Wowza Media Server 3.5 Includes Support for Closed Captioning, Transcoder Overlays, and More
Modifications to the server also include HTTP origin delivery of ABR content into caching networks
At last month's Video Infrastructure Summit (VIS) in London, both RealNetworks and Wowza allowed me to provide a "sneak peek" at a few features for their soon-to-be-launched media server upgrades. Real launched v15 of its Helix Universal Media Server last week, and Wowza launches version 3.5 of the Wowza Media Server on Tuesday.
The "sneak peek" at the Europe event only listed bullet points on a number of features, but with the launch Wowza announces a bit more detail around three features: closed captioning, HTTP origin, and transcoder overlays.
According to Wowza Media vice-president of product management Chris Knowlton, this has been a highly requested feature. As mentioned by a Real representative during the VIS panel, this feature has always been a bit of a black art when it comes to media servers. While we've had options like SMIL and timed-text for well over 14 years, there really have been no true closed-captioning standards implementations until earlier this year.
Knowlton says Wowza seeks to address that issue by supporting both 508a- and 608a-compliant closed captioning for live and on-demand video streams in Wowza Media Server 3.5.
For years, customers have been able to use Wowza Media Server in an origin-edge configurations for RTMP live and on-demand streaming. Yet with the advent of adaptive bitrate (ABR) content segmentation for delivery via HTTP—Adobe HLS, Apple HLS, or Microsoft Smooth Streaming—there's been no way in Wowza Media Server to deliver HTTP ABR content directly into caching networks such as most CDNs.
"The main reason for this," said Wowza chief technologist Charlie Good, "was that each Wowza URL contained a unique session ID that would 'bust' the downstream caches. The reason was our ability to uniquely address an HTTP fragment or “chunk” to a specified user and user session. With WMS 3.5, when in HTTP Origin mode, we change the URL structure to eliminate this issue."
"This modification," added Dave Stubenvoll, Wowza's CEO, "allows any CDN or enterprise caching network to accept and cache HTTP streams from Wowza Media Server and make full use of their HTTP caching, scaling, and acceleration capabilities."
According to Wowza, the transcoder add-on (one of more than 20 add-on modules Wowza offers) has been a success. The company is moving to normalize pricing across a number of its premium add-ons, dropping the price of the transcoder add-on in the process. At the same time, Wowza is adding an additional tool to the add-on in the form of transcoder overlays.
"The Transcoder has a new, comprehensive overlay capability," said Knowlton. "Transcoder can now do crawls, bugs, and logos, without the need for an internal encoder."
Stubenvoll also pointed out that the transcoder add-on offers limited aggregate advertising opportunities, given the ability to separate the video fragmentation from the overlay capabilities.
"Since Transcoder handles integration of the graphic overlay on top of the video stream," he said, "we think Transcoder will find its way into the toolkit of many Wowza Media Server users."
Finally, one other topic of note: A number of media server vendors, including Wowza, have made noise recently about their server's ability to saturate a 10Gbps port. While this isn't typical of small media server deployments, it is a benefit to those who use media servers in enterprise clusters or content delivery network (CDN) configurations.
Wowza's Knowlton said that WMS 3.5 is able to saturate a 10Gbps network port, but that most customers won't be pushing it quite to that level of saturation.
"We have anecdotal information from customers that [10Gbps saturation] can be accomplished using either dual quad-core or hex-core Xeon processors with 16-32 GB of RAM," said Knowlton. "But note that most high-volume customers that would try this during testing are more likely to run at an actual load of less than 8 Gbps, to save room for traffic surges."
I asked Knowlton if there was a way to test saturation in Transitions' lab, since we have a quad-core Xeon and and 10G physical plant. When asked whether there is a particular tool Wowza recommends for the 8-10Gbps test, Knowlton said there is an RTMP-based tool Wowza offers for load testing.
"There is an RTMP load testing tool for Wowza Media Server 3.x," said Knowlton, adding that it's available on a Wowza forum.
We'll have a deeper look at Wowza Media Server 3.5 in coming weeks.
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