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/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:FDL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Free Documentation License Usage
** Alternatively, this file may be used under the terms of the GNU Free
** Documentation License version 1.3 as published by the Free Software
** Foundation and appearing in the file included in the packaging of
** this file. Please review the following information to ensure
** the GNU Free Documentation License version 1.3 requirements
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****************************************************************************/
/*!
\example multimedia/spectrum
\title Spectrum Example
\ingroup multimedia_examples
\brief Analyzing a raw audio stream using the FFTReal library.
\e Spectrum demonstrates how the \l{Qt Multimedia} module can be used to
analyze an audio stream while recording it, and also play the recorded
stream.
\image spectrum-demo.png
Because Qt Multimedia allows the application to access the raw audio
stream, the data can either be inspected or modified by the application.
The Spectrum Analyzer example displays three pieces of information while
audio is being either captured or played back:
\list
\li Information about the raw audio stream, shown in the uppermost widget:
\list
\li The amount of data currently in the buffer, shown in blue
\li The segment of data which was most recently analysed to compute
the frequency spectrum, shown in green
\li The raw audio waveform, shown in white and scrolling from right to
left
\endlist
\li A representation of the frequency spectrum, shown at the lower left
\li The current RMS level of the audio stream, and the recent 'high
watermark' level, shown at the lower right
\endlist
Spectrum analysis is performed by calculating the Fast Fourier Transform
(FFT) of a segment of audio data. An open-source library,
\l{http://ldesoras.free.fr/prod.html}{FFTReal}, against which the
application is dynamically linked, is used to compute the transform.
\include examples-run.qdocinc
*/
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