Playing sound files one after another in flex AIR code - apache-flex

Question

I have a set of sound clips to be played one after another in a sequence with couple of time interval inbetween.
In my case, its a question - followed by the set of four options.
When I write the below code, all the audop files start together at same time. How can I had time delay inbetween, so that the second clip plays only after the first one is over, and the third one starts playing, only when the second option is over.
I am with Flex AIR AS 3. See code below. Thanks in advance.
private function playCoundClips(): void
{
//set audio clips
var questionClipSource : String = "assets/quiz_voiceovers/" + questionCode + "Q.mp3";
var optionAClipSource : String = "assets/quiz_voiceovers/" + questionCode + "a.mp3";
var optionBClipSource : String = "assets/quiz_voiceovers/" + questionCode + "b.mp3";
var optionCClipSource : String = "assets/quiz_voiceovers/" + questionCode + "c.mp3";
var optionDClipSource : String = "assets/quiz_voiceovers/" + questionCode + "d.mp3";
playThisClip(questionClipSource);
playThisClip(optionAClipSource);
playThisClip(optionBClipSource);
playThisClip(optionCClipSource);
playThisClip(optionDClipSource);
}
private function playThisClip(clipPath : String) : void
{
try
{
clipPlayingNow = true;
var soundReq:URLRequest = new URLRequest(clipPath);
var sound:Sound = new Sound();
var soundControl:SoundChannel = new SoundChannel();
sound.load(soundReq);
soundControl = sound.play(0, 0);
}
catch(err: Error)
{
Alert.show(err.getStackTrace());
}
}
Thanks
Sumit

Answer 1

The problem is you are spawning multiple asynchronous calls. Implement a complete call back function on Sound and then call your playThisClip function inside the callback function. (You can sleep for predefined time before calling)

Answer 2

Time delay, is a very bad idea (in 99% of the case).
Have a look at the SOUND_COMPLETE event (see the doc)
This event is triggered when the sound stops playing.
So, it's now very easy to play sounds in sequence.
A simple example (not tested but idea is here) :
//declare somewhere a list of sounds to play
var sounds:Array=["sound_a.mp3","sound_a.mp3"];//sounds paths
//this function will play all sounds in the sounds parameter
function playSounds(sounds:Array):void{
if(!sounds || sounds.length==0){
//no more sound to play
//you could dispatch an event here
return;
}
var sound:Sound=new Sound();
sound.load(new URLRequest(sounds.pop()));
var soundChannel:SoundChannel = sound.play();
soundChannel.addEVentListener(Event.SOUND_COMPLETE,function():void{
soundChannel.removeEventListener(Event.SOUND_COMPLETE,arguments.callee);
playSounds(sounds);
});
}

Answer 3

This helped me
http://livedocs.adobe.com/flex/3/html/help.html?content=Working_with_Sound_09.html
One need to write code for:
sound.addEventListener(Event.ENTER_FRAME, onEnterFrame);
soundControl.addEventListener(Event.SOUND_COMPLETE, onPlaybackComplete);
private function onEnterFrame(event:Event):void
{
var estimatedLength:int =
Math.ceil(sound.length / (sound.bytesLoaded / sound.bytesTotal));
var playbackPercent:uint =
Math.round(100 * (soundControl.position / estimatedLength));
}
private function onPlaybackComplete(event:Event):void
{
Alert.show("Hello!");
}