Explicit signalling of DRM/C2PA key-rotation or various init segment updates #17
Description
As noted in the MSF meeting on February 5, 2026, we need a mechanism for clients to be notified when the init segment changes due to key rotation or any other reason. A couple of ideas were discussed on this topic:
- Have a separate track that sends the init segment whenever an update occurs. The group raised concerns regarding synchronization between these two tracks.
- Include the init segment as an extension header.
- Explicitly signal key rotation in the extension header.
- Explicitly signal that an object requires a new init segment via a simple extension header indicating that the latest init segment is required to decode the object (optionally including a reference to the location of that init segment in the separate track).
The goal is to ensure that clients can easily switch to new tracks and reliably obtain the appropriate init segment for that track, including when a key rotation occurs.