康卡斯特公司 Content Delivery Summit Keynote: Live Linear Explained

“I’m not going to be talking about a CDN,” said Jason Burgess, a 康卡斯特公司 software and systems architect, during his Content Delivery Summit 2014 keynote address. “今天，我想和你们谈谈 Xfinity TV Go.”

Xfinity TV Go有“超过30个”,000 hours of on-demand programming and 50 channels of live television,伯吉斯说. “We call our IP video development platform VIPER."

As the lead on 康卡斯特公司’s VIPER IP video engineering team, Burgess is responsible for the architecture and development of solutions for adaptive bitrate delivery of video-on-demand and linear content for Xfinity TV Go and other next-generation IP video products at 康卡斯特公司.

“按需, 或视频点播, we transcode high-quality course content into multi-bitrate MPEG-4 and then prepackage content into a Common Intermediate Format based on DASH,伯吉斯说. These additional extensions to DASH make it easier for 康卡斯特公司 to handle the content distribution internally.

“每当有人要求提供内容, we have CDN edges scattered across 25 sites across the United States,伯吉斯说. “The CIF storage is a multi-petabyte system that we replicate across both sites.”

Burgess then explained the live linear approach of VIPER.

“Everything is completely identical to the VOD system,伯吉斯说, noting that RAM is used for live linear rather than the multi-petabyte storage for on-demand content.

“One of the best features we have is Download & Go,伯吉斯说, discussing the fact that 康卡斯特公司 subscribers can download a large part of the on-demand library thanks to a single digital rights management (DRM) solution. The DRM solution ties into approximately 25 key license servers geographically dispersed around the United States.

“除了, we don’t apply the DRM until the request time,伯吉斯说, noting that this provides for quick response in the case of a breach.

“We collect events from every IP player, including the Xfinity TV Go app,伯吉斯说. “这让我们能够实时诊断问题, a key feature for operations team so that they can determine whether certain areas of the country are experiencing low playback quality." 康卡斯特公司 then uses the data to provide self-healing capabilities for the system.

Burgess described the analytics architectures starting with the applications, 然后是数据收集, 数据处理, and data persistence via MemSQL accessible via a real-time applications programming interface (API).

“This data is then available to our operations team, as well as any application views,伯吉斯说.

Burgess also talked about advertising, noting that Xfinity TV Go used industry-standard ad standards.

“We use industry standards but have also worked with standards bodies to create new standards where needed,伯吉斯说. “We have ways to create segment boundaries anywhere in the stream based on metadata we receive. We also are able to support local and national dynamic ad insertion (DAI) on line streams.”

Xfinity uses 免费的wheel and other ad-decision systems, and the analytics platform allows for “complete and accurate accounting for linear ad viewing.”

“We now have the ability to individual target users for ads,伯吉斯说, noting that several customers are excited about this ability.

“CDN再也帮不了你了, because the CDN can’t cache hundreds of thousands of unique copies of the manifest,伯吉斯说.

Burgess described a solution that 康卡斯特公司 created to work within the CDN’s limitations, 根据主舱单. 康卡斯特公司 is also looking to address manifest manipulation on the client side, 但这是有挑战的, 其中最重要的是与苹果合作.

康卡斯特公司 is beginning to gain insight into what decisions an end-user makes when faced with a blackout. Burgess also noted that emergency alerts are possible on Xfinity TV Go for the first time, 尽管它们还没有被使用过.

“VIPER has been designed from the ground up to enable rapid development and deployment of IP video applications,伯吉斯说. “这为部署提供了其他选择, since we can support other formats and DRM providers in our just-in-time packager.”