I have chromecast custom receiver. I know how to send the common key values through mediaMetadata.putString(MediaMetadata.KEY_TITLE, "Something"); and capture them in the receiver. I am wondering if there is a way to send custom fields as metadata. Something like mediaMetadata.putString("...customField", "Something else");. Each type of media only allows a fixed set of fields, but I would like to change this. Is this possible?
No you cannot use custom keys in MediaMetaData. You can add your own namespace to send the data or you can piggyback on custom data that some api calls provide.