MV-HEVC with alpha channel

Does the new MV-HEVC vision pro spatial video format supports having an alpha channel? I've tried converting a side by side video with alpha channel enabled by using this Apple example project, but the alpha channel is being removed.

https://developer.apple.com/documentation/avfoundation/media_reading_and_writing/converting_side-by-side_3d_video_to_multiview_hevc

I decoded the alpha channel in an MV-HEVC encoded with spatial-media-kit in Davince Resolve. Unlike the EXR sequence from the source, the MV-HEVC had to manually turn on the setting of premultiply alpha for the clip.

I tried to change the multiviewSettings AVVideoCodecKey: AVVideoCodecType.hevc to AVVideoCodecKey: AVVideoCodecType.hevcWithAlpha, However, it gave me an error: Appended tagged buffers with PTS CMTime(value: 0, timescale: 2400, flags: __C.CMTimeFlags(rawValue: 1), epoch: 0) Asset writer failed with error: Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSLocalizedFailureReason=An unknown error occurred (-12782), NSLocalizedDescription=The operation could not be completed, NSUnderlyingError=0x600003727840 {Error Domain=NSOSStatusErrorDomain Code=-12782 "(null)"}}, ["NSLocalizedFailureReason": An unknown error occurred (-12782), "NSLocalizedDescription": The operation could not be completed, "NSUnderlyingError": Error Domain=NSOSStatusErrorDomain Code=-12782 "(null)"]

any ideas on how to fix that and enbale alpha channel support for MV-HEVC? thanks

MV-HEVC with alpha channel
 
 
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