Qt Reference Documentation

utils.h Example File

demos/spectrum/app/utils.h
 /****************************************************************************
 **
 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation ([email protected])
 **
 ** 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 UTILS_H
 #define UTILS_H

 #include <QtCore/qglobal.h>
 #include <QDebug>

 QT_FORWARD_DECLARE_CLASS(QAudioFormat)

 //-----------------------------------------------------------------------------
 // Miscellaneous utility functions
 //-----------------------------------------------------------------------------

 qint64 audioDuration(const QAudioFormat &format, qint64 bytes);
 qint64 audioLength(const QAudioFormat &format, qint64 microSeconds);

 QString formatToString(const QAudioFormat &format);

 qreal nyquistFrequency(const QAudioFormat &format);

 // Scale PCM value to [-1.0, 1.0]
 qreal pcmToReal(qint16 pcm);

 // Scale real value in [-1.0, 1.0] to PCM
 qint16 realToPcm(qreal real);

 // Check whether the audio format is PCM
 bool isPCM(const QAudioFormat &format);

 // Check whether the audio format is signed, little-endian, 16-bit PCM
 bool isPCMS16LE(const QAudioFormat &format);

 // Compile-time calculation of powers of two

 template<int N> class PowerOfTwo
 { public: static const int Result = PowerOfTwo<N-1>::Result * 2; };

 template<> class PowerOfTwo<0>
 { public: static const int Result = 1; };

 //-----------------------------------------------------------------------------
 // Debug output
 //-----------------------------------------------------------------------------

 class NullDebug
 {
 public:
     template <typename T>
     NullDebug& operator<<(const T&) { return *this; }
 };

 inline NullDebug nullDebug() { return NullDebug(); }

 #ifdef LOG_ENGINE
 #   define ENGINE_DEBUG qDebug()
 #else
 #   define ENGINE_DEBUG nullDebug()
 #endif

 #ifdef LOG_SPECTRUMANALYSER
 #   define SPECTRUMANALYSER_DEBUG qDebug()
 #else
 #   define SPECTRUMANALYSER_DEBUG nullDebug()
 #endif

 #ifdef LOG_WAVEFORM
 #   define WAVEFORM_DEBUG qDebug()
 #else
 #   define WAVEFORM_DEBUG nullDebug()
 #endif

 #endif // UTILS_H
X

Thank you for giving your feedback.

Make sure it is related to this specific page. For more general bugs and requests, please use the Qt Bug Tracker.