CMAF may be ready, but are you ready for CMAF

Common Media Application Format (CMAF) offers many advantages and simplifies OTT content protection. And in the last 18 months, the industry has progressed to make CMAF “ready” for deployment. But are you ready for it?

Good progress, but…

Let’s recap major OTT ecosystem changes in recent years:

  • DRM fragmentation began when browser plug-ins started to get phased out. Content owners also added hardware root of trust as a requirement for premium content. Operators now must support all native DRMs like PlayReady, Widevine and FairPlay if they want wide device reach.
  • MPEG DASH came on the scene in 2015, simplifying streaming technologies to just two flavors: HLS for Apple devices and DASH for everything else.
  • The industry converged further by supporting CMAF as the single video format for DASH and HLS. This happened when Apple added support for Fragmented MP4 (fMP4), though it still required a different playlist. Operators could now “package once, serve many.”
  • But there was a snag – not all DRMs supported the same encryption technology. Encrypting the file using two different encryption methods would duplicate your CDN cost. Once again, the tech giants came together and added AES-128 Cipher Block Chaining (CBC) support, at least to newer devices and browsers.

 Now, we have three major DRMs, two streaming technologies, one file format and one encryption technology. We can optimize OTT infrastructure and operational costs and deliver better quality services. So, what are we waiting for?

 The fine print

To implement CMAF with CBC, a few changes are needed:

  1. On the DRM license server, you must support PlayReady 4.x for CMAF-compliant devices. No other changes are needed on Widevine and FairPlay DRM license servicers.
  2. Packagers must be able to package and encrypt fMP4 files with AES-128 CBC and generate playlists for HLS and DASH. Some packagers already offer these capabilities.
  3. Consumer devices and browsers must support CMAF and AES-128 CBC. On managed devices, you’d need to update your implementation to support CMAF video files. This is where the trouble starts because many devices simply can’t support CMAF and CBC.

Are you ready to leave older devices behind?

Here is a snapshot of CMAF client coverage:

  • Devices and browsers using FairPlay are good to go. Good news here!
  • PlayReady is a major issue because only Xbox One, S and X devices support AES-128 CBC. By implementing CMAF and CBC, you would be leaving behind any customers who access your service using Edge browsers or Internet Explorer, PlayStations or TEE-based STBs unless you could get them to switch to the latest Chrome or Firefox browsers.
  • Widevine support using HLS and CMAF is broad, with some limitations:
    • It works with Chrome browser (68+), Chromium (68+), Chromecast, and Android (P or later).

Knowing how quickly the OTT market evolves and how cost efficient operators must be to compete, I predict most operators will decide to support CMAF by 2020.

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