flash on 2011-9-22
/**
* Copyright AndreMichelle ( http://wonderfl.net/user/AndreMichelle )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/hbNd
*/
package
{
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.events.Event;
import flash.events.SampleDataEvent;
import flash.media.Sound;
import flash.media.SoundChannel;
import flash.system.Capabilities;
import flash.text.TextField;
import flash.text.TextFieldAutoSize;
import flash.text.TextFormat;
import flash.utils.ByteArray;
/**
* Quick LatencyCheck
*
* @author Andre Michelle
*/
public class DemoLatency extends Sprite
{
private static const TESTS: Vector.<int> = Vector.<int>( [ 2048, 3072, 4096, 8192 ] );
private const buffer: ByteArray = new ByteArray();
private const sounds: Vector.<Sound> = new Vector.<Sound>();
private const channels: Vector.<SoundChannel> = new Vector.<SoundChannel>();
private const textField: TextField = new TextField();
private const outputs: Vector.<String> = new Vector.<String>();
private var _buildIndex: int = 0;
public function DemoLatency()
{
textField.autoSize = TextFieldAutoSize.LEFT;
textField.defaultTextFormat = new TextFormat( 'Verdana', 10, 0x0, false );
textField.text = '';
addChild( textField );
buffer.length = TESTS[ int( TESTS.length - 1 ) ] << 3; // MAX SAMPLES * sizeof float (times two: stereo)
stage.align = StageAlign.TOP_LEFT;
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.addEventListener( Event.ENTER_FRAME, enterFrame );
}
private function enterFrame( event: Event ): void
{
if( _buildIndex < TESTS.length )
{
sounds[_buildIndex] = new Sound();
sounds[_buildIndex].addEventListener( SampleDataEvent.SAMPLE_DATA, sampleData );
channels[_buildIndex] = sounds[_buildIndex].play();
++_buildIndex;
}
textField.text = '';
textField.appendText( 'System\t' + Capabilities.os + '\n' );
textField.appendText( 'Player\t' + Capabilities.version + ' ' + Capabilities.playerType + '\n' );
textField.appendText( '--------------------------------------------------------------------\n' );
var i: int = 0;
var n: int = outputs.length;
for( ; i < n ; ++i )
{
textField.appendText( outputs[i] + '\n' );
}
}
private function sampleData( event: SampleDataEvent ): void
{
var index: int = sounds.indexOf( event.target );
if( -1 == index )
throw new Error();
buffer.position = 0;
event.data.writeBytes( buffer, 0, TESTS[index] << 3 );
if( channels.length > index && channels[index] != null )
{
// Compute difference from writing and audible audio data
const latency: Number = event.position / 44.1 - channels[index].position;
outputs[index] = 'Providing ' + TESTS[index] + ' samples results in ' + latency.toFixed(3) + 'ms latency';
}
}
}
}