At 7:49 PM -0500 12/14/04, Tom Barry wrote: >You really do not like interlace. ;-) NO. I REALLY DO NOT like interlace... ;-) >And you are somewhat optimistic, and may be surprised. For instance I >think I read D-Theater is filtered for interlace and, IIRC, not even >coded with repeat flags. This may be true. At the moment the mass market is still interlaced. Only those who are going after the HDTV niche can afford to optimize their content for HDTV, although there is real progress on the coverage of live sports, where it looks like 720P is beginning to dominate. This makes it easy to downconvert to SDTV, while retaining many of the advantage of progressive acquisition and production (particularly the improvements in slo-mo). > >And the blu-ray folks are still trying to use MPEG-2. MPEG-2 is not the culprit, although the additional tools in AVC will produce better results at the same bit rate. The culprit is the source. If you filter it for presentation on an interlaced display, you are throwing away information that is useful for progressive displays. The key is to start with the highest quality PROGRESSIVE source. Form there it is easier to encode (even with MPEG-2) and it is easy to produce a properly filtered interlaced output, whether for 480i or 1080i. >I agree 4:2:0 is way too sparse. (as is 24 FPS) Hollywood seems to like 24P; I don't think it is going away. But Hollywood also understands that that the viewer DOES benefit from full color resolution. 4:2:0 is not a bad thing, IF the source is progressive, since it is easy to filter (scale) the color difference signals in both the H & V axis. But you are throwing away some useful color details that CAN be seen. 4:2:2 is an artefact of interlace, and is meaningless in the context of progressive formats. 4:4:4 delivers more color detail - I have seen demonstrations of source that was transferred as 4:4:4 and 4:2:0, then encoded using MPEG-2. On high end DLP projectors the difference is highly visible, especially on computer generated imagery. There are even more benefit if we expand the color space beyond the present Rec 709 limits and use logarithmic encoding of the uncompressed source to extend the color gamut while preserving the "knee and shoulder" characteristics of the film source. > >But why screw around? If they made HD-DVD's with modern codecs they >could probably use 4:4:4 at 1080p@24. It is true that 1024x576 RGB >could look very good but we might as well go the whole way once we can >afford the bits. 1280 x 720 @ 24P with 4:4:4 color is MORE THAN ADEQUATE for 99.9% of ALL home theater installations. You can make a case for 1920 x 1080@24P for BIG SCREEN theatrical e-cinema displays, but 2 Mpixel resolution is NOT necessary until the screen size exceeds 100 inch diagonal. > >Just because we couldn't see it on almost all current displays (1080i or > 720p fixed) doesn't mean we shouldn't do it. So we should optimize the source for 0.01% of the market? I think not. While we may well be moving in the direction of displays that can support 1920 x 1080 @ 60P, there will be little visible benefit in delivering 1920 x 1080 source to these displays. Scaling 1280 x 720 up to fill these displays will produce virtually indistinguishable results, except for the reduction in the number of scenes that fall apart because of compression artefacts. The key, as I keep stating is the delivery of HIGH QUALITY SAMPLES, not necessarily HIGH RESOLUTION samples. What DIgital TV needs is consistency in presentation quality. The ability, on rare occasions, to sneak a little more resolution through the pipe, is strongly outweighed by the presence of compression artefacts when the pipe is inadequate for the delivery of those extra details. > >I would happily be willing to wait for my upscaling display on that >format until I could afford a 4kx2k fixed pixel display. And what benefit would YOU derive from a 4K x 2K display? How big would you expect the screen to be, and at what distance would you sit to watch it? (Hint) The 1+ Mpixel DLP theater projectors still produce better pictures than any 2 Mpixel projection system I have seen. That being said, I have not seen a projector based on the new 2 Mpixel DLP chips. Regards Craig ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.