Thread: cameras and pc integration

it sounds like there is a little misunderstanding on what everything does.

I think there is... We all seem to be on the same subject, same ideas, but different implementations causing different discussions.

it really depends on what the pc is doing-- in most cases, letting the pc "do it's thing" the hit that this takes will be very minimal. some of my customers have complained of a very slight audio echo from this process-- i would have to guess it is in the 100-200milli-second range-- not huge, but enough to be a tiny bit behind.

but if you have a kid in back playing a video, it could become a big hit, and could slow down how fast the live view gets updated(if the pc normally recorded at 30fps, but might drop to something like 10-15fps).

but this also is dependent on the capture card that you use. some do a very good job encoding the camera signal, to the point that the cpu is barely needed, others really rely on the cpu for encoding...

If the computer doesn't record, just displays a live view, no audio on pc side either, I don't think the hit would be enough to notice. Now, the dvr, or dvr with built in multiplexer would do all the recording. This leaves the pc to not have to worry about recording, yet we'll still have recordings that can be accessed via dvr. I think this sounds right.

overall, for 4 cameras and a dvr, your talking about 400mA + 5A, so about 5.5A draw-- less then a set of headlights.

Leaving headlights on overnight is never a good thing... Even with today's batteries I've done it and never had an issue, but if these are left on all the time just in case motion sensing needs to record something, this could cause huge issues. Since you've worked with cameras and dvr's before, have you ever worked with the motion sensing? If the cameras stay on with little power draw, is there a different wire, voltage, etc that comes from the camera for that detection? If there is, a simple relay could be triggered to power the dvr back up until the motion sensing/recording is done... Maybe we're crossing discussions again, it's a lot to learn .

Originally Posted by detlion1643

If the computer doesn't record, just displays a live view, no audio on pc side either, I don't think the hit would be enough to notice.

the pc actually will needs to work almost as hard to display a live view as it does to display live view and record. the only difference is that the hdd also gets a little of a workout.

Originally Posted by detlion1643

Leaving headlights on overnight is never a good thing... Even with today's batteries I've done it and never had an issue, but if these are left on all the time just in case motion sensing needs to record something, this could cause huge issues. Since you've worked with cameras and dvr's before, have you ever worked with the motion sensing? If the cameras stay on with little power draw, is there a different wire, voltage, etc that comes from the camera for that detection? If there is, a simple relay could be triggered to power the dvr back up until the motion sensing/recording is done... Maybe we're crossing discussions again, it's a lot to learn .

i really have not done much work with the camera sensing the motion..

all of the locations i work with have the cameras send the video back to the dvr, and then the dvr decides to record on motion or not. usually by looking at the percent of pixels that change.


most of the "small enough for car use" cameras don't have motion detection options-- this is the first one i could locate that has it-- it is about 3-4" long:
http://www.ktnc.co.kr/english/viewtopic.php?t=444

i believe that the motion detection option works through the data port on the back of the camera. i think it 'talks' to a similarly-branded dvr. but because i don't use this option, i really don't know..


using a relay to trigger the dvr to startup usually wouldn't work for quick motion events.

even though the stand-alone dvr's have faster startup times, they still take around 5-10sec before they start recording.

this is one of the biggest hurdles for me..


in-car power draw:

with the engine off, on average, any draw above 500mA is considered a parasitic draw that will eventually kill the battery.

the only way i can think of to overcome this is to install either a device like this with a built-in battery, or use a very small recorder, with only one camera, and a second car battery...

the first is slightly undesirable because of it's overall size on the windshield. and the second is undesirable because i drive a convertible, and already cramped for space..

So remind me once again what all this sophisticated motion detection and instant-on DVR stuff will do that $99 worth of Viper car alarm won't? I mean, couldn't you wire one of those little stand alone DVR cameras that record onto an SD card to the car alarm so that when it fires, the camera starts recording? I can think of about a dozen different ways you could detect intrusion or motion in your car that would be far more reliable and fullproof than using video motion detection. Not that I don't admire the whole geekiness of the project...'cause I do!

VegasGuy

^ there is not a advantage.

a alarm system will better protect your car while your away then any camera system ever could.

camera systems are best known as 'passive'-- meaning that they do not prevent, or inhibit theft in any way.

the typical reason for installing cameras anywhere is for accidents-- primarily to prove who is at fault, or who is lying.

Wow I almost found what I want!!!
The new range rover Evoque has a 5 camera system that you can select different combination of views on the 8" touch screen
http://www.youtube.com/watch?v=Ezs6T-spkio
Now I just need to shift a few of them under the car and figure out how to record them all for later editing

Is that oem stuff they put in it? Looks cool nonetheless.

I can think of using 5 webcams where I could program software to look at 5, select so many to see bigger, loop through them, etc... So while feasible, we still run into the issue we were trying to discuss about the cpu usage. Trying to record all 5 of them would almost negate using the computer to do much else unless they were all recorded with the worst resolutions, but that would be pointless.

It's a hard situation to 'get right'. We all want lightning fast, best resolution, able to multitask solutions. Combining those with recording cameras is hard.

Exactly right, not sure what the solution was yet..

And yes that was the new "baby" range rover and is an oem system witht he five cameras. I was just interested to see it on the UK top gear and thought that it was exactly how I want mine to behave with the addition of recording.

Originally Posted by soundman98

i really have not done much work with the camera sensing the motion..

all of the locations i work with have the cameras send the video back to the dvr, and then the dvr decides to record on motion or not. usually by looking at the percent of pixels that change.


most of the "small enough for car use" cameras don't have motion detection options-- this is the first one i could locate that has it-- it is about 3-4" long:
http://www.ktnc.co.kr/english/viewtopic.php?t=444

i believe that the motion detection option works through the data port on the back of the camera. i think it 'talks' to a similarly-branded dvr. but because i don't use this option, i really don't know..

I have four cameras in the sequoia (one behind the rear window, one inside the grille, two below each mirror), connected to a Multiplexer, a DVR (with motion detection option). I don't use motion detection, but I could - that's a DVR option. As you said above, detecting pixel change, you pretty much set the relevant area you want it to look for movement. It has nothing to do with cameras, 3 of my cameras are pretty small, and the DVR only connects to them via composite. The mini DVR also has a battery, so it could work for a while on batteries, specially with motion detection want.

BTW, one of my cameras is supposed to be "high resolution" but since they all connect via composite cable, the noise and the overall image quality are very, very similar. In ideal lighting conditions is hard to discern between the least and the most expensive camera.