DirectSound: “Value does not fall within the expected range.” when initializing Notify

Question

I'm getting that exception when I try to run a simple DirectSound program. Here's the code:

using System;
using System.Runtime.InteropServices;
using System.Threading;
using Microsoft.DirectX.DirectSound;

namespace AudioDemo
{
    class Program
    {
        [DllImport("user32.dll")]
        private static extern IntPtr GetDesktopWindow();

        static void Main(string[] args)
        {
            // output device

            var device = new Device();
            device.SetCooperativeLevel(GetDesktopWindow(), CooperativeLevel.Normal);

            // format description

            var format = new WaveFormat
            {
                BitsPerSample = 8,
                Channels = 1,
                FormatTag = WaveFormatTag.Pcm,
                SamplesPerSecond = 8000
            };

            format.BlockAlign = (short)(format.BitsPerSample / 8 * format.Channels);
            format.AverageBytesPerSecond = format.SamplesPerSecond * format.BlockAlign;

            var outputLatency = 20;
            var frameSize = format.AverageBytesPerSecond * outputLatency / 1000;

            // buffer 

            var description = new BufferDescription
            {
                BufferBytes = frameSize,
                Format = format,
                DeferLocation = true,
                GlobalFocus = true
            };

            var outputBuffer = new SecondaryBuffer(description, device);

            // buffer notifications

            var notify = new Notify(outputBuffer);

            // ...
        }
    }
}

I get the exception on the last line (var notify = new Notify(outputBuffer);).

Not sure what went wrong. The buffer was initialized correctly.

Answer 1

It's not clear to me what you're trying to do with your outputLatency and frameSize variables, or with the BufferBytes property, but my guess is there is where your problem is.

Answer 2

"A SecondaryBuffer object will support notification events only if its BufferDescription.ControlPositionNotify is set to true."

(https://msdn.microsoft.com/en-us/library/windows/desktop/ms812460.aspx)

So try this:

        var description = new BufferDescription
        {
            BufferBytes = frameSize,
            Format = format,
            DeferLocation = true,
            GlobalFocus = true,
            ControlPositionNotify = true
        };

I've had the same exception, but this solved the problem!