MainWindow.xaml.cs

using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using System.Windows;
using CSCore;
using CSCore.Codecs;
using CSCore.MediaFoundation;
using CSCore.SoundOut;
using CSCore.Streams;
using CSCoreWaveform.Annotations;
using Microsoft.Win32;

namespace CSCoreWaveform
{
    /// <summary>
    ///     Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : INotifyPropertyChanged
    {
        private readonly ISoundOut _soundOut;
        private ObservableCollection<WaveformDataModel> _channels = new ObservableCollection<WaveformDataModel>();
        private NotificationSource _notificationSource;
        private ISampleSource _sampleSource;

        public MainWindow()
        {
            InitializeComponent();
            DataContext = this;
            _soundOut = new WasapiOut();
        }

        public ObservableCollection<WaveformDataModel> Channels
        {
            get { return _channels; }
            private set
            {
                if (Equals(value, _channels))
                    return;
                _channels = value;
                OnPropertyChanged();
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        private async void Open_Click(object sender, RoutedEventArgs e)
        {
            var ofn = new OpenFileDialog {Filter = CodecFactory.SupportedFilesFilterEn};
            if (ofn.ShowDialog() == true)
            {
                _soundOut.Stop();
                if (_notificationSource != null)
                    _notificationSource.Dispose();

                var source = CodecFactory.Instance.GetCodec(ofn.FileName);
                
                //since the mediafoundationdecoder isn't really accurate what position and length concerns
                //read the whole file into a cache
                if (source is MediaFoundationDecoder)
                {
                    if (source.Length < 10485760) //10MB
                    {
                        source = new CachedSoundSource(source);
                    }
                    else
                    {
                        Stopwatch stopwatch = Stopwatch.StartNew();
                        source = new FileCachedSoundSource(source);
                        stopwatch.Stop();
                        Debug.WriteLine(stopwatch.Elapsed.ToString());
                    }
                }
                source.Position = 0;
                //load the waveform
                await LoadWaveformsAsync(source);
                source.Position = 0;

                _sampleSource = source.ToSampleSource();
                _notificationSource = new NotificationSource(_sampleSource) {Interval = 100};
                _notificationSource.BlockRead += (o, args) => { UpdatePosition(); };
                _soundOut.Initialize(_notificationSource.ToWaveSource());
                _soundOut.Play();
            }
        }

        private async Task LoadWaveformsAsync(IWaveSource waveSource)
        {
            Channels = null;
            //read the specified waveSource into n arrays of samples where n is the number of channels of the waveSource
            var channelData = await WaveformData.GetData(waveSource);
            //by setting the Channels property, the Waveform Control automatically renders the waveform
            Channels =
                new ObservableCollection<WaveformDataModel>(channelData.Select(x => new WaveformDataModel {Data = x}));
        }

        private void UpdatePosition()
        {
            Dispatcher.InvokeAsync(() =>
            {
                var x = (float) _sampleSource.Position / WaveformData.Length;
                foreach (var waveformData in Channels)
                {
                    waveformData.PositionInPerc = x;
                }
            });
        }

        [NotifyPropertyChangedInvocator]
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            var handler = PropertyChanged;
            if (handler != null)
                handler(this, new PropertyChangedEventArgs(propertyName));
        }

        private void MainWindow_OnClosing(object sender, CancelEventArgs e)
        {
            if (_soundOut != null)
                _soundOut.Dispose();
            if (_notificationSource != null)
                _notificationSource.Dispose();
        }

        private void Waveform_OnPositionChanged(object sender, PositionChangedEventArgs e)
        {
            if (_notificationSource != null)
            {
                var position = (long) (e.Percentage * WaveformData.Length);
                position -= position % _notificationSource.WaveFormat.BlockAlign;
                _notificationSource.Position = position;
            }
        }
    }

    public class WaveformDataModel : INotifyPropertyChanged
    {
        private float[] _data;
        private double _positionInPerc;

        public IList<float> Data
        {
            get { return _data; }
            set
            {
                if (Equals(value, _data))
                    return;
                _data = value.ToArray();
                OnPropertyChanged();
            }
        }

        public double PositionInPerc
        {
            get { return _positionInPerc; }
            set
            {
                if (value.Equals(_positionInPerc))
                    return;
                _positionInPerc = value;
                OnPropertyChanged();
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        [NotifyPropertyChangedInvocator]
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            var handler = PropertyChanged;
            if (handler != null)
                handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}