cta-wave / device-playback-task-force

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New Playback Requirement: Event Message Processing #53

Closed haudiobe closed 1 year ago

haudiobe commented 5 years ago

8.20 Event Message Processing CTA WAVE content may contain event messages of relevance for the application. The first version of this specification does not define a test for this.

haudiobe commented 4 years ago

(19/11/06 DPCTF)

W3C work does some work on this
DASH-IF (see published information) + MPEG developed (see CDAM.1) an Event Processing Model as well (more or less completed)
dash.js has a polyfill that will do the work (preferably make this polyfill library independent of dash.js) We start from the DASH-IF/MPEG model for playback requirements (Thomas)

For making the tests complete, we need

Content Requirements for Event messages in CTA WAVE Content Specification - at this stage no difference CMAF, only guidelines and recommendations. Would be good to have a specific normative section in Content Specification (augmented with recommendations and guidelines) => 2020 spec.
Need Test cases and test material for this purpose (John)

haudiobe commented 4 years ago

An initial proposal is provided here, but needs more work: https://1drv.ms/w/s!AiNJEPgowJnWgos-u32ftrH96QvscQ?e=vPuxHh

jpiesing commented 4 years ago

76 makes the point that some of the streams should have events in them as a matter of principle.

dsilhavy commented 3 years ago

dash.js uses the IsoBoxer library to check for EMSG boxes: https://github.com/madebyhiro/codem-isoboxer

Workflow is as simple as we check for EMSG after segments have been downloaded. Event handling is done in a separate class (EventController). We support version 1 and 2 events. This logic could be reused if required, although decoupling of other dash.js parts is required.

jpiesing commented 3 years ago

As far as I can tell. MSE implementations and browsers don't do anything with emsg boxes & should ignore them. If this is correct then there's nothing for WAVE to test here.

dsilhavy commented 3 years ago

I think Iraj and DASH-IF are working on this in the context of MSE v2. I agree that currently nothing can be tested here with MSE v1

haudiobe commented 2 years ago

At this stage this is implemented as a javascript library. No test are needed. It would be reasonable to refer to 1) processing model 2) Javascript library that can be used as a reference that includes a) IsoBoxer library to check for EMSG boxes: https://github.com/madebyhiro/codem-isoboxer b) https://github.com/Dash-Industry-Forum/dash.js/blob/development/src/streaming/controllers/EventController.js

Propose to add the above informative description.

gitwjr commented 1 year ago

@jpiesing noted that we decided to test to confirm event messaging does not break anything. Part of RFP: Change to test content generation scripts. Need to add event message to some content and do simple tests to see if anything breaks.
11/22/2022: No resolution.

gitwjr commented 1 year ago

Included in latest contract. Close.