New stream component - resume previous playing media thoughts

With the new stream component I am toying with the idea of casting cameras to a cast device but if something is playing I want the chromecas/hub to resume playing the previous media after some camera condition is true (time elapsed/state change). In Jason’s video for the .90 release blog https://www.home-assistant.io/blog/2019/03/20/release-90/ this happens but my hunch is the TV has built in cast support and after some condition is true an automation fires and switches his tv back to the hdmi input. Or he did it manually.

For instances where its not an input change, the device would need to remember the previously playing media, or do something in home assistant. As a long shot I tried calling the previous track service on the media_player serivce for the google hub but that did not work. I’ve not researched saving the state of a entity and parsing it for a service call to ‘resume’ but I’m guessing its possible.

Right now this is just a thought exercise and to see if its possible. I’m also curious what others think. The stream component is brand spanking new, I’m sure the dev has some pretty cool things planned.