- From: Chris Lowis <chris.lowis@bbc.co.uk>
- Date: Thu, 01 Dec 2011 14:03:24 +0000
- To: public-audio@w3.org
On 30/11/2011 17:58, Stephen Bannasch wrote: > I'd like to be able to sample and display both amplitude and frequency > domain representations of audio input from an audio source. If by "audio source" you mean the HTML <audio> element, then yes that is an example of the kind of thing that is possible with the proposed Audio APIs. I believe the Mozilla API will allow access to the amplitude data (the samples of the audio stream themselves) which you can then transform to a frequency domain representation using a javascript FFT implementation. I think the Webkit API as currently implemented does not give access to the audio samples, but does allow you to set up a block to calculate the spectrum (using an FFT). If you wish to capture audio from the browser, you'd need the getUserMedia API (http://www.whatwg.org/specs/web-apps/current-work/multipage/video-conferencing-and-peer-to-peer-communication.html), the current support for which is very patchy (I think Opera have a partial implementation, and I heard Erricson were working on something too but haven't released it). In the meantime, we've had some success with a Flash shim which allows audio input from the microphone: https://code.google.com/p/wami-recorder/ Hope that helps and that others can fill in the details or correct my mistakes! Cheers, Chris
Received on Thursday, 1 December 2011 14:03:18 UTC