[EME] Possible bug in FairPlay-protected HEVC content on older hardware

• Component: Media
• Status: NEW ---

[Tomas Bucher]

This might or might not be a bug, depending on the circumstances.

I am experimenting with playback of HEVC UHD content protected by FairPlay in Safari 12 and Safari Technology Preview. Our team has at its disposal a couple of Apple devices, namely iPad Air 2 (2014), MacBook Air (2015), iPhone 6S (2015), iPad (2018) and iPhone X (2017). All updated to recent software versions - iOS 12.1.x and macOS Mojave 10.14.3.

The HEVC HLS stream protected by FairPlay plays only on iPhone 6s, last gen iPad and iPhone X. iPad 2 and MacBook Air just end up with a media error after they receive license from the FairPlay license server and "webkitkeyadded" event is fired.

If I do not provide the decryption content key from the FairPlay license server encapsulated in CKC license message, but deliver the content key directly as a binary file as outlined here https://developer.apple.com/library/archive/technotes/tn2454/_index.html#//apple_ref/doc/uid/DTS40017630-CH1-CONTENT_AUTHORING_AND_CONTENT_PLAYBACK_ISSUES-QUICKLY_DIAGNOSING_CONTENT_KEY_AND_IV_ISSUES , the stream is properly decrypted and perfectly playable even on the rest of those devices.

It should also be noted that H.264 HLS stream protected by FairPlay is playable on all mentioned devices.

Based on these facts, I would simply blame it on some issue in the FairPlay CDM on specific devices with HEVC content and would ask you to take a look. However, it could also be expected behavior caused by hardware differences, but I could not find any additional info that would shed a light on which device generation is supported for this scenario and which is not.

Can you please comment on that and if the latter is the case, can you help identify devices, which are not supported?

[Radar WebKit Bug Importer]

<rdar://problem/49423313>

[Tomas Bucher]

We are aiming to start using HEVC with FairPlay encryption. However, we can't use it safely knowing that some end-users, despite having recent Safari, would be still unable to play the content.

Update to this ticket would be much appreciated.