[opendtv] Re: 1080p@60 for MPEG-2

At 11:53 AM -0500 11/12/07, John Shutt wrote:
The tables appear to be labeled "upper bounds for sampling density", so 576 is an upper bound for number of lines, and 30 is an upper bound for number of frames per second, but do not necessarily permit the 720x576x30 option.
The 720 x 576 x 30 option is not permissible in Main Profile at Main level because the resulting sample rate would be 12.4 Million pixels per second while the maximum sample clock for MP@ML is 10.368 M samples per second. The sample clock was set at 10.368 because this is the clock rate required for ITU-601 streams. 720 x 480 x 30 fps is permissible, but also is never used.
Would be nice to see how MPEG-2 compression does with a 1080 at 60p stream crammed into 19.39 Mb/s. I've heard a lot of people saying that progressive compresses better than interlace, so the question will be whether it compresses "better enough" to fit.
After reading the documents, it is my take that the proposed 1080p60 MPEG-2 "High Progressive" profile is intended for program acquition and editing, not necessarily for ATSC emission.
Certainly not for ATSC emission, but quite possibly for other forms or program distribution including Internet download less constrained channels (I can imagine a cheap camcorder that does 1080@60P using MPEG-2 ala HDV.
The reference to software encoders would apply to NLE software such as Final Cut Pro, not to ATSC stbs. This would allow 1080p60 masters to be created, and downsampled to 1080i30, 1080p30, or 720p60 for emission. 

This is already possible in FCP using several codecs.
After looking at several sites I am coming to the conclusion that Sony may want the new MPEG-2 level to support some broadcast products like an 1080@50/60P versions of XDCam. 

Regards
Craig



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