Version 0.9

Added: Filter type "IIR", which allows to specify a user-defined IIR filter of arbitrary order with custom coefficients.
Improved: For playback devices, the APO is now installed both as GFX (post-mix) and LFX (pre-mix) APO. Normally the filtering happens in GFX, but the command "Stage" allows to select LFX to apply effects based on the number of input channels.
Added: Expression language. The commands "If", "ElseIf", "Else", "EndIf", "Eval" and inline expressions allow to change the filter behaviour based on runtime conditions.
Added: Command "Copy", which copies audio data between channels.
Added: Command "Delay", which delays the audio on the currently selected channels.
Improved: Configuration files are now locked exclusively for writing while reading them.
Improved: There is now a transition (10 ms) from old to new configuration after loading.
Improved: Substantial internal restructuring to improve extensibility and maintainability. Filtering commands now work exactly in the order they were specified.
Fixed: When the microphone input was in stereo but the application requested a mono stream, the audio was heavily distorted.
Fixed: The sine sweep generated by the Benchmark application had floating-point precision issues leading to severe artifacts when certain filters were applied.

filters/DeviceFilterFactory.cpp

@@ -0,0 +1,116 @@
+/*
+	This file is part of EqualizerAPO, a system-wide equalizer.
+	Copyright (C) 2014  Jonas Thedering
+
+	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.
+*/
+
+#include "helpers/LogHelper.h"
+#include "helpers/StringHelper.h"
+#include "FilterEngine.h"
+#include "DeviceFilterFactory.h"
+
+using namespace std;
+
+void DeviceFilterFactory::initialize(FilterEngine* engine)
+{
+	deviceString = engine->getDeviceName() + L" " + engine->getConnectionName() + L" " + engine->getDeviceGuid();
+
+	mup::ParserX* parser = engine->getParser();
+	parser->DefineConst(L"deviceName", engine->getDeviceName());
+	parser->DefineConst(L"connectionName", engine->getConnectionName());
+	parser->DefineConst(L"deviceGuid", engine->getDeviceGuid());
+}
+
+vector<IFilter*> DeviceFilterFactory::startOfConfiguration()
+{
+	deviceMatches = true;
+
+	return vector<IFilter*>();
+}
+
+vector<IFilter*> DeviceFilterFactory::createFilter(const wstring& configPath, wstring& command, wstring& parameters)
+{
+	if(command == L"Device")
+	{
+		wstring value = StringHelper::trim(parameters) + L";";
+
+		vector<vector<wstring>> fullList;
+		vector<wstring> currentList;
+		wstring currentWord;
+
+		for(unsigned i=0; i<value.length(); i++)
+		{
+			wchar_t c = value[i];
+			if(c == L' ' || c == L';')
+			{
+				if(currentWord.length() > 0)
+				{
+					currentList.push_back(currentWord);
+					currentWord.clear();
+				}
+				if(c == L';' && currentList.size() > 0)
+				{
+					fullList.push_back(currentList);
+					currentList.clear();
+				}
+			}
+			else
+			{
+				currentWord += c;
+			}
+		}
+
+		bool matches = false;
+
+		for(unsigned i=0; i<fullList.size(); i++)
+		{
+			matches = true;
+
+			if(fullList[i].size() == 1 && StringHelper::toLowerCase(fullList[i][0]) == L"all")
+				break;
+
+			for(unsigned j=0; j<fullList[i].size(); j++)
+			{
+				wstring word = StringHelper::toLowerCase(fullList[i][j]);
+				if(StringHelper::toLowerCase(deviceString).find(word) == -1)
+				{
+					matches = false;
+					break;
+				}
+			}
+
+			if(matches)
+				break;
+		}
+
+		TraceF(L"%satching pattern \"%s\" with device \"%s\"", matches ? L"M" : L"Not m", value.substr(0, value.length()-1).c_str(), deviceString.c_str());
+		deviceMatches = matches;
+	}
+
+	if(!deviceMatches)
+		// skip line for further factories
+		command = L"";
+
+	return vector<IFilter*>();
+}
+
+std::vector<IFilter*> DeviceFilterFactory::endOfFile(const std::wstring& configPath)
+{
+	// in outer file, the device must have matched, otherwise the inner file would not have been included
+	deviceMatches = true;
+
+	return vector<IFilter*>();
+}