Authored by Damien Lucas, Co-Founder and CTO
Video quality available on OTT platforms is getting better and better. If you just got used to HD quality, get ready for Ultra HD, a standard that takes full advantage of 4K devices now on the market, from set-top boxes (ex. Apple TV 4K) to TVs (ex. Samsung Q9F QLED, Sony Bravia A1 OLED, etc). With enough pixels to fill four HD images, Ultra HD offers home users a resolution that’s pretty close to what they get in a movie theatre. Sound technologies are also making a major leap forward. Nice? Definitely. But there’s a catch.
Stronger DRM requirements
With ultra high video quality made available through OTT platforms, the consequences of digital piracy have become a major concern for content owners. Indeed, if a media file with limited image and sound quality leaks out, it will only make it so far. But losing control of a very popular 4K content that has only just been released (think Game of Thrones or Stranger Things) can have a hugely damaging impact on the producer’s bottom line.
This is why the development of Ultra HD content over OTT calls for higher requirements for digital rights management (DRM). This is particularly true if you consider the variety of playback devices in the users’ hands or in their homes, with varying levels of security.
Over the past five years, content owners have been asking for increasingly effective and bullet proof DRM technologies, that adapt to every device’s characteristics. This means a viewer with a jailbroken iPhone, with probably very low security, will not be allowed to access the same image quality as someone with a legit iOS. And encryption keys need to change from device type to device type, to make sure a key that has been broken on a low security device cannot be used to unlock a 4K content on a more strongly protected device. Encryption keys also rotate every minute, so a broken key may only potentially unlock one minute of playback.
Three main DRM technologies for content protection
Today’s major OS developers all supply a dedicated DRM technology : Widevine for Google, PlayReady for Microsoft, FairPlay for Apple. This means OTT service providers who wish to offer the right content protection on all user devices will need to store every media in three versions. Add to this three different video container formats (MPEG DASH, HLS, and Smooth Streaming) as discussed here, as well as a number of different video resolutions to fit all playback devices and network quality (France’s Canal Plus stores 12 levels of quality for its myCanal OTT service) and this adds up to a very large number of files to manage, for every piece of content.
A valid solution is provided by origin server vendors offering just-in-time packaging that includes DRM provisioning. With just-in-time packaging, original media content is stored centrally in an unencrypted form. When a viewer request comes in for a given media, a version is generated on-the-fly with video resolution, sound quality, container format and DRM encryption that matches the user’s device type. Only the most popular versions are cached for users with the same setup. This lets content distribution networks automatically strike the right balance between storage optimisation and bandwidth usage.
However, looking forward, there are other DRM challenges that OTT platforms will need to face, as OTT customers are demanding increasingly granular services. With a growing number of OTT platforms offering to purchase sports events or episodes of a TV show on an individual basis, DRM technologies will need to keep up with the trend.