CENC support is only for Mpeg-Dash ?Does HLS Supports CENC
I was able to find this in a quick google search:
Simple support for fragment MP4 files isn’t the only thing new with HLS. It now also supports DRM-protected fMP4 segments using MPEG-CENC (Common Encryption). It is supported by all the major browsers, and MPEG-DASH already supports DRM protected Fmp4 files.
https://cdn.net/what-is-cmaf-and-the-implication-for-hls/
