[Leaplist] Linux configurable ip surveillance camera systems

[Dan Cherry]

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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