Date: Sun, 9 Dec 2001 05:26:48 -0800 From: Tim Pozar <pozar@lns.com> To: User Raymond <raymond@one.com.au> Cc: freebsd-multimedia@FreeBSD.ORG Subject: Re: Using a Brooktree grabber as a security device Message-ID: <20011209052648.A72407@lns.com> In-Reply-To: <200112090915.TAA31024@gw.one.com.au>; from raymond@one.com.au on Sun, Dec 09, 2001 at 07:15:28PM %2B1000 References: <200112090915.TAA31024@gw.one.com.au>
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I am doing exactly this right now. At this point I am saving
640x480 images as JPEGs once a minute and then converting these
into MPEG files. Unfortunately this rate is just too slow to pick
up wanted action. If I did sample faster, say once a second, I
would be needing almost 3GB a day in images or about 5GB for MPEG
video files. It also makes it harder to find the frames I want.
Ideally you want software that does motion detection (such as edge,
etc.) that will only save frames that have significant changes in
them at a quick rates in order to capture as much as possible. I
am currently experimenting with a number of methods and packages
to do this. I will get back to folks with the end result.
Tim
On Sun, Dec 09, 2001 at 07:15:28PM +1000, User Raymond wrote:
> I have been given the job of implementing some security cameras,
> so I have purchased a Brooktree based frame grabber
> (bktr0: Askey/Dynalink Magic TView, Temic NTSC tuner) and a couple
> of CCD cameras (one B/W and one colour).
>
> At this point, I must admit to a very sketchy knowledge of multimedia
> in general and video in particular.
>
> I headed for the ports and looked at xawtv, fxtv and a few others and
> just became more confused - I can view what the camera sees, I can save
> this to a series of jpegs and there is a wealth of software there.
> My problem, then, what is the best way to do this; a series of jpegs
> (say two a second) or some form of video. I want to be able to keep
> (on a 40GB disk) up to a week of "film" and I want to be able to view
> this from a specified point in time.
>
> Any pointers gratefully received.
>
>
> Ray Newman
> Message sent at 07:21 PM on 09 Dec 2001 by PUP::RAYMOND. Id: 130344.
>
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--
Snail: Tim Pozar / LNS / 1978 45th Ave / San Francisco CA 94116 / USA
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