HTML5 Video + Bacon.js

player.coffee

class Player
  constructor: (@node, @src) ->
    @init()
    
  init: ->
    @node.src = @src
    @node.play()
  
  event: (type) ->
    Bacon.fromEventTarget(@node, type).map ".currentTarget"
  
  seek: (pos) ->
    @node.currentTime = pos

  progress: ->
    position = @event("timeupdate").map(".currentTime").toProperty()
    duration = @event("loadedmetadata").map(".duration").toProperty()
    duration.combine position, (duration, position) -> {duration, position}

player = new Player(document.getElementById("player"), "my-video.mp4")
player.progress().assign (x) -> console.log [x.position, x.duration].join("/")
player.event("ended").assign (x) -> console.log "ENDED"