/*****************************************************
*
* Copyright 2009 Akamai Technologies, Inc. All Rights Reserved.
*
*****************************************************
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
* License for the specific language governing rights and limitations
* under the License.
*
*
* The Initial Developer of the Original Code is Akamai Technologies, Inc.
* Portions created by Akamai Technologies, Inc. are Copyright (C) 2009 Akamai
* Technologies, Inc. All Rights Reserved.
*
* Contributor: Adobe Systems Inc.
*
*****************************************************/
package org.osmf.net
{
import flash.events.EventDispatcher;
import flash.events.NetStatusEvent;
import flash.events.TimerEvent;
import flash.net.NetStream;
import flash.utils.Timer;
CONFIG::LOGGING
{
import org.osmf.logging.Logger;
import org.osmf.logging.Log;
}
/**
* The NetStreamMetricsBase class serves as a base class for a provider of
* run-time metrics to the NetStreamSwitchManager and its set of switching
* rules. It calculates running averages for metrics that apply to all
* delivery methods.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public class NetStreamMetricsBase extends EventDispatcher
{
/**
* Constructor.
*
* Note that for correct operation of this class, the caller must set the
* resource which the monitored stream is playing.
*
* @param netStream The NetStream instance the class will monitor.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function NetStreamMetricsBase(netStream:NetStream)
{
super();
_netStream = netStream;
_droppedFPS = 0;
_lastFrameDropCounter = 0;
_lastFrameDropValue = 0;
_maxFPS = 0;
_averageDroppedFPSArray = new Array();
_timer = new Timer(DEFAULT_UPDATE_INTERVAL);
_timer.addEventListener(TimerEvent.TIMER, onTimerEvent);
netStream.addEventListener(NetStatusEvent.NET_STATUS, onNetStatusEvent);
}
/**
* Returns the DynamicStreamingResource which the class is referencing.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get resource():DynamicStreamingResource
{
return _resource;
}
public function set resource(value:DynamicStreamingResource):void
{
_resource = value;
_maxAllowedIndex = value != null ? value.streamItems.length - 1 : 0;
}
/**
* The NetStream object supplied to the constructor.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get netStream():NetStream
{
return _netStream;
}
/**
* The current stream index.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get currentIndex():int
{
return _currentIndex;
}
public function set currentIndex(value:int):void
{
_currentIndex = value;
}
/**
* The maximum allowed index value.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get maxAllowedIndex():int
{
return _maxAllowedIndex;
}
public function set maxAllowedIndex(value:int):void
{
_maxAllowedIndex = value;
}
/**
* The update interval (in milliseconds) at which metrics are recalculated. If
* set to zero, then metrics will not be recalculated.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get updateInterval():Number
{
return _timer.delay;
}
public function set updateInterval(value:Number):void
{
_timer.delay = value;
if (value <= 0)
{
_timer.stop();
}
}
/**
* The maximum achieved frame rate for this NetStream.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get maxFPS():Number
{
return _maxFPS;
}
/**
* The frame drop rate calculated over the last interval.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get droppedFPS():Number
{
return _droppedFPS;
}
/**
* The average frame-drop rate calculated over the life of the NetStream.
*
* @langversion 3.0
* @playerversion Flash 10
* @playerversion AIR 1.5
* @productversion OSMF 1.0
*/
public function get averageDroppedFPS():Number
{
return _averageDroppedFPS;
}
// Protected
//
/**
* Method invoked when the metrics should be recalculated. If
* updateInterval is set, this method will be invoked whenever the
* updateInterval is reached.
**/
protected function calculateMetrics():void
{
try
{
// Estimate max (true) framerate.
_maxFPS = netStream.currentFPS > _maxFPS ? netStream.currentFPS : _maxFPS;
// Frame drop rate, per second, calculated over last second.
if (_timer.currentCount - _lastFrameDropCounter > 1000 / _timer.delay)
{
_droppedFPS = (netStream.info.droppedFrames - _lastFrameDropValue) / ((_timer.currentCount - _lastFrameDropCounter) * _timer.delay/1000);
_lastFrameDropCounter = _timer.currentCount;
_lastFrameDropValue = netStream.info.droppedFrames;
}
_averageDroppedFPSArray.unshift(_droppedFPS);
if (_averageDroppedFPSArray.length > DEFAULT_AVG_FRAMERATE_SAMPLE_SIZE)
{
_averageDroppedFPSArray.pop();
}
var totalDroppedFrameRate:Number = 0;
for (var f:uint=0;f < _averageDroppedFPSArray.length;f++)
{
totalDroppedFrameRate += _averageDroppedFPSArray[f];
}
_averageDroppedFPS = _averageDroppedFPSArray.length < DEFAULT_AVG_FRAMERATE_SAMPLE_SIZE ? 0 : totalDroppedFrameRate / _averageDroppedFPSArray.length;
}
catch (error:Error)
{
CONFIG::LOGGING
{
logger.debug(".calculateMetrics() - " + error);
}
throw(error);
}
}
// Internals
//
private function onNetStatusEvent(event:NetStatusEvent):void
{
switch (event.info.code)
{
case NetStreamCodes.NETSTREAM_PLAY_START:
if (!_timer.running && updateInterval > 0)
{
_timer.start();
}
break;
case NetStreamCodes.NETSTREAM_PLAY_STOP:
_timer.stop();
break;
}
}
private function onTimerEvent(event:TimerEvent):void
{
if (isNaN(netStream.time))
{
_timer.stop();
}
else
{
calculateMetrics();
}
}
private var _netStream:NetStream;
private var _resource:DynamicStreamingResource;
private var _currentIndex:int;
private var _maxAllowedIndex:int;
private var _timer:Timer;
private var _averageDroppedFPSArray:Array;
private var _averageDroppedFPS:Number;
private var _droppedFPS:Number;
private var _lastFrameDropValue:Number;
private var _lastFrameDropCounter:Number;
private var _maxFPS:Number;
private static const DEFAULT_UPDATE_INTERVAL:Number = 100;
private static const DEFAULT_AVG_FRAMERATE_SAMPLE_SIZE:Number = 50;
CONFIG::LOGGING
{
private static const logger:Logger = Log.getLogger("org.osmf.net.NetStreamMetricsBase");
}
}
}
