FNA Vorbis Player

Vorbis.cs

using Microsoft.Xna.Framework.Audio;
using System;

namespace Fenix.Audio
{
    public class Vorbis : IDisposable
    {
        public int Channels { get; private set; }
        public int SampleRate { get; private set; }
        public float Duration { get; private set; }
        public SoundState SoundState { get; private set; }

        public Vorbis(string assetPath)
        {
            stbVorbisData = FAudio.stb_vorbis_open_filename(assetPath, out int error, IntPtr.Zero);
            var info = FAudio.stb_vorbis_get_info(stbVorbisData);

            Channels = info.channels;
            SampleRate = (int)info.sample_rate;
            Duration = FAudio.stb_vorbis_stream_length_in_seconds(stbVorbisData);
            SoundState = SoundState.Stopped;

            dynamicSoundEffectInstance = new DynamicSoundEffectInstance(SampleRate, (Channels == 1) ? AudioChannels.Mono : AudioChannels.Stereo);
            sampleReadBuffer = new float[SampleRate * Channels / 10];
        }

        public void Play(int playCount = 1, Action<Vorbis> playCompletedAction = null)
        {
            if(SoundState != SoundState.Stopped)
            {
                // todo: log warning
                return;
            }

            Reset();
            FillBuffer();

            this.playCount = playCount;
            this.playCompletedAction = playCompletedAction;
            dynamicSoundEffectInstance.BufferNeeded += DynamicSoundEffectInstance_BufferNeeded;
            dynamicSoundEffectInstance.Play();
            SoundState = SoundState.Playing;
        }

        public void Pause()
        {
            if (SoundState != SoundState.Playing)
            {
                // todo: log warning
                return;
            }

            dynamicSoundEffectInstance.Pause();
            SoundState = SoundState.Paused;
        }

        public void Resume()
        {
            if (SoundState != SoundState.Paused)
            {
                // todo: log warning
                return;
            }

            dynamicSoundEffectInstance.Resume();
            SoundState = SoundState.Playing;
        }

        public void Stop()
        {
            if (SoundState != SoundState.Playing && SoundState != SoundState.Paused)
            {
                // todo: log warning
                return;
            }

            dynamicSoundEffectInstance.Stop();
            dynamicSoundEffectInstance.BufferNeeded -= DynamicSoundEffectInstance_BufferNeeded;
            playCompletedAction = null;
            SoundState = SoundState.Stopped;
        }

        public void Reset()
        {
            FAudio.stb_vorbis_seek_start(stbVorbisData);
        }

        public DynamicSoundEffectInstance GetInstance()
        {
            return dynamicSoundEffectInstance;
        }

        private void DynamicSoundEffectInstance_BufferNeeded(object sender, EventArgs e)
        {
            FillBuffer();
        }

        private void FillBuffer()
        {
            var framesRead = ReadFrames(sampleReadBuffer, SampleRate / 10);
            if (framesRead != 0)
            {
                dynamicSoundEffectInstance.SubmitFloatBufferEXT(sampleReadBuffer, 0, framesRead * Channels);
            }
            else if (dynamicSoundEffectInstance.PendingBufferCount == 0)
            {
                if (playCount > 0)
                    playCount--;

                if (playCount == 0)
                {
                    Action<Vorbis> pca = playCompletedAction;
                    Stop();
                    pca?.Invoke(this);
                }
                else
                {
                    Reset();
                    FillBuffer();
                }
            }
        }

        private int ReadFrames(float[] interleavedSamples, int frameCount)
        {
            return FAudio.stb_vorbis_get_samples_float_interleaved(stbVorbisData, Channels, interleavedSamples, frameCount * Channels);
        }

        public void Dispose()
        {
            playCompletedAction = null;

            if (stbVorbisData != IntPtr.Zero)
            {
                FAudio.stb_vorbis_close(stbVorbisData);
                stbVorbisData = IntPtr.Zero;
            }
        }

        protected virtual void Dispose(bool disposing)
        {
            if (disposed)
                return;

            Dispose();
            disposed = true;
        }

        private bool disposed = false;
        private IntPtr stbVorbisData = IntPtr.Zero;

        private int playCount;
        private DynamicSoundEffectInstance dynamicSoundEffectInstance;
        private float[] sampleReadBuffer;
        private Action<Vorbis> playCompletedAction = null;
    }
}