Changed FFDShow DPL2 decoder to FreeSurround on OpenAL.

Right now SoundTouch doesn't work with FreeSurround, but I made OpenAL frequency-shift the output so that no buffer-underrun can happen.

OpenAL's current audio latency is ~30ms (was 36ms), in addition to WASAPI, PulseAudio, ALSA etc latency.

CMakeLists.txt

@@ -657,8 +657,9 @@ if(OPENAL_FOUND)
   else()
     message(STATUS "Using static soundtouch from Externals")
     add_subdirectory(Externals/soundtouch)
-    include_directories(Externals)
   endif()
+  message(STATUS "Using static FreeSurround from Externals")
+  add_subdirectory(Externals/FreeSurround)
 endif()
 
 if(NOT ANDROID)

Externals/FreeSurround/CMakeLists.txt

@@ -0,0 +1,14 @@
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+set(SRCS
+	source/ChannelMaps.cpp
+	source/KissFFT.cpp
+	source/KissFFTR.cpp
+	source/FreeSurroundDecoder.cpp
+	)
+
+add_library(FreeSurround STATIC ${SRCS})
+target_include_directories(FreeSurround PUBLIC include)
+add_definitions(-w)

Externals/FreeSurround/FreeSurround.vcxproj

@@ -0,0 +1,61 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{8498F2FA-5CA6-4169-9971-DE5B1FE6132C}</ProjectGuid>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Label="Configuration">
+    <ConfigurationType>StaticLibrary</ConfigurationType>
+    <PlatformToolset>v140</PlatformToolset>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'" Label="Configuration">
+    <UseDebugLibraries>true</UseDebugLibraries>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'" Label="Configuration">
+    <UseDebugLibraries>false</UseDebugLibraries>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+    <Import Project="..\..\Source\VSProps\Base.props" />
+    <Import Project="..\..\Source\VSProps\ClDisableAllWarnings.props" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <Lib>
+      <AdditionalLibraryDirectories>%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+    </Lib>
+    <ClCompile>
+      <AdditionalIncludeDirectories>$(ProjectDir)\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+    </ClCompile>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClInclude Include="include\FreeSurround\ChannelMaps.h" />
+    <ClInclude Include="include\FreeSurround\FreeSurroundDecoder.h" />
+    <ClInclude Include="include\FreeSurround\KissFFT.h" />
+    <ClInclude Include="include\FreeSurround\KissFFTR.h" />
+    <ClInclude Include="include\FreeSurround\_KissFFTGuts.h" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="source\ChannelMaps.cpp" />
+    <ClCompile Include="source\FreeSurroundDecoder.cpp" />
+    <ClCompile Include="source\KissFFT.cpp" />
+    <ClCompile Include="source\KissFFTR.cpp" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>

Externals/FreeSurround/FreeSurround.vcxproj.filters

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <ClCompile Include="source\ChannelMaps.cpp">
+      <Filter>source</Filter>
+    </ClCompile>
+    <ClCompile Include="source\FreeSurroundDecoder.cpp">
+      <Filter>source</Filter>
+    </ClCompile>
+    <ClCompile Include="source\KissFFT.cpp">
+      <Filter>source</Filter>
+    </ClCompile>
+    <ClCompile Include="source\KissFFTR.cpp">
+      <Filter>source</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="include\FreeSurround\_KissFFTGuts.h">
+      <Filter>include</Filter>
+    </ClInclude>
+    <ClInclude Include="include\FreeSurround\ChannelMaps.h">
+      <Filter>include</Filter>
+    </ClInclude>
+    <ClInclude Include="include\FreeSurround\FreeSurroundDecoder.h">
+      <Filter>include</Filter>
+    </ClInclude>
+    <ClInclude Include="include\FreeSurround\KissFFT.h">
+      <Filter>include</Filter>
+    </ClInclude>
+    <ClInclude Include="include\FreeSurround\KissFFTR.h">
+      <Filter>include</Filter>
+    </ClInclude>
+  </ItemGroup>
+  <ItemGroup>
+    <Filter Include="include">
+      <UniqueIdentifier>{776ecb31-6d5e-489f-bac9-b91a1b202345}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="source">
+      <UniqueIdentifier>{11345325-d67c-4a21-b2e9-c7c6c8cfc8b4}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+</Project>

Externals/FreeSurround/include/FreeSurround/ChannelMaps.h

@@ -0,0 +1,36 @@
+/*
+Copyright (C) 2010 Christian Kothe
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#ifndef CHANNELMAPS_H
+#define CHANNELMAPS_H
+#include "FreeSurroundDecoder.h"
+#include <map>
+#include <vector>
+
+const int grid_res = 21; // resolution of the lookup grid
+
+// channel allocation maps (per setup)
+typedef std::vector<std::vector<float *>> alloc_lut;
+extern std::map<unsigned, alloc_lut> chn_alloc;
+// channel metadata maps (per setup)
+extern std::map<unsigned, std::vector<float>> chn_angle;
+extern std::map<unsigned, std::vector<float>> chn_xsf;
+extern std::map<unsigned, std::vector<float>> chn_ysf;
+extern std::map<unsigned, std::vector<channel_id>> chn_id;
+
+#endif