| 1 | /****************************************************************************
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| 2 | **
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| 3 | ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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| 4 | ** All rights reserved.
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| 5 | ** Contact: Nokia Corporation ([email protected])
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| 6 | **
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| 7 | ** This file is part of the examples of the Qt Toolkit.
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| 8 | **
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| 9 | ** $QT_BEGIN_LICENSE:BSD$
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| 10 | ** You may use this file under the terms of the BSD license as follows:
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| 11 | **
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| 12 | ** "Redistribution and use in source and binary forms, with or without
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| 13 | ** modification, are permitted provided that the following conditions are
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| 14 | ** met:
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| 15 | ** * Redistributions of source code must retain the above copyright
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| 16 | ** notice, this list of conditions and the following disclaimer.
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| 17 | ** * Redistributions in binary form must reproduce the above copyright
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| 18 | ** notice, this list of conditions and the following disclaimer in
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| 19 | ** the documentation and/or other materials provided with the
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| 20 | ** distribution.
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| 21 | ** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
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| 22 | ** the names of its contributors may be used to endorse or promote
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| 23 | ** products derived from this software without specific prior written
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| 24 | ** permission.
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| 25 | **
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| 26 | ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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| 27 | ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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| 28 | ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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| 29 | ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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| 30 | ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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| 31 | ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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| 32 | ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 33 | ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 34 | ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 35 | ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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| 36 | ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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| 37 | ** $QT_END_LICENSE$
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| 38 | **
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| 39 | ****************************************************************************/
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| 40 |
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| 41 | #include "spectrum.h"
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| 42 | #include "utils.h"
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| 43 | #include <QByteArray>
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| 44 | #include <QtMultimedia/QAudioFormat>
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| 45 | #include <QtCore/qmath.h>
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| 46 | #include <QtCore/qendian.h>
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| 47 |
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| 48 | void generateTone(const SweptTone &tone, const QAudioFormat &format, QByteArray &buffer)
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| 49 | {
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| 50 | Q_ASSERT(isPCMS16LE(format));
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| 51 |
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| 52 | const int channelBytes = format.sampleSize() / 8;
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| 53 | const int sampleBytes = format.channels() * channelBytes;
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| 54 | int length = buffer.size();
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| 55 | const int numSamples = buffer.size() / sampleBytes;
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| 56 |
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| 57 | Q_ASSERT(length % sampleBytes == 0);
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| 58 | Q_UNUSED(sampleBytes) // suppress warning in release builds
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| 59 |
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| 60 | unsigned char *ptr = reinterpret_cast<unsigned char *>(buffer.data());
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| 61 |
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| 62 | qreal phase = 0.0;
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| 63 |
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| 64 | const qreal d = 2 * M_PI / format.frequency();
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| 65 |
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| 66 | // We can't generate a zero-frequency sine wave
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| 67 | const qreal startFreq = tone.startFreq ? tone.startFreq : 1.0;
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| 68 |
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| 69 | // Amount by which phase increases on each sample
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| 70 | qreal phaseStep = d * startFreq;
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