engine.h Example File

multimedia/spectrum/app/engine.h
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#ifndef ENGINE_H #define ENGINE_H #include "spectrum.h" #include "spectrumanalyser.h" #include "wavfile.h" #include <QAudioDeviceInfo> #include <QAudioFormat> #include <QBuffer> #include <QByteArray> #include <QDir> #include <QObject> #include <QVector> #ifdef DUMP_CAPTURED_AUDIO #define DUMP_DATA #endif #ifdef DUMP_SPECTRUM #define DUMP_DATA #endif class FrequencySpectrum; class QAudioInput; class QAudioOutput; /** * This class interfaces with the Qt Multimedia 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: explicit 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 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 bytes. */ 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 bytes. */ qint64 playPosition() const { return m_playPosition; } /** * Length of the internal engine buffer. * \return Buffer length in bytes. */ qint64 bufferLength() const; /** * Amount of data held in the buffer. * \return Data length in bytes. */ qint64 dataLength() const { return m_dataLength; } /** * 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 bufferLengthChanged(qint64 duration); /** * Amount of data in buffer has changed. * \param Length of data in bytes */ void dataLengthChanged(qint64 duration); /** * Position of the audio input device has changed. * \param position Position in bytes */ void recordPositionChanged(qint64 position); /** * Position of the audio output device has changed. * \param position Position in bytes */ 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 analyzed */ void levelChanged(qreal rmsLevel, qreal peakLevel, int numSamples); /** * Spectrum has changed. * \param position Position of start of window in bytes * \param length Length of window in bytes * \param spectrum Resulting frequency spectrum */ void spectrumChanged(qint64 position, qint64 length, const FrequencySpectrum &spectrum); /** * Buffer containing audio data has changed. * \param position Position of start of buffer in bytes * \param buffer Buffer */ void bufferChanged(qint64 position, qint64 length, const QByteArray &buffer); private slots: void audioNotify(); void audioStateChanged(QAudio::State state); void audioDataReady(); void spectrumChanged(const FrequencySpectrum &spectrum); private: void resetAudioDevices(); 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; WavFile* m_file; // We need a second file handle via which to read data into m_buffer // for analysis WavFile* m_analysisFile; 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; QString m_audioOutputCategory; qint64 m_playPosition; QBuffer m_audioOutputIODevice; QByteArray m_buffer; qint64 m_bufferPosition; qint64 m_bufferLength; qint64 m_dataLength; int m_levelBufferLength; qreal m_rmsLevel; qreal m_peakLevel; int m_spectrumBufferLength; QByteArray m_spectrumBuffer; SpectrumAnalyser m_spectrumAnalyser; qint64 m_spectrumPosition; int m_count; #ifdef DUMP_DATA QDir m_outputDir; #endif }; #endif // ENGINE_H

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