UWP: waveInOpen returns WAVERR_BADFORMAT

Question

I am trying to record audio in UWP using Winmm.dll. After I execute waveInOpen method (https://msdn.microsoft.com/en-us/library/dd743847(v=vs.85).aspx ) I always get WAVERR_BADFORMAT no matter the data I use (it also takes a long time abut 5s). My code looks as follows:

Recorder.cs:

Win32.WAVEFORMATEX waveFormatEx = new Win32.WAVEFORMATEX();
                waveFormatEx.wFormatTag = (ushort)Win32.WaveFormatFlags.WAVE_FORMAT_PCM;
                waveFormatEx.nChannels = 1;
                waveFormatEx.nSamplesPerSec = 8000;
                waveFormatEx.wBitsPerSample = 16;
                waveFormatEx.nBlockAlign = 2;
                waveFormatEx.nAvgBytesPerSec = 16000;

                Win32.MMRESULT hr = Win32.waveInOpen(ref hWaveIn, deviceId, ref waveFormatEx, delegateWaveInProc, 0, (int)Win32.WaveProcFlags.CALLBACK_FUNCTION);

Win32.cs:

[StructLayout(LayoutKind.Sequential)]
    public struct WAVEFORMATEX
    {
        public ushort wFormatTag;
        public ushort nChannels;
        public uint nSamplesPerSec;
        public uint nAvgBytesPerSec;
        public ushort nBlockAlign;
        public ushort wBitsPerSample;
        public ushort cbSize;
    }
[DllImport("winmm.dll")]
        public static extern MMRESULT waveInOpen(ref IntPtr hWaveIn, int deviceId, ref WAVEFORMATEX wfx, DelegateWaveInProc dwCallBack, int dwInstance, int dwFlags);

The same code with the same parameters works just fine in Windows Forms app (and executes in split second), but in UWP app it does't and i have no idea why. What is the correct format i could use in UWP?

Answer 1

While working with UWP projects, you could keep in mind: it is a limited subset of features (for the sake of security and cross-device compatibility). So, UWP project has nothing to do with Win32 API. And even if your code is compiling/running on the emulator, it will:

• Fail on ARM devices (as they have no Win32 DLLs for sure)
• Fail on app submission to Microsoft Store

So, if we're talking namely about audio, you have to consider WASAPI as it's 100% compatible with UWP https://msdn.microsoft.com/en-us/library/windows/desktop/dd371455(v=vs.85).aspx