Your applications can load sound data from five 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 being generated dynamically through the use of
the
sampleData
event handler
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.
The ActionScript 3.0 sound classes support sound files that are
stored in the mp3 format. They cannot directly load or play sound
files in other formats, such as WAV or AIFF. However, starting with
Flash Player 9.0.115.0, AAC audio files can be loaded and played
using the NetStream class. This is the same technique as is used
for loading and playing video content. For more information on this technique,
see
Working with video
.
Using Adobe Flash
Professional, you can import WAV or AIFF sound files and then embed
them into your application’s SWF files in the mp3 format. The Flash
Authoring tool also lets you compress embedded sound files to reduce
their file size, though this size reduction comes at the expense
of sound quality. For more information see “Importing Sounds” in
Using Flash
.
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
SoundChannel 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 policy file from the server when
loading a file. A SoundLoaderContext object is used as a parameter
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 metadata 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.
|
|
flash.media.AudioPlaybackMode
|
The AudioPlaybackMode class defines constants
for the
audioPlaybackMode
property of the SoundMixer
class.
|
Each sound that is loaded and played needs its own instance of
the Sound class and the SoundChannel class. The output from multiple
SoundChannel instances is then mixed together by the global SoundMixer
class during playback,
The Sound, SoundChannel, and SoundMixer classes are not used
for sound data obtained from a microphone or from a streaming media
server like Flash Media Server.
