This should do it:
{
"jsonrpc": "2.0",
"method": "Player.GetItem",
"params": {
"properties": [
"title",
"album",
"artist",
"season",
"episode",
"duration",
"showtitle",
"tvshowid",
"thumbnail",
"file",
"fanart",
"streamdetails"
],
"playerid": 1
},
"id": "VideoGetItem"
}
Check this out for further API examples.