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Diffstat (limited to 'examples/mobile/guitartuner/src/voiceanalyzer.cpp')
| -rw-r--r-- | examples/mobile/guitartuner/src/voiceanalyzer.cpp | 296 |
1 files changed, 0 insertions, 296 deletions
diff --git a/examples/mobile/guitartuner/src/voiceanalyzer.cpp b/examples/mobile/guitartuner/src/voiceanalyzer.cpp deleted file mode 100644 index d53b5ebb..00000000 --- a/examples/mobile/guitartuner/src/voiceanalyzer.cpp +++ /dev/null @@ -1,296 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies). -** Contact: http://www.qt-project.org/legal -** -** This file is part of the demonstration applications of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:LGPL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and Digia. For licensing terms and -** conditions see http://qt.digia.com/licensing. For further information -** use the contact form at http://qt.digia.com/contact-us. -** -** GNU Lesser General Public License Usage -** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 2.1 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 2.1 requirements -** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. -** -** In addition, as a special exception, Digia gives you certain additional -** rights. These rights are described in the Digia Qt LGPL Exception -** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. -** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 3.0 as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL included in the -** packaging of this file. Please review the following information to -** ensure the GNU General Public License version 3.0 requirements will be -** met: http://www.gnu.org/copyleft/gpl.html. -** -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -#include "voiceanalyzer.h" - -/** - * Constant used to scale the cut-off density for the fft helper. - */ -const static float CutOffScaler = 0.05; - -/** - * Force the precision to be "1/PrecisionPerNote" notes - * near the target frequency. - */ -const static int PrecisionPerNote = 4; - -/** - * TargetFrequencyParameter is a constant which implies the index at - * which corresponds to the target frequency. - * 0.5 * N * 1/TargetFrequencyParameter is (about) the index which - * corresponds to the given target frequency. - * Effectively TargetFrequencyParameter = 2^z, and the z*TargetFrequency - * is the maximum frequency that can be noticed. - */ -const static int TargetFrequencyParameter = 4; - - -VoiceAnalyzer::VoiceAnalyzer(const QAudioFormat &format, QObject *parent): - QIODevice(parent), - m_format(format), - m_frequency(0), - m_position(0), - m_fftHelper(new FastFourierTransformer(this)) -{ - Q_ASSERT(qFuzzyCompare(M_SAMPLE_COUNT_MULTIPLIER, - float(2)/(M_TWELTH_ROOT_OF_2 -1.0))); - m_totalSampleCount = qRound(qreal(PrecisionPerNote) - *TargetFrequencyParameter - *M_SAMPLE_COUNT_MULTIPLIER); - m_samples.reserve(m_totalSampleCount); - int i = 2; - int j = 1; - for (; i < TargetFrequencyParameter; i *= 2) { - j++; - } - m_maximumVoiceDifference = j*12; - - setCutOffPercentage(CutOffScaler); -} - -/** - * Opens the parent QIODevice. Sets up the analysation parameters. - */ -void VoiceAnalyzer::start(qreal frequency) -{ - m_stepSize = (qreal) 1.0 * m_format.sampleRate() - / (TargetFrequencyParameter*2*frequency); - m_frequency = frequency; - open(QIODevice::WriteOnly); -} - -/** - * Closes the parent QIODevice, thus the voice is not analysed anymore. - * Resets the m_samples QList. - */ -void VoiceAnalyzer::stop() -{ - m_samples.clear(); - m_samples.reserve(m_totalSampleCount); - close(); -} - -/** - * Called when data is obtained. Stores each m_stepSize sample - * into a QList to be analysed. - */ -qint64 VoiceAnalyzer::writeData(const char *data, qint64 maxlen) -{ - const int channelBytes = m_format.sampleSize() / 8; - int sampleSize = m_format.channels() * channelBytes; - int m_stepSizeInBytes = m_stepSize*sampleSize; - // assert that each sample fits fully into the data - Q_ASSERT((m_position % sampleSize)==0); - const uchar *ptr = reinterpret_cast<const uchar *>(data); - while (m_position < maxlen) { - if (m_samples.size() < m_totalSampleCount) { - m_samples.append(getValueInt16(ptr+m_position)); - } - else { - analyzeVoice(); - m_samples.clear(); - m_samples.reserve(m_totalSampleCount); - // fast forward position to the first position after maxlen or to the maxlen - m_position += ((m_stepSizeInBytes - 1 + maxlen - m_position) / - m_stepSizeInBytes) * m_stepSizeInBytes; - break; - } - m_position += m_stepSizeInBytes; - } - m_position -= maxlen; - return maxlen; -} - -/** - * Interprets ptr as a pointer to int value and returns it. - */ -qint16 VoiceAnalyzer::getValueInt16(const uchar *ptr) -{ - qint16 realValue = 0; - if (m_format.sampleSize() == 8) - { - const qint16 value = *reinterpret_cast<const quint8*>(ptr); - if (m_format.sampleType() == QAudioFormat::UnSignedInt) { - realValue = value - M_MAX_AMPLITUDE_8BIT_SIGNED - 1; - } else if (m_format.sampleType() == QAudioFormat::SignedInt) { - realValue = value; - } - } else if (m_format.sampleSize() == 16) { - qint16 value = 0; - if (m_format.byteOrder() == QAudioFormat::LittleEndian) - value = qFromLittleEndian<quint16>(ptr); - else - value = qFromBigEndian<quint16>(ptr); - - if (m_format.sampleType() == QAudioFormat::UnSignedInt) { - realValue = value - M_MAX_AMPLITUDE_16BIT_SIGNED; - } else if (m_format.sampleType() == QAudioFormat::SignedInt) { - realValue = value; - } - } - return realValue; -} - -/** - * Takes a number between 0 and 1, scales it with CutOffScaler, - * multiplies it with maximum density, and then gives it - * to the fft helper. - */ -void VoiceAnalyzer::setCutOffPercentage(qreal cutoff) -{ - cutoff = CutOffScaler*cutoff; - if (m_format.sampleSize() == 8) { - float t = cutoff*m_totalSampleCount*M_MAX_AMPLITUDE_8BIT_SIGNED; - m_fftHelper->setCutOffForDensity(t); - } - else if (m_format.sampleSize() == 16) { - float t = cutoff*m_totalSampleCount*M_MAX_AMPLITUDE_16BIT_SIGNED; - m_fftHelper->setCutOffForDensity(t); - } -} - -/** - * Returns the current target frequency. - */ -qreal VoiceAnalyzer::frequency() -{ - return m_frequency; -} - -/** - * Returns the maximum absolute value sent by - * the voiceDifference() signal. - */ -int VoiceAnalyzer::getMaximumVoiceDifference() -{ - return m_maximumVoiceDifference; -} - -/** - * Returns the maximum precision per note - * near the target frequency. - */ -int VoiceAnalyzer::getMaximumPrecisionPerNote() -{ - return PrecisionPerNote; -} - -/** - * Analyzes the voice frequency and emits appropriate signals. - */ -void VoiceAnalyzer::analyzeVoice() -{ - m_fftHelper->calculateFFT(m_samples); - int index = m_fftHelper->getMaximumDensityIndex(); - - // If index == -1 - if (index == -1) { - // The voice is to be filtered away. - // Emit the lowVoice signal and return. - emit lowVoice(); - qDebug() << "low voice"; - return; - } - // Else, continue - - // Let the correctIndex to be - // the nearest index corresponding to the correct frequency. - qreal stepSizeInFrequency = (qreal)m_format.sampleRate() - / (m_totalSampleCount * m_stepSize); - qreal newFrequency = qreal(index) * stepSizeInFrequency; - // Calculate the nearest index corresponding to the correct frequency. - int correctIndex = qRound(m_frequency / stepSizeInFrequency); - qreal value = 0; - - // If the obtained frequency is more than - // log_2(TargetFrequencyParameter) octaves less than the m_frequency: - - // Note: - // Instead of m_frequency/TargetFrequencyParameter > newFrequency, - // the comparison is done without a div instructions by - // m_frequency > newFrequency * TargetFrequencyParameter. - - if (m_frequency > newFrequency * TargetFrequencyParameter) { - // Set the difference value to be -m_maximumVoiceDifference. - qDebug() << "compare" << "low" << newFrequency << m_frequency - stepSizeInFrequency * correctIndex << (m_frequency - stepSizeInFrequency * correctIndex) / stepSizeInFrequency; - value = -m_maximumVoiceDifference; - } - // Else, if the obtained frequency is more than - // log_2(TargetFrequencyParameter) octaves more than the m_frequency: - else if (m_frequency*TargetFrequencyParameter < newFrequency) { - // Set the difference value to be m_maximumVoiceDifference. - qDebug() << "compare" << "high" << newFrequency << m_frequency - stepSizeInFrequency * correctIndex << (m_frequency - stepSizeInFrequency * correctIndex) / stepSizeInFrequency; - value = m_maximumVoiceDifference; - } - // Else: - else { - // Calculate the difference between the obtained and the correct - // frequency in tones. - // Use stepSizeInFrequency * correctIndex instead of - // m_frequency so that the value is zero when there is correct - // voice obtained. Set the difference value to be - // log(frequency / target frequency) * 12 / log(2). - value = log(newFrequency / (stepSizeInFrequency * correctIndex)) - * 12 / M_LN2; - qDebug() << "compare" << value << newFrequency << m_frequency - stepSizeInFrequency * correctIndex << (m_frequency - stepSizeInFrequency * correctIndex) / stepSizeInFrequency; - } - - // Emit voiceDifference signal. - QVariant valueVar(value); //Has to be QVariant for QML - emit voiceDifference(valueVar); - - // If the correctIndex is index, emit the correctFrequency signal. - if (correctIndex == index) { - emit(correctFrequency()); - } -} - -/** - * Empty implementation for readData, since no data is provided - * by the VoiceAnalyzer class. - */ -qint64 VoiceAnalyzer::readData(char *data, qint64 maxlen) -{ - Q_UNUSED(data); - Q_UNUSED(maxlen); - - return 0; -} |