Before you
can control a sound, you need to load the sound into the Adobe AIR application.
There are five ways you can get audio data into AIR:
-
You can load an external sound file such as an mp3 file
into the application.
-
You can embed the sound information into a SWF file, load
it (using
<script src="[swfFile].swf" type="application/x-shockwave-flash"/
>)
and play it.
-
You can get audio input using a microphone attached to a
user’s computer.
-
You can access sound data that’s streamed from a server.
-
You can dynamically generate sound data.
When you load sound data from an external sound file, you can
begin playing back the start of the sound file while the rest of
the sound data is still loading.
Although there are various sound file formats used to encode
digital audio, AIR supports sound files that are stored in the mp3
format. It cannot directly load or play sound files in other formats
like WAV or AIFF.
While you’re working with sound in AIR, you’ll likely work with
several classes from the runtime.flash.media package. The Sound
class is the class you use to get access to audio information by
loading a sound file or assigning a function to an event that samples
sound data and then starting playback. Once you start playing a
sound, AIR gives you access to a SoundChannel object. An audio file that
you’ve loaded can only be one of several sounds that an application
plays simultaneously. Each individual sound that’s playing uses
its own SoundChannel object; the combined output of all the SoundChannel
objects mixed together is what actually plays over the speakers.
You use this SoundChannel instance to control properties of the
sound and to stop its playback. Finally, if you want to control
the combined audio, the SoundMixer class gives you control over
the mixed output.
You can also use several other runtime classes to perform more
specific tasks when you’re working with sound in AIR. For more information
on all the sound-related classes, see
Understanding the sound architecture
.
The Adobe AIR developer’s center provides a sample application:
Using Sound in an HTML-based Application
(http://www.adobe.com/go/learn_air_qs_sound_html_en).
