As we all now appreciate, unified communications video conferences provide very rich interpersonal interactions between remote parties. However, on any given call, some participants may have access to powerful endpoints and all the bandwidth they need, others may be joining the conference on a mobile device connected to a public WiFi network: such are the realities of communications in the 21st Century.
With this challenge in mind, the IMTC’s Scalable and Simulcast Video Activity Group (SSV AG) recently announced the completion of its H.265 HEVC Modes specification (the full name being “Specification of Interoperable Scalability Modes for the HEVC Video Coding Standard for Unified Communication Applications”). This document defines a mechanism to enable devices with a lower display resolution, lower processing power and access to limited network bandwidth to participate in video conferences with high-end, multi-monitor telepresence systems while optimizing the bandwidth consumed by each leg of the conference.
Publishing a standards specification is but the first step in generating adoption and broad deployment of a technology. Systems from various vendors have to be able to interoperate with each other, and product engineering teams need a mechanism to test their implementations as they work through to ‘General Availability’. The technology industry has traditionally solved this problem via a range of mechanisms such as:
• Bi-lateral interoperability agreements between vendors
• Certification bodies, such as the Wi-Fi Alliance
• 3rd party product testing laboratories deploying proprietary test plans and tools
• Multi-lateral test events, such as the IMTC’s annual SuperOp
While these arrangements have served the industry well, the repeated feedback required by product engineering teams in a test/fix cycle is not addressed. For this reason, the SSV AG decided to follow a different path by building a product verification tool that IMTC members can download and use in privacy and comfort of their own labs at zero cost.
The Unified Communications Interoperability Forum, a predecessor of the current IMTC, executed an RFP process in 2012, from which HCL Technologies Ltd was selected as a test implementation vendor. Work started on this project in 2014, with HCL engineers participating in the SSV AG meetings to understand the emerging specification. Once the specification was nearing completion, HCL developed a test specification which was reviewed and approved by the SSV AG members. After that document was complete, HCL went ahead and developed the tool itself.
The tool is a command line tool which takes, as its input, a video bitstream file generated by the vendor’s product. The tool analyzes the video file, looking at the various data attributes embedded in the video frame data, ensuring that the vendor’s implementation is compliant with the specification. Engineers are able to review a test log generated by the tool to gain invaluable feedback that allows them to eventually verify their successful implementation. This test/fix approach significantly shortens the standards verification process and gives vendors the confidence they need to engage in tests at 3rd party venues and events and to ultimately launch a compliant and interoperable product.
The SSV HEVC Modes test tool has just completed the testing phase and all bugs discovered to date have been closed. The tool is now entering a maintenance phase of testing; enabling IMTC members to download the tool (including source code and documentation) to use, adapt or modify in their own labs as they see fit. Any further bugs found during this phase should be reported to the AG. However, HCL’s contract has concluded so bug fixing is now the responsibility of IMTC members.
Access to the SSV HEVC Modes test tool is a free benefit of ITMC membership, as is the earlier ‘SIPv6 over IPv6’ compliance test tool. To gain access to the IMTC github repository, please contact the IMTC Member Services Help Desk email@example.com