Re: Web Audio API Proposal

Hello Chris,

Had another chance to go over your api today. I am going to be making  
a javascript layer implementation of your spec which will work on top  
of the mozilla audio data api.
This should allow us to review and quickly prototype new features or  
changes on our working firefox implementation.

One question Richard brought up on IRC which I could not find an  
answer for in your API is how do we add existing DOM audio elements to  
the graph? An audio element is in essence a Source and Destination  
node, How would I inject a lowpass filter into the pipeline? In the  
mozilla API we do this by muting the audio element and then reading  
out frames, filtering and then piping to a second non-DOM Audio  
element (Hacky, I know).

Here is a rough setup of how this might work, could you fill in the  
gaps for me?

var context = new AudioContext();
var lowpass = context.createLowPass2Filter();
var audio = document.getElementById('audioEle');

function filterSound() {
   var source = context.createAudioBuffer(audio); // perhaps passing  
in the audio element here generates 1 frame worth of buffer as it  
plays ?
   source.connect(lowpass);
   lowpass.connect(context.destination);
}
Re,
Corban