SharpDX 3.0.1 XAudio2 VoiceSendDescriptor holds invalid data

[quasaroq]

Hi, I use this code

m_gameAudioVoice = new SubmixVoice(m_audioEngine);
m_gameAudioVoiceDesc = new VoiceSendDescriptor[] { new VoiceSendDescriptor(m_gameAudioVoice) };

But when I immediately look into m_gameAudioVoiceDesc[0].OutputVoice.VoiceDetails.InputChannelCount it causes exception (VoiceDetails is broken), the same for sourceVoice.SetOutputVoices(m_gameAudioVoiceDesc)

I tried SharpDX 3.0.0 and 3.0.1 both cause exceptions, older versions (2.x) were ok on Windows7. Can somebody, please, help me?

[xoofx]

I guess this was fixed by #710 not pushed yet to a public version but you can grab dlls from the latest build

[waltdestler]

Nope, not fixed by #710; I just tried reproducing and I get a crash when accessing VoiceSendDecriptor.OutputVoice.VoiceDetails (NullReferenceException inside the VoiceDetails getter) that I don't get when accessing the VoiceDetails property of the voice passed into the VoiceSendDescriptor. I'll look into this and see if I can figure out what's going on, since I've gotten familiar with the XAudio2 code lately.

SetOutputVoices is working fine for me, though.

[waltdestler]

Okay, so I found the issue, but I'm not sure what the best way to solve it is.

Here's the implementation of Voice.VoiceDetails:

    public SharpDX.XAudio2.VoiceDetails VoiceDetails
    {
        get
        {
            SharpDX.XAudio2.VoiceDetails __output__; 
            GetVoiceDetails(out __output__);

            // Handle 2.7 version changes here
            if (device.Version == XAudio2Version.Version27)
            {
                __output__.InputSampleRate = __output__.InputChannelCount;
                __output__.InputChannelCount = __output__.ActiveFlags;
                __output__.ActiveFlags = 0;
            }

            return __output__;
        }
    }

The NullReferenceException is because device is null, and device is null because VoiceSendDescriptor.OutputVoice creates its returned Voice object via the constructor that takes an IntPtr, which doesn't set the device field.

    public Voice OutputVoice
    {
        get
        {
            return OutputVoicePointer==IntPtr.Zero?null:new Voice(OutputVoicePointer);
        }
        set
        {
            OutputVoicePointer = value.NativePointer;                
        }
    }

[quasaroq]

Thank you, I added check for null device and it seems to be OK.

if (device != null && device.Version == XAudio2Version.Version27)

[waltdestler]

If that fixes the bug for your particular situation, then great, but it's not really a general fix. With XAudio 2.8+ (Windows 8+), it'd work fine, but with XAudio 2.7 (Windows 7) that code will return incorrect data.