Jump to content
Splat

Help: Need a new DVR unit

Recommended Posts

Hey guys. We've had a Nuvico 4-channel unit for some years in our pizzeria and it finally bit the dust. We're looking to move up to a 6 or 8 channel unit without breaking the bank. The only real need is to access the dvr via www, the channel capacity, and output/backup to USB stick or external hd. We don't need POS, PTZ control, or super-high res video. Is there anything good for around $1k or under or is that just not advisable? Thank you.

Share this post


Link to post
Share on other sites

check out the intellicam slim line DVRs .. good price and has the USB mouse and USB backup, remote software and browser application, and D1 on all channels - its their basic unit though, they have an enterprise one as well. Also there is a mac version of the remote software from the chinese manufacturer which was just released though its a bit slow and possibly buggy still.

Share this post


Link to post
Share on other sites

Might as well second that seeing that intellicam is manufactured by my supplier Dahua.

 

But let's look at the range. cost will depend on a few things:

 

(1) Spatial Resolution - do you really need the highest level of resolution? remember high detail isn't really noticeable when you are observing whole scene's but does become important when you start needing to observe fine detail such as notes or writing. The dahua dvr provides 4CIf resolution on channel 1 for the 4-8 channel entry level units and the rest of the channels are standard CIF, on the 16 channel unit you will also get 4CIF on channel 9. Can you get by with high resolution on 2 channels and standard on the other?

 

(2) Temporal Resolution: If you do need all channels at 4CIF, does it need to be real time. Most vendors hype up the real time issue, but in reality 5fps is adequate for a residential install, while most service stations are happy with 7fps. Casino's banks and cash points may spec real time 4CIF. The dahua DVR allows you to customize the frame rates on each channel. The difference between 5fps and 25fps is actually just fractions of a second.

 

(3) Storage - machines come in 1U, 1.5U and 2U form factor - the larger forms having higher hard drive capacity. So determining the length of recording to be held is important.

 

(4) Network. - The dahua machines offer dual streaming, which means you can optimize the network transmission on one stream without losing quality at the local machine.

 

The Dahua DVR's offer entry level CIF realtime machines with selected 4CIF channels, moving up to the mid range which allows 4CIF on all channels around 12-15fps, and then into the top of the range model with full realtime 4CIF.

 

By the way your $1K target is very doable - with the top of the range dahua 16 Channel at full 4CIF probably in the region of about $600. Check the above though as you may not actually need to spend that much.

Share this post


Link to post
Share on other sites

Dahua is D1 on the US side of the globe

Well cropped D1 at 704x480

 

Also with the slim line the local encoding affects the remote encoding.

It is dual stream but only if one counts the next to useless substream.

cant speak for the others as Ive only used the slim line.

 

Some of the larger machines also have a different processor .. for the faster real time D1 on all channels.

 

And its a huge difference between 5 and 25fps ... least over here.

But IMO quality matters more.

Share this post


Link to post
Share on other sites

Thanks for the info guys. Rory, do you have a link for Intellicam or for a specific unit(if that's ok with the admin)? I'm not finding much on them. I don't know if it's their site but www.intellicamusa.com isn't working. Thanks.

Share this post


Link to post
Share on other sites

Just for the record:

 

D1 PAL: 720x576

D1 NTSC: 720x486

4CIF PAL : 704 x 576

4CIF NTSC 704 x 480

 

Regarding the difference between 5 & 25fps it all depends on the specific application and intent.

 

Scientific studies have shown that the location of a users focus of attention does not significantly change given frame rates between 5 & 25fps suggesting that the selection of visual cues which defines a users area of interest is not adversely affected by frame rate variation.

 

Very few users would discern the difference between 25 & 30fps. In any case the point was that 5fps may be suitable for some applications while 25fps might be for others -----i could hardly accept that every surveillance application demands 30fps temporal resolution.

Share this post


Link to post
Share on other sites
Just for the record:

 

D1 NTSC: 720x486

4CIF NTSC 704 x 480.

 

Sorry but thats not totally correct.

D1 NTSC is 720x480

D1 NTSC Cropped is 704x480 - Also known as 4CIF

 

But the main thing is, the Dahua DVR itself calls it D1 in the menu setup, even if it is not 720x480, Full D1.

Share this post


Link to post
Share on other sites

Forgive me for belaboring the point, but it is a very important one in our industry.

 

This is what I have ,

 

D1 is 720x480 pixels

4CIF is 704x480 pixels

DCIF is 528x320 pixels

2CIF is 704x240 pixels

CIF is 352x240 pixels

QCIF is 176x120 pixels

 

Are these figures not correct?

Share this post


Link to post
Share on other sites

Hmmm....

 

We did point this out to them and they started putting 4CIF in brackets where they mentioned D1.

 

The explanation we have is that due to the limitations of CCD sizes in cameras, if DVR manufacturers where to provide full D1 resolution, there would be a grey area on either side of the image.

Share this post


Link to post
Share on other sites

Yeah ive read the 8 pixels on either side dont contain anything useful .. but I guess D1 is a selling point .. when someone mentions the name 4CIF all they see is CIF

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×