[Leaplist] Linux configurable ip surveillance camera systems

[Dan Trevino]

On Tue, Feb 23, 2010 at 1:06 PM, Dan Cherry <dan.s.cherry at gmail.com> wrote:
> Fred, Kevin, Otto,
> Thanks for the speedy replies.  I'm digesting the info, and looking for
> products that will meet the suggestions - seems like everything has a
> shortcoming or conflict with what I think I want.  I'll take it over to
> LeapBS, and see if I can home in on a solution there.  Again, Thanks
>
> Dan
>
> Fred Moore wrote:
>>
>> Dan Cherry wrote:
>>>
>>> Anybody have any experience with ip based surveillance systems?
>>>
>>> D-Link has some reasonably priced hardware, but the initial set up is
>>> through Windows.
>>>
>>> Also, has anyone any thoughts on Linux accessible surveillance dvr's
>>> (vs. feeding IP camera output directly to a PC for storage)?
>>>
>>> I'm considering 4 cameras with a dvr expandable to 8 cameras.
>>>
>>> Finally, should I just fall back to older analog cameras that feed
>>> into a DVR that is IP accessible?  That seems like the best bang for
>>> the buck, but the least flexible.  Hmmm, come to think of it, how much
>>> flexibility do you need in a video surveillance system?
>>>
>>> Any thoughts on the subject would be welcome,
>>> Thanks,
>>> Dan
>>>
>>
>> Do that for a living..  My knowledge is yours for the asking.
>>
>> Don't think about Web cams as they are not good IP cameras they don't
>> get you to a codec till the high bandwidth video gets to the computer.
>> Camera Trade offs,  CCD vs CMOS imager, and size, equate to quality,
>> light level, streaming rates, and video compression at cameras. Personally
>> I would never install a CCD imager camera, but 90% of the
>> camera's on the market use this technology, why because of the advent of
>> phones with cameras built in.  The CCD imager has forced a huge price
>> reduction.  Don't know where you live, but I can show you the difference.
>>
>> DVR.  "Digital Video Recorder" (not for recording IP camera), DVR's have
>> analog video input.  Almost all DVR hardware have A/D converters on
>> input.  Mostly not good deals because of the unknowns internals (more
>> explained next).  Stay with Analog or IP, and don't mix them.
>>
>> Most  DVR, start with a 4-CIF video image (input), only to have it
>> immediately  reduced to a 1-CIF image via pixel trashing, then run it
>> through a lossy codec and store it, in MJPEG,  in MJPEG every frame
>> carries 100% of the infomation and the storage goes way up compared to
>> MPEG4, H.264 etc, when you reach these codec's you input 1/4 the image,
>> and move to P/I frames.  P frames very from recorder to recorder if we
>> assume a P frame of 1 second and are streaming at 15 FPS, recording
>> looks fine in playback but suddenly rewind viewing, and searching is
>> very ugly why because the I frames can not be reconstructed backwards,
>> so rewind is a hideously jumpy 1 FPS image.  The problem is you don't
>> know on cheap junky recorders what they are doing inside at the codec
>> level.  Take H.264 "best bandwidth compression" we have,  While the P
>> frame rate is part of the standard, some recorders are doing P frame
>> rates as far out as 15 seconds, unless they see movement and then they
>> record more P frames.  Why? they don't have the processing power, or the
>> storage capability to store it properly.  All of this costs money.  This
>> is not goodness.
>>
>> Flexibility: unless you have something with good analytics, you don't
>> have a security system, you have a recording system. Security systems
>> notify of something going wrong, or at the very least have a mechanism
>> which will flag the recording of an event.  Otherwise if you want to
>> know when something happened, start watching 24 hours/day of recordings.
>>
>>
>>
>> Analytics like, motion, virtual fences, Image identification (car,
>> person), camera moved, camera shaking, identification are all
>> availability.   The better they are the higher the costs.  Most simple
>> motion analytics at the camera fall down when place outside and the wind
>> is blowing, or it is raining.  No camera manufacture has resolved this.
>> Good VMS (Video Managements Systems) have solved this years ago, can you
>> say processing power?  The higher resolution of the camera, the more
>> processing power it takes.
>>
>> I deal with things like virtual video fencing, and image recognition
>> every day.  Its all processed at the VMS, why Camera's can distinguish
>> movement, but was it a bird, dog, person, car, rain, or wind.  Depending
>> on quality you can go from 1000 alarms/day to view or search, or 1 real
>> event per day.  Cost is the difference.
>>
>> There are a couple of Linux solutions at the VMS level, but don't
>> recommend them.  All I know of want to also be compatible with windows,
>> unix, Mac..  can you say Java.
>> Some of the things to consider.
>> codec between the recorder and the camera?  codec's are the trade off
>> between  network bandwidth, resolution, storage requirements, and
>> processing power.
>>
>> D-link is total junk, it is built for 1-CIF camera's (1/4 analog
>> signals), if you are going IP you need 1D capability, and the horsepower
>> to manage it, or there is no reason to go with IP.
>>
>> This is a huge topic, or we can move it to BS as this is not Linux
>> centric.. I will assist you if you give me some more information or give
>> me a call..  cell 407-304-0709 Regards.. Fred
>>
>
>
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What is your opinion on zoneminder?

Dan
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