Xela19115
join:2000-10-06
Richboro, PA
 ·Verizon FIOS
| Re: Current speed? Actually it's QAM not QUAM. QAM stands for Quadrature Amplitude Modulation. In one 6 Mhz channel cable company using QAM-256 mode can send 38.8 Mbps of digital video/audio.
Digital video is compressed with MPEG-2 codec. An 1080i HD program can be compressed to a maximum of 19 Mbps (usually it's around 15-16 Mbps). Using QAM-256 mode 2-3 HD channels can be multiplexed. If you use MPEG-4 or WMV9 codecs bandwidth requerement is about 1/2-1/3 of MPEG-2.
1080p HD video if encoded using next generation codecs (MPEG-4) and transmitted using QAM-256 or QAM-1024 -- very doable.
Thing is that there is probably very little noticeable picture quality improvement. If it was like 4096p then of course by all means I want that. But the difference between 1080i and 1080p - is not really worth it. | |
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Corvus
Flaming Tards Since 2003
Premium,VIP
join:2003-11-26 | Re: Current speed? Thanks for the info, maybe you can answer this one: I've heard that 1080i is use in movie industry when working on a movie, anything about that?
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Jesus saves, but only Buddha makes incremental backups. | |
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Lumberjack
Premium
join:2003-01-18
Newport News, VA | Re: Current speed? It would make sense to capture and render at the highest quality for a big budget film (at least to me). Once complete it can be easily down converted for film, DVD, streams, etc...
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My homies is in da hizouse! | |
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cailyoung
join:2003-06-30
Australia | Re: Current speed? Most big budget films capture in "academy 2K", or basically 2048P. They might rough-cut with 1080i to make display on a TV easier, but generally on-line footage will be in '2K' image files. The data is stored on D1 tapes. | |
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