Content Steering signaling and live manifest update

[bbert]

For live streams with manifest updates, in case the content steering signaling (BaseURL, Location, ContentSteering) is provided only in the first manifest but not in the manifest updates, what shall be the client behavior?

1. shall the client invalidate the content steering signaling, and therefore keep the selected BaseURL and Location before manifest update for next fragment and manifest requests, and stop the steering manifest updates ?
2. or shall it maintain all the logic according to signaling received in the 1st manifest ?

From IOP, section 5.3.3.3:
"In addition, updates in the MPD only extend the timeline. This means that information provided in a previous version of the MPD shall not be invalidated in an updated MPD."

In my understanding players should be conformed to option 2, but to date dash.js seems to be conformed to option 1.

Option 2 would enable setting up a content steering proxy service that manipulates and adds content steering signaling in the MPD and redirect subsequent manifest requests to a different Location, avoiding players to refresh the manifest from this proxy service.

Regards
Bertrand

[haudiobe]

TF Call:

• Questions:
  • Can you update/change the steering information and if so, what does it mean for the client behaviour?
    • dash.js for example stops steering logic
  • Can you change the steering information for a specific media time or real-time? Again what is the client behaviour.

It would be good to collect on what should be the desired function and based on this we update spec.

[haudiobe]

IOP 2024/10/29

• Use Case: Manifest from different CDNs
• Objective: Manifest updates should not change Content Steering information. No invalidation.
• Option 1:
  • disallow changes, disallow removal
  • on client, even if changes happen, continue steering to the original information. If steering server responds 404, you may change to new information.
• Option 2:
  • allow changes and removal
  • on client, even if changes happen, continue steering to the original information. If steering server responds 404, you may change to new information.

We favour option 2, but want to receive comments if anyone has concerns