topical media & game development
student-mma-16-AudioBuffer.ax
student-mma-16-AudioBuffer.ax
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/*
Copyright(C) 2007 Andre Michelle and Joa Ebert
PopForge is an ActionScript3 code sandbox developed by Andre Michelle and Joa Ebert
http://sandbox.popforge.de
This file is part of PopforgeAS3Audio.
PopforgeAS3Audio is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
PopforgeAS3Audio is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>
*/
package
{
import de.popforge.audio.output.*;
import mx.controls.Alert;
import flash.media.Sound;
import flash.media.SoundChannel;
import flash.media.SoundTransform;
import flash.utils.ByteArray;
import flash.utils.Endian;
The class @ax-student-mma-16-AudioBuffer creates an endless AudioStream
as long as the buffer is updated with new samples
author: Andre Michelle
public class @ax-student-mma-16-AudioBuffer
{
The internal minimal sound buffer length in samples(PC)
static public const UNIT_SAMPLES_NUM: uint = 2048;
Stores a delegate function called, when the @ax-student-mma-16-AudioBuffer is inited.
public var onInit: Function;
Stores a delegate function called, when the @ax-student-mma-16-AudioBuffer has complete its cycle.
public var onComplete: Function;
Stores a delegate function called, when the @ax-student-mma-16-AudioBuffer is started.
public var onStart: Function;
Stores a delegate function called, when the @ax-student-mma-16-AudioBuffer is stopped.
public var onStop: Function;
private var multiple: uint;
private var channels: uint;
private var bits: uint;
private var rate: uint;
private var sound: Sound;
private var soundChannel: SoundChannel;
private var trans: SoundTransform;
private var _numBytes: uint;
private var _numSamples: uint;
private var bytes: ByteArray;
private var samples: Array;
private var firstrun: Boolean;
private var playing: Boolean;
private var
Creates an @ax-student-mma-16-AudioBuffer instance.
parameter: multiple Defines the buffer length (4times recommended)
parameter: channels Mono(1) or Stereo(2)
parameter: bits 8bit(8) or 16bit(16)
parameter: rate SamplingRate 5512Hz, 11025Hz, 22050Hz, 44100Hz
public function @ax-student-mma-16-AudioBuffer( multiple: uint, channels: uint, bits: uint, rate: uint )
{
Audio.checkAll( channels, bits, rate );
this.multiple = multiple;
this.channels = channels;
this.bits = bits;
this.rate = rate;
firstrun = true;
init();
}
Updates the @ax-student-mma-16-AudioBuffer samples for the next playback cycle
Must be called after the new samples are computed
public function update(): ByteArray
{
bytes.length = 0;
var i: int;
var s: Sample;
var l: Number;
var r: Number;
switch( channels )
{
case Audio.MONO:
if( bits == Audio.BIT16 )
{
for( i = 0 ; i < _numSamples ; i++ )
{
s = samples[i];
l = ( s.left + s.right ) / 2;
if( l < -1 ) bytes.writeShort( -0x7fff );
else if( l > 1 ) bytes.writeShort( 0x7fff );
else bytes.writeShort( l * 0x7fff );
s.left = s.right = 0;
}
}
else
{
for( i = 0 ; i < _numSamples ; i++ )
{
s = samples[i];
l = ( s.left + s.right ) / 2;
if( l < -1 ) bytes.writeByte( 0 );
else if( l > 1 ) bytes.writeByte( 0xff );
else bytes.writeByte( 0x80 + l * 0x7f );
s.left = s.right = 0;
}
}
break;
case Audio.STEREO:
if( bits == Audio.BIT16 )
{
for( i = 0 ; i < _numSamples ; i++ )
{
s = samples[i];
l = s.left;
r = s.right;
if( l < -1 ) bytes.writeShort( -0x7fff );
else if( l > 1 ) bytes.writeShort( 0x7fff );
else bytes.writeShort( l * 0x7fff );
if( r < -1 ) bytes.writeShort( -0x7fff );
else if( r > 1 ) bytes.writeShort( 0x7fff );
else bytes.writeShort( r * 0x7fff );
s.left = s.right = 0;
}
}
else
{
for( i = 0 ; i < _numSamples ; i++ )
{
s = samples[i];
l = s.left;
r = s.right;
if( l < -1 ) bytes.writeByte( 0 );
else if( l > 1 ) bytes.writeByte( 0xff );
else bytes.writeByte( 0x80 + l * 0x7f );
if( r < -1 ) bytes.writeByte( 0 );
else if( r > 1 ) bytes.writeByte( 0xff );
else bytes.writeByte( 0x80 + r * 0x7f );
s.left = s.right = 0;
}
}
break;
}
SoundFactory.fromByteArray( bytes, channels, bits, rate, onNewBufferCreated );
return bytes;
}
Starts the @ax-student-mma-16-AudioBuffer playback
public function start(): Boolean
{
if( playing ) return false;
if( soundChannel != null )
soundChannel.stop();
if( sound != null )
soundChannel = sound.play( 0, 1, trans );
playing = true;
if( onStart != null )
onStart( this );
return true;
}
Returns true, if the @ax-student-mma-16-AudioBuffer is playing
public function isPlaying(): Boolean
{
return playing;
}
Returns number of channels.
public function getChannels(): uint
{
return channels;
}
Returns number of bits.
public function getBits(): uint
{
return bits;
}
Returns samplingRate in Hz
public function getRate(): uint
{
return rate;
}
Returns length of the buffer (sampleNum / UNIT_SAMPLES_NUM)
public function getMultiple(): uint
{
return multiple;
}
Returns samples for overriding with new amplitudes
public function getSamples(): Array
{
return samples;
}
Returns number of samples
public function get numSamples(): uint //-- read only
{
return _numSamples;
}
Returns current peak(left)
public function get leftPeak(): Number
{
return soundChannel == null ? 0 : soundChannel.leftPeak;
}
Returns current peak(right)
public function get rightPeak(): Number
{
return soundChannel == null ? 0 : soundChannel.rightPeak;
}
Returns true, if the @ax-student-mma-16-AudioBuffer is inited
public function get isInit(): Boolean
{
return isInit;
}
Returns number of milliseconds of each buffer
public function get millisEachBuffer(): Number
{
return 2048000 / rate * multiple;
}
private function init(): void
{
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
