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// Copyright (C) 2022 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#ifndef QAUDIOHELPERS_P_H
#define QAUDIOHELPERS_P_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include <QtMultimedia/private/qtmultimediaglobal_p.h>
#include <QtMultimedia/qaudioformat.h>
#include <QtCore/qspan.h>
#include <QtCore/qmath.h>
#include <vector>
QT_BEGIN_NAMESPACE
namespace QAudioHelperInternal {
Q_MULTIMEDIA_EXPORT void qMultiplySamples(float factor,
const QAudioFormat &format,
const void *src,
void *dest,
int len) noexcept Q_DECL_NONBLOCKING_FUNCTION;
Q_MULTIMEDIA_EXPORT
void applyVolume(float volume,
const QAudioFormat &,
QSpan<const std::byte> source,
QSpan<std::byte> destination) noexcept Q_DECL_NONBLOCKING_FUNCTION;
enum class NativeSampleFormat : uint8_t {
uint8_t,
int16_t,
int32_t,
int24_t_3b, // 3 byte lsb
int24_t_4b_low, // 4 byte
float32_t,
};
Q_MULTIMEDIA_EXPORT
void convertSampleFormat(QSpan<const std::byte> source, NativeSampleFormat sourceFormat,
QSpan<std::byte> destination,
NativeSampleFormat destinationFormat) noexcept Q_DECL_NONBLOCKING_FUNCTION;
Q_MULTIMEDIA_EXPORT
NativeSampleFormat bestNativeSampleFormat(const QAudioFormat &fmt,
QSpan<const NativeSampleFormat> supportedNativeFormats);
Q_MULTIMEDIA_EXPORT
QAudioFormat::SampleFormat bestSampleFormat(NativeSampleFormat);
Q_MULTIMEDIA_EXPORT
NativeSampleFormat toNativeSampleFormat(QAudioFormat::SampleFormat);
constexpr size_t bytesPerSample(NativeSampleFormat fmt) noexcept Q_DECL_NONBLOCKING_FUNCTION
{
switch (fmt) {
case NativeSampleFormat::uint8_t:
return 1;
case NativeSampleFormat::int16_t:
return 2;
case NativeSampleFormat::int24_t_3b:
return 3;
case NativeSampleFormat::int24_t_4b_low:
case NativeSampleFormat::float32_t:
case NativeSampleFormat::int32_t:
return 4;
default:
Q_UNREACHABLE_RETURN(0);
}
}
Q_MULTIMEDIA_EXPORT
std::optional<float> sanitizeVolume(float volume, float lastVolume);
Q_MULTIMEDIA_EXPORT
void fillSilence(QSpan<std::byte>, NativeSampleFormat) noexcept Q_DECL_NONBLOCKING_FUNCTION;
Q_MULTIMEDIA_EXPORT
void fillSilence(QSpan<std::byte>, QAudioFormat) noexcept Q_DECL_NONBLOCKING_FUNCTION;
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Resample interleaved float32 PCM using Catmull-Rom interpolation.
Q_MULTIMEDIA_EXPORT
QByteArray resampleAudioCatmullRom(QSpan<const float> input, int nChannels,
int inputRate, int outputRate);
class Q_MULTIMEDIA_EXPORT CatmullRomInterpolator
{
public:
CatmullRomInterpolator(int nChannels, int inputRate, int outputRate);
~CatmullRomInterpolator() = default;
CatmullRomInterpolator(const CatmullRomInterpolator &) = delete;
CatmullRomInterpolator &operator=(const CatmullRomInterpolator &) = delete;
void reset();
struct ResampleResult
{
QSpan<const float> remainingInput;
QSpan<float> output;
};
ResampleResult process(QSpan<const float> input,
QSpan<float> output) noexcept Q_DECL_NONBLOCKING_FUNCTION;
private:
void advancePosition();
int m_nChannels = 0;
float m_ratio = 1.0f;
qsizetype m_iPos = 0; // integer frame index in absolute frame space
float m_fPos = 0.0f; // fractional phase [0, 1) within current frame
qsizetype m_inputFramesConsumed = 0;
std::vector<float> m_history; // history of 3 frames
};
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
enum class UpmixScaling {
Duplicate, // mono → L=R=src[0]
EqualPower, // mono → L=R=0.707*src[0]
};
Q_MULTIMEDIA_EXPORT
QByteArray upmixMonoToStereo(QSpan<const float>, UpmixScaling scaling = UpmixScaling::Duplicate);
Q_MULTIMEDIA_EXPORT
void upmixMonoToStereo(QSpan<float> out, QSpan<const float> in,
UpmixScaling scaling = UpmixScaling::Duplicate) noexcept
Q_DECL_NONBLOCKING_FUNCTION;
enum class DownmixScaling {
Average, // L+R → 0.5*L + 0.5*R
KeepPower, // L+R → 0.707*L + 0.707*R
};
Q_MULTIMEDIA_EXPORT
QByteArray downmixStereoToMono(QSpan<const float> input,
DownmixScaling scaling = DownmixScaling::Average);
Q_MULTIMEDIA_EXPORT
void downmixStereoToMono(QSpan<float> out, QSpan<const float> in,
DownmixScaling scaling = DownmixScaling::Average) noexcept
Q_DECL_NONBLOCKING_FUNCTION;
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
} // namespace QAudioHelperInternal
Q_MULTIMEDIA_EXPORT
QDebug operator<<(QDebug dbg, QAudioHelperInternal::NativeSampleFormat);
QT_END_NAMESPACE
#endif // QAUDIOHELPERS_P_H