Color Subsampling And 10-Bit Video In The HD-DVD Standard
Dear Gary: Concerning the upcoming HD-DVD standard I fully support a 1080p standard with the option of lossless MLP audio. In addition, I suggest that two outdated video standards are no longer the only option and there is the option to move to the current state-of-the-art. I’m talking about color subsampling. The HD-DVD standard should include a compression standard that can handle 4:4:4 full resolution data without color subsampling. As feature films are more and more mastered with DI technology in 4:4:4 and the HD is made from this master it should be able to reproduce this master without filtering down the chrominance component. It’s still up to the studios to release a lower quality version first with color subsampling as long as digital projection in cinemas is “only” 2K 4:4:4 to keep a quality edge over home cinema, but they should be able to release 4:4:4 at a later date without changing the standard and require new players to be bought. This is true for 8-bit video. Provide for 10-bit video in the standard as an option that can be used or not used for now, but is available for the best quality as provided by the DI. There should be no built-in need in the standard to dither critical color gradients to avoid banding if the master element needs no dither.
Michel Hafner
Contributing Editor Joe Kane Comments:
Those are neat goals but we aren’t there yet on the video side. The limitation is the ability to record video once it is processed. The most expensive, commonly available recorder for HD video is the HD D-5. It’s a compressed 10-bit, 4:2:2 recorder. We can process at the rates you suggest but just can’t practically store or distribute them.
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