Testing Original Dahua HDCVI

Salas O'Brien • IPVMU Certified

Hmm. Wouldn't this compete with HDcctv? I though Dahua was one of the main players in the HDcctv Alliance. Did they drop out?

Ethan Ace

In reply to Richard Lavin

It does compete with HDcctv (as much as anyone can compete with a non-player), and it's actually been turned into an HDcctv "standard" in their 2.0 specs, clled HDcctv AT. However, we know of multiple manufacturers who are planning or producing HDCVI equipment, but not calling it HDcctv AT. In that way it's sort of like Intersil's SLOC, which Sony jumped on first with their hybrid cameras, but others followed.

Richard Lavin

Salas O'Brien • IPVMU Certified

Has the HDcctv label become so toxic that even Alliance members are chosing not to use it? That's sad.

Rukmini Wilson

Good Work!

A couple of observations concerning the Live Test. The latencies are similar however the CVI seems noticeably smoother, do you agree?

Disclaimer: I understand that the latency test is designed for just that, latency, not quality. I also understand the FOVs are not the same and the lens is different. Having said that, its would be hard for a buyer to ignore the significant apparent video quality issues shown in the latency test. Maybe you wouldn't mind doing some perfunctory 'hand waving' in regard to the following issues:

Contrast/resolution is worse on IP view, kinda hazy.

Significant motion blur exists on the IP view, CVI is crisp. You can check this just by pausing the video anywhere there is motion...

Maybe one problem is the border of the IP monitor is making it smaller as well as preventing it from displaying in pixel for pixel mode? Or maybe an unwanted interaction is occurring between the monitor refresh rate and the camcorder?

Small suggestion, when you do this type of test, maybe its possible to get the actual live view captured by the camcorder as well. By having the model walk somewhere behind the monitors, you could get all three in the frame...

Juan Abbondanza

I think this is a good idea:

"Small suggestion, when you do this type of test, maybe its possible to get the actual live view captured by the camcorder as well. By having the model walk somewhere behind the monitors, you could get all three in the frame..."

Ari Erenthal

Chesapeake & Midlantic

TL;DR HD-CVI is what Todd Rockoff has been promising HD-CCTV would be?

Sharvil Patel

My understanding is HDCVI is not same as HD-SDI. Although they act same, they are actually 2 different technologies - HDCVI does not follow SMPTE standards while HD-SDI is based on SMPTE. You have to do a little search on SMPTE to know this. HDCVI will work just as smoothly as analogue cameras, even on poor grade quality cable / connectors and for long distances (up to 500m), while HD-SDI is very different in comparison to its counterpart. HS-SDI is only good for approx 100m cable runs and requires repeater/s to support longer than specified run/s. Also it produces good result only on high-grade coax. HDCVI gear is almost half cost than HD-SDI due to non-SMPTE-standards and is Dahua's proprietary registered / patented terminology. It's already a big hit in OEM and developing markets like Americas, Russia, Indian sub continent etc. Similar HD video producing technique, but using CAT5/6 type cabling - without IP cameras, is also now in existence on a very limited scale and is called "HD-MDI". It's getting really interesting!

Sharvil Patel

Dahua actually have HDCVI as well as HD-SDI product ranges. Obviously they are putting much less effort into HD-SDI. What TODD ROCKOFF has been hammering about for years is HD-SDI, not HDCVI. HDCVI is Dahua's proprietary standard, and I am sure Todd would not have a high opinion about it, perhaps he dislikes HDCVI just as much he hates IP!! ;-)

Ari Erenthal

Chesapeake & Midlantic

Sorry, I meant, the idea of cheap, idiot-proof (or at least idiot-resistant) HD video over coax is what the HD-CCTV Alliance have been promising for years, and now Dahua has found a way to deliver it without the Alliance's help.

Rukmini Wilson

Todd would not have a high opinion about it, perhaps he dislikes HDCVI just as much he hates IP!! ;-)

Not true, apparently Todd had shortsightedly used up all his hate on IP video and now is left without any for new technologies... :)

Seriously though, one would imagine today to be a bittersweet one for the King of Coax, since most all the arguments he vigorously championed apply to both HD-CVI as well as HD-todd, and therefore he must be thrilled to see some validation of his vision after all this time, a triumph made all the more sweet coming from his most vociferous critic.

Although at the same time and in equal measure, he may be profoundly forlorn, because although he was Head of the Prom committee, he alas, has no date, and now might be consigned to a mere footnote, in the book regarding what should rightfully be known as Rockoff's Knockoff...

Rukmini Wilson

Update: Todd actually officially loves HD-CVI. It is, as Ethan pointed out, the third technological pillar of the transmission enemble, formally called HD-cctv AT, and when it is referred to in that manner it makes Todd officially very happy indeed. He recently puffered this statement, for instance...

Dahua's unique perspective on the diverse needs of the surveillance market, coupled with its extensive technical resources, promises to contribute greatly to the HDcctv standard.

Here is the official IPVM coverage of the most recent HDcctv turmoil.

The Alliance web site url is www.highdefcctv.org

Note:Choosing a domain containing the 'defective' letters defcctv, was possibly their first marketing mistake, but hardly their worst, and certainly not their last...

Eric Pineda

We have done several project already with CVI and everytime the customers were all floored by the quality of the video and the clarirty. Was pushing IP hard before but with this technology, you can walk into any existing system and have them running full HD in a matter of minutes up to a few hours with very little cost. This is a huge game changer in my opinion!

Birger Kollstrand

Very interesting subject!

Would it be possible to enhance the latency test so that we can actually get the ms of latency for the HD-CVI?

John Honovich

In reply to Birger Kollstrand

IPVM

Birger, I am not sure how we can measure it precisely. We would need to be able to get a 'start' and 'stop' time but I am not sure given the camera and monitor setup we could do that with great accuracy. Anyone with ideas, please share.

Luke Maslen

IPVMU Certified

I found a useful article when learning about why there can be more latency when controlling PTZ cameras with IP systems vs analog. The article is Measuring Latency for Video Surveillance Systems written by Rhys Hill et al. and published in 2009. The PDF is directly available for download from this link. I believe the methodology for testing latency, used in the article, could be applicable here.

Birger Kollstrand

We have done som simple tests where we put up a millisecond counter on a PC monitor. Then we use the camera to record that and place it side by side with the counter on the screen. we can then se both the "benchmark" and the stream at the same time.

To get the results we then use a second recorder and pause the recording. Then we see the delta between the "benchmark" counter and the recorded counter in different stages of the recording.

A print screen can also be used, but then we only get that one instance to compare.

Sharvil Patel

HDCVI transmitting device (camera) sends uncompressed uncrypted open HD video signals over coax, much like analogue surveillance, so I don't think signal delay is of any concern. However, if someone is too keen to get into nitty-gritty, then have to use a special device called 'TDR' (Time Domain Reflectometer); these are hard to source and expensive devices. I am unsure of any other cheaper alternative method to measure time delay on coaxial signals.

Sharvil Patel

Does any one know of any other manufacturer besides Dahua who produces HDCVI gear as good as and cost-effective as Dahua? Dahua has a very limited range of 1080P HDCVI cameras. Most are 720P, which is not good enough in some applications.

John Honovich

IPVM

Sharvil, My understanding is that HD CVI is Dahua proprietary technology but that they are licensing it to others.

HD CVI has been generally available for a short time so I think that's a factor in limitations on product options.

I suspect FLIR's upcoming MPX is going to be a CVI offering.

If anyone has recommendations on other suppliers, please share.

Sharvil Patel

Ah I see! Flir has managed to penetrate into SMB market by offering full product-range, after their Lorex & Digimerge acquisition in 2013. Good on them. Another similar technology also exists now, which uses UTP instead of coaxial cabling. Its called "HD-MDI". With this tech, the transmitting devices (aka cameras) would have standard RJ45 jacks on them, much like IP cameras; the video signals here are not encoded & encrypted.

Mike Dotson

Formerly of Seneca • IPVMU Certified

What does everyone think about the fact that this is a 'proprietary' technology which will lock you in to only the vendors that support this?

I ask because this is what the old analog giants Vicon and Pelco had in place...so what makes this any different other than the cameras offer a better cost/performance metric?

Birger Kollstrand

In reply to Mike Dotson

It does make us cautious. We are interested to see how this progress with Dahua and how they intend to open up the technology in regards to standardization.

Jarrett Hansen

Where would one purchase Dahua products? CSC and scansource I assume do not carry these products?.

John Honovich

In reply to Jarrett Hansen

IPVM

Jarrett, it varies by country. In the US, typically it is through OEMs/re-lablers - Q-See and IC Realtime are two of the biggest. Nelly's Security is another that member's discuss.

We know one US distributor who sells Dahua branded products - DH Vision. There might be others but it seems uncommon.

Undisclosed Manufacturer #1

Does anyone know if you can set up and encoder on these cameras?

John Honovich

In reply to Undisclosed Manufacturer #1

IPVM

I don't know if Dahua sells HD CVI encoders, but there HD CVI DVRs are so inexpensive and essentially act as encoders anyway.

Jason Fitch

IPVMU Certified

The reason that I am asking about encoders is that they are installing these in a different facility recording locally and then they want us to bring them to another facility for recording on our system for investigation.

Ethan Ace

In reply to Jason Fitch

Like a lot of the Dahua DVR/NVRs, you can get an RTSP stream of each channel. On the two we're using the stream is:

rtsp://IP_ADDRESS/cam/realmonitor?channel=1&subtype=0

Where "channel=X" is the channel you want to see, obviously, and "subtype=" is 0 for the main stream or 1 for the secondary stream.

Assuming your VMS supports RTSP streams, and nearly all of them do one way or another, it shouldn't be a problem to record the stream. You just have to set it framerate and bitrate on the DVR.

We actually regularly stream out of these DVRs to Exacq during these tests because it's easier to work with exports that way.

Juan Carrillo

John and Ethan,

Really nice report, very usefull for us, as we are testing HDCVI as well.

I reenforce Birger´s suggestion of enhancing latency test.

As we know in real world the installations sometimes are very poor, both on analog (like the 1000´poorly crimped thin cables) and on IP (poor bandwidth, bad quality switches).

HDCVI claim is that it will work with almost zero latency in any installation, while on IP should be a perfect scenario.

Another suggestion is to test with UTP cables, including passive video baluns. In our tests the performance was surprisely good, and installation cost in this scenario is even lower than coax.

Regards

Juan Carrillo

Intelbras SA - Brazil

John Honovich

In reply to Juan Carrillo

IPVM

What other latency tests do you want us to do? Outside of trying to measure it in milliseconds.

Juan Carrillo

(http://www.clintonelectronics.com/reqcatalog_video7.php)

Hi John,

Maybe the latency test could be done with long distance cables, and decrease bandwidth on IP step by step and see the consequence on the latency/lag.

Dahua is promoting "no lag" as one of the key advantages of the technology.

Of course on a perfect IP instalation, where there is no limitations of bandwidth/budget, the IP cameras would work perfectly, with very low latency/lag.

But per our experience (at least in our market) real life IP instalations have serious limitations on bandwidth. On situations where you need a very high bitrate on IP to keep the quality (speed dome, doors with lots of people) I believe HDCVI would have better performance.

There is video from Clinton where they show the "lag" comparison. Of course the video is about HDSDI, and they hide lots of disadvantages of HDCVI (cost, distance limitations and so on).

On HDCVI the issues that made HDSDI not sucessful are mostly solved (cost, distance). Big problem is that HDCVI are not compatible with analog systems nor HDSDI. It is a proprietary standard and customers may not feel confortable with that.

Kind Regards

Juan

Carlos Espinoza

I saw in the ISCWest that also Yuxin Camstar has HDCVI DVR's and Cameras, not only Dahua.

John Honovich

In reply to Carlos Espinoza

IPVM

Carlos, thanks. My understanding is that they are licensing out the CVI camera chips to 3rd parties so you should expect to see more options.

I am not sure what the DVR options will be though.

Juan Carrillo

Hi John,

You are right, they are selling camera chips to many 3rd parties.

They are also selling for DVR manufacturers, so you can expect some other branded offers in the market.

The strategy is to make the standard popular.

Regards

Juan

Jon Lagace

"Like Dahua NVRs, the HD CVI DVRs support RTSP out so these recorders could be used as super low cost encoders integrated into major VMS systems"

Does anyone have any more information on the above?

Does rtsp allow for motion etc?

Ethan Ace

In reply to Jon Lagace

RTSP is the video stream with no other information or configuration. The VMS is simply recording the stream and that's it. Server side motion must be used with RTSP.

Dawid Adamczyk

Does HD-CVI works over UTP or there are any HD-CVI coax-UTP converters? What about HD-CVI FO converters? Are there any already?

Tim Shen

Hi All,

CVI supports UTP and also just launched tri-brid CVI DVR last week which embraces signals of IP, CVI and analog.

Sharvil Patel

Hi Tim, thank you for your comment. Does HDCVI work over UTP using standard passive/active baluns or does it require special (and expensive) coax-to-UTP converters like HD-SDI? Can you please also verify claims re: RTSP out on HDCVI DVRs for individual channels for third-party integration (ie. VMS)? What are Dahua's near future plans on releasing broader range of HDCVI cameras? HD-SDI consortium is already working on standardizing 4K HDSDI CCTV, will this be the case for HDCVI too in Dahua's pipeline in near/far future?

Dawid Adamczyk

Could you give an example of coax-to-UTP converter of HD-SDI and HD-CVI?

Tim Shen

Hi Sharvil,

CIV works over UTP using standard baluns, not like what SDI has to do via a converters.
Yes, we will release more CVI cameras in next two quarters. And for our 4K camera, it is currently not based on our CVI and in the future, we definitely have to consider that.

Luke Maslen

IPVMU Certified

Ethan, given that varifocal lenses are not currently available with the HDCVI cameras, can you tell me what angle each of the lens options equates to for the horizontal field of view, e.g. which one would give a 90 degree horizontal field of view? How about the default lenses that came with the cameras you purchased? Thank you for your help.

Luke Maslen

•May 22, 2014

IPVMU Certified

I obtained an answer to this question from Secuexpress as follows.

Lens length vs Degrees

2.5mm. 130°
2.8mm. 120°
3.6mm. 92°
4.0mm. 70.6°
6.0mm. 54°
8.0mm. 43°
12 mm. 29°
15 mm. 21°

Undisclosed End User #2

Are there already any HD-CVI cameras that would have a RJ-45 port, so one can simply plug the UTP cable in, without the need for a balun? Possibly also the DVR, but, we could survive that...

Ari Erenthal

In reply to Undisclosed End User #2

Chesapeake & Midlantic

There aren't that many cameras with that feature, generally speaking. Pelco, Videolarm, and Vitek are the only manufacturers that have more than a handful of models.

Ethan Ace

Do those models generally have an RJ45 jack or are they more commonly screw terminal? That was one gripe I always had with the UTP cameras...they didn't terminate too cleanly.

Ari Erenthal

Chesapeake & Midlantic

Well, I want to say screw terminal, but the honest answer is I haven't checked in years. If I want UTP, I'll pick the best camera and use a balun. I don't think I've ever selected a camera based on wether it had UTP or not.

Rukmini Wilson

In reply to Undisclosed End User #2

Are there already any HD-CVI cameras that would have a RJ-45 port... also the DVR...

Subversive. If such an animal were extant, just imagine the glassy customer look you would get as you tried to explain the difference between cameras connected by cat 5 to a NVR with a built in switch vs. cameras connected by cat 5 to a DVR with built-in baluns. (Warning satire ahead)

Informative Installer: Well, confusingly the connectors are superficially similar, but these are actually two vastly different underlying architectures, under the hood...

Consumate Consumer: Really? The boxes look the same in every way. How so?

II: Well the NVR is actually a mini IP network, like a tiny internet, where any of its nodes can communicate with any other directly, right out of the box.

CC: Oh I get it! The other one you need to buy something to be able to do that, right?

II: Rrrig...No, actually that's not entirely desirable in this application. But did I mention that these are IP Cameras and they go to Eleven! (hundred $)

CC: Huh? Because they're MegaPixel, right?

II: Not exactly, its complicated... Listen, when did you say your husband would be home, Missus...ah, Missus?

CC: Rockoff, nice to meet you.

Vance Kozik

It would be an even more compelling alternative to IP if power to the camera ran up the coax. There's still something to be said for the elagance of PoE. A coax/power combo cable will do the job but you still have to deal with power tails on each side and either a screw terminal central power supply or lots of power bricks on the DVR side. Other than that, the ease of use, pricing and resolution looks like an IP threat to me, at least for smaller deployments. I can easily see a branded version of this showing up at Costco and Sam's soon.

Ari Erenthal

Chesapeake & Midlantic

In reply to Vance Kozik

When I first started in this business, lots of our cameras still ran on 110V. Siamese cables and power supplies hardly seem like an imposition to me.

Vance Kozik

True, but it's all relative. Compared to running CAT5E and simply plugging it in on each side, it's certainly easier and tidier than power tails and power supplies. CAT5E also happens to be less than half the cost of Siamese cables.

Ari Erenthal

Chesapeake & Midlantic

In reply to Vance Kozik

You run preterminated Cat5? Why?

Vance Kozik

I was comparing 1000' bulk spools of Siamese vs. CAT5E.

Point taken. Yes, you still have to terminate the CAT5 cable.

Rukmini Wilson

Ethan Ace

In reply to Vance Kozik

It's already at Costco.

Jeremiah Boughton

I just called IC Realtime and they stated that they're the Premier US Distribution partner for Dahua in the US. The sales guys asked me why I wanted to go to HDCVI versus the Dahua IP version as the IP version cost less money than the HDCVI analog camera and them rambled on about the benefits of IP versus analog, like I did not know any better, and then he started to say HDCVI does have some benefits like distance and exhisting coax. He also told me IP runs over Cat 5 or 6 cable were HDCVI runs over coax. I told him I would call him back once I decided on my model numbers I would like to test out.

Has anybody else run into this at Distribution or IC RealTime?

HDCVI Pricing is more money than the IP equivolent? (Ethan?) (Maybe because inventory was low?)
Getting an education on security camera basics when trying to order?

Is it really better to order Dahua cameras from Amazon, at least for testing purposes?

Update - I'm starting to wonder if he was getting HDCVI mixed up with HDSDI.

John Honovich

In reply to Jeremiah Boughton

IPVM

We ordered from SecuExpress, a Chinese online store because they had Dahua branded HDCVI in stock. For testing purposes, that seems to be a straightforward way to go. We had no problems.

Is IC Realtime calling HD CVI, HD AVS? It appears that way.

As for price, I suppose different re-sellers can charge what they like, but, from everything else we've seen, Dahua HD CVI costs less than Dahua HD IP.

Jeremiah Boughton

You may be right, but it makes it more confusing. They do not mention HDCVI in any of the HD AVS specs. They also told me they are the Premier Distribution partner for Dahua in the US. To me that means it should be under the Dahua name and not OEM'ed then.

John Honovich

In reply to Jeremiah Boughton

IPVM

I've never seen IC Realtime market, sell or even publicly acknowledge the Dahua relationship.

And I agree, the rebranding and changing names makes things more confusing. It's a structural weakness in the Dahua go to market strategy.

Mitja Vavpotic

Regarding the RJ45 thread above:

John, I vote for you to talk to Dahua and have them create a HD-CVI camera/DVR with RJ45 ports, one pair for data and the other one (or two) for power. This would be neat and cheap.

Jim Daly

•May 25, 2014

Hi Tim Shen,

Can you say why Dahua does not offer a vari-focal in any of their HD-CVI cameras? Dahua offer a 2.8, 3.6, 4, 6, 8 and 12mm lens options. Thats 6 cameras in total instead if one vari focal 2.8 to 12mm lens.

problem with focus or what?

regards

Jim

Luke Maslen

IPVMU Certified

Hi Jim, Dahua do provide their HDCVI chipsets to third party camera manufacturers so one can find varifocal HDCVI cameras such as the ones from WinVision. I'm guessing Dahua don't use varifocal lenses so as to keep their cameras as affordable as possible. I would like to see them add varifocal lenses, WDR (their box camera already has WDR) and super low light level support. These would all come at a cost but presumably still at a competitive cost to IP cameras.

Jim Daly

Hi Luke, Thank you.

Jim

Rukmini Wilson

I'm guessing Dahua don't use varifocal lenses so as to keep their cameras as affordable as possible...

I can't think of a better theory, but on the other hand its hard to imagine the cost of added internal stock safety levels, different manufacturing runs, channel balancing, more returns and more reshipping could outweigh the added cost for a vari-focal... Also considering the fact that they could buy them locally at the Shenzhen swap meet, and get a bigger price break for buying 6 times as many of the same lens... Maybe there is an engineering complication, or some OEM strategy that eludes us in addition to penny pinching...

Jim Daly

•May 25, 2014

John,

Discussions like this one that can make me reconsider Hi Definition (1080p) over coax as an option justify my pro subscription.

Jim

Victor Telfer

A similar system, HD-XVI is being sold in Canada at Tri-Ed thru WatchnetDVR

John Honovich

In reply to Victor Telfer

IPVM

Victor, thanks. Are you sure this WatchnetDVR is not simply relabeling HD-CVI or someone else HD-SDI? Their website does not give me the impression of them being a real manufacturer.

Btw, I am curious what Dahua is going to do with other instances of relabeling as its going to cause confusion about what works with what (does HD-CVI work with HD AVS? etc.).

Rukmini Wilson

Are you sure this WatchnetDVR is not simply relabeling HD-CVI or someone else HD-SDI? ..does HD-CVI work with HD AVS? etc.).

Serious question, as far as HD-CVI compatibility is concerned, assuming you could source your own chips that certify to HDcctv AT, you could label your device as HD-CVI compatible, since Dahua claims HD-CVI is compatible with HD-cctv AT, and not theoretically not pay Dahua anything? Yes/No

Or do all roads leads to Hangzhou and whatever they want to charge you? And yes I know they have esentially become the Alliance, but maybe their model is more like Java/Sun then ONVIF, and are willing to let people compete with against them with their own brand, for the benefit of greater adoption, for now at least... Agree?

John Honovich

IPVM

My understanding is that you can only buy HD-CVI chips from Dahua. If that's true, by definition, all of them should work with each other.

The problem is specification confusion. Dahua calls it HD-CVI, IC Realtime calls it HD-AVS, CrappyCam calls it HD-CCI, etc.). You don't know if it's all the same thing and the OEM / relabeler may go to great lengths to hide their status.

Luke Maslen

IPVMU Certified

In Australia, the distributor of Dahua products has rebadged the products with their own brand name, makes no reference to HDCVI on their website and charges x4 to x5 the price compared with Chinese online resellers. I've based my figures on a quote I received from them for HDCVI cameras and a DVR. I don't think this can be good for Dahua.

John Honovich

IPVM

Luke, good feedback and sorry to hear about that.

This is a key structural risk for HD-CVI adoption and Dahua, in general. I am not sure if they are going to adopt a 'real' branded channel structure (like pretty much every other major manufacturer) but until they do so, these issues will be significant and their market growth will be limited.

Luke Maslen

•Jun 04, 2014

IPVMU Certified

Hi John, I wish to correct my previous post which was based on Dahua providing me with the name of just one distributor in Australia. Today I attended the first day of the Security 2014 trade show in Melbourne and discovered multiple Dahua distributors. I don't know why Dahua did not mention the other distributors to me but I'm looking forward to some better local pricing.

John Honovich

•Jun 04, 2014

IPVM

Luke, thanks for the feedback!

We've had similar difficulties getting a list for the US.

I believe, part of the problem, is that Dahua often has restrictions in their agreements that prevent / discourage them from identifying their partners. This might sound bizarre but the partners often want to market it as their own so that they can sucker convince naive people that they are manufacturing it themselves.

Victor Telfer

I'm a little late in this discussion, but I think the theme is, make up your own last 3 CAPS letters

Luke Maslen

IPVMU Certified

Hi Ethan, in the HDCVI Connection Video, you showed a pair of BNC connectors coming from a camera. You stated one BNC was for video and the other for power to the camera. However when you connected the video connector to the DVR, the video immediately appeared on the display even though you had not plugged the power connector into anything. So why did the video appear on the display? I don't have experience with analog systems so don't know where the BNC connector for power was supposed to go. Could you enlighten me please? Thank you!

Jim Daly

Hi Luke, In the video clip you refer to above Ethan used Pre-made Siamese CCTV cable. It has a BNC for video and 12v DC jack for power on each end. Pre-made Siamese CCTV cable picture

Luke Maslen

IPVMU Certified

Thanks very much Jim. Now that I know what to look for, I rewatched the clip and this time I saw the orange power jacks were connected to black power plugs which explains why the camera just worked in the video. I had not noticed the black power plugs were connected simply because they were black and the video moved through the connection quickly.

Jim or Ethan, would you expect the HDCVI camera would come with the 12v DC power adapter, as it's not mentioned in the specs on Dahua's website?

It would become messy having lots of these power bricks lying around if one hooked up 8 cameras to a DVR. Are you aware of any kind of single power supply which might offer multiple 12v DC jacks so all cameras could neatly connect to the one power supply without the need for lots of power bricks? Connecting to a single power supply would make it easy to connect the camera power to a UPS. Thank you for your help.

Ethan Ace

The cameras don't come with 12 VDC adapters, but if you buy things in a kit, like Q-See, they generally do.

You can buy multi-output plug in supplies like this one fairly cheaply.

Luke Maslen

IPVMU Certified

That's a perfect solution. Thanks very much Ethan!

Ethan Ace

Hi Luke, they actually are plugged in. It's difficult to see but if you see the connectors circled in red here, the red female jacks are connected to a black multi-output cable coming from a 12VDC supply.

Also in the videos where we use the PTZ, we used the same cable in some cases but didn't use the power connector. The PTZ needed 24 VAC and we powered it from a larger local transformer.

Luke Maslen

IPVMU Certified

Thank you very much for making the connection picture crystal clear. I missed that the first 3 times I watched the video. No wonder I can't work out how some magic tricks are performed!

For the regular dome and bullet cameras, can one use a central transformer with multiple 12v DC jacks to power multiple cameras? Does such a transformer exist to keep the power arrangements neat? I'd love it if Dahua added that to their DVR but maybe it's a good idea to keep power supplies seperate in case anything goes wrong. Thank you for your help!

Jim Daly

As Ethan mentioned above you can buy 12v DC 5A power supplies with 4 pigtails and these are very popular. Or you can buy a boxed power supply with some extra functionality like this one from unknown ebay seller it looks more professional. Or you can put the one Ethan showed you into a nice box yourself and it will look ok too.

Luke Maslen

IPVMU Certified

Hi Jim, thanks for the useful link. Until I clicked on it, I thought you were just talking about a presentation box!

Ari Erenthal

Chesapeake & Midlantic

You can power multiple cameras off a single transformer, but then of course you run into problems if you run out of amperage.

You can use a Y cable to plug two cameras into a transformer, or a four way splitter for four cameras.

12vdc transformers with more than 2A output are available but in my experience aren't as reliable. If you've got a bunch of cameras to power up, better to use a power supply with multiple screw terminal inputs mounted in an enclosure, like this one.

Luke Maslen

IPVMU Certified

Hi Ari, many thanks for spelling out the options, providing links and for providing your opinion on reliability. That's very helpful information.

Ari Erenthal

Chesapeake & Midlantic

That's what we're here for.

Rukmini Wilson

No wonder I can't work out how some magic tricks are performed!

Ethan is a straight shooter, but one wonders whether he even considered 'messin with our heads' a little after your first question about the power cable looking like it wasn't plugged in. Something spooky like "Luke, that is weird ahhh, well get back to you"....

Jim Daly

It’s not surprising that the price for the same product can vary wildly from companies like Qvis, ICRealtime and others who re-band Dahua product.

A simple and transparent example of this can be seen in the pricing of the smart phone app : € 3.81 for Dahua gDMSS, € 3.69 for Qvis iApollo Emap and unbelievably € 23.38 for ICRealtime ICRss Pro. The same App! These are the Google play store prices on 27/5/14, last time I checked iTunes had similar pricing.

So what multiple will the HD-AVS rebrand be of the HD-CVI price?

Jim Daly

Has anyone looked at the file size of HD-CVI? I know the price of HDD storage is no longer the issue it was.

Most people here expect to get a system (analogue) capable of recording continuously (24/7) for a month at a minimum of 6 fps on the highest resolution.

Any idea how HDD hungry HD-CVI is?

Ethan Ace

Hi Jim, the compression settings on the HD-CVI DVRs we tested were very similar to those of Dahua IP cameras we've tested, and bitrates were fairly similar. I don't have hard numbers off the top of my head but we'll plug cameras in and add bandwidth to the report later today.

Jim Daly

Hi Ethan, have you had a chance to look at the bandwidth / HDD usage?

Jim

Ethan Ace

Hi Jim, thanks for reminding me. We did look at it.

Using the 1080p IP camera and the HDCVI DVR with 1080p camera attached, we standardized compression to "4" (out of 6), set it to VBR, 30 FPS. Bandwidth was, as expected, very similar, ranging from about 1.6 Mb/s to about 4 Mb/s, depending on what FOV we used.

There were times when one or the other camera ran slightly higher, but I'm talking a matter of a few hundred Kb/s, not Mb/s.

The HDCVI camera was noticeably sharper, as well, even with sharpness turned down. This accounted for its higher bandwidth in some scenes. I don't contribute that to being an HDCVI-specific issue. We've seen it vary tremendously from camera to camera, and it just happened to be in that camera in this case.

John Honovich

IPVM

Jim,

To add to Ethan's comments, structurally HD CVI and SDI should be about the same bandwidth as HD IP cameras. The resolutions are typically the same (720p / 1080p), it's just that the encoding is done in different places - for IP, on the camera, for SDI / CVI, in the DVR.

Keith Fraley

Q-See® Official Site - Home Security Camera Systems | Wireless Security Cameras

RIP Analog cameras. We have installed about 8 of these systems so far and I believe analog cameras are officially dead. I cant think of any reason to install an analog system over a hdcvi system. The hdcvi systems are so cheap and the quality is so good we are no longer offering analog systems at all.

Seems Qsee has just started to sell a rebranded dahua hdcvi system.

Luke Maslen

IPVMU Certified

In reply to Keith Fraley

HDCVI is till analog but it's better than traditional analog. What I'd like to learn is conceptually how it works. In the past, you had to use 3 analog component cables to achieve high definition analog video. Composite analog video only used one cable due to lower bandwidth requirements but would only support standard definition video. So how have the clever folks at Dahua squeezed HD1080p analog video through a single, composite video cable? Perhaps a more lossy color space has been used but I didn't think that would be enough to reduce the bandwidth or else people would have used that trick long ago. Can anyone shed any light on why only a single video cable is required?

Ethan Ace

It's not fully analog. It's digitally encoded and analog modulated. There are some low level tech details of it on this page.

The simple version is: think of your cable TV. A single cable with 1000 MHz bandwidth is carrying how many hundreds of digital channels? A lot of them HD. Yes, you see some compression artifacts here and there, but things look generally good. Now imagine you had 1000 MHz to only carry a single 720p or 1080p stream minimally compressed stream plus audio and really low bitrate serial data. It's not that far of a stretch.

And before any techies come in a tell me there are flaws in this explanation and it's an oversimplification: I know. But it's the gist of it.

Rukmini Wilson

It's not fully analog. It's digitally encoded and analog modulated.

Every signal is fully Analog* (continuous), at all times

An Analog signal may be interpreted digitally if one is encoded on it.

Digital encoding is acheived by analog modulation, not in addition to it.

Digital and Analog are not mutually exclusive.

Digital encoding of data is no more than an agreed upon interpretation of analog signals

Ancient Smoke signals could be considered a digital signal transmitted through analog modulation. How? One of the 'tests' of true digital signal encoding is the fact that it can be losslessly transmitted over any distance, i.e. without signal degradation. Agreed upon smoke signals could be read and retransmitted by other smoke stations, like a ethernet hub. As long as the smoke had not degraded too much before the next station read it, it could be repeated forever. Just like any digital signal...

*In the macro world we live in. However true digital signaling is on the horizon in the form of quantum computing and communication, stay tuned..

Luke Maslen

IPVMU Certified

Hi Ethan, thank you for explaining the theory and also for the useful reference link. Your information has demystified HDCVI for me.

On the linked page, it referred to a German camera vendor named CPPLUS which was new to me. Their HDCVI offerings are mostly rebadged Dahua cameras. However they do have one attractive model which features a varifocal lens and claims 50m IR range. The CP-UVC-T3100L5 camera case looks pretty much the same as the Dahua HAC-HFW2100E which only has fixed lens options and claims a 20m IR range. It would be great to hear from anyone who has tried the CPPLUS model to see how well it performs, and also to find out pricing.

Rukmini Wilson

...but I didn't think that would be enough to reduce the bandwidth or else people would have used that trick long ago.

They have been using it for some time now. It's absolutely amazing to me that $20 run of 75 Ohm coax brings into my living room 100+ channels of HD and 200+ of SD as well as high-speed internet at 15Mbps ds, and digital phone service. Then of course it needs to come out of the set-top box on a $50 HDMI 3 cable, for no more than the last 3m, to insure the highest possible fidelity!

Of course they compress the crap out of the HD, (not as nearly as much as we do, tho), but still its pretty impressive.

Can anyone shed any light on why only a single video cable is required?

Bandwidth is a function of frequency

the higher the frequency, the shorter the wavelength,

the shorter the wavelength, the more waveforms you can receive in an interval

the more waveforms you receive, the more bits you get

the more bits you get, the more pixels you can display

the more pixels you display, the more you can charge your customer

For RG6 coax I think the theoretical limit on frequency is somewhere around 6Ghz. In practice I think cable-tv channels take around 1Ghz.

Keep in mind that were not talking digital per se, here.

But, as I believe the irrepressible Jim Hall said once said, its all analog really, digital is just what people agree to make out of it in their own mind.

Luke Maslen

IPVMU Certified

Hi Rukmini, thank you for your clear, conceptual explanation.

John Honovich

IPVM

In reply to Keith Fraley

Keith,

Thanks for sharing the Q-See link. Weirdly, you see they are calling it 'Analog HD'. 8 outdoor integrated IR cameras and a 2TB DVR for $999 is a pretty good price.

Again, what's weird, if this is a Dahua rebrand / HD CVI offering, Q-See has gone to great lengths to obscure it.

Keith Fraley

Its definitey dahua. Most everything Qsee sells is dahua but I dont think they want people to know that.

Undisclosed Manufacturer #1

Costco has one listed for $499 for 720p

John Honovich

In reply to Undisclosed Manufacturer #1

IPVM

You're right! Here's the Costco listing for an 'Analog HD' 8 720p HD cameras and a 2TB DVR for $499. Crazy... Wow.

Btw, here's Q-See's 'AnalogHD' marketing video:

John Honovich

In reply to Undisclosed Integrator #3

IPVM

Since this discussion is now past 100 comments, if you don't have specific questions on the test itself, e.g., you see a related product you have questions on, start a new discussion.

It's becoming very hard to follow such a long thread. We like discussing and providing feedback on different topics but it's easier for everyone when it's done in specific new discussions.

Undisclosed Integrator #3

•Jun 05, 2014

too bad fullHD 16 channel HD-CVI DVR is not existing yet.

Sharvil Patel

•Jun 05, 2014

I believe Dahua have just released some new tribrid (analogue, HDCVI & IP) DVRs that are up to 16 channels in full-HD (and beyond for IP only).

Karoly Turoczi

•Jun 05, 2014