It has been widely reported that the player does not pass BTB over HDMI. It also clips whites.
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Hd-a1 Sd...where Did The Blacks Go?
Playing the sd thx optimizer on the hda1 shows no shadow at all on the thx contrast setup logo. Does this mean the blacks below the backround are missing? Isn't this a bad bad thing for sd platback, yet people report they like this player better than, well everything else for sd playback. What gives?
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I just watched Apollo 13. at the part where they are picked up at sea I can see detail in the Black wet suit a diver is wearing.
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Of course you can, it's a light scene, so the "black" suit detail is well above the 16 (7.5 IRE) level that the player clips at. Watch a dark SD disk, like the matrix, where a much larger portion of the image is at or below 16, to see the loss in detail.
Considering the importance of HDMI to the format (or for anyone who wants to upscale standard def DVDs on the player), and the emphasis on PQ by Toshiba, I really think this is THE number one problem they need to solve, and do it quick (ok, it's the number one problem amongst those that could be solved with a firmware update).
| Originally Posted by gstspyder I just watched Apollo 13. at the part where they are picked up at sea I can see detail in the Black wet suit a diver is wearing. |
Considering the importance of HDMI to the format (or for anyone who wants to upscale standard def DVDs on the player), and the emphasis on PQ by Toshiba, I really think this is THE number one problem they need to solve, and do it quick (ok, it's the number one problem amongst those that could be solved with a firmware update).
so the parts of the image that are supposed to be blacker are made into a lighter shade of black, or is that blacker part completely deleted? Why is there no shadow in the thx logo?
Clipping means deleting (or more specifically, not passing the information on to the tv). On the RGB colorspace of 0-255 (with 0 being black annd 255 being white) the Toshiba is clipping everything at the NTSC standard, e.g. below 16 and above 235. Which if you do the math is about 15% of the grayscale, which is a LOT of information.
So, I should be using component and not hdmi for hd-dvd. I have to use hdmi for sd-dvd b/c the component doesn't output 1080i for SD-DVD.
Rafael
Rafael
clipping is only on sd...right?
I've read all the reports of it not passing BTB over HDMI.. but I swear I see it on mine. I get the shadow on the THX optimizer. I will check DVE but I remember looking at it when i first got it and I did 3 all 3 vertical bands of black. I'm running it via HDMI through a Pio Elite 72txv then out to a Toshiba 46HM84.
Maybe I'm not looking for the right thing?
Maybe I'm not looking for the right thing?
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So if I switch from hdmi to component will I see a better picture quality when viewing a HD DVD movie?
| Originally Posted by ottscay Clipping means deleting (or more specifically, not passing the information on to the tv). On the RGB colorspace of 0-255 (with 0 being black annd 255 being white) the Toshiba is clipping everything at the NTSC standard, e.g. below 16 and above 235. Which if you do the math is about 15% of the grayscale, which is a LOT of information. |
Yes. Until the firmware fix is available. We need a callibration disc for HD-DVD.
Rafael
Rafael
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I will give that a go tonight. I guess since they don't allow upconversion via component of std DVD's I could just make backup copies. Weid in that by them trying to stop people from stealing their content they in effect force me to do just that.
| Originally Posted by rfgmdporsc Yes. Until the firmware fix is available. We need a callibration disc for HD-DVD. Rafael |
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No, clipping is on all sources, the results are just more objectionable on SD material.
| Originally Posted by samalmoe clipping is only on sd...right? |
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This is incorrect. RGB colorspace uses 0-255 but designates 0 as black and 255 as white and doesn't include blacker than black (BTB) or whiter than white (WTW) by design.
The issue with the A1 is that in the YCbCr colorspace which utilizes 16-235 with 16 designated black and 235 white, the BTB (0-15) and WTW (236-255) info are missing. See http://en.wikipedia.org/wiki/CCIR_601
The THX drop shadow is a representation of BTB. You can't see it with the A1 over HDMI because the BTB/WTW are missing or "cliipped out".
With the display properly calibrated for black level (brightness) and white level (contrast) the BTB/WTW clipping issue should make little difference in most viewing. The differences will be subtle if any and typically noticed on the upper end of the scale with loss of minor details in very white areas. I wouldn't have noticed it if hadn't been pointed out to me.
The issue needs to be fixed, but try it yourself with both HDMI/Component and see for yourself. You may decide to continue to use HDMI for convenience sake.
It's still possible to set brightness via the THX pattern without BTB. You set it so the 7th box from the bottom right just dissappears. The THX directions mention this as well for those DVD players that won't pass BTB. Other test patterns like those on AVIA don't require BTB to set brightness either.
| Originally Posted by ottscay Clipping means deleting (or more specifically, not passing the information on to the tv). On the RGB colorspace of 0-255 (with 0 being black annd 255 being white) the Toshiba is clipping everything at the NTSC standard, e.g. below 16 and above 235. Which if you do the math is about 15% of the grayscale, which is a LOT of information. |
The issue with the A1 is that in the YCbCr colorspace which utilizes 16-235 with 16 designated black and 235 white, the BTB (0-15) and WTW (236-255) info are missing. See http://en.wikipedia.org/wiki/CCIR_601
The THX drop shadow is a representation of BTB. You can't see it with the A1 over HDMI because the BTB/WTW are missing or "cliipped out".
With the display properly calibrated for black level (brightness) and white level (contrast) the BTB/WTW clipping issue should make little difference in most viewing. The differences will be subtle if any and typically noticed on the upper end of the scale with loss of minor details in very white areas. I wouldn't have noticed it if hadn't been pointed out to me.
The issue needs to be fixed, but try it yourself with both HDMI/Component and see for yourself. You may decide to continue to use HDMI for convenience sake.
It's still possible to set brightness via the THX pattern without BTB. You set it so the 7th box from the bottom right just dissappears. The THX directions mention this as well for those DVD players that won't pass BTB. Other test patterns like those on AVIA don't require BTB to set brightness either.
thanks cpcat for the explaination
I get a better image and sound from the toshiba than from my pioneer 79avi much to my surprise, so I'd like to use the a1 only, so I was wondering if i was missing out on much, as i sure couldnt see a difference. i'll try the thx thingy again...good tip. I'd have to say the a1 and the ruby are a killer combo..
I get a better image and sound from the toshiba than from my pioneer 79avi much to my surprise, so I'd like to use the a1 only, so I was wondering if i was missing out on much, as i sure couldnt see a difference. i'll try the thx thingy again...good tip. I'd have to say the a1 and the ruby are a killer combo..
I tried using the component out and I'm not really sure if it's better than hdmi or not but then my vision is not all that good.
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Can you name a specific spot where "The Matrix" contains stuff that is encoded below video 16? And how do you check that? I know how I check, with a test disk that contains BTB and a DLP where I can see where the mirrors start to come on or not, but I'm wondering how you determine that things are encoded below video 16. As I pretty much mentioned on another thread, being equal to the "black" bars in 2.35:1 material doesn't work.
--Darin
| Originally Posted by ottscay Watch a dark SD disk, like the matrix, where a much larger portion of the image is at or below 16, to see the loss in detail. |
--Darin
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Wow. I'll say.
| Originally Posted by samalmoe I'd have to say the a1 and the ruby are a killer combo.. |
Wow. I'll say.
The video processor in your display needs that below black and above white head room allow you to adjust the picture better, you'r meant to adjust your display so 16 is black and 235 is white. Your not meant to see that data it's there purely to aid video processing, but it's still important.
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This is not necessarily true. This is especially the case with Peak Whites (>235) which will be resolved on a CRT display. This is actually why I refrain from calling them "Whiter than whites" because they are really "peak whites." This distinguishes these levels from "Blacker than black." BTB in a rough sense will not be imaged at the display(depending on display black level float some may become visible.) "Whiter than white" seems to imply that those levels likewise will or should be calibrated away or not imaged on the display which is misleading. That's why I always refer to levels outside the 16-235 bounds as "blacker than black" and "peak whites" respectively, but not "whiter than white."
| Your not meant to see that data it's there purely to aid video processing, |
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