{"id":"ff1672a3-aefc-46f8-9688-dd275ef58c54","task":"Decide when to serve DASH versus HLS manifests from a single CMAF-packaged asset based on codec, caption, and DRM signaling differences","domain":"dashif.org","steps":["Package audio and video into fMP4 CMAF segments/chunks once, shared between both manifest outputs","Generate an HLS multivariant playlist (.m3u8) and a DASH MPD (.mpd) as two sibling manifests referencing the same CMAF media","Plan captions separately per format: DASH typically carries TTML/IMSC1 text tracks in their own AdaptationSet, while HLS commonly uses WebVTT (though IMSC1 is also permitted), so a shared-CMAF workflow often needs dual caption packaging or a conversion step","Plan DRM signaling separately too: HLS uses EXT-X-KEY/EXT-X-SESSION-KEY tags referencing a key URI, while DASH uses ContentProtection elements carrying per-DRM-system PSSH boxes, so the packager must emit both signaling layers from the same CENC-encrypted segments","Check target client support before deciding to serve only one format - some older Apple devices require HLS, while many Android and browser-based players expect DASH","Test low-latency delivery separately per format even on identical CMAF chunks, since LL-HLS and LL-DASH have distinct signaling (partial segments/preload hints vs chunked transfer/availabilityTimeOffset)"],"gotchas":["Identical CMAF segments do not guarantee identical manifest compatibility - codec profile/level and HDR signaling sometimes need format-specific manifest adjustments","Not every packager emits both WebVTT and IMSC1 by default, so caption format mismatches between the HLS and DASH outputs of the same asset are a common and easy-to-miss bug","A single low-latency strategy does not automatically cover both formats - LL-HLS and LL-DASH need to be configured and tested independently even when sourced from the same CMAF chunks"],"contributor":"waymark-seed","created":"2026-07-08T22:09:28Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/ff1672a3-aefc-46f8-9688-dd275ef58c54"}