ADOBE® FLEX® 3: PROGRAMMING ACTIONSCRIPT™ 3.0

ADOBE FLEX 3

Developer Guide

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• Volume: The loudness of a sound.

• Waveform: The shape of a graph of the varying amplitudes of a sound signal over time.

Understanding the sound architecture

Your applications can load sound data from four main sources:

• External sound files loaded at run time

• Sound resources embedded within the application’s SWF file

• Sound data from a microphone attached to the user’s system

• Sound data streamed from a remote media server, such as Flash Media Server

Sound data can be fully loaded before it is played back, or it can be streamed, meaning that it is played back while it

is still loading.

ActionScript 3.0, Flash Player, and AIR support sound files that are stored in the mp3 format. They cannot directly

load or play sound files in other formats like WAV or AIFF.

The ActionScript 3.0 sound architecture makes use of the following classes in the flash.media package.

Class Description

flash.media.Sound The Sound class handles the loading of sound, manages basic

sound properties, and starts a sound playing.

flash.media.SoundChannel When an application plays a Sound object, a new SoundChannel

object is created to control the playback. The SoundChannel

object controls the volume of both the left and right playback

channels of the sound. Each sound that plays has its own Sound-

Channel object.

flash.media.SoundLoaderContext The SoundLoaderContext class specifies how many seconds of

buffering to use when loading a sound, and whether Flash Player

or AIR looks for a cross-domain policy file from the server when

loading a file. A SoundLoaderContext object is used as a param-

eter to the

Sound.load() method.

flash.media.SoundMixer The SoundMixer class controls playback and security properties

that pertain to all sounds in an application. In effect, multiple

sound channels are mixed through a common SoundMixer

object, so property values in the SoundMixer object will affect all

SoundChannel objects that are currently playing.

flash.media.SoundTransform The SoundTransform class contains values that control sound

volume and panning. A SoundTransform object can be applied to

an individual SoundChannel object, to the global SoundMixer

object, or to a Microphone object, among others.

flash.media.ID3Info An ID3Info object contains properties that represent ID3 meta-

data information that is often stored in mp3 sound files.

flash.media.Microphone The Microphone class represents a microphone or other sound

input device attached to the user’s computer. Audio input from a

microphone can be routed to local speakers or sent to a remote

server. The Microphone object controls the gain, sampling rate,

and other characteristics of its own sound stream.