By Garey Hassler, Comcast
Television audiences expect the best video quality their devices can render and to have it available for viewing in seconds. Years of video quality branding, like high-definition (HD) and 4K, and other consumer educational efforts, have fashioned discernible viewers capable of distinguishing sharpness, brightness and resolution and equating this to quality. Furthermore, with decades of broadcast consumption, viewers have been observing diminishing tune times, or time-to-first-frame (TTFF), creating an expectation, which can be challenging to achieve in a redundant IP video service.
Multichannel video program distributors (MVPDs) can dramatically improve their ability to achieve viewers’ expectations by enhancing a video origin to support Hypertext Transfer Protocol Version 2.0 (HTTP/2) [1], synchronizing video transcoding and packaging, applying video quality measuring, and automating origin selection.
A proof-of-concept (POC) was constructed to independently measure the video quality of a single video source, relative to the synchronized transcoding and packaging of two geographically dispersed sites. Applying automated decision logic on the quality measurements to select an origin for distribution on a per-fragment interval ensures the highest quality is distributed to viewers. Utilizing (HTTP) version 2.0 PUSH method to immediately distribute the IP content through a content delivery network (CDN), reduces network traversal from a roundtrip-time to an end-to-end latency.
Evaluations of the POC were conducted in simultaneous test executions compared with existing client/server production components, in a non-isolated network, thus any network congestion or impairments applied equally to the test measurements. Preliminary test results over multiple executions indicate a 45% – 56% improvement in TTFF, while delivering the highest quality video fragment to all test players.