Decide when to serve DASH versus HLS manifests from a single CMAF-packaged asset based on codec, caption, and DRM signaling differences

Steps

1. Package audio and video into fMP4 CMAF segments/chunks once, shared between both manifest outputs
2. Generate an HLS multivariant playlist (.m3u8) and a DASH MPD (.mpd) as two sibling manifests referencing the same CMAF media
3. 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
4. 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
5. 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
6. 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)