--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/spectrum/app/engine.h Fri Jun 11 14:24:45 2010 +0300
@@ -0,0 +1,311 @@
+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+** $QT_END_LICENSE$
+**
+*****************************************************************************/
+
+#ifndef ENGINE_H
+#define ENGINE_H
+
+#include "spectrum.h"
+#include "spectrumanalyser.h"
+#include "wavfile.h"
+
+#include <QObject>
+#include <QByteArray>
+#include <QBuffer>
+#include <QVector>
+#include <QtMultimedia/QAudioDeviceInfo>
+#include <QtMultimedia/QAudioFormat>
+
+#ifdef DUMP_CAPTURED_AUDIO
+#define DUMP_DATA
+#endif
+
+#ifdef DUMP_SPECTRUM
+#define DUMP_DATA
+#endif
+
+#ifdef DUMP_DATA
+#include <QDir>
+#endif
+
+class QAudioInput;
+class QAudioOutput;
+class FrequencySpectrum;
+class QFile;
+
+/**
+ * This class interfaces with the QtMultimedia audio classes, and also with
+ * the SpectrumAnalyser class. Its role is to manage the capture and playback
+ * of audio data, meanwhile performing real-time analysis of the audio level
+ * and frequency spectrum.
+ */
+class Engine : public QObject {
+ Q_OBJECT
+public:
+ Engine(QObject *parent = 0);
+ ~Engine();
+
+ const QList<QAudioDeviceInfo>& availableAudioInputDevices() const
+ { return m_availableAudioInputDevices; }
+
+ const QList<QAudioDeviceInfo>& availableAudioOutputDevices() const
+ { return m_availableAudioOutputDevices; }
+
+ QAudio::Mode mode() const { return m_mode; }
+ QAudio::State state() const { return m_state; }
+
+ /**
+ * \return Reference to internal audio buffer
+ * \note This reference is valid for the lifetime of the Engine
+ */
+ const QByteArray& buffer() const { return m_buffer; }
+
+ /**
+ * \return Current audio format
+ * \note May be QAudioFormat() if engine is not initialized
+ */
+ const QAudioFormat& format() const { return m_format; }
+
+ /**
+ * Stop any ongoing recording or playback, and reset to ground state.
+ */
+ void reset();
+
+ /**
+ * Load data from WAV file
+ */
+ bool loadFile(const QString &fileName);
+
+ /**
+ * Generate tone
+ */
+ bool generateTone(const Tone &tone);
+
+ /**
+ * Generate tone
+ */
+ bool generateSweptTone(qreal amplitude);
+
+ /**
+ * Initialize for recording
+ */
+ bool initializeRecord();
+
+ /**
+ * Position of the audio input device.
+ * \return Position in microseconds.
+ */
+ qint64 recordPosition() const { return m_recordPosition; }
+
+ /**
+ * RMS level of the most recently processed set of audio samples.
+ * \return Level in range (0.0, 1.0)
+ */
+ qreal rmsLevel() const { return m_rmsLevel; }
+
+ /**
+ * Peak level of the most recently processed set of audio samples.
+ * \return Level in range (0.0, 1.0)
+ */
+ qreal peakLevel() const { return m_peakLevel; }
+
+ /**
+ * Position of the audio output device.
+ * \return Position in microseconds.
+ */
+ qint64 playPosition() const { return m_playPosition; }
+
+ /**
+ * Length of the internal engine buffer.
+ * \return Buffer length in microseconds.
+ */
+ qint64 bufferDuration() const;
+
+ /**
+ * Amount of data held in the buffer.
+ * \return Data duration in microseconds.
+ */
+ qint64 dataDuration() const;
+
+ /**
+ * Returns the size of the underlying audio buffer in bytes.
+ * This should be an approximation of the capture latency.
+ */
+ qint64 audioBufferLength() const;
+
+ /**
+ * Set window function applied to audio data before spectral analysis.
+ */
+ void setWindowFunction(WindowFunction type);
+
+public slots:
+ void startRecording();
+ void startPlayback();
+ void suspend();
+ void setAudioInputDevice(const QAudioDeviceInfo &device);
+ void setAudioOutputDevice(const QAudioDeviceInfo &device);
+
+signals:
+ void stateChanged(QAudio::Mode mode, QAudio::State state);
+
+ /**
+ * Informational message for non-modal display
+ */
+ void infoMessage(const QString &message, int durationMs);
+
+ /**
+ * Error message for modal display
+ */
+ void errorMessage(const QString &heading, const QString &detail);
+
+ /**
+ * Format of audio data has changed
+ */
+ void formatChanged(const QAudioFormat &format);
+
+ /**
+ * Length of buffer has changed.
+ * \param duration Duration in microseconds
+ */
+ void bufferDurationChanged(qint64 duration);
+
+ /**
+ * Amount of data in buffer has changed.
+ * \param duration Duration of data in microseconds
+ */
+ void dataDurationChanged(qint64 duration);
+
+ /**
+ * Position of the audio input device has changed.
+ * \param position Position in microseconds
+ */
+ void recordPositionChanged(qint64 position);
+
+ /**
+ * Position of the audio output device has changed.
+ * \param position Position in microseconds
+ */
+ void playPositionChanged(qint64 position);
+
+ /**
+ * Level changed
+ * \param rmsLevel RMS level in range 0.0 - 1.0
+ * \param peakLevel Peak level in range 0.0 - 1.0
+ * \param numSamples Number of audio samples analysed
+ */
+ void levelChanged(qreal rmsLevel, qreal peakLevel, int numSamples);
+
+ /**
+ * Spectrum has changed.
+ * \param position Position of start of window in microseconds
+ * \param length Length of window in microseconds
+ * \param spectrum Resulting frequency spectrum
+ */
+ void spectrumChanged(qint64 position, qint64 length, const FrequencySpectrum &spectrum);
+
+private slots:
+ void audioNotify();
+ void audioStateChanged(QAudio::State state);
+ void audioDataReady();
+ void spectrumChanged(const FrequencySpectrum &spectrum);
+
+private:
+ bool initialize();
+ bool selectFormat();
+ void stopRecording();
+ void stopPlayback();
+ void setState(QAudio::State state);
+ void setState(QAudio::Mode mode, QAudio::State state);
+ void setFormat(const QAudioFormat &format);
+ void setRecordPosition(qint64 position, bool forceEmit = false);
+ void setPlayPosition(qint64 position, bool forceEmit = false);
+ void calculateLevel(qint64 position, qint64 length);
+ void calculateSpectrum(qint64 position);
+ void setLevel(qreal rmsLevel, qreal peakLevel, int numSamples);
+
+#ifdef DUMP_DATA
+ void createOutputDir();
+ QString outputPath() const { return m_outputDir.path(); }
+#endif
+
+#ifdef DUMP_CAPTURED_AUDIO
+ void dumpData();
+#endif
+
+private:
+ QAudio::Mode m_mode;
+ QAudio::State m_state;
+
+ bool m_generateTone;
+ SweptTone m_tone;
+
+ QFile* m_file;
+ WavFile m_wavFile;
+
+ QAudioFormat m_format;
+
+ const QList<QAudioDeviceInfo> m_availableAudioInputDevices;
+ QAudioDeviceInfo m_audioInputDevice;
+ QAudioInput* m_audioInput;
+ QIODevice* m_audioInputIODevice;
+ qint64 m_recordPosition;
+
+ const QList<QAudioDeviceInfo> m_availableAudioOutputDevices;
+ QAudioDeviceInfo m_audioOutputDevice;
+ QAudioOutput* m_audioOutput;
+ qint64 m_playPosition;
+ QBuffer m_audioOutputIODevice;
+
+ QByteArray m_buffer;
+ qint64 m_dataLength;
+
+ qreal m_rmsLevel;
+ qreal m_peakLevel;
+
+ int m_spectrumLengthBytes;
+ QByteArray m_spectrumBuffer;
+ SpectrumAnalyser m_spectrumAnalyser;
+ qint64 m_spectrumPosition;
+
+ int m_count;
+
+#ifdef DUMP_DATA
+ QDir m_outputDir;
+#endif
+
+};
+
+#endif // ENGINE_H