Add subtitle(additional text/title) to sender and default receiver

[rupisaini123]

Use Cases

We would like have additional subtitle just like how chromecast have. This text is shown under the title on chromecast receiver app.
This can be enhancement on fcast-sender, to pass in this property.

Also, we can enhance our default fcast receiver app, to add/show the subtitle under the title with smaller font size compared to title.

Proposal

No response

References

No response

[Michael-Hollister]

I'm not sure if/when sub-title support would be added to the FCast protocol and default receivers (as this is more of a niche use-case), but most of the implementation is available for adding custom metadata in the play message: https://gitlab.futo.org/videostreaming/fcast/-/wikis/Protocol-version-3#playmessage

I don't believe the SDK currently exposes this field though, which is something I guess we need to add. You would have to make a custom receiver though to read your custom metadata and render the sub-title.