Question

I’m streaming an MP3 file in AS3. All is working fine (I can play it) but I’m looking to implement a ‘seek’ bar. This means I will need to cache the file (as it’s being downloaded) and then access the cached data when the user seeks a specific time in the song.

The code to actually play the mp3 stream:

function openStream( stream )
{
    var s:Sound = new Sound();
    var req:URLRequest = new URLRequest(stream);
    var context:SoundLoaderContext = new SoundLoaderContext(500, true);
    s.load(req, context);
    s.play();

}

So how would I cache the file as it’s being downloaded and then access the data from the cache?

I know this is pretty far from a trivial task, so I would be grateful if you could even just provide a few links to some tutorials/docs/articles.

Answer 1

You do not need to cache the sound for this.

The downloaded sound data is is available as long as the sound object lives in memory.

So all you need to do is take the sound object outside the function into the class scope..

Also the play function returns the current SoundChannel used by the Sound.

private var snd:Sound = new Sound();
private var channel:SoundChannel;

function openStream( stream ) { 

     ... 

     channel = snd.play();
}

To implement the seek functionality you may make use of,

• bytesLoaded (To know how much of the sound is downloaded)

• soundChannel.position (To know current sound position)