Version 1.0

Added: Configuration Editor, which allows to edit configurations in a graphical user interface. Contains GUIs for most commands supported by E-APO, but as lines can also be edited directly, all commands can be used.
Added: Command "GraphicEQ", which can act as a regular, fixed-band graphic equalizer (via the GUI) but also supports variable bands so that any desired frequency response can be specified. Internally, it is implemented via convolution with a generated IR.
Added: Command "Convolution", which allows to convolve the signal with a user-provided impulse response to achieve e.g. equalization or reverberation effects.
Improved: Configurator performs checks for registry values that are needed for the operation of E-APO, which may be changed by driver installations, fixing the values if necessary.
Improved: Configurator shows which is the default device as a hint to the user.

filters/ConvolutionFilter.cpp

@@ -0,0 +1,136 @@
+/*
+	This file is part of EqualizerAPO, a system-wide equalizer.
+	Copyright (C) 2015  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 "stdafx.h"
+#include <cmath>
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#define ENABLE_SNDFILE_WINDOWS_PROTOTYPES 1
+#include <sndfile.h>
+#include <fftw3.h>
+
+#include "helpers/LogHelper.h"
+#include "helpers/MemoryHelper.h"
+#include "ConvolutionFilter.h"
+
+using namespace std;
+
+ConvolutionFilter::ConvolutionFilter(wstring filename)
+{
+	this->filename = filename;
+	filters = NULL;
+}
+
+ConvolutionFilter::~ConvolutionFilter()
+{
+	cleanup();
+}
+
+vector<wstring> ConvolutionFilter::initialize(float sampleRate, unsigned maxFrameCount, vector<wstring> channelNames)
+{
+	cleanup();
+
+	channelCount = (unsigned)channelNames.size();
+
+	SF_INFO info;
+
+	SNDFILE* inFile = sf_wchar_open(filename.c_str(), SFM_READ, &info);
+	if(inFile == NULL)
+	{
+		LogF(L"Error while reading impulse response file: %S", sf_strerror(inFile));
+	}
+	else if(abs(sampleRate - info.samplerate) > 1.0f)
+	{
+		LogF(L"Impulse response sample rate (%d Hz) does not match device sample rate (%f Hz)", info.samplerate, sampleRate);
+	}
+	else
+	{
+		TraceF(L"Convolving using impulse response file %s", filename.c_str());
+		unsigned fileChannelCount = info.channels;
+		unsigned frameCount = (unsigned)info.frames;
+
+		float* interleavedBuf = new float[frameCount * fileChannelCount];
+
+		sf_count_t numRead = 0;
+		while(numRead < frameCount)
+			numRead += sf_readf_float(inFile, interleavedBuf + numRead * fileChannelCount, frameCount - numRead);
+
+		sf_close(inFile);
+		inFile = NULL;
+
+		float** bufs = new float*[fileChannelCount];
+		for(unsigned i=0; i<fileChannelCount; i++)
+		{
+			float* buf = new float[frameCount];
+			float* p = interleavedBuf + i;
+			for(unsigned j=0; j<frameCount; j++)
+			{
+				buf[j] = p[j*fileChannelCount];
+			}
+
+			bufs[i] = buf;
+		}
+
+		filters = (HConvSingle*)MemoryHelper::alloc(sizeof(HConvSingle) * channelCount);
+		for(unsigned i=0; i<channelCount; i++)
+		{
+			hcInitSingle(&filters[i], bufs[i % fileChannelCount], frameCount, maxFrameCount, 1);
+		}
+
+		for(unsigned i=0; i<fileChannelCount; i++)
+		{
+			delete[] bufs[i];
+		}
+		delete bufs;
+		delete interleavedBuf;
+	}
+
+	return channelNames;
+}
+
+#pragma AVRT_CODE_BEGIN
+void ConvolutionFilter::process(float** output, float** input, unsigned frameCount)
+{
+	if(filters == NULL)
+		return;
+
+	for(unsigned i=0; i<channelCount; i++)
+	{
+		float* inputChannel = input[i];
+		float* outputChannel = output[i];
+		HConvSingle* filter = &filters[i];
+
+		hcPutSingle(filter, inputChannel);
+		hcProcessSingle(filter);
+		hcGetSingle(filter, outputChannel);
+	}
+}
+#pragma AVRT_CODE_END
+
+void ConvolutionFilter::cleanup()
+{
+	if(filters != NULL)
+	{
+		for(unsigned i=0; i<channelCount; i++)
+			hcCloseSingle(&filters[i]);
+
+		MemoryHelper::free(filters);
+		filters = NULL;
+	}
+}