Upgrading Analog CCTV To New IP Based System?

If you want to reuse the cable you have 3 options.   

1) Keep the analog cameras and use encoders to bring the analog cameras into your VMS.

2) Use IP to COAX adaptors and use IP cameras. Most of the time unless the cable runs are very long and challenging to replace it's cheaper to run new CAT cable. 

3) Use new HD analog/TVI/CVI encoders and replace the current analog cameras with HD analog cameras.

Hanwha which has the same VMS as DWG has new HD analog encoders including a 16 channel unit. If you want to go down the HD analog road I would take a long look at Hanwha. 

I agree with Michael's #2 option - 2 x 16-port encoders are the easiest way to go.  You get to keep the cameras (assuming they're working well), keep the cabling, and keep the power supplies.  Make sure you have a decent little switch for the added network traffic.  I'm partial to Axis encoders but have had success with others like Bosch.  Also, some VMS manufacturers like Milestone, Genetec and Exacq offer appliances with built-in encoder cards, so external rack-mount encoders may not be necessary.  Consider adding some cable management brackets or switching to thin coax between your patch panels and the encoder/appliance, it'll be neater.

I prefer using external encoders as apposed to encoders built into the recorder. This way if one of the encoders goes bad you are not having to send the recorder in for repair and thus not recording anything. Axis encoders like the M7016 work really well and also do motion detection. Exacq does a great job working with these and also you would only need 8 IP licenses for all 32 cameras. The software is easy to use as well. This makes converting to IP a snap!

Depending on your budget you might try a combination of IP to coax encoders (Nitek is my favorite) and analog to IP encoders.  Make your most important cameras IP with the Nitek and then leave the others coax.  But watch the pricing it may be better to just go ahead and run UTP/STP Cat cable than to buy all of those encoders.  But if you have a historical problem or asbestos etc. the converters may be your best bet.  

Sometime next month I'm going to research the possibility of receiving digital video streams from DVRs into a VMS

Basically, the idea is that if DVR is streaming multiple HD streams via RTSP, it is - at least theoretically - possible to receive these streams as if they are from RTSP cams

In this situation, I use HD-TVI encoders (I used to use M7014/M7016).  This allows them to update existing analog cameras to 720/1080 or above analog cameras (pricing about $70-$200 per camera).  I always recommend that new cameras be IP based.  

A 16 channel HD-TVI encoder is about $900 my cost ($600 for an 8 channel) with a license per quad, which comes out to about $350 per camera cost plus labor to update to HD for interior cameras (1/4 license cost, $150 camera, $150 labor) versus $800-1000+ (plus patch and poe ports) for a similar IP camera to be installed.  Exterior cameras pose a better cost effective upgrade, since you just replace the existing for a $500 cost (versus $1200-1500 for an IP -40C rated device).  

The HD-TVI encoders are a game changer.  (I have not seen any coax-ethernet converters last more than a couple of years - Veracity/Altronix/etc).  Another plus is that the SSA on a quad HD-TVI device is 25% of an IP camera.

I also swear by the HD-TVI encoders. You can't beat the value of reusing all the old cabling and the 1/4 license cost per channel. A few things to consider though are 1. Be wary of the cable lengths in play. The vast majority of HD-TVI cameras are 12 VDC and they tend to draw about half an amp so you can run into line loss issues if the runs are longer than 150 to 200 ft. There are 24VAC models which you can run as far as the old analogue cameras but not as many and they are a bit more costly but still loads cheaper than going with IP, switches, cable, etc.

2. With encoders you can get a lot more cameras onto a server than with IP because of the  4 to 1 channel/license ratio. Theoretically you could run 64 1080p HD-TVI cameras on an Exacq LC series box (16 IP inputs) but you need to be cognisant of the amount of throughput and disk storage that would be required. We tend to stick to no more than 32 HD-TVi cameras max on the box and then have the other channels of IP available for applications where HD-TVI won't work (higher res, multi imager, etc)

3. We use Hik encoders with Exacq servers and according to Exacq's testing, ALL of the cameras on an encoder have to be the same resolution. You can put in the encoder and hook up all of the old analogue cameras but if you want to change 1 camera to HD-TVI then you have to do the rest on the encoder at the same time. I have heard tales from the field that on occasion they have mixed old analogue and HD on the same encoder and it worked but I would want to do some thorough testing to insure that it really does work.

Hik recently released an encoder that will do up to 5 MP HD-TVI. I'm hoping it will end up on Exacq's compatability list soon.

One more relatively cheap solution to consider. 

You may use a PC with a capture card for receiving your analog signals and DeskCamera software for converting video feed from the capture card to ONVIF.

Normally DeskCamera streams PC screens and webcams , however in that case most probably the capture card will also be picked up and recognized as webcam/webcams and DeskCamera will be able to convert it ONVIF camera.

There are some capture cards on the market with multiple input ports support and  DeskCamera itself supports up to 20 input sources, so theoretically you may convert up to 20 cameras with only single setup and 80usd license, depends to your capture card.

The bottleneck here is - there is no particular list of capture cards which were tested  with DeskCamera, however we received several positive feedbacks about avermedia cards

I think I will end up finding an encoder (figure the hik stuff is still ok to use if its just an encoder) that will work out of the box with Exacq and then upgrade all the cameras to HD Analog. Thank you for the great advice.

Question for those of you that are using Hik encoders with Exacq, are you experiencing any problems with the Illegal login lockout in the Hik unit preventing Exacq from reconnecting after a system restart? I've had this happen several times at our only site with the hik encoder. Disabling in exacq for 30 minutes and reconnecting is the only fix.