Skitter moves to patent prioritized VBR

Skitter TV, one of several providers of hybrid TV/over-the-top video platforms to emerge in the last couple years, has filed a provisional patent application with the U.S. Patent and Trademark Office for a variable bit rate (VBR) video streaming solution for multicast IPTV and Internet TV environments.

VBR has been used before by service providers and content delivery network firms like Akamai, but Skitter’s take on it is called Prioritized VBR.

“Prioritized VBR is different than traditional VBR streaming in that we are streaming live VBR video as if it is constant bit rate video on the network,” said Mark Sauer, managing director and senior fellow at Skitter. “That is, getting the VBR stream through a network that is rate limited will be possible with prioritized VBR, but not with the typical VBR solution.”

Skitter President and co-founder Robert Saunders added, “Variable bitrate video streams are typically used to deliver pre-recorded on-demand video over the Internet. Our protocol is optimized for the delivery of live television over bandwidth-constrained networks such as DSL.”

Prioritized VBR is now available in the second generation of Skitter's Acclaim family of live MPEG-4 video encoders. The Acclaim gear also continues to support CBR. Many video providers use CBR technology to control video’s demands on network capacity, but CBR also can cause quality degradation and actually add to capacity demand issues with buffering requirements, according to Skitter. Priortized VBR brings an element of control and flexibility to manage quality of service on a stream-by-stream basis and adjust bit rate as needed.

Sauer offered this real-world example for use of prioritized VBR: “Say you have a stream set to 2 Mb/s average bit rate using VBR on a typical encoder. It may peak to 6 Mb/s for short intervals. If you are trying to get this stream through an ADSL modem that can only stream 2.1 Mb/s max, then the 6 Mb/s peak from a typical VBR will not get through to the decoder, causing corruption. With Prioritized VBR via our Acclaim Video Encoders, it will still get through.”