PCM Audio not properly stereo with LWJGL3 backend

[hujasonx]

Issue details

PCM audio played via Gdx.audio.newAudioDevice does not properly play stereo content with the LWJGL3 backend, but does with the default desktop backend. It's not fully mono but it isn't stereo to the correct extent either.

Reproduction steps/code

public class Test extends ApplicationAdapter {
	AudioDevice audioDevice;
	float deviceSamples[] = new float[1024];
	float x = 0;
	@Override
	public void create () {
		audioDevice = Gdx.audio.newAudioDevice(44100, false);
	}

	@Override
	public void render () {
		new Thread() {
			@Override
			public void run() {
				while (true) {
					try {
						for (int a = 0; a < 1024; a += 2) {
							float sample = .2f * (float) Math.sin(x);
							x += 0.0005;
							deviceSamples[a] = 0; // Left speaker should be silent.
							deviceSamples[a + 1] = sample; // Right speaker should make noise.
						}

						audioDevice.writeSamples(deviceSamples, 0, deviceSamples.length);
						int latency = audioDevice.getLatency();
						sleep(500 * latency / 44100);
					} catch (Exception e) {
						e.printStackTrace();
					}
				}
			}
		}.start();
	}
}

Expectation: Sound only comes out of the right speaker.
Reality: Sound comes mostly out of the right speaker, but also somewhat from the left. It works fine when using the default lwjgl2 backend, but not with the lwjgl3 backend.

Version of LibGDX and/or relevant dependencies

libgdx 1.10.0

Please select the affected platforms

• Android
• iOS
• HTML/GWT
• [ X] Windows
• Linux
• MacOS

[mgsx-dev]

i can reproduce the issue, i'm working on a fix.