Wednesday, July 18, 2018

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Nuts & Bolts of Using WebRTC in ProAV

By Tim Kridel, Special to InfoComm International®

WebRTC is one of the hottest topics in pro AV, with plenty of hand-wringing about whether it will commoditize video conferencing or grow the market by creating more endpoints that SIP and H.323 systems can connect to. Either way, it’s clear that there’s already enough customer interest that AV pros need to figure out how to support it.

“Everybody under the sun is asking about WebRTC these days, but the reality is that adoption is in the early stages,” says Ami Barzelay, Vidyo solutions architect, business development.

One fundamental difference between traditional SIP/H.323 video conferencing and WebRTC is that the latter uses a mesh architecture. That’s fine for one-on-one conferences, such as a financial advisor using WebRTC to provide white-glove service to a high-value client.

Mesh starts to cause problems when there are several participants because each one gets a separate video feed from everyone else. That adds up to a lot of bandwidth, which is an obvious problem on, say, a corporate LAN that’s already overloaded or when some participants are using mobile devices, where video can quickly drain a data bucket.

But mesh also shows how problems sometimes are opportunities. AV vendors and integrators can offer customers the option of using a traditional video conferencing bridge, which would collect the WebRTC participants’ feeds and send a single, consolidated stream down to each endpoint.

Some of those customers might already own a bridge. The integrator or vendor can add value in their eyes by showing how it can be extended to support WebRTC. Those that don’t own a bridge could be sold one, either as an on-premises solution or as a hosted service. Either way, mesh’s drawbacks are an example of why WebRTC won’t necessarily cannibalize sales of traditional video conferencing hardware, software and services.

“WebRTC is a subset of people who need to use video communications,” says Michal Raz, Vidyo vice president of business development. “There’s still going to be people with SIP, H.323 and other codecs.”

Some integrators agree.

“People will continue to buy Lync-optimized endpoints and 323/SIP endpoints, but a new market segment will likely emerge and begin to grow,” says Brad Johnston, Solutionz Conferencing COO.

Bridging the Differences

A bridge or some other piece of infrastructure also is required to connect one WebRTC user with another. Unlike traditional video conferencing systems, Lync or Skype, WebRTC―at least in its current form―doesn't have address books, so users have no way of finding or connecting directly to one another. Something has to provide a meeting room for them to dial into or a way for others to dial out to them.

“You need some infrastructure to make it all work because people are going to meet somewhere,” says Simon Dudley, LifeSize video evangelist.

One example is LifeSize's UVC suite, which includes a product that provides address books and recording for up to 25 concurrent WebRTC participants. Enterprises could install it on their own server in a VMware environment, or they could buy a standalone node.

“A lot of our resellers love selling a 1RU box,” Dudley says. “Now you can see why the video conferencing industry is excited by this. The number of people who can get involved goes through the roof. Instead of making money selling $100,000 meeting rooms, we start selling $20,000 pieces of infrastructure, but a lot more people get involved.”

Another way that AV pros can stay relevant in WebRTC is by helping customers overcome interoperability challenges.

“Not all WebRTC client implementations are going to be the same, so you want to look to the people who are already doing desktop video conferencing and [can] apply that knowledge to WebRTC.” Raz says. “One WebRTC client might not be able to talk to another WebRTC client because they use different signaling.”

WebRTC doesn’t require clients to use a specific type of signaling protocol, such as Jingle, because that would limit developers’ ability to innovate. When WebRTC is used for B2B or B2C communications, the enterprise’s session border controller (SBC) becomes a factor because they have their own protocols. So when helping a customer implement WebRTC, it’s important to see which protocols are used by its SBC vendor and its WebRTC client vendor.

“The integrator is going to have to follow whatever recommendations the vendor has,” Raz says.

One common issue with any standard is that if all vendors did was follow the standard, they wouldn't have many market-differentiation opportunities aside from price. It’s possible that vendors will add more collaboration features to make their WebRTC solutions stand out from the pack. Whether that will create additional interoperability issues remains to be seen.

“The WebRTC standard itself is only going to be implemented by a limited number of vendors as it is a browser API and associated media plane functionality implemented in browsers,” says Andrew Hutton, chair of the International Multimedia Telecommunications Consortium’s WebRTC Interoperability Activity Group. “Therefore I don’t believe we will see the same type of proprietary extensions. The opportunities for differentiation come from building innovative applications based on the functionality provided by the browser, as we have seen with other Web technologies.”

Firewall Déjà Vu

WebRTC is the latest example of how AV, IT and telecom are converging.

“If integrators want to play in this space, they’re going to have to expand their knowledge base to the underlying network technologies, [such as] the firewall,” says Nick Hawkins, Polycom senior director of advanced technology for the APAC region. “There are technologies defined in WebRTC to enable firewall traversal—such as STUN, ICE and TURN—but they still need to be configured as part of the deployment.”

Years ago, firewalls were a challenge for traditional video conferencing systems until vendors developed traversal solutions. WebRTC benefits from that work.

“It was recognized as an issue due to all that past experience and addressed in the standard,” says Val Matula, Avaya Labs head of multimedia research. “The standard calls for a STUN TURN server to be positioned straddling a firewall or a network address translation (NAT) [node] inside and outside.

“It’s the function of the STUN TURN server to help negotiate a media path across a compliant firewall or border control device. Inside the browser, they specify that if you can't make a direct connection, go back and ask the Web server where the STUN TURN server is that you [should] use to make the connection.”

If setting up the connection involves a straight shot through an SBC or firewall, the process takes only a second or two. If the STUN TURN server is involved, set up can take 5 to 15 seconds. To participants, that delay can be annoying or prompt them to try restarting the session.

The speed and latency of the network also affects the user experience. So like other examples of AV-IT convergence, WebRTC can mean that integrators will have to assess and upgrade the customer’s LAN, MAN or WAN – assuming that the IT department doesn’t want to take on that task.

“A ratty network is going to create a problem, as it does with all video,” says Solutionz’s Johnston. “You want to make sure you’ve got adequate bandwidth.”

If there isn’t, the user experience can suffer because WebRTC isn’t as flexible and forgiving as traditional video conferencing technologies.

“You get what you get on WebRTC,” Matula says. “[There's] none of the sensing, auto adjusting and tradeoff between voice and video priority in terms of which packets are sent out. It assumes that you have a good enough channel to get the job done. If not, you’ll renegotiate the whole session down to a lower parameter.”

Are you already working with WebRTC? Not yet, but planning to? Share your experiences and questions with InfoComm’s LinkedIn Group, Facebook or Twitter (@InfoComm) communities.
 IVS Imaging is a distributor & manufacturer of PTZ cameras specifically for the WebRTC markets. Please visit our website or Facebook page for more information on how IVS Imaging can help you transition.

Sony SRG300H

 What do you look for in a PTZ camera? If your answer is stunning image quality coupled with smooth robotic control at an affordable price, take a look at Sony’s new SRG Camera Series. The new SRG series joins Sony’s widely used EVI and BRC product lines, giving customers a greater choice of high-quality remote camera options. The SRG-300H is a new desktop and ceiling mount 1080p/60 HD PTZ camera with a 30x optical zoom. It incorporates Sony’s high sensitivity 1/2.8-type Exmor™ CMOS sensor with the latest imaging technology and field-proven operability. The SRG-300H is equipped with several new features including View-DR processing to master the harshest lighting conditions as well as the industry recognized VISCA™ protocol and built-in IP control. In addition, the SRG-300H is available in a black or white housing. The SRG-300H is ideal for house of worship, videoconferencing, distance learning, entertainment/seminar venues and remote monitoring of small to medium sized rooms.


Contact IVS Imaging now for pricing & availability!

Sony SRG120DH


Sony SRG120DH 12x 1080p/60 HD PTZ Camera. What do you look for in a PTZ camera? If your answer is stunning image quality coupled with smooth robotic control at an affordable price, take a look at Sony’s new SRG Camera Series. The new SRG series joins Sony’s widely used EVI and BRC product lines, giving customers a greater choice of high-quality remote camera options. The SRG-120DH is a new desktop 1080p/60 HD PTZ camera with a 12x optical zoom. It incorporates Sony’s high sensitivity 1/2.8-type Exmor™ CMOS sensor with the latest imaging technology and field-proven operability. The SRG-120DH is equipped with several new features including View-DR processing to master the harshest lighting conditions as well as the industry recognized VISCA™ protocol and built-in IP control. The SRG-300H is available in a silver housing. The SRG-120DH is ideal for videoconferencing and remote monitoring applications. 



  • View-DR (Wide Dynamic Range) Feature: View-DR provides extremely wide dynamic range with Sony’s full-capture Wide-D technology - utilizing the Exmor™ CMOS sensor’s high-speed readout capability and
  • Visibility Enhancer (VE) that provides a high level of chrominance and luminance. Achieves up to 130dB. (29.97fps)
  • Camera Control: VISCA over IP technology allows for easy control of camera over IP connection.
  • High Image Quality: The SRG cameras incorporate Sony’s high-sensitivity 1/2.8 -type
  • Exmor CMOS sensor and the latest View-DR™ technology. Also their 60p shooting capability realizes smooth, reduced blur life-like images.
  • XDNR™ Technology: XDNR technology reduces noise and provides clear images in both moving and still objects under low light conditions.

USB3.0 Challenges Mainstream Camera Interfaces

Courtesy of Andy Wilson, Editor in Chief, Vision Systems Design

The dizzying number of competing camera interface standards might leave many engineers wondering which one, if any, might emerge over the next few years as a clear leader. For Arndt Bake, COO at Basler (Ahrensburg, Germany;, the choice is clear - USB 3.0, and its faster successor USB 3.1, will start to dominate the world of computer vision after 2020.

Bake explains that his company views the camera market in three segments - high end, mainstream and entry level. At present, each of these segments is served by a number of camera interface standards.

USB 2.0 - an interface standard widely used in the computer peripheral market is capable of an effective throughput of 280Mbit/sec, Bake claims, will be superseded by the new "superspeed" USB 3.0 interface which, with its faster 4Gbit/s data rate, will dominate the entry level market and take a substantial share of the mainstream market. Not only that, but

Bake also believes that cameras based on the new "superspeed" USB 3.0 will totally replace those based on the Firewire standard by the year 2020, despite the fact that the latest incarnation of the Firewire specification (IEEE 1394-2008) can theoretically deliver an effective throughput of up to 3.2 Gbits/s - speeds that could potentially mean that the standard would compete directly with USB 3.0. Bake believes, however, that USB will dominate the market, due to its high bandwidth and its cost which will reduce as the number of consumer products that adopt it increases.

At the top end of the mainstream camera market, the dominant computer to camera interface at the present time is Camera Link, which is offered in Base, Medium, Full and Extended Full configurations with data transfer speeds of up to 6.8Gbits/s. However, Bake thinks that, over the long haul, even the Camera Link standard will face stiff competition from USB, since once the newer USB 3.1 standard is adopted, with its data transfer speeds up to 10Gbit/s, many existing Camera Link applications will migrate to this standard.

At the very high-end, Bake admits that one camera interface standard - CoaXPress - has come to dominate, having stolen the thunder from the competing Camera Link HS standard which has failed to gain a foothold. But CoaXPress is a standard that he believes will also eventually come under threat from USB 3.1. At the present time, the CoaXPress interface enables cameras to be connected to frame grabbers at bit rates from 1.25 Gbit/s to 6.25 Gbit/s per cable - up to 25Gbit/s if systems integrators employ frame grabbers and cameras with four cables. At 10Gbit/s, however, USB 3.1 could mean that all but those computer vision systems that demand the very highest speed could find themselves using a USB interface.

To enable its customers to quickly upgrade their camera-based systems from one interface standard to another, Basler has developed a suite of software called Pylon. Based on the GenApi module of the GenICam reference implementation, it offers a single generic programming interface for programming the functionality of any Basler camera with a Windows or Linux PC. No matter what interface technology the cameras are using or what features they are implementing, the application programming interface (API) remains the same, easing the task of the systems integrator.

For its part, Basler appears to have no intentions, at present time at least, to compete in the high end camera market served by CoaXPress. Its position is to continue to serve its customers in the mainstream factory automation, ITS and medical and life sciences fields. To do so, it will consolidate its position supporting the Camera Link and GigE interfaces while looking to the future by developing a suite of USB based cameras.



Evaluating Machine Vision Cameras versus Comparing Camera Specification Documents

Evaluating Machine Vision Cameras versus Comparing Camera Specification Documents


Many of our customers ask us how they should evaluate cameras in order to find the best solution for their application. There are several reasons why we feel the Photon Transfer Curve (PTC) is useful, especially if you are trying to get the most out of your imaging system such as when detecting small differences between images or using the pixel information as data for measurements. We have shared some detailed information on how to measure the Photon Transfer Curve for CCD or CMOS machine vision cameras because we feel it is an important part of camera evaluation and selection.

Camera vendors provide a lot of detailed specifications about their cameras, but as we have discussed it is challenging to connect all of the camera specifications to the image details you require and to know how the camera will perform under your system settings.  The biggest advantage of measuring the Photon Transfer Curve of different cameras yourself is that you can verify the camera performance with your own equipment and environment such as integration time, illumination conditions (continuous/strobed, spectral range), optics, filters, etc. which can all have an effect on the performance.  You are then not only comparing cameras under the same conditions, but also comparing them under conditions that are relevant to your system/application.

Should you have some questions about how to perform the measurements, there are many resources or courses available. 

As you could read in an earlier blog, the EMVA 1288 standard provides details on how to accurately measure many camera parameters in a controlled environment.  This can be very useful for camera manufacturers as guidelines to present specifications or for qualifying cameras during development. (Note that the Photon Transfer Curve is measured by EMVA 1288 too!)

But instead of using the EMVA 1288 test setup, you can also use your own system to gather the measurement data needed to construct the PTC and derive important camera parameters like full well capacity, read noise, dynamic range and linearity.

If you are a customer that wants to get the most out of your system, we strongly suggest that you invest in testing and understanding camera performance.

Testing of a camera using your specific imaging conditions may show behavior and image artifacts that are not seen under "standard" conditions that are used during camera testing in the factory of the camera vendor. In practice we've often identified significant differences in camera behavior from different vendors - even between cameras that are using the same image sensor!

There is no camera in the world that that will be an optimal fit for your application.  Your competitive advantage depends on your electro-optical system, measurements algoirthm, etc. being unique.  Therefore, to summarize the top 3 reasons for measuring the PTC are so you can:

  • Verify and compare camera performance under the relevant system conditions.
  • Better communicate questions to the supplier or understand customization requirements.
  • Go beyond megapixels/second to quantify image quality to parameterize the outgoing inspection at the supplier or incoming inspection needed to have consistency in series production. 

IVS Imaging is a distributor & manufacturer of machine vision cameras, lenses, cabling, monitors, filters, interface boards & more. IVS is your one stop shop for all your vision needs. IVS Imaging is known across the USA for carrying imaging products from leading manufactures, including Sony Cameras and Accessories, Basler Industrial Cameras, Hitachi Surveillance Cameras, Toshiba Network-based IP Cameras, and Sentech Advanced Digital and OEM cameras. Contact IVS Imaging for all your imaging products, parts, and accessories needs.

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