Re: OT: Why is usb data many times the cpu hog that firewire is?

Gene Heskett
2005-02-21T22:08:32Z

On Monday 21 February 2005 13:29, Wichert Akkerman wrote:
>Previously Gene Heskett wrote:
>> Thats what I was afraid of, which makes using it for a motion
>> detected burgular alarm source considerably less than practical
>> since the machine must be able to do other things too.
>
>Dependin on the type of compression used you might be able to detect
>motion by analyzing the compressed datastream.
>
Its jpg coming out of the camera, but I don't know to capture the raw
stream and do the comparisons. One would have to first subtract the
expected peak values of the sensors noise (snow if you will), either
by a running average obtained by frame addition on a pixel by pixel
basis. Somehow, that seems to imply a decoded stream. And thats
obviously not going to be anything but cpu intensive too. So I'm
less than enthusiastic that its a workable solution unless one is
able to dedicate a machine to that job exclusively. X10 FIR's like
the EagleEye or HawkEye will need to be used to detect when the
recording should be started (and stopped)

Many thanks to the responders here.

>Wichert.

--
Cheers, Gene
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