fix(video): emit ec-3 for JOC on iOS#16
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superuser404notfound merged 1 commit intoMay 24, 2026
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iOS AVPlayer strictly enforces RFC 6381 codec strings in HLS variant attributes. The engine emits `ec+3` for EAC-3 with JOC (Atmos) tracks to match Apple's HLS Authoring Spec recommendation, but iOS treats `ec+3` as an unknown codec and silently drops the variant: `asset.load(tracks)` returns 0 and the item fails to open with `AVFoundationErrorDomain -11848 "Cannot Open"` (underlying `CoreMediaErrorDomain -15517`). macOS / tvOS tolerate `ec+3` and play the same variant. Gate the JOC marker so iOS emits the standard `ec-3` instead. JOC is unaffected because the `dec3` box in the segment fMP4 still carries the JOC marker — downstream receivers detect Atmos from that, not from the playlist codec string. macOS and tvOS keep emitting `ec+3`. Effect: DV + Atmos titles now play on iOS instead of failing at variant selection.
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Thanks! Clean, surgical fix, and the note about JOC surviving via the |
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Summary
Gate the audio codec advertisement so iOS emits
ec-3for EAC-3 with JOC (Atmos) tracks; macOS and tvOS keep emittingec+3.Why
iOS AVPlayer strictly enforces RFC 6381 codec strings in HLS variant attributes. The engine advertises
ec+3for JOC tracks to match Apple's HLS Authoring Spec recommendation, and macOS / tvOS tolerate that fine. iOS does not: it treatsec+3as an unknown codec and silently drops the variant during selection, soasset.load(tracks)returns 0 and the item fails to open with:AVFoundationErrorDomain -11848 "Cannot Open"CoreMediaErrorDomain -15517Switching iOS to plain
ec-3lets AVPlayer accept the variant. JOC is unaffected — thedec3box in the segment fMP4 still carries the JOC marker, which is what receivers use to detect Atmos. Only the playlist codec string changes.Effect
ec+3.