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author | Gareth Stockwell <ext-gareth.stockwell@nokia.com> | 2010-04-29 16:30:16 (GMT) |
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committer | Gareth Stockwell <ext-gareth.stockwell@nokia.com> | 2010-05-05 09:24:01 (GMT) |
commit | e9dda3cabdcfdeb5d659b94640410b486ad58921 (patch) | |
tree | 169f3f6651c09d1775983c271df169be78d524d4 /demos/spectrum/app/spectrumanalyser.h | |
parent | 6c8acf656a9293db2fdbad569bb1fa3a83975462 (diff) | |
download | Qt-e9dda3cabdcfdeb5d659b94640410b486ad58921.zip Qt-e9dda3cabdcfdeb5d659b94640410b486ad58921.tar.gz Qt-e9dda3cabdcfdeb5d659b94640410b486ad58921.tar.bz2 |
Add spectrum analyzer demo app
This application is a demo which uses the QtMultimedia APIs to
capture and play back PCM audio. While either recording or playback
is ongoing, the application performs real-time level and frequency
spectrum analysis.
Reviewed-by: Alessandro Portale
Diffstat (limited to 'demos/spectrum/app/spectrumanalyser.h')
-rw-r--r-- | demos/spectrum/app/spectrumanalyser.h | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/demos/spectrum/app/spectrumanalyser.h b/demos/spectrum/app/spectrumanalyser.h new file mode 100644 index 0000000..9d7684a --- /dev/null +++ b/demos/spectrum/app/spectrumanalyser.h @@ -0,0 +1,188 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the examples of the Qt Toolkit. +** +** You may use this file under the terms of the BSD license as follows: +** +** Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are met: +** - Redistributions of source code must retain the above copyright notice, +** this list of conditions and the following disclaimer. +** - Redistributions in binary form must reproduce the above copyright notice, +** this list of conditions and the following disclaimer in the documentation +** and/or other materials provided with the distribution. +** - Neither the name of Nokia Corporation and its Subsidiary(-ies) nor the +** names of its contributors may be used to endorse or promote products +** derived from this software without specific prior written permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +** AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +** ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +** LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +** INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +** CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +** ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +** POSSIBILITY OF SUCH DAMAGE. +** +*****************************************************************************/ + +#ifndef SPECTRUMANALYSER_H +#define SPECTRUMANALYSER_H + +#include <QByteArray> +#include <QObject> +#include <QVector> + +#ifdef DUMP_SPECTRUMANALYSER +#include <QDir> +#include <QFile> +#include <QTextStream> +#endif + +#include "frequencyspectrum.h" +#include "spectrum.h" + +#ifndef DISABLE_FFT +#include "FFTRealFixLenParam.h" +#endif + +class QAudioFormat; +class QThread; +class FFTRealWrapper; + +class SpectrumAnalyserThreadPrivate; + +/** + * Implementation of the spectrum analysis which can be run in a + * separate thread. + */ +class SpectrumAnalyserThread : public QObject +{ + Q_OBJECT +public: + SpectrumAnalyserThread(QObject *parent); + ~SpectrumAnalyserThread(); + +public slots: + void setWindowFunction(WindowFunction type); + void calculateSpectrum(const QByteArray &buffer, + int inputFrequency, + int bytesPerSample); + +signals: + void calculationComplete(const FrequencySpectrum &spectrum); + +private: + void calculateWindow(); + +private: +#ifndef DISABLE_FFT + FFTRealWrapper* m_fft; +#endif + + const int m_numSamples; + + WindowFunction m_windowFunction; + +#ifdef DISABLE_FFT + typedef qreal DataType; +#else + typedef FFTRealFixLenParam::DataType DataType; +#endif + QVector<DataType> m_window; + + QVector<DataType> m_input; + QVector<DataType> m_output; + + FrequencySpectrum m_spectrum; + +#ifdef SPECTRUM_ANALYSER_SEPARATE_THREAD + QThread* m_thread; +#endif +}; + +/** + * Class which performs frequency spectrum analysis on a window of + * audio samples, provided to it by the Engine. + */ +class SpectrumAnalyser : public QObject +{ + Q_OBJECT +public: + SpectrumAnalyser(QObject *parent = 0); + ~SpectrumAnalyser(); + +#ifdef DUMP_SPECTRUMANALYSER + void setOutputPath(const QString &outputPath); +#endif + +public: + /* + * Set the windowing function which is applied before calculating the FFT + */ + void setWindowFunction(WindowFunction type); + + /* + * Calculate a frequency spectrum + * + * \param buffer Audio data + * \param format Format of audio data + * + * Frequency spectrum is calculated asynchronously. The result is returned + * via the spectrumChanged signal. + * + * An ongoing calculation can be cancelled by calling cancelCalculation(). + * + */ + void calculate(const QByteArray &buffer, const QAudioFormat &format); + + /* + * Check whether the object is ready to perform another calculation + */ + bool isReady() const; + + /* + * Cancel an ongoing calculation + * + * Note that cancelling is asynchronous. + */ + void cancelCalculation(); + +signals: + void spectrumChanged(const FrequencySpectrum &spectrum); + +private slots: + void calculationComplete(const FrequencySpectrum &spectrum); + +private: + void calculateWindow(); + +private: + + SpectrumAnalyserThread* m_thread; + + enum State { + Idle, + Busy, + Cancelled + }; + + State m_state; + +#ifdef DUMP_SPECTRUMANALYSER + QDir m_outputDir; + int m_count; + QFile m_textFile; + QTextStream m_textStream; +#endif +}; + +#endif // SPECTRUMANALYSER_H + |