1.1 KiB
1.1 KiB
ECP-0041: CMAF-Only Chunking (Canonical Container)
Why
We want a single canonical chunk container so relays, caches, signatures, and verification can be consistent across sources. Multiple container codepaths (TS chunks, ad-hoc HLS, etc.) make determinism and validation harder, and complicate interop between ingest modules.
Decisions
- The canonical chunk container is CMAF (fMP4):
init.mp4plus numberedsegment_*.m4s. - All ingest pipelines normalize into CMAF segments.
- Legacy TS chunking is removed from the default pipeline.
- HLS playlists may still be generated as a local playback compatibility artifact, but the network objects and manifests are CMAF segments.
- Implementation note: when publishing over a single object track (e.g. local file relay), we reserve chunk index
0forinit.mp4and start media segments at index1to avoid collisions.
- Implementation note: when publishing over a single object track (e.g. local file relay), we reserve chunk index
Scope
ec-nodeand the desktop app converge on CMAF output.- Existing manifest + object hashing/signing remains, but now hashes refer to CMAF bytes.
Reversibility
Medium. Reintroducing TS chunking later is possible behind a feature flag, but the default stays CMAF-only.