Hook / Plugin Access HLS Playlist Custom Tags

[derekdowling]

Have you read the FAQ and checked for duplicate open issues? Yes.

Is your feature request related to a problem? Please describe.

The HLS video backend that I am looking to use with Shaka encodes server side ad insertion metadata into HLS playlist files using EXT-X-DATERANGE tags. This metadata is used to manage visibility of custom ad player UI elements while also supplying data to that element to display ad duration, count, remaining time, etc.

Describe the solution you'd like

Plugin hooks similar to that of Caption Parsing and Displaying but for SSAI metadata or even more generally for custom EXT-X-* or EXT-X-DATERANGE derived events, whatever level of abstraction seems the most useful or generally applicable for all Shaka consumers. Basically I want the ability to parse timed events from playlist tags, push them into a queue, have Shaka determine when the event should be emitted, and then have a "Displayer" for doing something interesting with them.

This issue covers a similar use case: #1983.

Describe alternatives you've considered
From looking at the plugin/customization guide, it doesn't appear that there is an easy way to access this information. To accomplish this today, it appears I would have to override the default HlsParser, which is undesirable.

[dazilb]

Are there any updates on this issue?