1 files changed, 139 insertions, 0 deletions
diff --git a/examples/spectrum/spectrumapp/utils.cpp b/examples/spectrum/spectrumapp/utils.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** 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 Digia Plc 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QAudioFormat>
+#include "utils.h"
+
+qint64 audioDuration(const QAudioFormat &format, qint64 bytes)
+{
+    return (bytes * 1000000) /
+        (format.sampleRate() * format.channelCount() * (format.sampleSize() / 8));
+}
+
+qint64 audioLength(const QAudioFormat &format, qint64 microSeconds)
+{
+   qint64 result = (format.sampleRate() * format.channelCount() * (format.sampleSize() / 8))
+       * microSeconds / 1000000;
+   result -= result % (format.channelCount() * format.sampleSize());
+   return result;
+}
+
+qreal nyquistFrequency(const QAudioFormat &format)
+{
+    return format.sampleRate() / 2;
+}
+
+QString formatToString(const QAudioFormat &format)
+{
+    QString result;
+
+    if (QAudioFormat() != format) {
+        if (format.codec() == "audio/pcm") {
+            Q_ASSERT(format.sampleType() == QAudioFormat::SignedInt);
+
+            const QString formatEndian = (format.byteOrder() == QAudioFormat::LittleEndian)
+                ?   QString("LE") : QString("BE");
+
+            QString formatType;
+            switch (format.sampleType()) {
+            case QAudioFormat::SignedInt:
+                formatType = "signed";
+                break;
+            case QAudioFormat::UnSignedInt:
+                formatType = "unsigned";
+                break;
+            case QAudioFormat::Float:
+                formatType = "float";
+                break;
+            case QAudioFormat::Unknown:
+                formatType = "unknown";
+                break;
+            }
+
+            QString formatChannels = QString("%1 channels").arg(format.channelCount());
+            switch (format.channelCount()) {
+            case 1:
+                formatChannels = "mono";
+                break;
+            case 2:
+                formatChannels = "stereo";
+                break;
+            }
+
+            result = QString("%1 Hz %2 bit %3 %4 %5")
+                .arg(format.sampleRate())
+                .arg(format.sampleSize())
+                .arg(formatType)
+                .arg(formatEndian)
+                .arg(formatChannels);
+        } else {
+            result = format.codec();
+        }
+    }
+
+    return result;
+}
+
+bool isPCM(const QAudioFormat &format)
+{
+    return (format.codec() == "audio/pcm");
+}
+
+
+bool isPCMS16LE(const QAudioFormat &format)
+{
+    return isPCM(format) &&
+           format.sampleType() == QAudioFormat::SignedInt &&
+           format.sampleSize() == 16 &&
+           format.byteOrder() == QAudioFormat::LittleEndian;
+}
+
+const qint16  PCMS16MaxValue     =  32767;
+const quint16 PCMS16MaxAmplitude =  32768; // because minimum is -32768
+
+qreal pcmToReal(qint16 pcm)
+{
+    return qreal(pcm) / PCMS16MaxAmplitude;
+}
+
+qint16 realToPcm(qreal real)
+{
+    return real * PCMS16MaxValue;
+}