LNXSDK/Kha/Backends/HTML5/kha/capture/AudioCapture.hx

package kha.capture;

import js.html.audio.AudioProcessingEvent;
import kha.audio2.Buffer;

class AudioCapture {
	static var input: js.html.audio.MediaStreamAudioSourceNode;
	static var processingNode: js.html.audio.ScriptProcessorNode;
	static var buffer: Buffer;

	public static var audioCallback: Int->Buffer->Void;

	public static function init(initialized: Void->Void, error: Void->Void): Void {
		if (kha.audio2.Audio._context == null) {
			error();
			return;
		}

		var getUserMedia = untyped __js__("navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia");
		getUserMedia.call(js.Browser.navigator, {audio: true}, function(stream: Dynamic) {
			input = kha.audio2.Audio._context.createMediaStreamSource(stream);

			var bufferSize = 1024 * 2;
			buffer = new Buffer(bufferSize * 4, 2, Std.int(kha.audio2.Audio._context.sampleRate));

			processingNode = kha.audio2.Audio._context.createScriptProcessor(bufferSize, 1, 0);
			processingNode.onaudioprocess = function(e: AudioProcessingEvent) {
				if (audioCallback != null) {
					var input1 = e.inputBuffer.getChannelData(0);
					var input2 = e.inputBuffer.getChannelData(0);
					for (i in 0...e.inputBuffer.length) {
						buffer.data.set(buffer.writeLocation, input1[i]);
						buffer.writeLocation += 1;
						buffer.data.set(buffer.writeLocation, input2[i]);
						buffer.writeLocation += 1;
						if (buffer.writeLocation >= buffer.size) {
							buffer.writeLocation = 0;
						}
					}
					audioCallback(e.inputBuffer.length * 2, buffer);
				}
			}

			input.connect(processingNode);
			// input.connect(kha.audio2.Audio._context.destination);
			initialized();
		}, function() {
			error();
		});
	}
}