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View Full Version : Linux webcam - How hard is this?



personthingy
03-05-2007, 05:47 PM
I have a TV card with vid in, in the form of a small RCA socket, and a camera that looks over my main door. I also of course have a home web-server running apache on etch

The question is how hard would it be to get it so that a fairly standard web cam could be set up, allowing anyone in the house, or outside of the house to go to something like www.mydomain/maindoorcam and see who is at the door?

How demanding would it be? server is a secondhand P3 running (by memory) at 900Mhz with 256Mb of RAM, and anything that might make it work harder than a low usage web-server is expected to is in the not possible bin.

Graham L
03-05-2007, 05:59 PM
for a start... (www.google.co.nz/search?hl=en&q=linux+webcam+howto&btnG=Google+Search&meta=)

personthingy
03-05-2007, 06:08 PM
Yip.... that was scary, and what really got me was that just about everything there assumed a USB type webcam, rather than a camera that has an RCA plug hanging off a TV card.
I would have assumed what i had would have been easier

/me lost, and not afraid to admit it.

Graham L
03-05-2007, 06:16 PM
I think you'll be best to use a simple USB webcam.

A CCD video camera and video card means you would be doing a web television implementation.That's going to be very resource-hungry.

The webcam will have a few hundred kilobytes per frame, then it will be compressed quite nicely. You don't need full moving pictures ... just recognisable images.

winmacguy
03-05-2007, 06:19 PM
I read an interesting article a year ago about a guy who had a similar set up with his Mac in the UK and to cut a long story short- he got video footage of the burglar nicking stuff with a nice pic of his face looking at the camera( the burglar didn't know the computer was switched on)
try this link its not Linux, but it might help.
http://www.100share.com/laptop-home-security.htm

personthingy
03-05-2007, 06:27 PM
True....
All i need from this is to be able to see who is at the door, not exactly what they are doing any specific millisecond I was thinking of having a page that reloads, and therefore offers refreshed image every few seconds rather than several images per second!

Perhaps the camera, that is already in place might be better employed elsewhere?

I had this idea that the card could be trained to only save a new jpg (or whatever) every few seconds from the CCTV cams stream..... It seems i may have to rethink this.

Graham L
03-05-2007, 06:32 PM
The problem with the full video is that you have to cope with the camera output all the time, even if you are selecting a few frames every few seconds. The software to handle that is likely to be big and running all the time, because it has to keep synchronism to capture the frame stream. The disk space used might be fairly large, too. The USB web camera takes a picture when you tell it to. That's very simple.

personthingy
03-05-2007, 06:39 PM
OK... next question.........

What might be a good cam to use for this?

The door is well lit by the large streetlight of a main road almost directly beside it, and the only other concerns are size and price..
In other words a small black camera that was less than $50 is a far better option than most i could think of.
Also, there would be about 15 meters of cable. Any reason not to use some of the cat5 scrap i have to extend the USB cord on the cam?

Graham L
03-05-2007, 06:49 PM
USB does require USB cable, and it's supposed to be 5m max. There are USB/catX converter modules available, to get up to 50m or so, but they might be expensive.

Can you find an old webcam with a serial connector? I think they were around before there was USB. ;)

The image sensors are pretty sensitive ... but isn't your visitor facing away from the street lights?

winmacguy
03-05-2007, 07:23 PM
The only problem with back lighting is it won't show the persons face. You could try a wireless streaming camera at the door to save on cables that is activated by a motion sensor connected to a light so that it only comes on and lights the person when they are standing there. It can then provide secure footage to a backup server if needed.

personthingy
03-05-2007, 09:45 PM
The entrance is near the street, as the street was expanded, so i have no front yard at all. The 2 nearest streetlights are either side of the doorway effectively, and they are big bright ones that are at the fencelines rather than the kerb.

It couldn't be more perfect!
We had the existing cam plugged into a TV, but no-one here has such a thing now, so therefore it's idle......

winmacguy
03-05-2007, 10:02 PM
Sounds like your lighting shouldn't be too much of a problem.
If you go for a USB web cam you would need to make sure it is weather proof or alternatively you could contact an actual company that specializes in webcam security set ups. I saw a few at recent homeshow in Auckland. I guess it depends on what your budget is.
Depending on the quality of the video footage, the best codec to use would be h.264 possibly over wireless or Firewire and either as a photo image or set as 2-4 seconds of streamed footage.

personthingy
03-05-2007, 10:20 PM
Sounds like your lighting shouldn't be too much of a problem. ......The point i was going to make above before i allowed myself distraction, is/was that the previous camera showed almost no loss of quality at night......

Yeah... looks like i'm going to looking out for a cheap webcam, or something.

winmacguy
03-05-2007, 10:37 PM
Yeah... looks like i'm going to looking out for a cheap webcam, or something.

All weather wireless cam over an SSL link would save you from being limited by distance or cable length. I know that these are available as i have been considering something similar myself that would only be activated when a motion sensor is triggered. Also possibly having the clip or footage sent via a secure FTP link to another server in case your on site computer was stolen is also a good idea. It might cost a wee bit to set up but it could be a lot cheaper than having to replace your stolen property later - even with insurance.

personthingy
03-05-2007, 10:47 PM
Actually the cam is more about seeing who is at the door so i can decide if i want to hear the knocking or not. However, a record of who is there in case someone gets through the fortification surrounding the concrete cave i live in and tries to steal stuff would be handy......

Actually, i don't think i'm much of a target for thieves, all i got here is computer junk, cheap tools, and industrial scale sound gear. Nothing that's attractive for a quick sale of non descript gear at the local pub, dealer, or pawn shop.

winmacguy
03-05-2007, 10:51 PM
Well there is always the potential annoyance of being broken into by a person with too much time on their hands. I am sure you could configure the camera just to take a snapshot of whoever is at the door.
try this link with how to instructions...
It has some suggested retailers for cams as well.
http://www.simplehelp.net/2006/09/27/how-to-use-your-pc-and-webcam-as-a-motion-detecting-and-recording-security-camera/