added basic solution

6 files changed, 234 insertions, 0 deletions

diff --git a/MFCCDotNet/MFCCDotNet.sln b/MFCCDotNet/MFCCDotNet.sln
new file mode 100644
index 0000000..454706b
--- /dev/null
+++ b/MFCCDotNet/MFCCDotNet.sln
@@ -0,0 +1,22 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 14
+VisualStudioVersion = 14.0.25420.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "MFCCDotNet", "MFCCDotNet\MFCCDotNet.fsproj", "{05825573-931A-4A57-B553-7E3AFF19B479}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{05825573-931A-4A57-B553-7E3AFF19B479}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{05825573-931A-4A57-B553-7E3AFF19B479}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{05825573-931A-4A57-B553-7E3AFF19B479}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{05825573-931A-4A57-B553-7E3AFF19B479}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal
diff --git a/MFCCDotNet/MFCCDotNet/AssemblyInfo.fs b/MFCCDotNet/MFCCDotNet/AssemblyInfo.fs
new file mode 100644
index 0000000..b312b4f
--- /dev/null
+++ b/MFCCDotNet/MFCCDotNet/AssemblyInfo.fs
@@ -0,0 +1,35 @@
+namespace MFCCDotNet.AssemblyInfo
+
+open System.Resources
+open System.Reflection
+open System.Runtime.CompilerServices
+open System.Runtime.InteropServices
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[<assembly: AssemblyTitle("MFCCDotNet")>]
+[<assembly: AssemblyDescription("")>]
+[<assembly: AssemblyConfiguration("")>]
+[<assembly: AssemblyCompany("")>]
+[<assembly: AssemblyProduct("MFCCDotNet")>]
+[<assembly: AssemblyCopyright("Copyright ©  2016")>]
+[<assembly: AssemblyTrademark("")>]
+[<assembly: AssemblyCulture("")>]
+[<assembly: NeutralResourcesLanguage("en")>]
+
+// Version information for an assembly consists of the following four values:
+// 
+//       Major Version
+//       Minor Version 
+//       Build Number
+//       Revision
+// 
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [<assembly: AssemblyVersion("1.0.*")>]
+[<assembly: AssemblyVersion("1.0.0.0")>]
+[<assembly: AssemblyFileVersion("1.0.0.0")>]
+
+do
+    ()
\ No newline at end of file
diff --git a/MFCCDotNet/MFCCDotNet/MFCC.fs b/MFCCDotNet/MFCCDotNet/MFCC.fs
new file mode 100644
index 0000000..59159a7
--- /dev/null
+++ b/MFCCDotNet/MFCCDotNet/MFCC.fs
@@ -0,0 +1,104 @@
+namespace MFCCDotNet
+
+open System.Numerics
+open MathNet.Numerics.LinearAlgebra
+open MathNet.Numerics.IntegralTransforms
+open MathNet.Numerics
+
+module public MFCC =
+    type triangle_filter = { start_bin: int; peak_bin: int; end_bin: int; }
+
+    let mel (frequency) =
+        1125.0 * log10 (1.0 + (frequency / 700.0));
+
+    let hertz (mel) =
+        700.0 * exp ((mel / 1125.0) - 1.0)
+
+    let mutable _filterbank : seq<triangle_filter> = null
+
+    //See http://practicalcryptography.com/miscellaneous/machine-learning/guide-mel-frequency-cepstral-coefficients-mfccs/#computing-the-mel-filterbank
+    let compute_filterbank (num_filters, fft_size, sample_rate) =
+        if not (isNull _filterbank) then
+            _filterbank
+        else
+            let lower_freq = 300.0;
+            let upper_freq = 8000.0;
+            let lower_mel = mel(lower_freq);
+            let upper_mel = mel(upper_freq);
+            let mel_spacing = (upper_mel - lower_mel) / float (num_filters + 1);
+            let points_hertz = seq { for i in 0 .. (num_filters + 1) do yield hertz(lower_mel + (float i * mel_spacing)) };
+            let fft_bin_points = points_hertz |> Seq.map(fun hertz_point -> int (floor ((float fft_size + 1.0) * float (hertz_point / sample_rate))));
+
+            _filterbank <- seq {
+                for i in 1 .. num_filters do
+                    yield {
+                        start_bin = fft_bin_points |> Seq.item(i - 1);
+                        peak_bin = fft_bin_points |> Seq.item(i);
+                        end_bin = fft_bin_points |> Seq.item(i + 1);
+                    };
+            };
+            _filterbank
+
+    let apply_filter (fft_output, filter : triangle_filter) =
+        let total = Array.length fft_output - 1;
+        seq {
+            for i in 0 .. total do
+                if (i = filter.peak_bin) then
+                    yield fft_output.[i];
+                elif (i > filter.start_bin && i < filter.peak_bin) then
+                    let filter_weight = float (i - filter.start_bin) / float (filter.peak_bin - filter.start_bin);
+                    yield fft_output.[i] * filter_weight;
+                elif (i > filter.peak_bin && i < filter.end_bin) then
+                    let filter_weight = float (filter.end_bin - i) / float (filter.end_bin - filter.peak_bin);
+                    yield fft_output.[i] * filter_weight;
+                else yield 0.0;
+        }
+
+    //A more efficient Seq.sum(apply_filter())
+    let apply_and_sum_filter (fft_output : float[], filter : triangle_filter) =
+        let mutable total = 0.0;
+        for i = filter.start_bin to filter.end_bin do
+            if (i = filter.peak_bin) then
+                total <- total + fft_output.[i];
+            elif (i > filter.start_bin && i < filter.peak_bin) then
+                let filter_weight = float (i - filter.start_bin) / float (filter.peak_bin - filter.start_bin);
+                total <- total + fft_output.[i] * filter_weight;
+            elif (i > filter.peak_bin && i < filter.end_bin) then
+                let filter_weight = float (filter.end_bin - i) / float (filter.end_bin - filter.peak_bin);
+                total <- total + fft_output.[i] * filter_weight;
+        total;
+
+    //https://en.wikipedia.org/wiki/Discrete_cosine_transform
+    let dct (input:float[]) =
+        let N = Array.length input;
+        let output = Array.zeroCreate<float>(N);
+        for k in 0 .. N - 1 do
+            for n in 0 .. N - 1 do
+                let xn = input.[n];
+                Array.set output k (output.[k] + (xn * cos((float System.Math.PI / float N) * (float n + 0.5) * (float k))));
+
+        Array.set output 0 (output.[0] * (1.0 / sqrt 2.0))
+        let scale = sqrt (2.0 / float N)
+        output |> Array.map(fun el -> el * scale)
+
+    let compute (samples : float[], num_filters, num_features) =
+        let hamming = Window.Hamming(Array.length samples);
+        let windowed_samples = samples |> Array.mapi(fun index sample -> sample * hamming.[index]);
+
+        let mutable complex_output = windowed_samples |> Array.map(fun sample -> Complex(sample, 0.0));
+        Fourier.Forward(complex_output);
+        let abs_output = complex_output |> Array.map(fun sample -> sqrt ((sample.Real * sample.Real) + (sample.Imaginary * sample.Imaginary)));
+        //for extra optimization
+        //let abs_output = complex_output |> Array.map(fun sample -> abs sample.Real + abs sample.Imaginary);
+
+        let filters = compute_filterbank(num_filters, Array.length abs_output, 48000.0);
+        let accumulator = Array.zeroCreate<float>(Array.length abs_output);
+
+        let mel_output = filters |>
+                            Seq.take(num_features) |>
+                            Seq.map(fun filter -> log10(apply_and_sum_filter(abs_output, filter))) |>
+                            Seq.toArray;
+                            //|> Seq.fold (fun acc el -> acc |> Array.mapi(fun index acc_el -> acc_el + (el |> Seq.nth(index)))) accumulator;
+
+        let dct_output = dct(mel_output);
+        dct_output;
\ No newline at end of file
diff --git a/MFCCDotNet/MFCCDotNet/MFCCDotNet.fsproj b/MFCCDotNet/MFCCDotNet/MFCCDotNet.fsproj
new file mode 100644
index 0000000..55b4f00
--- /dev/null
+++ b/MFCCDotNet/MFCCDotNet/MFCCDotNet.fsproj
@@ -0,0 +1,61 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>05825573-931a-4a57-b553-7e3aff19b479</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <RootNamespace>MFCCDotNet</RootNamespace>
+    <AssemblyName>MFCCDotNet</AssemblyName>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkProfile>Profile7</TargetFrameworkProfile>
+    <TargetProfile>netcore</TargetProfile>
+    <TargetFSharpCoreVersion>3.7.4.0</TargetFSharpCoreVersion>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <Name>MFCCDotNet</Name>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <Tailcalls>false</Tailcalls>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <WarningLevel>3</WarningLevel>
+    <DocumentationFile>bin\Debug\MFCCDotNet.XML</DocumentationFile>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <Tailcalls>true</Tailcalls>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <WarningLevel>3</WarningLevel>
+    <DocumentationFile>bin\Release\MFCCDotNet.XML</DocumentationFile>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="FSharp.Core">
+      <Name>FSharp.Core</Name>
+      <AssemblyName>FSharp.Core.dll</AssemblyName>
+      <HintPath>$(MSBuildExtensionsPath32)\..\Reference Assemblies\Microsoft\FSharp\.NETCore\$(TargetFSharpCoreVersion)\FSharp.Core.dll</HintPath>
+    </Reference>
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="AssemblyInfo.fs" />
+    <Compile Include="PortableLibrary1.fs" />
+    <None Include="Script.fsx" />
+  </ItemGroup>
+  <PropertyGroup>
+    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">12</MinimumVisualStudioVersion>
+  </PropertyGroup>
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.Portable.FSharp.Targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>
\ No newline at end of file
diff --git a/MFCCDotNet/MFCCDotNet/Script.fsx b/MFCCDotNet/MFCCDotNet/Script.fsx
new file mode 100644
index 0000000..0519c09
--- /dev/null
+++ b/MFCCDotNet/MFCCDotNet/Script.fsx
@@ -0,0 +1,6 @@
+// Learn more about F# at http://fsharp.org. See the 'F# Tutorial' project
+// for more guidance on F# programming.
+
+#load "PortableLibrary1.fs"
+open MFCCDotNet
+
diff --git a/MFCCDotNet/MFCCDotNet/packages.config b/MFCCDotNet/MFCCDotNet/packages.config
new file mode 100644
index 0000000..f109b94
--- /dev/null
+++ b/MFCCDotNet/MFCCDotNet/packages.config
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="FSharp.Core" version="4.0.0.1" targetFramework="portable45-net45+win8" />
+  <package id="MathNet.Numerics" version="3.13.0" targetFramework="portable45-net45+win8" />
+  <package id="MathNet.Numerics.FSharp" version="3.13.0" targetFramework="portable45-net45+win8" />
+</packages>
\ No newline at end of file