One of the key points Jim L mentioned in referring to blue laser discs is
the separation of the file format from the physical format. The camera can
be switched to record either DVCAM or IMX video on the same optical disc.
This means that the recorder is already behaving more like a data drive
than a dedicated video recorder in the traditional way that DVCAM has to be
recorded on a DVCAM tape, or IMX video on an IMX tape in a Sony IMX
machine. Remember that DVCAM is a particular flavour of the broader DV
'family' just like MiniDV and DVCPro, and that IMX is a subset of the MPEG2
family. This makes it easy to map into a .dif or .mpg file or, preferably
into an MXF wrapper. This file is the thing you archive by storing for a
while, and then migrating.
It would be nice to go one step further, and have a completely generic data
tape drive like LTO2 built into the camera, instead of optical disc or
flash memory. You could then physically take out the tape and put into any
LTO data drive rather than having to use a particular Sony player, or
stream data over a network. Richard Hess raised this point in another
discussion. There are a few issues in converting streams to files in real
time, and buffering on hard disc may be needed, but we're almost at the
stage where we could have a field camera capable of recording 24 hours of
DV at 25 Mb/s, or 12 hours of MPEG2 at 50MB/s, or roughly 2 hours of
uncompressed component video on an US$80 tape. S-AIT holds roughly 5 hours
uncompressed for around US$170. I'm not a believer in long-term survival of
tape, but it's cheap and easy to migrate in 5 years when a better medium
Acquisition media, whether video tapes, optical discs, hard discs or flash
memory are all more expensive than high capacity data tapes, and therein
lies the problem. It is more economical [as Leo points out] to erase and
re-use the acquisition medium rather than to save it for the future.
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