Gnomecast offers a very easy way of casting local video and audio files to Chromecast devices from Linux. It is ideal for quickly playing an audio or video file on your Chromecast, without waiting for some media server to index it.
While it uses a very basic interface and you won’t find many advanced options, this Gnome (uses Gtk+ and Python) Chromecast player takes care of most things you’d need. Besides being able to play / pause, control the volume or seek, Gnomecast lets you add subtitles, and it automatically transcodes both audio and video files that can’t be played directly by Google Chromecast devices.
With the popularity of Android TV, I wonder if the physical Chromecase hardware will still exist in a few years. We know the Chromecast functionality works on Android TV and some Roku devices.