Detect and change playbackRate

gistfile1.txt

    /** function set_speed(speed)
      * Set the video speed
      *
      * @param double speed - target speed
      *
      * @return void
      */
    this.is_set_speed_enabled = function(){
        if(typeof(this.mediaelement_media) === 'object'
                && this.mediaelement_media !== null
                && typeof(this.mediaelement_media.playbackRate) === 'number'
                && this.mediaelement_media.playbackRate > 0){
            return true;
        }
        else{
            return false;
        } 
    }

    this.set_speed = function(speed) {
        if(this.is_set_speed_enabled()) this.mediaelement_media.playbackRate = speed;
    }

    this.get_speed = function(speed) {
        if(this.is_set_speed_enabled()) return this.mediaelement_media.playbackRate;
        else return 1;
    }

    this.increase_speed = function(deltaSpeed){
        var minSpeed = 0.50;
        var maxSpeed = 2.00
        var newSpeed = QL_player.get_speed() + deltaSpeed;
        if(newSpeed < minSpeed) newSpeed = minSpeed;
        if(newSpeed > maxSpeed) newSpeed = maxSpeed;
        QL_player.set_speed(newSpeed);
    }

    this.decrease_speed = function(deltaSpeed){
        this.increase_speed(-deltaSpeed);
    }