Test recording microphone data using LibVLCSharp

Program.cs

using System;
using System.IO;
using LibVLCSharp.Shared;

namespace test_microphone_recording
{
    internal class Program
    {
        private static MemoryStream stream;
        private static LibVLC vlc;
        private static string AudioFormat = "S16N";
        private static uint Channels = 2;
        private static uint SampleRate = 44100;
        private static MediaPlayer mediaPlayer;

        private static void Main(string[] _)
        {
            Core.Initialize();

            vlc = new LibVLC("--no-video", "--no-sout-video");
            //vlc.Log += (_, _) => { };
            var media = new Media(vlc, "dshow://", FromType.FromLocation, ":no-video", ":dshow-vdev=none", ":dshow-adev=");
            mediaPlayer = new MediaPlayer(media);
            mediaPlayer.SetAudioFormatCallback(AudioSetup, AudioCleanup);
            mediaPlayer.SetAudioCallbacks(PlayAudio, PauseAudio, ResumeAudio, FlushAudio, DrainAudio);
            mediaPlayer.SetAudioFormat(AudioFormat, SampleRate, Channels);

            Console.WriteLine("Press 'Esc' to quit. Press any other key to pause/play.");
            Console.WriteLine(nameof(PlayAudio));
            mediaPlayer.Play();

            while (true)
            {
                if (Console.ReadKey(true).Key == ConsoleKey.Escape)
                {
                    break;
                }

                if (!mediaPlayer.IsPlaying)
                {
                    Console.WriteLine(nameof(PlayAudio));
                    mediaPlayer.Play();
                }
                else
                {
                    mediaPlayer.Pause();
                }
            }
        }

        private static unsafe void PlayAudio(IntPtr data, IntPtr samples, uint count, long pts)
        {
            var bytes = new ReadOnlySpan<byte>(samples.ToPointer(), (int)(count * sizeof(float)));
            stream.Write(bytes);
        }

        private static int AudioSetup(ref IntPtr opaque, ref IntPtr format, ref uint rate, ref uint channels)
        {
            Channels = channels;
            string formatString;

            unsafe
            {
                fixed (void* formatPtr = &format)
                {
                    formatString = new string((sbyte*)formatPtr);
                }
            }

            Console.WriteLine($"{nameof(AudioSetup)} | format: {formatString} | channels:{channels} | rate: {rate}");
            stream = new MemoryStream();
            return 0;
        }

        private static void DrainAudio(IntPtr data)
        {
            Console.WriteLine(nameof(DrainAudio));
            stream.Flush();
        }

        private static void FlushAudio(IntPtr data, long pts)
        {
            Console.WriteLine(nameof(FlushAudio));
            stream.Flush();
        }

        private static void ResumeAudio(IntPtr data, long pts)
        {
            Console.WriteLine(nameof(ResumeAudio));
            stream.SetLength(0);
        }

        private static void PauseAudio(IntPtr data, long pts)
        {
            Console.WriteLine(nameof(PauseAudio));
            var streamMediaInput = new StreamMediaInput(stream);
            var media = new Media(vlc, streamMediaInput, ":imem-cat 1", ":demux=rawaud");
            var playbackPlayer = new MediaPlayer(media);
            playbackPlayer.SetAudioFormat(AudioFormat, SampleRate, Channels);
            playbackPlayer.Play(media);

            playbackPlayer.Stopped += Cleanup;
            playbackPlayer.EndReached += Cleanup;

            void Cleanup(object _, EventArgs __)
            {
                Console.WriteLine(nameof(Cleanup));
                playbackPlayer.Dispose();
                playbackPlayer = null;
                media.Dispose();
                streamMediaInput.Dispose();
            }
        }

        private static void AudioCleanup(IntPtr opaque)
        {
            Console.WriteLine(nameof(AudioCleanup));
            stream.Dispose();
            stream = null;
        }
    }
}