Minor updates for fingerprinter

Fingerprinter/Audio/AudioDecoder.cs

@@ -18,38 +18,6 @@ public abstract class AudioDecoder : IAudioDecoder
         protected int sampleRate;
         protected int channels;
 
-        protected int sourceSampleRate;
-        protected int sourceBitDepth;
-        protected int sourceChannels;
-        protected int duration;
-
-        protected bool ready;
-
-        public int SourceSampleRate
-        {
-            get { return sourceSampleRate; }
-        }
-
-        public int SourceBitDepth
-        {
-            get { return sourceBitDepth; }
-        }
-
-        public int SourceChannels
-        {
-            get { return sourceChannels; }
-        }
-
-        public int Duration
-        {
-            get { return duration; }
-        }
-
-        public bool Ready
-        {
-            get { return ready; }
-        }
-
         public int SampleRate
         {
             get { return sampleRate; }
@@ -60,7 +28,7 @@ public int Channels
             get { return channels; }
         }
 
-        public abstract void Load(string file);
+        public AudioProperties Format { get; protected set; }
 
         public abstract bool Decode(IAudioConsumer consumer, int maxLength);
 

Fingerprinter/Audio/AudioProperties.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Fingerprinter.Audio
+{
+    public class AudioProperties
+    {
+        /// <summary>
+        /// Gets the sample rate of the audio source.
+        /// </summary>
+        public int SampleRate { get; private set; }
+
+        /// <summary>
+        /// Gets the sample rate of the audio source (must be 16 bits per sample).
+        /// </summary>
+        public int BitDepth { get; private set; }
+
+        /// <summary>
+        /// Gets the number of channels.
+        /// </summary>
+        public int Channels { get; private set; }
+
+        /// <summary>
+        /// Gets the duration of the audio source (in seconds).
+        /// </summary>
+        public int Duration { get; private set; }
+
+        public AudioProperties()
+            : this(0, 0, 0, 0)
+        {
+        }
+
+        public AudioProperties(int sampleRate, int bitDepth, int channels, int duration)
+        {
+            this.SampleRate = sampleRate;
+            this.BitDepth = bitDepth;
+            this.Channels = channels;
+            this.Duration = duration;
+        }
+    }
+}

Fingerprinter/Audio/IAudioDecoder.cs

@@ -14,16 +14,6 @@ namespace Fingerprinter.Audio
     /// </summary>
     public interface IAudioDecoder : IDecoder, IDisposable
     {
-        int SourceSampleRate { get; }
-        int SourceBitDepth { get; }
-        int SourceChannels { get; }
-
-        int Duration { get; }
-        bool Ready { get; }
-
-        /// <summary>
-        /// Load an audio file.
-        /// </summary>
-        void Load(string file);
+        AudioProperties Format { get; }
     }
 }

Fingerprinter/Audio/NAudioDecoder.cs

@@ -12,53 +12,32 @@ namespace Fingerprinter.Audio
     using NAudio.Wave;
 
     /// <summary>
-    /// Decode using the NAudio library. Great audio library, but the MP3 decoder is kinda slow.
+    /// Decode using the NAudio library..
     /// </summary>
     public class NAudioDecoder : AudioDecoder
     {
         WaveStream reader;
-        string extension;
-
-        public override void Load(string file)
-        {
-            // Dispose on every new load
-            Dispose(false);
-
-            ready = false;
-
-            extension = Path.GetExtension(file).ToLowerInvariant();
+        string file;
 
-            if (extension.Equals(".wav"))
-            {
-                reader = new WaveFileReader(file);
-            }
-            else
-            {
-                reader = new Mp3FileReader(file);
-            }
-
-            var format = reader.WaveFormat;
-
-            this.sampleRate = format.SampleRate;
-            this.channels = format.Channels;
+        public NAudioDecoder(string file)
+        {
+            this.file = file;
 
-            this.sourceSampleRate = format.SampleRate;
-            this.sourceBitDepth = format.BitsPerSample;
-            this.sourceChannels = format.Channels;
-            this.duration = (int)reader.TotalTime.TotalSeconds;
-            this.ready = (format.BitsPerSample == 16);
+            // Open the WaveStream and keep it open until Dispose() is called. This might lock
+            // the file. A better approach would be to open the stream only when needed.
+            Initialize();
         }
 
         public override bool Decode(IAudioConsumer consumer, int maxLength)
         {
-            if (!ready) return false;
+            if (reader == null) return false;
 
             int remaining, length, size;
             byte[] buffer = new byte[2 * BUFFER_SIZE];
             short[] data = new short[BUFFER_SIZE];
 
             // Samples to read to get maxLength seconds of audio
-            remaining = maxLength * this.sourceChannels * this.sampleRate;
+            remaining = maxLength * this.Format.Channels * this.sampleRate;
 
             // Bytes to read
             length = 2 * Math.Min(remaining, BUFFER_SIZE);
@@ -81,6 +60,33 @@ public override bool Decode(IAudioConsumer consumer, int maxLength)
             return true;
         }
 
+        private void Initialize()
+        {
+            var extension = Path.GetExtension(file).ToLowerInvariant();
+
+            if (extension.Equals(".wav"))
+            {
+                reader = new WaveFileReader(file);
+            }
+            else
+            {
+                reader = new Mp3FileReader(file);
+            }
+
+            var format = reader.WaveFormat;
+
+            this.sampleRate = format.SampleRate;
+            this.channels = format.Channels;
+
+            this.Format = new AudioProperties(format.SampleRate, format.BitsPerSample,
+                format.Channels, (int)reader.TotalTime.TotalSeconds);
+
+            if (format.BitsPerSample != 16)
+            {
+                Dispose(true);
+            }
+        }
+
         #region IDisposable implementation
 
         private bool hasDisposed = false;
@@ -99,6 +105,7 @@ public void Dispose(bool disposing)
                 {
                     reader.Close();
                     reader.Dispose();
+                    reader = null;
                 }
             }
 

Fingerprinter/Fingerprinter.csproj

@@ -36,16 +36,17 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="NAudio, Version=1.7.2.19, Culture=neutral, processorArchitecture=MSIL">
-      <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\packages\NAudio.1.7.2\lib\net35\NAudio.dll</HintPath>
+    <Reference Include="NAudio, Version=1.7.3.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\NAudio.1.7.3\lib\net35\NAudio.dll</HintPath>
+      <Private>True</Private>
     </Reference>
     <Reference Include="System" />
     <Reference Include="System.Drawing" />
     <Reference Include="System.Windows.Forms" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Audio\AudioDecoder.cs" />
+    <Compile Include="Audio\AudioProperties.cs" />
     <Compile Include="Audio\BassDecoder.cs" />
     <Compile Include="Audio\IAudioDecoder.cs" />
     <Compile Include="Audio\NAudioDecoder.cs" />

Fingerprinter/MainForm.cs

@@ -1,14 +1,14 @@
-using System;
+using AcoustID;
+using AcoustID.Web;
+using Fingerprinter.Audio;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
-using AcoustID;
-using AcoustID.Web;
-using Fingerprinter.Audio;
-using System.Threading;
 
 namespace Fingerprinter
 {
@@ -24,9 +24,6 @@ public MainForm()
         private void MainForm_Load(object sender, EventArgs e)
         {
             Fpcalc.Path = @"D:\Projects\AcoustId\extern\fpcalc.exe";
-
-            decoder = new NAudioDecoder();
-            //decoder = new BassDecoder();
         }
 
         private void btnOpen_Click(object sender, EventArgs e)
@@ -36,26 +33,32 @@ private void btnOpen_Click(object sender, EventArgs e)
 
             if (dlg.ShowDialog() == DialogResult.OK)
             {
-                lbFile.Text = dlg.FileName;
+                if (decoder != null)
+                {
+                    decoder.Dispose();
+                }
 
-                ResetAll();
+                try
+                {
+                    decoder = new NAudioDecoder(dlg.FileName);
+                    //decoder = new BassDecoder();
 
-                decoder.Load(dlg.FileName);
+                    lbFile.Text = dlg.FileName;
 
-                int bits = decoder.SourceBitDepth;
-                int channels = decoder.SourceChannels;
+                    ResetAll();
+
+                    int bits = decoder.Format.BitDepth;
+                    int channels = decoder.Format.Channels;
 
-                if (decoder.Ready)
-                {
                     lbAudio.Text = String.Format("{0}Hz, {1}bit{2}, {3}",
-                        decoder.SourceSampleRate, bits, bits != 16 ? " (not supported)" : "",
+                        decoder.Format.SampleRate, bits, bits != 16 ? " (not supported)" : "",
                         channels == 2 ? "stereo" : (channels == 1 ? "mono" : "multi-channel"));
 
-                    lbDuration.Text = decoder.Duration.ToString();
+                    lbDuration.Text = decoder.Format.Duration.ToString();
 
                     btnFingerPrint.Enabled = true;
                 }
-                else
+                catch
                 {
                     lbAudio.Text = "Failed to load audio";
                     lbDuration.Text = String.Empty;
@@ -244,7 +247,7 @@ private void ProcessFile(string file)
         {
             if (File.Exists(file))
             {
-                if (decoder.Ready)
+                if (decoder != null)
                 {
                     //btnOpen.Enabled = false;
                     btnFingerPrint.Enabled = false;

Fingerprinter/packages.config

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="NAudio" version="1.7.2" targetFramework="net40-Client" />
+  <package id="NAudio" version="1.7.3" targetFramework="net40-client" />
 </packages>