SK Broadband first operator to implement per-title encoding

Technology trailblazer SK Broadband has apparently kicked off a new per-title encoding system for its Btv VoD service, in a country first, according to local news site Pulse, which we have contacted for clarity on its sources given the lack of any official press release from parent company SK Telecom.

The premise of per-title encoding – pioneered by Netflix – is to improve image quality by applying different bitrate ladders to content depending on its unique level of complexity. A common problem is that a high default bitrate is wasteful for storage and CDN bandwidth resources, and therefore costs, while even general-purpose bitrate ladders for high to low resolutions fail to cater for factors like different aspect ratios or frames per second.

So, simply put, what per-title encoding does is apply an adjusted encoding profile to a piece of content, with individually optimized compute settings, prior to encoding the video asset, enabling better image quality before being sent via the normal workflow – thereby reducing storage and delivery costs. In the case of Netflix, its on-device client then runs adaptive streaming algorithms which instantaneously select the best encode to maximize video quality, while avoiding playback interruptions due to rebuffers.

For SK Broadband, Pulse describes the approach as an upgrade based on applied data experience to its library of 6,000 on-demand assets. “Previously, content encoding was carried out based on visual judgement of operators, but the latest per-title system runs an analysis to develop an optimal encoding recipe to provide optimized image quality to viewers,” reports Pulse in slightly broken English, citing an unnamed official from SK Broadband.

We understand that SK sources a mix of Media Excel and AWS Elemental encoding technologies and we have contacted both vendors to establish the extent of their involvement, if any, in the new per-title encoding project. Media Excel’s MPEG-4 AVC encoding and transcoding product, the Hero platform, was selected by Telecom for multiscreen services in 2012 so may have since been updated, while Elemental was selected around the 2015 to 2016 timeframe to supply its Live and Server video processing products for 4K UHD content over both OTT and DTH services.

Edit: A Media Excel representative has informed us that its Hero platform still powers live streaming for SK, with its latest configuration. Regarding per-title encoding, SK is using a local company that provides machine learning algorithms to estimate its encoding profiles. Then, it can apply the recommendation of that engine to whatever VoD transcoder it wishes (both Media Excel and Elemental allow for profiles to be adjusted dynamically through APIs.)

Local coverage also claims SK will expand per-title encoding to other content assets across its services next year, which include the newer mobile IPTV service Oksusu (which translates to Corn), which integrates some live channels from its sister Btv mobile IPTV service, but also offers the VoD platform Hoppin. Oksusu costs the same as Btv Mobile at $2.60 a month, but is available to subscribers of other carriers, while Btv is an SK Telecom exclusive, which have a combined subscriber base of around 14 million.

Aside from Netflix, SK Broadband seems to be the only other major video service provider publicly implementing a per-title encoding system, making SK the first and only operator to be using it as far as we can establish, although the technique is aligning more closely with content adaptive encoding techniques.

Compression technology vendor Bitmovin recently rolled out a free online resource called the Per-title Ladder Benchmark Tool, allowing content owners and network operators to get guidance on optimal encoding configuration, which to us suggests there is little demand, despite Netflix using and benefiting from per-title encoding technology since pre-2015.