Scaleable Video Coding: the key to widespread VC adoption?

Posted on

With Polycom joining the ranks of Scaleable Video Coding supporters, SVC technology is being heralded as the future of video communication for at least the next decade. Bur what is SVC, and why does it represent paradigm shift in the way that we communicate with video? VC News reports.

For many existing VC users the single biggest challenge is extending the reach of video out from the videoconferencing suite to desktops throughout the organisation and beyond. At the same time, remote workers, branch offices and the many SMEs that need to participate in video meetings need a stable and consistent for communication that can cope with the congested and notoriously unreliable infrastructure of the public internet.

Following the introduction of mobile and desktop solutions from the major VC vendors, considerable progress has been made on dealing with problems commonly encountered with internet communication – most notably bandwidth variability, latency and packet loss – but problems remain. Add to this a new set of issues created by the diversity of end-points (everything from a smartphone to a high-end telepresence suite) and the need for a different approach to the way that we exchange real-time voice and video is apparent.

New standards

When the current generation of VC technologies were created, there was an assumption that high-quality VC solutions would sit within a high-quality communications network, installed for the purpose. The requirements of the system were known, and the bit rate was predetermined for a specific solution and application.

SVC solutions will have widespread appeal because they overcome the frustrations experienced by many users of IP-based VC. (Picture courtesy Vidyo)

Changes in working practices, the diversity of end-points and a move to the adoption of integrated IP solutions has highlighted the limitations of earlier VC technologies, and created an opportunity for a technology designed to operate in the IP environment. Scalable Video Coding (SVC) is attracting support as the new flexible, interoperable standard that supports high-quality video communication over the Internet and between a wide range of devices.

SVC has its origins in video streaming. Included in both the MPEG-2 and MPEG-4 recent advances in processor power have supported the adoption of the technology for real-time, two-way video communications. Now, SVC technology has the ability to deliver consistent, high-quality video and audio experiences at any bandwidth and over networks prone to packet loss and congestion, like the public internet and mobile broadband networks.

Market impact

The advantage of SVC is that a video communication solution, using SVC exclusively, doesn’t need a bridge (or Multipoint Control Unit (MCU)), reducing costs dramatically and bringing a range of different device types and formats into the solution. The impact on the adoption of VC could be dramatic.

Back in 2006, Wainhouse Research calculated that today’s videoconferencing market is approximately 125,000 room systems and an equivalent number of enterprise desktop systems per year, the potential desktop market for IP videoconferencing applications in the enterprise is between 5,000,000 and 10,000,000 units per year for PC-based applications, an equivalent number on the PC consumer side, and as much as five times that number for 3G mobile telephony users.

The reasons cited by Wainhouse why SVC offers this potential for explosive growth in VC are that the technology deals with almost all of the current concerns of users. The first of these is cost of deployment. SVC solutions run on standard hardware, with a resulting cost saving of up to half when compared to traditional VC solutions.

Secondly, SVC solutions are highly compatible with current network architectures, which allow quality of service can be assigned to different media types. Assigning high priority to the base layer and lower priority to the enhancement layers is economical with both bandwidth and the costs of deployment.

Finally, SVC solutions will have widespread appeal because they overcome the frustrations experienced by many users of IP-based VC. SVC is resistant to frame or sequence dropout prompted by packet loss. At worst, users should experience some degradation as performance is impaired by the removal of enhancement layers. In-call latency also compares favourably with traditional architectures.

Market forces

With all these advantages, why haven’t SVC solutions run away with the market in the four years since Wainhouse published its original report? There are a number of reasons for this, not least of which is the VC community’s absolute focus on quality. The emphasis placed on the alternative reality of telepresence by the VC mainstream, for example, was diametrically opposed to burgeoning public support for PC-based personal video communication.

SVC solutions run on standard hardware, with a resulting cost saving of up to half when compared to traditional VC solutions. (Picture courtesy Vidyo)

SVC allows you to have both with the same basic technology.

The second constraint on the adoption of SVC has been support from industry leaders. The technology has been pioneered by Vidyo, which has announced that it is to partner with HP, but the real turning is the announcement by Polycom that it will be adopting SVC technology in future solutions.

Polycom’s adoption of H.264 SCV technology for its current and future solutions and UC initiatives will put pressure on other vendors to do likewise. Polycom says that SVC will be made available at no cost to strategic partners that support open and interoperable communications standards through industry forums such as the Unified Communications Interoperability Forum (UCIF).

Polycom promises that its SVC solutions “will result in superior economics for customers deploying UC solutions”, but of at least as much interest to Polycom’s existing customers is the company’s assurance that the new SVC components will interoperate seamlessly with existing deployments. The company says that “this approach contrasts with competitive offerings by uniting the islands of communication and not requiring customers to rip-and-replace existing systems”.

SVC then has the potential to provide high quality video across a congested public internet, at the appropriate resolution, frame rate and image size for a wide range of devices. SVC is the technology with the potential to create end-to-end video communication throughout organisations and to provide the reach to remote workers. As such, it is the key to widespread VC adoption.

SVC: how does it work?

  • SVC standardises the encoding of high-quality video bit streams that also contains one or more subset bit streams or layers. Described in the Annex G extension of the H.264/MPEG-4 AVC video compression standard, SVC uses a scalable video encoder to compresses a raw video sequence into these multiple layers, one of which is the base layer. The base layer can be independently decoded and can provide a low level of video quality.
  • Further compressed layers are called enhancement layers, and these provide additional quality to the received video stream. Enhancement layers are decoded in conjunction with the base layer. Adding the base layer to all of the enhancement layers provides the best available quality. Where the endpoints are unable to utilise the frame rate, image size or resolution available from the full bit stream, the base layer and just the appropriate enhancement layers are used to display the optimal result.
  • This multi-layered approach offers the potential for both peer-to-peer communication over IP or 3G, utilising the appropriate resolution, image size or frame rate, and the creation of intelligent networks which provide only the appropriate layers to a heterogeneous mix of endpoints.

This entry was posted in Features. Bookmark the permalink.

Leave a Reply

issue link

Channel Zone

Video Reports:

Fatal error: Uncaught exception 'Zend_Gdata_App_HttpException' with message 'Expected response code 200, got 410 GDataNoLongerAvailableExceptionNo longer available' in /var/www/ucnews/wp-content/plugins/VCNews-Youtube/Zend/Gdata/App.php:709 Stack trace: #0 /var/www/ucnews/wp-content/plugins/VCNews-Youtube/Zend/Gdata.php(221): Zend_Gdata_App->performHttpRequest('GET', 'http://gdata.yo...', Array, NULL, NULL, NULL) #1 /var/www/ucnews/wp-content/plugins/VCNews-Youtube/Zend/Gdata/App.php(875): Zend_Gdata->performHttpRequest('GET', 'http://gdata.yo...', Array) #2 /var/www/ucnews/wp-content/plugins/VCNews-Youtube/Zend/Gdata/App.php(763): Zend_Gdata_App->get('http://gdata.yo...', NULL) #3 /var/www/ucnews/wp-content/plugins/VCNews-Youtube/Zend/Gdata/App.php(205): Zend_Gdata_App->importUrl('http://gdata.yo...', 'Zend_Gdata_YouT...', NULL) #4 /var/www/ucnews/wp-content/plugins/VCNews-Youtube/Zend/G in /var/www/ucnews/wp-content/plugins/VCNews-Youtube/Zend/Gdata/App.php on line 709