On 26 Jun 2002 03:56:06 -0700, talsharf@hotmail.com (Tal Sharfi) wrote:

>I have looked for some information about firewire, but I couldn't seem
>to find an answer to a question I have.
>I am planning to buy a computer.
>Athlon 1800 with some 160Mb HD for video editing of videos that are
>about 4-5 hours long.
>I want to buy a board with a firewire jack (I already have a camera
>with a firewire output).
>My question is: regarding the compression that is needed to be done
>(1:5), when uploading the video to the HD, does this hardware is
>enough, or, do I need some other hardware to handle the compression
>for me ? Anyway, who does the compression? The CPU? The camera? Is it
>been done on real-time when uploading the movie? Or, has to be done
>later?

The compression is done in-camera before the data is
transferred to the tape as digital data; FireWire simply
transfers this (constant-rate) data stream to the computer's
hard-drive. After that, in the computer, the digital is
either unchanged, or changed (not necessarily in "real
time") during the process of "rendering" modifications you
have chosen to make in the video footage (as with color
shifts, transitions, overlayed titles, etc.). Upon export,
the unchanged data is combined with the changed data in
the video digital data stream fed back out to the camera,
for mastering. Both the camera (hardware, real-time) and
the computer (generally software, real-time) are capable
of translating the digital stream to analogue format for
viewing...