No x.v.color on Bu-ray, not even in the future???

[mainman]

On this forum, this guy posted something about x.v.color.

02. Deep Color and xvYC are not found on any Blu-ray or HD DVD discs, and never will be, because its not included in the spec, and isn't possible.

This cant be true, can it?

Link:
http://www.ps3forums.com/showthread.php?t=100263

[Papi4baby]

Read the first line on the spec.
http://www.sonystyle.com/webapp/wcs/...52921665228713

http://en.wikipedia.org/wiki/XvYCC

XvYCC is part of HDMI 1.3 not blu ray alone.

[mainman]

Originally Posted by Papi4baby

Read the first line on the spec.
http://www.sonystyle.com/webapp/wcs/...52921665228713

http://en.wikipedia.org/wiki/XvYCC

XvYCC is part of HDMI 1.3 not blu ray alone.

The guy is claiming Blu-ray spec doenst support x.v.color. Not HDMI 1.3.

The sonystyle link says:
"BD/DVD/CD playback4 and AVC-HD with x.v.Color output"

Doesnt say anything about Blu-ray movies being capable of xv.color.

[DavePS3]

When I looked into this a while back, those two color specs were not made for Blu-Ray, they were for DVD camcorders etc. Check Wikipedia. If memory serves, XV and the other one are strictly for the consumer end of the camcorder biz.

[DavePS3]

HDMI 1.3 supports those color codes but they have nothing to do with BD or HD-DVD.

[mainman]

Originally Posted by DavePS3

When I looked into this a while back, those two color specs were not made for Blu-Ray, they were for DVD camcorders etc. Check Wikipedia. If memory serves, XV and the other one are strictly for the consumer end of the camcorder biz.

I placed a question concerning this in the insiders thread. Let's hope one of the insiders will answer my question.

[DavePS3]

I think it was Sony who developed the two codes so for example, if your new camcorder has those codes and you use them in recording, then you take the disc out and pop it in your BD player to watch what you recorded, you wont lose the extra color codes because the player, the HDMI1.3 and possibly your display support it.

[Rob Zuber]

I'm pretty sure the video specs for Blu-Ray and HD-DVD (for movies) do not accommodate deep color. It will be used for games.

[DavePS3]

I think we're both right here, Rob. I knew there was another source for the two codes but couldn't remember what it was. I think it's explained at the HDMI website... maybe that's where I saw it.

[Deciazulado]

Well DVDs have been mastered watching SMPTE "C" colors but coded in NTSC parameters for years and viceversa, so I don't see why they couldn''t do it that way. PAL and SMPTE "C" color gamut is more or less similar to HDTV color gamut, as the NTSC color gamut is to the XvYCC

[Papi4baby]

But saying BD doestn' support it because is not on the spec is stupid. Good thing we dont have finish specs. I can't see it too dificult to implement.

[scott1256ca]

I can't see it too dificult to implement.

You can have a look at Penton-man's response on the insider thread, but the problem is that no existing BD players could play back the movies if you were to suddenly start employing deep colour. So it would require a new gen. of players and new movies incompatible with older players.

Penton-man, in the insider thread says that he doesn't think deep colour would fit on a BD 50. I don't understand why not. It would just require a little more compression.

I'm more an RGB guy than a YPrPb guy (meaning I don't have to think about it much). Current 8 bit colour in RGB space means 24 bits/pixel. I think of deep colour as 10 bit colour, meaning 30 bits/pixel. I just don't see why you can't compress that.

Yes, I understand that as you get finer resolution, you start to come close to the noise floor, which makes lossless compression difficult, but it shouldn't stop lossy, which is what AVC etc. give us. The major visual benefit to us viewers, as I see it, should translate to less or no visual posterization, which is a problem with a number of movies. Particularly the earlier ones. The way to deal with it is dithering, which is kind of a crappy solution. I don't know why BD didn't include it in the spec in the first place. Even if it weren't implemented right away, at least it would make older players compatible.

Perhaps it is a processing power issue for playback. If they wanted to wait for it, they may have had to push back the launch even further.

[Papi4baby]

Yeah i read that too thanks

[NutsAboutPS3]

Originally Posted by scott1256ca

The major visual benefit to us viewers, as I see it, should translate to less or no visual posterization, which is a problem with a number of movies.

Posterisation is a problem of lack of bitrate, there is no need for deep colour to solve it. I've never noticed posterisation on any DVDs I own, because DVDs had plenty of bitrate for their resolution, it's really only a problem that has come along with HD formats.

This is just a very rough calculation, but with a DVD9 you could have an average bitrate around 7.5Mbps (combined video+audio) for a 2.5 hr movie at 720x576 (x480 for NTSC). 1920x1080 is 5 times as many pixels as 720x576, so an equivalent HD bitrate is 37.5Mbps. Most HD movies don't use an average bitrate this high, though in theory a BD50 can fit a 2.5 hour movie at 44Mbps (combined video+audio). I would be very surprised if a movie encoded at this bitrate showed any posterisation.

Most current TVs can't even display every colour from a 24 bit palette anyway.

[scott1256ca]

Posterisation is a problem of lack of bitrate

Not by any definition I can find.
http://www.pcmag.com/encyclopedia_te...i=49550,00.asp

Definition of: posterization

The effect produced when a photographic image is displayed or printed with a small number of colors or shades of gray. For example, displaying color photographs or video with 16 colors produces a visible posterization, but the images are discernible. At 256 colors, the flesh tones on color images are still mildly posterized. For realistic flesh tones, it takes 65K colors. For absolute realism, it requires 16M colors.

http://www.cambridgeincolour.com/tut...terization.htm

Posterization occurs when the bit depth of an image has been decreased so much that it has a visual impact on the image. The term posterization is used because it can influence your photo similar to how the colors may look in a mass-produced poster where the print process uses a limited number of color inks. This effect ranges from subtle to quite pronounced, although one's tolerance for posterization may vary.

Both of those definitions fit in with my understanding.

[Digital Filmmaker]

The bitrates quoted for DVDs are, of course, for using MPEG 2 compression. Blu-ray discs encoded with MPEG 4 (AVC) have the advantage of a more efficient codec (higher quality) per given bitrate. So, if you have a movie on BD using the AVC codec at 30+mbps, you are getting a far better and cleaner image than by using the MPEG 2 codec.

I saw a high definition disc shootout a few years ago at the Sonic booth at the NAB show between an uncompressed D5HD master source of scenes from Lawrence of Arabia and both Blu-ray and HD-DUD prototype disc players playing the identical scenes sychronized with the D5 master. The two formats were showing the scenes from discs encoded with identical codecs and at the maximum bitrates allowed by each format.

The results were very impressive. The most telling scenes were of the gentle gradations of sun, sky and desert displayed on all three sources. Both disc formats looked impressive, with sharp HD images that matched the resolution of the D5 master. The difference between them became clear, however, when it came to matching the smooth gradations of the scenes mentioned above. The HD-DUD disc betrayed a lower maximum bitrate by showing subtle (and sometimes not so subtle) banding and contouring taking place. The Blu-ray disc, on the other hand, was a near-perfect representation of the D5HD master. Very smooth and even gradations with nary the slightest hint of compression.

I knew at that point that Blu-ray was THE choice and would win any format war that might result in the future if the formats stayed separate. Today, it continues to be true - and we are seeing the results with every passing day.

[NutsAboutPS3]

Originally Posted by scott1256ca

The effect produced when a photographic image is displayed or printed with a small number of colors or shades of gray. For example, displaying color photographs or video with 16 colors produces a visible posterization, but the images are discernible. At 256 colors, the flesh tones on color images are still mildly posterized. For realistic flesh tones, it takes 65K colors. For absolute realism, it requires 16M colors.

Precisely - Blu-ray already has the required 16M colours, and therefore will not exhibit posterisation if there is sufficient bitrate for it to utilise its capabilities.

Originally Posted by scott1256ca

Posterization occurs when the bit depth of an image has been decreased so much that it has a visual impact on the image. The term posterization is used because it can influence your photo similar to how the colors may look in a mass-produced poster where the print process uses a limited number of color inks. This effect ranges from subtle to quite pronounced, although one's tolerance for posterization may vary.

This reduction in bit depth will only occur if the encode is starved of bitrate.

Originally Posted by Digital Filmmaker

The bitrates quoted for DVDs are, of course, for using MPEG 2 compression. Blu-ray discs encoded with MPEG 4 (AVC) have the advantage of a more efficient codec (higher quality) per given bitrate. So, if you have a movie on BD using the AVC codec at 30+mbps, you are getting a far better and cleaner image than by using the MPEG 2 codec.

Agreed.

Originally Posted by Digital Filmmaker

.....The difference between them became clear, however, when it came to matching the smooth gradations of the scenes mentioned above. The HD-DUD disc betrayed a lower maximum bitrate by showing subtle (and sometimes not so subtle) banding and contouring taking place. The Blu-ray disc, on the other hand, was a near-perfect representation of the D5HD master. Very smooth and even gradations with nary the slightest hint of compression.

Exactly - proof if any were needed that posterisation is purely a problem that occurs with insufficient bitrate, the formats already have sufficient colour depth if they have enough bitrate to make use of it.

[CptGreedle]

Doesn't really matter if BD can support it or not.. if no BD player can because HDMI does not then right now BD can not.
Either way.. i know of nothing that uses it now anyways.

[ricster]

I have bought the 4k version of ghostbusters today and upon firing it up my tv informed me.



The back cover states that xvYCC blu ray player and TV are required to play these new titles.

[ronjones]

Originally Posted by ricster

I have bought the 4k version of ghostbusters today and upon firing it up my tv informed me.

..............................
The back cover states that xvYCC blu ray player and TV are required to play these new titles.

Of course this disc is only "master in 4K" while the disc itself is still 1080p. However, it is intended to be displayed with a somewhat expanded color gamut (xvYCC). It really must be noted that while this is an wider color gamut than regular HD (ITU rec.709) is it still a far smaller color gamut that specified for true 4K Ultra HD (ITU rec. BT.2020). Hopefully the upcoming standard for Blu-ray 4K disc will conform to rec. BT.2020.