Quote:
Originally posted by jberger
MPEG is already a compressed format, that's why it's MPEG to start with. HDTV is a compressed signal, so you don't need 600GB hard drives to record it. |
That is correct, although the storage required is fairly significant; here are some numbers for anyone who is interested:
1080i - Up to 18 Mbps, which is 2.25 MB/second. One hour of video would require up to 8.1GB of storage.
720p - Up to 16 Mbps, which is 2 MB/second. One hour of video would require up to 7.2GB of storage.
480i - Around 5 Mbps, which is 0.6 MB/second. One hour of video would require around 2.1GB of storage.
However, these numbers can be much less depending on what's going on at any time. Fast-action things such as sports use much more bandwidth than talking-heads shows; the HDTV bandwidth usage can drop by half in such cases.
Anyway, a current-generation 80-hour ReplayTV (such as the 4508) with its 80GB hard drive has enough storage to record only about 10 (ten) hours of OTA HDTV signals or 40 (forty) hours of OTA SDTV signals.
This all means a theoretical ReplayHDTV 6080 would indeed require 640GB of storage (and could probably be sold for around $800 or $900 today). There would actually be considerably less complexity than with the current ReplayTVs, since there is no digitizing or MPEG-encoding circuitry required. And it would also be easy to make it record two HDTV signals at once, just requiring a second $5 tuner. But I'm not surprised that such a beast has not yet made it to market, since HDTV has not really "caught on" yet with the public (or even the PVR-buying public).
I still would like to see a PVR with 640
TB of storage that would record the entire spectrum (say 100 HDTV channels) simultaneously. That would be sweet, and would give you access to a full month's worth of programming on every network.

At today's prices, it would only cost around half a million dollars, give or take.
Jim