Issues with latest development build

Audio
1

Today I downloaded the latest development build after uninstalling 3.5. I ran my game, and it threw a NullReferenceException the moment I tried to play a sound. It’s worth noting that I recently switched to a new computer which is connected to a TV screen, with no other source of audio. Before I tried the development build, no exception was thrown, but no audio played.

Also, with the latest installer, the game window starts in a different position from before, with some of the window going past the edge of the screen. That’s not too difficult to fix, I can just manually set the window position, but it is different from before.

Here’s the exception details. Could it be related to XACT?

System.NullReferenceException was unhandled
HResult=-2147467261
Message=Object reference not set to an instance of an object.
Source=MonoGame.Framework
StackTrace:
at Microsoft.Xna.Framework.Audio.SoundEffectInstance.PlatformClearFilter()
at Microsoft.Xna.Framework.Audio.SoundEffectInstancePool.GetInstance(Boolean forXAct)
at Microsoft.Xna.Framework.Audio.SoundEffect.GetPooledInstance(Boolean forXAct)
at Microsoft.Xna.Framework.Audio.SoundEffect.Play()
at ThankGoodnessForGravity.SoundManager.PlaySound(SoundEffects effect) in D:\Source\ThankGoodnessForGravity\ThankGoodnessForGravity\ThankGoodnessForGravity\SoundManager.cs:line 46
at ThankGoodnessForGravity.Robot.CheckSequenceSignals() in D:\Source\ThankGoodnessForGravity\ThankGoodnessForGravity\ThankGoodnessForGravity\Robot.cs:line 632
at ThankGoodnessForGravity.Robot.Update() in D:\Source\ThankGoodnessForGravity\ThankGoodnessForGravity\ThankGoodnessForGravity\Robot.cs:line 257
at ThankGoodnessForGravity.Level.Update() in D:\Source\ThankGoodnessForGravity\ThankGoodnessForGravity\ThankGoodnessForGravity\Level.cs:line 65
at ThankGoodnessForGravity.Game1.Update(GameTime gameTime) in D:\Source\ThankGoodnessForGravity\ThankGoodnessForGravity\ThankGoodnessForGravity\Game1.cs:line 168
at Microsoft.Xna.Framework.Game.DoUpdate(GameTime gameTime)
at Microsoft.Xna.Framework.Game.Tick()
at MonoGame.Framework.WinFormsGameWindow.RunLoop()
at MonoGame.Framework.WinFormsGamePlatform.RunLoop()
at Microsoft.Xna.Framework.Game.Run(GameRunBehavior runBehavior)
at ThankGoodnessForGravity.Program.Main() in D:\Source\ThankGoodnessForGravity\ThankGoodnessForGravity\ThankGoodnessForGravity\Program.cs:line 18
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:

2

@Tom did some work on XACT, so something might have broke…

3

Not XACT specifically, but maybe related to the changes to support audio effects on the underlying sound system.

In fact I think I see the bug here…

https://github.com/mono/MonoGame/blob/develop/MonoGame.Framework/Audio/SoundEffectInstance.XAudio.cs#L309

My guess is that _voice is still null at this point. I’ll investigate and setup a fix.

Are you using the Windows DirectX platform or Desktop GL?

4

I’m using DirectX. I would try it with DesktopGL, but I don’t have access to my main dev PC at the moment.

5

And, I just tried the same project on my laptop, using the latest development build, and ran into the same two issues, which means it’s probably not system-dependent.

More curiously, I started a new project, added a random wav file to content, loaded it using Content.Load, and then added this code to the Update method:

if (Keyboard.GetState().IsKeyDown(Keys.Space) && !soundPlayed)
{
     soundPlayed = true;
     effect.Play();
}

Pressing space will not throw an exception, but it also won’t play a sound. It does reach effect.Play(), though, which I checked using Run to Cursor.

If I get rid of the check for if the sound has already been played, though, an exception is thrown.

if (Keyboard.GetState().IsKeyDown(Keys.Space))
{
     soundPlayed = true;
     effect.Play();
}

Both machines are running Windows 10.

One more note. I changed the code in the Update method to this:

if (Keyboard.GetState().IsKeyDown(Keys.Space))
{
     if (!keyDown)
     {
          soundPlayed = true;
          effect.Play();
     }
     keyDown = true;
}
else keyDown = false;

This ensures that effect.Play() is only called the moment the space bar is pressed.
I ran the program and pressed the space bar once, and no exception was thrown. After waiting until the sound should definitely have finished playing, I pressed the space bar again, and then got the NullReferenceException. This seems to imply that the issue occurs only when a SoundEffect has been played more than once.

6

FYI. https://github.com/mono/MonoGame/pull/5009

7

I’ve confirmed that with that PR merged, the exception is no longer thrown. Now I just need to figure out why I’m getting no sound at all.