BD and HD color depth?

[Nielo TM]

Are both HD and BD mastered in 24bit (8bit per shade) or in deep colors (30, 36 and 48bit)?

If the answer is 24bit, then what's the point of HDMI supporting “deep colors”?

[MikeK]

If the answer is 24bit, then what's the point of HDMI supporting “deep colors”?

AFAIK, it's 8bit 4:2:0 colour - same for both disc formats. Not sure about SkyHD, but I'd be surprised if it were any different.

What's the point of deep colour? Probably none for now, but who knows in 5 years time.........

[Nielo TM]

Sorry, just figured it out. Id it is 24bit, player manufacturers can super sample it to deepcolor. Just like they did with DVD players. The only weird part is that CRT TVs didn't have any depth processing but nearly all HDTVs do?

[StooMonster]

It's the codec (MPEG-2 or AVS/H.264 or VC-1) not the physical structure (HD DVD or Blu-ray) that is important in answering this question.

All these codecs in HD DVD and Blu-ray configuration use 24-bit (8-bit per channel) colour in 4:2:0 for encoding

Sky HD (MPEG-2 for SD channels and H.264 for HD ones) also uses 4:2:0 for transport stream, but the settopbox outputs 24-bit 4:4:4 in RGB or YPbPr.

When the 4:2:0 chroma encoding is expanded to 4:4:4 the players can use greater bit depth (e.g. 30-bit / 10-bits per channel) and then transmit this over HDMI 1.3

However, like "upscaling" the displays will do this anyway -- and sometimes better than players -- if you could force player to output the raw 4:2:0 rather than the more typical 4:2:2

See http://en.wikipedia.org/wiki/Chroma_subsampling for more info.

Originally Posted by Nielo TM

what's the point of HDMI supporting “deep colors”?

Marketing mostly.

StooMonster