-12885 "CoreMediaErrorDomain" "unsupported crypt format."

Hi There,

We are currently testing HEVC with FPS on ATV4 and 4K.

Unencrypted HEVC plays fine on both - so we know the stream is supported. However, only the ATV4K (and iOS and Safari) plays content encrypted with Fairplay.

The ATV4 throws the following error:

<SEGPUMP> segPumpParseIndexFile: 0x101047000: alternate [] could not be played due to unsupported crypt format; removing it from alternate list

<<<< FigStreamPlayer >>>> fpfs_haltStream: #Version: 1.0
#Software: AppleCoreMedia/1.0.0.17L256 (Apple TV; U; CPU OS 13_4 like Mac OS X; en_au)
#Date: 2020/04/17 15:17:19.019
#Fields: date time uri cs-guid s-ip status domain comment cs-iftype
2020/04/17 15:17:19.019 https://path/to/content/removed/index_1.m3u8 14062C37-21D3-48C1-A7AE-4F0F2C7401AC - -12885 "CoreMediaErrorDomain" "unsupported crypt format." wifi-infra

I added some more logging and this now shows:

****** assetFailedToPrepareForPlayback:playerItem.error: Error Domain=AVFoundationErrorDomain Code=-11848 "See -[AVPlayerItem errorLog] for 3 events" UserInfo={NSLocalizedDescription=Cannot Open, NSUnderlyingError=0x281b6a6d0 {Error Domain=NSOSStatusErrorDomain Code=-12925 "(null)"}, NSDebugDescription=See -[AVPlayerItem errorLog] for 3 events, NSLocalizedFailureReason=The media cannot be used on this device.} *********

I'm assuming this means that FPS + HEVC is not supported by ATV4?

I've tried to find references to "unsupported crypt format" but am not having much luck. Has anyone else experienced something similar?