Video conferencing: Loud and clear
There are many considerations that need to be addressed in expanding video conferencing systems such as Skype into a larger meeting room. Steve Montgomery looks at the steps to create an effective and intelligible system.
We are using video communication far more frequently than ever before. Businesses and commercial organisations are taking advantage of the rise in popularity, and the acceptance of staff to use it, by installing dedicated videoconferencing facilities throughout their offices.
Videoconferencing, as opposed to audio conferencing, implies the use of video cameras. To be effective, they must be positioned and controlled correctly. Ty Buell, PSO solution architect at Zoom Video Communications suggests that: “When people are seated their eye level is about 42-in from the floor. Placing the camera lens at that height gives people at the far end of the call a natural eye-level experience, which is much better than putting the camera above the displays in conference rooms. This, incidentally, seems to have come from the idea of placing a webcam on top of the monitor on a desktop. The field of view of the camera is also important and typically the people at the very front corners of the table are the ones who need to be considered. Moving the furniture or adjusting the camera to the correct FOV to capture those people is most important.”
“The camera position is crucial in stimulating natural conversation,” agrees Arnoud Helmantel, product manager EMEA for Vaddio. “During a meeting people will look at the display. Because of this the camera needs to be as close as possible to the centre of the display. Ideally, for a natural looking shot, the camera should be at the eye level of the participants.” Holger Stoltze, senior director of technical sales and marketing for Yamaha Unified Communications makes an additional point: “When interactive displays are being used, it is better to place the camera on top of the display.”
With rapid advances in camera technology there is an abundance of choice to suit every type of installation. The video codecs used with the cameras to compress and transmit images over a wide area network are dropping in price. This, as Buell points out is a major benefit: “Traditionally, the codec would form the bulk of the purchase cost, but with powerful software codecs now a fraction of the price of a traditional hardware codec, users have access to high quality imaging at low cost. With this reduction we are seeing more deployment. Commercial organisations can be video-enabled throughout many rooms as it isn't so cost-prohibitive anymore.
Consequently users are able to spend a larger part of their budget on audio and video infrastructure like cameras and microphones. Joe Mann, head of sales engineering at BlueJeans believes that this saving is being spent on better AV technology. “A high-quality camera with advanced features like HDR and facial recognition is coming more to the forefront of the hardware buying process, showing that businesses are happy to increase spend on meeting technologies if they improve the experience for all involved.”
Currently HD cameras are the most common type and easily capable of capturing images in sufficiently high resolution to serve most applications. The price of 4K cameras is enabling them to be used more frequently. Although, as Helmantel points out: “Most software codecs cannot handle resolutions over 1080p and internet bandwidth will often limit the output resolution further making 4K output of a camera currently unnecessary in the large majority of cases.”
Camera performance should be a consideration in installations. Many videoconferencing systems are used in existing office meeting rooms and conference rooms rather than dedicated VC suites. There is less possibility in these environments to manage ambient lighting and the camera must be able to deal with a wide range of situations. “Lighting in most meeting rooms is generally not optimal for video capture, so it is important to select a camera that can handle wide dynamic scenes such as variable incoming sunlight,” he says. “Cameras need a fair amount of light to produce a good looking image. Lack of sufficient light will introduce noise into the image, less accurate colours and general video quality degradation.”
Good lighting is important in video interaction, but it tends to be one of the most commonly overlooked components of meeting room design. “When setting up a video conference, organisations should be aware that rooms with windows facing the camera can be most susceptible to challenges as the camera iris will close to compensate for the additional light, leaving faces looking like shadows,” explains Mann. “Even the best cameras need effective lighting to capture detail and colour. Businesses should consider installing overhead and front-facing lighting, this will help compensate for external environmental factors, improving the use of video for effective communication.”
Cameras designed for single user applications are not suited to huddle rooms or conference rooms. Selection of the camera should be based on the size of the room. Wide and ultra wide angle cameras are ideal for small rooms in order to capture all attendees. Moving–head cameras are preferable in larger spaces such as conference rooms and presentation suites
Automatic features are available that detect the number of attendees in a meeting and adjust the field of view to ensure that everyone is included in the image transmitted. PTZ (pan, tilt zoom) cameras with auto tracking and auto zoom are particularly suited to presentation and lecture rooms. Stijn Ooms, technology director at Crestron summarises features of their cameras: “Crestron Flex includes a 4K camera with digital auto zoom. The system detects the number and location of people in the room and frames them to deliver lifelike image quality at the receiver end.” The Flex system connects users’ own devices into the corporate VC system. “Flex includes the option for users to bring their own device but extends their audio reach and inserts the room camera into a video call in place of the device’s own camera. It can also detect the number of people in the room and provides this data to our cloud-based management tool XIO Cloud. This enables companies to better understand the actual usage of rooms for future resource planning decisions.”
The ability for videoconferencing systems to pick up audio within the room is also essential. Some degree of audio processing is advisable to enhance the final sound quality. Mann: “High-quality microphones and arrays placed close to participants will reduce the potential for reverberation and increase intelligibility. Sound processing on the microphones can filter out background noise. Dolby Voice for example provides background noise reduction, voice placement and superior fidelity, removing some of the traditional barriers to effective communication in a meeting.”
A well known maxim in the video industry is that too improve the viewer’s perception of a film, the quality of the soundtrack should be enhanced. Whilst our brains can compensate for slightly reduced level of picture quality, they are not so capable of dealing with inferior audio. In the videoconferencing applications this holds true too. We accept, noisy video but struggle with poor quality sound to a lesser degree.
Correct positioning of speakers is essential says Stoltze: “The audio in the room should be coordinated with the mouths of the video participants on the displays in order to create a more lifelike human interaction experience. In smaller rooms, the ideal solution may be a sound bar or forward-firing speakers. Large rooms are best served by line array technology with limited audio loss over distance and ceiling mounted speakers may be necessary to achieve the coverage required to deliver a comfortable experience.”
Ideally the room should be designed and furnished to minimise reflective surfaces through the use of acoustic panels, artwork, soft furnishings and curtains, although these are not always desirable or conducive to the business environment. Furniture is often overlooked. However it can not only make the room more enjoyable to use, and hence productive, but can add significantly to the performance.
Luke Hughes, founder and managing director of furniture design specialist, Luke Hughes, explains their role in the process: “As furniture designers, we are dedicated to keeping buildings relevant in a rapidly changing world whilst maintaining their architectural integrity and evoking their genuine character. The aim is for the furniture to appear as though it has always been there, whilst helping to deliver the technical services required in a busy, modern office.
“Our customers invest for the long term, which ultimately carries a lower cost and a higher return, enabling them to optimise their assets. We help them achieve this through making buildings more efficient, by using spaces more effectively and prioritising flexibility.”
Videoconferencing is undoubtedly an important and versatile tool for today’s business community. The objective is to create systems that users don’t actually notice and are not distracted by, thereby allowing them to focus on their conversations. But it is not simply a case of installing a few pieces of hardware and linking it to the in-room audiovisual system. To get the best possible performance takes knowledge, dedication and appropriate equipment. Fortunately that is all available with the AV sector, which means that there are endless opportunities for dealers and integrators to help organisations and generate income.