utils.cpp Example File
multimedia/spectrum/app/utils.cpp
#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;
qreal pcmToReal(qint16 pcm)
{
return qreal(pcm) / PCMS16MaxAmplitude;
}
qint16 realToPcm(qreal real)
{
return real * PCMS16MaxValue;
}