OwlCore.Storage.OpenAL

Handle your audio devices like simple files and folders.

Featuring:

Capture devices via OpenALCaptureDeviceFolder. Contains files corresponding to available capture devices whose Stream continuously reads samples from the capture device.

Install

Published releases are available on NuGet. To install, run the following command in the Package Manager Console.

PM> Install-Package OwlCore.Storage.OpenAL

Or using dotnet

> dotnet add package OwlCore.Storage.OpenAL

Usage

var captureDevicesFolder = new OpenALCaptureDevicesFolder();

// Iterate through all capture devices
await foreach (var captureDevice in captureDevicesFolder.GetFilesAsync(cancellationToken))
    Console.WriteLine($"Capture device: {captureDevice.Name}");

// Get default capture device
var defaultDevice = (OpenALCaptureDeviceFile)await captureDevicesFolder.GetItemAsync($"{captureDevicesFolder.Id}/default");

// Change buffer format or sample rate as needed
defaultDevice.Format = BufferFormat.Mono8;

// Open device stream
await using var deviceStream = (OpenALCaptureDeviceStream)await deviceFile.OpenReadAsync(cancellationToken);

// Create wav buffer helper (via Naudio.Wave)
// Because the stream buffer can only be so large, we use the BufferedWaveProvider to collect enough buffered samples to fill a TimeSpan.
var captureBufferInterval = TimeSpan.FromSeconds(5);
var wavBufferProvider = new BufferedWaveProvider(deviceStream.WaveFormat)
{
    BufferDuration = captureBufferInterval,
};

// Read device file stream continuously until cancelled
while (!cancellationToken.IsCancellationRequested)
{
    // Read samples from stream
    // OpenALCaptureDeviceStream should fill it with as many samples as it can given the provided buffer size. The rest is padded with zeros.
    var sampleBuffer = new byte[deviceStream.WaveFormat.ConvertLatencyToByteSize(500)];
    var sampleBufferBytesRead = await deviceStream.ReadAsync(sampleBuffer, 0, sampleBuffer.Length, cancellationToken);
    if (sampleBufferBytesRead == 0)
        continue;

    // Ignore empty buffers
    if (sampleBuffer.All(static x => x == default))
        continue;

    // Copy buffered samples from device stream into our BufferedWaveProvider
    wavBufferProvider.AddSamples(sampleBuffer, 0, sampleBufferBytesRead);

    // When the full duration has been reached, do something with the full buffer.
    if (wavBufferProvider.BufferedDuration >= wavBufferProvider.BufferDuration)
    {
        // For example
        // Buffer is full, reset buffered provider and continue;
        var currentProvider = wavBufferProvider;
        buffersToProcessLoop.Add(currentProvider);

        wavBufferProvider = new BufferedWaveProvider(deviceStream.WaveFormat)
        {
            BufferDuration = captureBufferInterval,
        };
    }
}

Financing

We accept donations here and here, and we do not have any active bug bounties.

Versioning

Version numbering follows the Semantic versioning approach. However, if the major version is 0, the code is considered alpha and breaking changes may occur as a minor update.

License

All OwlCore code is licensed under the MIT License. OwlCore is licensed under the MIT License. See the LICENSE file for more details.

Arlodotexe / OwlCore.Storage.OpenAL