Linux sound issues (native c++)

[guzzard]

The audio is really bad on native c++ in Linux (at least for me). Listen to the two attached samples. Every time I build and run there are distortions, but the distortions sounds a little bit different each time (??). If i run a Krom or HTML5 from the same project there are no sound issues.

This code is playing ogg-files using kha.audio1.Audio.play().

linux_native_sound_issues.zip

[RobDangerous]

That's hard to debug for me because it works fine on the systems I could test. Do you run it in release mode?

[guzzard]

Hi @RobDangerous,

Made a correction above, it's ogg-files not wav-files. It's an Armory project, and the wav-files are encoded upon exporting the project.

The sound issues are present in both debug and release native c++ builds.

When playing the ogg-files in Audacity they sound fine, so there seem to be no issue with the ogg encoding.

[RobDangerous]

Do wav files work better?

[guzzard]

Created a minimal Kha project with this Project.hx:

package;

import kha.Framebuffer;
import kha.Scheduler;
import kha.System;
import kha.input.Keyboard;
import kha.input.KeyCode;
import kha.Sound;

class Project {

	var s:Sound;

	public function new() {
		System.notifyOnRender(render);
		Scheduler.addTimeTask(update, 0, 1 / 60);
		Keyboard.get().notify(onKeyDown, onKeyUp);
		
		var description = { files: ["run1.wav"] };
		kha.LoaderImpl.loadSoundFromDescription(description, function(b:kha.Sound) {
			b.uncompress(function () {
				s = b;
			});
		});
	}

	function update(): Void {
	}

	function render(framebuffer: Framebuffer): Void {
	}

	public function onKeyDown(key:KeyCode):Void {
	}
	
	public function onKeyUp(key:KeyCode):Void {
		switch (key){
			case KeyCode.One:
				kha.audio1.Audio.play(s, false);
			default:
		}
	}
}

It uses the same method of loading and playing the sound as the Armory project, but loads a wav-file instead. Same issues here, in both debug and release native c++ builds. Krom works fine, no sound issue. Attached a sample.

sound_issue_wav_minimal_kha.ogg.zip

[RobDangerous]

That's strange, Krom should be much more likely to cause trouble, uses the same audio backend plus has to transfer audio data from js. Can you compile Krom yourself and also test that?

[guzzard]

In self-compiled Krom still no sound issues, both debug or release version of Krom work fine. I compiled only the Krom executable, and took rest of the files from Deployment folder. Could that have an effect or is it a valid test?

[RobDangerous]

That's a valid test. But now I have absolutely no idea what's going on.

[guzzard]

Did some more testing on the minimal Kha project with native C++ build. Don't think it's related to the compiling, but rather seem to be related to starting/running the executable.

I tested 20-25 times, launching the executable and playing the sound, and two or three those times the sound played without any distortion, rest of the times the sound had distortion that sounded a bit different on every launch.

On Krom however there is no sound issues regardless of how many times I test.

Don't know if that helps, or complicates things even more..

[juakob]

can it be a problem with the files itself, wrong bits per sample or bytes per second? still strange that sometimes works. just to discard that try some sounds from https://github.com/Kha-Samples/BlocksFromHeaven/tree/master/Assets

[sh-dave]

We had some similar issue when only using alsa. After installing and switching to pulse as the audio device (or whatever this is called), everything sounds good.

[RobDangerous]

Also with Krom working fine and direct Kore builds being troublesome?

[RobDangerous]

Hm, according to https://wiki.ubuntuusers.de/Soundsystem/ pulse it the default on Ubuntu. That might open up some options to reproduce that problem.

[sh-dave]

I only tested Kore, can't use Krom b/c of missing networking.

Edit: And we use a custom debian based distribution, that doesn't include a lot of stuff by default to keep the size small, so pulse wasn't installed by default.

[RobDangerous]

OK, deinstalling pulse next time I boot into Linux. Thanks!