD tests eventually though. )

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post #14 of 49 Old 04-26-2012, 06:30 PM
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I think one of the points that you might be missing is that YCbCr isn't a standard.

YCbCr can be rec.601, rec.709 or it's used in PNG encoding and so on. But the actual encoding/decoding scheme differs per implementation.

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post #15 of 49 Old 04-26-2012, 10:21 PM
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Quote:
Originally Posted by Smackrabbit View Post

I have the Sony S590 here now, and should know over the weekend if the output is perfect or not for both RGB and YCbCr, but some other questions this raised with me (I'm admittedly reading quickly right now):

- With the evaluations being done on two different displays, one or both could have an issue, and is adding an extra variable to the testing

The HDMI RGB color mode tests were performed on two different displays (Sony HD CRT & Gateway HD LCD), using two different connections (DVI & HDMI), and two different resolutions (1080i & 1080p). I deliberately used different displays, connections and resolutions to rule those out as possible sources of the green push and green clipping in that mode.

Quote:


- Using DVDs here, or DVD content, could be a bad idea. Since DVD uses Rec 601 and Blu-ray uses Rec 709 for encoding, the formula to get from YCbCr to RGB is slightly different. Typically a player will apply a matrix twist to this to get the correct values for HD from an SD DVD, but what if it doesn't? Then the displays are seeing a 1080p signal and assuming it's HD and using Rec 709 to display it, but really it should be using different values to convert YCbCr to RGB. That's yet another variable introduced that you can't account for in the results.

As you know from previous discussions, I'm aware of the potential twisting issues with upscaled DVDs. That's one reason why I performed tests with still PNG files as well, to help rule out upscaling and 601->709 color-space conversion as a potential source of the problems.

HDTV and sRGB (the "standard" color-space for PCs and the web) use the same color primaries/white point. So there's really no reason for a BD player to be "adapting" the color of still PNG computer files for display on an HDTV the way the Sony players seem to be doing.

The fact that I'm getting the same type of green push and clipping errors on PNG files and DVDs leads me to believe there's something more fundamental going on to cause this. (Maybe just a "style choice" on Sony's part.)

Quote:


- Since RGB is just converted from YCbCr, if you have an issue in YCbCr then you should have an issue in RGB. If you don't then the issue to me is more likely that a display is handing the two colorspaces differently, but since you are using two different displays for two different colorspaces, I'd say there's a 99% chance it's the display that is causing the issue. Especially with the results being exactly the same across all the players. That leads me to think its more of a methodology issue than a player issue.

There could be some madness in my method. The results seem pretty consistent so far though. And I've done just about everything I can think of to try to rule out other sources than the player as the cause of the errors I'm seeing.

You needn't take my word it on though. If you're experienced in calibration (and even if you're not), you can DL the still tests patterns here to a thumb drive and give them a test ride for yourself, if you wish. (I invite you to do so and prove me wrong, because I've had pretty good experiences with my Sony players in the past, and would like to find one with correct color output, or I wouldn't be bothering with all this. ) Just don't leave em on screen too long if you have a plasma or other display susceptible to burn-in.

Quote:


The different things that would have to be eliminated in my mind would be:

- The test content needs to be 4:2:0 encoded onto a Blu-ray, just like actual Blu-ray content is

Not within my power at the moment (though I'm working on it).

Quote:


- The display has to be the same for all of them

The 24" Gateway was used for all tests in both the RGB and YCbCr HDMI color modes. And both the Gateway and Sony CRT were used for the RGB HDMI color mode tests. The likelihood of both displays producing the same decoding errors in the RGB HDMI color mode seems somewhat remote to me.

Quote:


- You'd need separate test patterns for YCbCr and RGB, to make sure if the issue is in the conversion or something else

You'll have to go into more detail on this (if you want to). I am in the process of trying to put together a reliable MP4 encoding set up. And will probably grab at least one commercial BD calibration disc for comparison, to further expand my tests.

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post #16 of 49 Old 04-26-2012, 10:22 PM
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Quote:
Originally Posted by sotti View Post

I think one of the points that you might be missing is that YCbCr isn't a standard.

I get that Joel. RGB and YCbCr are just generic color spaces. And I concede that it's possible for a Blu-ray player to produce different results with HD YCbCr Blu-ray video files than with SD DVD-Video files.

As mentioned above though, it seems odd/unlikely to me that a Blu-ray player would perform better with SD DVD files than with HD BD files, which is one possible way of looking at our combined results on the S580 in in the HDMI RGB color mode. (My SD DVD tests looked ok in the HDMI RGB mode, but I believe the Secrets HD BD tests showed errors.)

IMO, a more likely explanation for the discrepancy in this particular case is that Sony may have fixed the decoding in the S580's HDMI RGB color mode in a later rev of the player. That is pure speculation though... at least until I can get my hands on another unit to retest.

Chris also acknowledged this possibility in a previous discussion btw...

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Originally Posted by Smackrabbit View Post

Sony has also released firmware updates for the S570 and S580 since we tested those, so performance might have improved, but I haven't retested them to see.

The interesting thing in all this (to me anyway) is that the Secrets S580 results look alot like my S185, S380 and S390 results. Green push and improperly mapped luma values (in both RGB and YCbCr HDMI modes) which are undoubtedly related to, or the cause of green clipping in my RGB HDMI color mode tests on those three lower-end players.

The only real points of contention here are the results on the S580 HDMI RGB color mode. My DVD test said it was ok. Their BD tests (which were done about a year earlier) said it wasn't, and was pushing green and mapping luma too brightly, like in the YCbCr mode. So my one DVD test on the S580 is really the only outlier here so far.

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YCbCr can be rec.601, rec.709 or it's used in PNG encoding and so on. But the actual encoding/decoding scheme differs per implementation.

Also, AFAIK, the PNG format has no support for YCbCr. I believe it's RGB (with optional alpha channel) only.

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post #17 of 49 Old 04-27-2012, 09:52 AM
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Originally Posted by ADU View Post

As mentioned above though, it seems odd/unlikely to me that a Blu-ray player would perform better with SD DVD files than with HD BD files, which is one possible way of looking at our combined results on the S580 in RGB mode. (My SD DVD tests looked ok in RGB mode, but I believe the Secrets HD BD tests showed errors.)

We had errors in RGB and YCbCr, but they were consistent with each other.

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IMO, a more likely explanation for the discrepancy in this particular case is that Sony may have fixed the decoding in the S580's RGB mode in a later rev of the player. That is pure speculation though... at least until I can get my hands on another unit to retest.

That would require Sony to have specifically fixed the issue in one colorspace and then either elected not to copy it over to YCbCr (if they are calculated in different areas), or more likely, intentionally added code to make it fail. The YCbCr to RGB code was working correctly in the S580, the issue was with the initial 4:2:0 to 4:4:4 or 4:2:2 conversion, so for this to be the case, they would have had to intentionally messed up the data more, which is highly unlikely.

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The interesting thing in all this (to me anyway) is that the Secrets S580 results look alot like my S185, S380 and S390 results. Green push and improperly mapped luma values (in both RGB and YCbCr modes) which are undoubtedly related to, or the cause of green clipping in my RGB mode tests on those three lower-end players.

Actually, our testing doesn't show this at all. It shows that luma (and therefore green) is lower than expected on output, so instead of 235 you are getting 210 or something close to that. Since this is the case (255 comes out at 231 instead of 255) then if you are seeing clipping at a value even lower than this, that would be your display that is clipping and not the unit. The Sony was incorrect when tested, but in a totally different way than you think you are seeing.

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The RGB color tests were performed on two different displays (Sony HD CRT & Gateway HD LCD), using two different connections (DVI & HDMI), and two different resolutions (1080i & 1080p). I deliberately used different displays, connections and resolutions to rule those out as possible sources of the green push and green clipping.

Have you tested the displays with a reference pattern generator and test patterns at all colorspaces to make sure they don't have issues themselves? This is why we avoid using a display, as you could be testing the display as much or more than you are testing the player itself.

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As you know from previous discussions, I'm aware of the potential twisting issues with upscaled DVDs. That's one reason why I performed tests with still PNG files as well, to help rule out upscaling and 601->709 color-space conversion as a potential source of the problems.

HDTV and sRGB (the "standard" color-space for PCs and the web) use the same color primaries. So there's really no reason for a BD player to be "adapting" the color of still PNG computer files for display on an HDTV the way the Sony players seem to be doing.

Using PNG has nothing to do with 601->709, but also has nothing to do with a 4:2:0 to other color space conversion. You're starting with RGB, and as there are no RGB sources on Blu-ray, it has nothing to do with clipping Blu-ray content potentially. It's like saying "My decompression program does ZIP files incorrectly, therefore it also does RAR and TAR files incorrectly as well."

[quote=ADU;21956673]The fact that I'm getting the same type of green push and clipping errors on PNG files and DVDs leads me to believe there's something more fundamental going on to cause this. (Maybe just a "style choice" on Sony's part.)

There could be some madness in my method. The results semm pretty consistent so far though. And I've done just about everything I can think of to try to rule out other sources than the player as the cause of the errors I'm seeing.[quote=ADU;21956673]

Or, since there is a consistency to the tests in the error being recorded, there is something in the methodology itself that is introducing the error and the players are working correctly.

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As indicated above though, I also performed tests using YCbCr format MPEG-2 DVD-Video.

You're using DVD format video to test Blu-ray performance, when the YCbCr to RGB conversions in the two are different. If the value encoded on the disc is 100,100,100 you can get two different values depending on if you are targeting Rec 601 or 709, which is another source of error.

I'm hoping to test the 590 this afternoon, and since it has the same general hardware as the 390 (It has different bonus features, such as 2D-3D conversions and such, but the decoding performance should be the same) we can see where it falls. Right now there are so many potential sources for error (incorrect source material, displays can't do the content correctly, displays aren't calibrated correctly, 601 to 709 twist is incorrect, not reading the monitor correctly, etc...) that I can't say with any certainly what, if anything, the results are saying.

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post #18 of 49 Old 04-27-2012, 12:51 PM
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Quick Sony BDP-S590 Notes:
- Perfect at 4:2:2 and 4:4:4
- RGB is broken. Green hits 254 at 218, not 254, or 86%.

So, if you are seeing 90% but not 92% in RGB, something else in that testing method is broken, as from 86% on up they would be identical in RGB mode.

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post #19 of 49 Old 04-28-2012, 01:08 PM
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Originally Posted by Smackrabbit View Post

Quick Sony BDP-S590 Notes:
- Perfect at 4:2:2 and 4:4:4
- RGB is broken. Green hits 254 at 218, not 254, or 86%.

So, if you are seeing 90% but not 92% in RGB, something else in that testing method is broken, as from 86% on up they would be identical in RGB mode.

Thank you for posting this S590 info, Chris.

Quote:


- Perfect at 4:2:2 and 4:4:4

By "perfect", I take it you mean that there's no clipping apparent in the S590's HDMI YCbCr color modes, in the standard video color range, which is exactly what my tests show above for the S185, S380 and S390.

In spite of our different approaches, so far your HD video test results on the S590 are looking pretty much identical to my PNG and DVD test results on the S185, S380, and S390.

We both agree that there's no visible clipping of green (or other colors) near white in the normal video color range in the YCbrCr HDMI color modes on these players. And we also agree that there is some visible clipping of the green values within the standard 16-235 video color range in the RGB HDMI color mode. All we appear to disagree on at the moment is exactly where the clipping in the RGB mode begins. But I think I can explain that as well, if you'll bear with me...

To calculate % stimulus for something like a PNG file in 24-bit (8-bit per color component) 0-255 RGB format, all you need to do is divide the RGB clip value by 255.

Calculating % stimulus for something like a DVD or BD video file in 16-235 YCbCr video format is a bit more involved though, because the head and foot room (and video black step) need to be factored in. Here are two simple equations which can be used for that:


(RGB clip value - 16) / (235 - 16) = stimulus

or simply...

(RGB clip value - 16) / 219 = stimulus

If you're using Rec. 709 compliant high-definition YCbCr Blu-ray video files for the S590 tests, then you need to use an equation like this, rather than simply dividing by 255, or 254 as you've done above. (I figured you were already aware of this btw, or I probably would have mentioned it earlier.)

If your RGB "clip value" of ~218 is plugged into either of these video equations, the answer that comes out is 92.24% stimulus.


(218 - 16) / 219 = .9224

Since you can't measure above 254 on your equipment though, I'm guessin that the actual clip point for green on the player is probably a step higher, which would be 219, or about 92.69% stimulus.


(219 - 16) / 219 = .9269

Either way, the result is consistent with my PNG and DVD-Video tests in the RGB HDMI color modes on the Sony S185, S380 and S390 BD players (92-93% stimulus as shown on the table above). So it appears my methods are workin pretty well despite our different approaches. I would not describe the YCbCr HDMI color modes on these players as "perfect" though, because my PNG and DVD tests also suggest they're pushing green in both the RGB and YCbCr HDMI color modes. Perhaps you'll find something similar on the S590 as well, as you get a bit deeper into your color tests on that unit.

I also played around a bit with the different Picture Quality Modes in the Video Settings on the S390. And I can confirm that there are differences in the clipping of video content when switching between those settings in the HDMI RGB color mode. Here's the way my DVD-Video tests break-down...

Video Settings / Picture Quality Mode: Green Clip Point in RGB HDMI Color Mode:
Standard 92-93% Stimulus
Bright Room 91-92% Stimulus
Theater Room 100% Stimulus
(no clipping in standard color range)

This feature seems quite buggy on the S390 btw. I had to cycle the power off and on to get each setting to "stick". My general recommendation would be to leave it set at "Standard".

Although there was no clipping apparent in the "Theater Room" mode (in the standard 16-235 video color range), the gamma on that setting also looked a bit funky to me. So I don't recommend using it. All three modes appear to push green as well. As far as I can tell, there is no way to eliminate the green push on the S185, S380 and S390 with just the players' settings alone, unless Sony can do fix for the issue. Some users might be able to compensate for this issue on their HDTV's though, especially if they have advanced decoder controls like in the service mode of my Sony CRT.

However, the green clipping can be avoided on these players by simply using the YCbCr HDMI color modes rather than the RGB mode. This is borne out by both Chris's and my tests. Unfortunately, using the YCbCr color modes is not an option for me, because the DVI input on my older Sony CRT only works with the RGB HDMI color mode.

Also, in case it's still unclear which tests I performed on which displays, here's a quick synopsis...

HDMI Color Mode: Display(s) Used for Tests:
RGB Gateway FHD2400 LCD (HDMI) & Sony 34XBR800 CRT (DVI)
YCbCr 4:2:2 Gateway FHD2400 LCD (HDMI)
YCbCr 4:4:4 Gateway FHD2400 LCD (HDMI)

I made a few tweaks to the graph and other posts above to hopefully make this somewhat clearer there as well.

One other thing I'll add is that the Picture Quality Modes in the Sony players' Video Settings appear to have no effect on PNG, JPEG or other still images. Those modes only seem to apply to video content (i.e. DVDs, BDs, and other video files).

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post #20 of 49 Old 04-28-2012, 01:50 PM
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Quote:
Originally Posted by Smackrabbit View Post

We had errors in RGB and YCbCr, but they were consistent with each other...

...Right now there are so many potential sources for error (incorrect source material, displays can't do the content correctly, displays aren't calibrated correctly, 601 to 709 twist is incorrect, not reading the monitor correctly, etc...) that I can't say with any certainly what, if anything, the results are saying.


I'll give you this Chris... I can't really tell what's going on inside the players in terms of the Luma and Chroma processing. So I apologize if I misspoke or put incorrect words in your mouth about that. All I can really tell is what's going on in terms of the end result on the display after the video data has been converted back to the RGB domain.

It's clear that we are looking at the data on these players through slightly different lenses (figuratively speaking). But it appears to me that our results are mostly in agreement so far. You asked how I arrived at my results, and I've obviously done a poor job of explaining it so far. But I'm doing the best I can, given the different points of view that we seem to be coming from.

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post #21 of 49 Old 04-28-2012, 07:39 PM
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On Theater it clips as well, though I don't like saying clips, it more compresses dynamic range on green, as that better explains what is going on to me. That's the issue with rating Theater at 100%, is that is incorrect as well. The 235 value is actually mapping to 242, so the dynamic range has been compressed from 16-235 down to 16-229. You're scoring it at 100% because the loss isn't apparent, though there is an average dE76 of 2.37 for green (and 1.4 if you use dE94) which will cause a clearly visible shift in greens. Red and Blue also has issues in every mode with RGB enabled. Peak dEs of 4.5 or so occur in the middle of range for green in Theater. Theater manages to have a smaller dE than Standard with RGB, but I haven't looked at Red and Blue much due to time issues.

I have no idea why the Sony is wrong with RGB at Standard as YCbCr is perfect. I have to do the math for the other modes to see if it does YCbCr to RGB correctly, but if it does, I'm going to assume they made a firmware mistake and hopefully they will fix it.

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post #22 of 49 Old 04-30-2012, 10:49 PM
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Quote:
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The Panasonic 210, as mentioned, is perfect.

Several of you mentioned the Panasonic 210. Is there something wrong with the 110? My parents have it and I don't see any issue with it.
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post #23 of 49 Old 05-01-2012, 02:29 AM
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Several of you mentioned the Panasonic 210. Is there something wrong with the 110? My parents have it and I don't see any issue with it.

I've only tested the 210 and not the 110 but if setup correctly it is likely the same.

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post #24 of 49 Old 05-01-2012, 01:48 PM
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Quote:
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On Theater it clips as well, though I don't like saying clips, it more compresses dynamic range on green, as that better explains what is going on to me. That's the issue with rating Theater at 100%, is that is incorrect as well. The 235 value is actually mapping to 242, so the dynamic range has been compressed from 16-235 down to 16-229. You're scoring it at 100% because the loss isn't apparent...

I'm glad you brought this up. You're absolutely right that my DVD-Video clip test only checks for errors within the standard 16-235 video color range (aka "studio swing levels"), because my MPEG encoder automatically compresses full 0-255 RGB color data/patterns into that range. Hence, the following note on the tables above...

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(100% stimulus = no visible clipping in normal color range)

At the moment, I don't have a reliable test for clipping outside the normal 16-235 range, in the BTB (0-15) or WTW (236-255) color regions, on video content. I can make an educating guess as to what might be going on there though, in some cases.

For example, although there are no signs of clipping near video white in the 16-235 range in the YCbCr HDMI modes on the S185, S380 and S390, there are other strong indicators in my PNG and DVD tests that these players are not mapping colors correctly and are pushing more Green (or Luma) in the YCbCr modes, as well as in the RGB HDMI color mode. This suggests to me that the players may be clipping some or all of the Green or Luma values above video white (235) in the YCbCr HDMI color modes (with Picture Quality mode set to "Standard").

If the S590 works the same way, then I suspect you'll find Green/Luma clipping above 235 video white in the YCbCr HDMI color modes on that player as well (in "Standard" PQ Mode)... if you also have a test for that.

You may also find that Red and Blue are clipped above 235 video white in the RGB HDMI color mode, because that seems to be the pattern here.

IMO, both the RGB and YCbCr HDMI color modes are "broken" (to use your term) on these players, because they're both mapping the colors incorrectly and pushing too much green. The problem is just more apparent in the RGB HDMI color mode because the color values are clipped at a lower level in that mode (green lowest of all).

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Peak dEs of 4.5 or so occur in the middle of range for green in Theater.

Gamma is obviously a bit higher in the Theater Room mode than in the other PQ Mode settings (Bright Room is lowest). But gradients also seemed a bit "funky" to me beyond just the boosted gamma in that mode. So maybe there's some sigmoidal contrast enhancement as well, or somethin along those lines. Not sure about that though.

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I have no idea why the Sony is wrong with RGB at Standard as YCbCr is perfect. I have to do the math for the other modes to see if it does YCbCr to RGB correctly, but if it does, I'm going to assume they made a firmware mistake and hopefully they will fix it.

I don't know whether it's deliberate or not, but green/luma push is a common technique used to artificially boost the brightness (or green-ness) of video content on both players and displays, perhaps to appeal to what someone else here described as the "over-50 golfer demographic" (because it makes the grass on golf courses look more green).

I'm getting the same or similar color results on most of Sony's recent BD players though. So it seems quite possible that it's being done intentionally either for style/brightness purposes, or as a shortcut to save on the cost of programming, graphics/decoding chips and mfr'ing.

I tested an LG BP220 BD player over the weekend and it's exhibiting the same type of green push/clipping in it's Standard video setting in the RGB HDMI mode as the Sonys. The LG has user controls for Contrast, Brightness, Color and Sharpness though, which can at least be used to fix the green clipping issue in the RGB HDMI color mode. (Not sure about the green push yet.)

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post #25 of 49 Old 05-01-2012, 03:34 PM
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Quote:
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IMO, both the RGB and YCbCr HDMI color modes are "broken" (to use your term) on these players, because they're both mapping the colors incorrectly and pushing too much green. The problem is just more apparent in the RGB HDMI color mode because the color values are clipped at a lower level in that mode (green lowest of all).

In Standard Mode, using YCbCr 4:2:2 or 4:4:4, the S590 is perfect and certainly not broken. The RGB mode in Standard color space has an issue and I'm asking them about it, as I'm guessing it's a bug and not desired behavior.

Quote:


Gamma is obviously a bit higher in the Theater Room mode than in the other PQ Mode settings (Bright Room is lowest). But the gradients also seemed a bit "funky" to me beyond just the boosted gamma in that mode. So maybe there's some sigmoidal contrast enhancement as well, or somethin along those lines. Not sure about that though.

I wouldn't use the term gamma for this, as gamma would control how quick a display is moving from light to dark. Here the player is removing dynamic range, in one of two directions, to simulate gamma. Gamma doesn't lead to a loss of detail, removing dynamic range does, so I wouldn't call it gamma.

Quote:


I'm getting the same or similar color results on most of Sony's recent BD players though. So it seems quite possible that it's being done intentionally either for style/brightness purposes, or as a shortcut to save on the cost of programming, graphics/decoding chips and mfr'ing.

There's always a chance the YCbCr to RGB issue is in the HDMI transmitter chip as that's been the case before. If so, then either Sony won't be able to fix it, or they'll have to come up with a transform that changes the YCbCr values to something else before the transmitter chip that then results in correct values after the chip. That might not be possible either, though. I'm hoping it's just a firmware bug.

I also could care less if companies add these modes, as long as they describe them better. Don't say "Use in a dark room" if it really means "Use to simulate a dark room on a TV calibrated for a bright room". Suggesting that using these modes based on room conditions is incorrect when you should really setup your display based on viewing conditions.

Quote:


I tested an LG BP220 BD player over the weekend and it's exhibiting the same type of green push/clipping in it's Standard video setting in the RGB HDMI mode as the Sonys. The LG has user controls for Contrast, Brightness, Color and Sharpness though, which can at least be used to fix the green clipping issue in the RGB HDMI color mode. (Not sure about the green push yet.)

But what does using this control cause to happen with the other colors? Using that to fix one issue is going to lead to another issue.

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post #26 of 49 Old 05-01-2012, 06:31 PM
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Quote:
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In Standard Mode, using YCbCr 4:2:2 or 4:4:4, the S590 is perfect and certainly not broken.

If this is true, then I'm glad for the S590 folks who can use those YCbCr modes. However, based on what I've seen on other recent Sony players, I'm still pretty skeptical about this, Chris. (Maybe I'll pick up an S590 to try as well.)

In my tests, the S390 is not clipping the bright green values in the normal 16-235 video range in it's YCbCr HDMI modes. But there are other pretty unambiguous signs to me that it's still pushing green or luma more strongly than red and blue in the YCbCr HDMI modes (like in the RGB mode).

If I increase the contrast setting* on my Gateway LCD to the point where the display begins to clip the detail just below video white in the YCbCr HDMI modes, the first color that begins to show evidence of clipping (by a large amount) is green, which is not typical behavior for my LCD.

Most LCDs will clip the RGB color levels somewhat unevenly if you overdrive the Contrast setting on them. And my Gateway LCD panel is no exception to that general rule. But the amount of green clipping that I'm seeing when I raise the LCD's Contrast control on the S390's YCbCr HDMI input is not normal for this display. All of the green detail between 90% and 100% stimulus is swallowed up before there's any sign of red or blue clipping on the S390's YCbCr HDMI input.

This (and also tests with my decoder patterns) suggests to me that the S390 player is mapping the green/luma values more brightly than red and blue in the YCbCr modes, and probably also clipping the green/luma values slightly above video white (235), to push more green in that mode.

Do you have any way to check for signs of red, green (or luma), and blue clipping above 235 video white in the YCbCr HDMI modes on the S590? If the WTW green or luma detail clips at a lower level than red and blue in the S590's YCbCr HDMI modes, it would probably confirm my suspicions on this.

(*Footnote: on my Gateway LCD, Contrast & Saturation both have to be raised together to maintain proper color balance on the HDMI input, which is what was done for the above tests.)

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post #27 of 49 Old 05-01-2012, 09:05 PM
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When I say it's perfect, that means that for YCbCr, every single value is bit-perfect from 1-254, and for RGB it is bit-perfect from 0-255. No ambiguity, no questions, no worries about WTW or BTB. With the S590 in Standard mode, using YCbCr output, there is zero difference from what is on the disc and what is being output. With RGB, there is something going on that is leading to an incorrect signal, which is causing green to rise too fast and red and blue to not rise fast enough.

With the way we test, there is no question on if it's correct or not. No monitors that might work incorrectly, no patterns that are in the wrong format, just straight test and data. The player I just got today has an issue where in certain midtones, it isn't a steady gradient, but is slightly off for a few values, then recovers. It would be nearly impossible to pick up using the eye and a display, but I can repeat the tests and see how it's behaving and it's consistent.

So with the Sony BDP-S590 and YCbCr modes, there is nothing wrong with them, at all, in Standard mode.

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post #28 of 49 Old 05-01-2012, 09:45 PM
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ADU, you realize Chris has access to some extremely high end hardware including signal analyzers?

He's pulling his results directly from the HDMI wire. He's got the gear to isolate the player and test it's performance in a vacuum.

If your observations are different, you need to start looking at the other hardware you are using to test with.

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SpectraCal
CalMAN Lead Developer
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post #29 of 49 Old 05-01-2012, 10:23 PM
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I also looked into other hardware to use for testing and finding something that does 4:2:2, 4:4:4 and RGB and allows full access to an HDCP stream was hard to impossible to find. The QD882 was the only thing I could find a year ago that worked, but I haven't searched since then.

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Senior Editor, Secrets of Home Theater and High Fidelity, www.hometheaterhifi.com
Displays Editor, AnandTech.com
Contributor, HDGuru.com and Wirecutter.com
ISF Level II Certified Calibrator, ReferenceHomeTheater.com
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post #30 of 49 Old 05-02-2012, 09:31 AM
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this is most likely the same analyzer HDMI.org/ATC certified testing stations use as part of the HDMI manufactures Compliance Testing process, Specification ?

http://www.quantumdata.com/products/882E.asp
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