QAudioFormat Class▲
-
Header: QAudioFormat
-
CMake:
find_package(Qt6 REQUIRED COMPONENTS Multimedia)
target_link_libraries(mytarget PRIVATE Qt6::Multimedia)
-
qmake: QT += multimedia
-
Group: QAudioFormat is part of multimedia, multimedia_audio
Detailed Description▲
An audio format specifies how data in a raw audio stream is arranged. For example, how the stream is to be interpreted.
QAudioFormat contains parameters that specify how the audio sample data is arranged. These are the frequency, the number of channels, and the sample format. The following table describes these in more detail.
|
Parameter |
Description |
|---|---|
|
Sample Rate |
Samples per second of audio data in Hertz. |
|
Number of channels |
The number of audio channels (typically one for mono or two for stereo). These are the amount of consecutive samples that together form one frame in the stream |
|
Sample format |
The format of the audio samples in the stream |
This class is used in conjunction with QAudioSource or QAudioSink to allow you to specify the parameters of the audio stream being read or written, or with QAudioBuffer when dealing with samples in memory.
You can obtain audio formats compatible with the audio device used through functions in QAudioDevice. This class also lets you query available parameter values for a device, so that you can set the parameters yourself. See the QAudioDevice class description for details. You need to know the format of the audio streams you wish to play or record.
Samples for all channels will be interleaved. One sample for each channel for the same instant in time is referred to as a frame in Qt Multimedia (and other places).
Member Type Documentation▲
enum QAudioFormat::AudioChannelPosition▲
Describes the possible audio channel positions. These follow the standard definition used in the 22.2 surround sound configuration.
|
Constant |
Value |
Description |
|---|---|---|
|
QAudioFormat::UnknownPosition |
0 |
Unknown position |
|
QAudioFormat::FrontLeft |
1 |
|
|
QAudioFormat::FrontRight |
2 |
|
|
QAudioFormat::FrontCenter |
3 |
|
|
QAudioFormat::LFE |
4 |
Low Frequency Effect channel (Subwoofer) |
|
QAudioFormat::BackLeft |
5 |
|
|
QAudioFormat::BackRight |
6 |
|
|
QAudioFormat::FrontLeftOfCenter |
7 |
|
|
QAudioFormat::FrontRightOfCenter |
8 |
|
|
QAudioFormat::BackCenter |
9 |
|
|
QAudioFormat::LFE2 |
19 |
|
|
QAudioFormat::SideLeft |
10 |
|
|
QAudioFormat::SideRight |
11 |
|
|
QAudioFormat::TopFrontLeft |
13 |
|
|
QAudioFormat::TopFrontRight |
15 |
|
|
QAudioFormat::TopFrontCenter |
14 |
|
|
QAudioFormat::TopCenter |
12 |
|
|
QAudioFormat::TopBackLeft |
16 |
|
|
QAudioFormat::TopBackRight |
18 |
|
|
QAudioFormat::TopSideLeft |
20 |
|
|
QAudioFormat::TopSideRight |
21 |
|
|
QAudioFormat::TopBackCenter |
17 |
|
|
QAudioFormat::BottomFrontCenter |
22 |
|
|
QAudioFormat::BottomFrontLeft |
23 |
|
|
QAudioFormat::BottomFrontRight |
24 |
enum QAudioFormat::ChannelConfig▲
This enum describes a standardized audio channel layout. The most common configurations are Mono, Stereo, 2.1 (stereo plus low frequency), 5.1 surround, and 7.1 surround configurations.
|
Constant |
Value |
Description |
|---|---|---|
|
QAudioFormat::ChannelConfigUnknown |
0 |
The channel configuration is not known. |
|
QAudioFormat::ChannelConfigMono |
QtPrivate::channelConfig(FrontCenter) |
The audio has one Center channel. |
|
QAudioFormat::ChannelConfigStereo |
QtPrivate::channelConfig(FrontLeft, FrontRight) |
The audio has two channels, Left and Right. |
|
QAudioFormat::ChannelConfig2Dot1 |
QtPrivate::channelConfig(FrontLeft, FrontRight, LFE) |
The audio has three channels, Left, Right and LFE (low frequency effect). |
|
QAudioFormat::ChannelConfig3Dot0 |
QtPrivate::channelConfig(FrontLeft, FrontRight, FrontCenter) |
The audio has three channels, Left, Right, and Center. |
|
QAudioFormat::ChannelConfig3Dot1 |
QtPrivate::channelConfig(FrontLeft, FrontRight, FrontCenter, LFE) |
The audio has four channels, Left, Right, Center, and LFE (low frequency effect). |
|
QAudioFormat::ChannelConfigSurround5Dot0 |
QtPrivate::channelConfig(FrontLeft, FrontRight, FrontCenter, BackLeft, BackRight) |
The audio has five channels, Left, Right, Center, BackLeft, and BackRight. |
|
QAudioFormat::ChannelConfigSurround5Dot1 |
QtPrivate::channelConfig(FrontLeft, FrontRight, FrontCenter, LFE, BackLeft, BackRight) |
The audio has 6 channels, Left, Right, Center, LFE, BackLeft, and BackRight. |
|
QAudioFormat::ChannelConfigSurround7Dot0 |
QtPrivate::channelConfig(FrontLeft, FrontRight, FrontCenter, BackLeft, BackRight, SideLeft, SideRight) |
The audio has 7 channels, Left, Right, Center, BackLeft, BackRight, SideLeft, and SideRight. |
|
QAudioFormat::ChannelConfigSurround7Dot1 |
QtPrivate::channelConfig(FrontLeft, FrontRight, FrontCenter, LFE, BackLeft, BackRight, SideLeft, SideRight) |
The audio has 8 channels, Left, Right, Center, LFE, BackLeft, BackRight, SideLeft, and SideRight. |
enum QAudioFormat::SampleFormat▲
Qt will always expect and use samples in the endianness of the host platform. When processing audio data from external sources yourself, ensure you convert them to the correct endianness before writing them to a QAudioSink or QAudioBuffer.
|
Constant |
Value |
Description |
|---|---|---|
|
QAudioFormat::Unknown |
0 |
Not Set |
|
QAudioFormat::UInt8 |
1 |
Samples are unsigned 8 bit signed integers |
|
QAudioFormat::Int16 |
2 |
Samples are 16 bit signed integers |
|
QAudioFormat::Int32 |
3 |
Samples are 32 bit signed integers |
|
QAudioFormat::Float |
4 |
Samples are floats |
Member Function Documentation▲
[default] QAudioFormat::QAudioFormat()▲
Constructs a new audio format.
Values are initialized as follows:
-
sampleRate() = 0
-
channelCount() = 0
[default] QAudioFormat::QAudioFormat(const QAudioFormat &other)▲
Construct a new audio format using other.
[default] QAudioFormat::~QAudioFormat()▲
Destroy this audio format.
qint32 QAudioFormat::bytesForDuration(qint64 microseconds) const▲
Returns the number of bytes required for this audio format for microseconds.
Returns 0 if this format is not valid.
Note that some rounding may occur if microseconds is not an exact fraction of the sampleRate().
See Also▲
See also durationForBytes()
qint32 QAudioFormat::bytesForFrames(qint32 frameCount) const▲
Returns the number of bytes required for frameCount frames of this format.
Returns 0 if this format is not valid.
See Also▲
See also bytesForDuration()
[constexpr] int QAudioFormat::bytesPerFrame() const▲
Returns the number of bytes required to represent one frame (a sample in each channel) in this format.
Returns 0 if this format is invalid.
[constexpr] int QAudioFormat::bytesPerSample() const▲
Returns the number of bytes required to represent one sample in this format.
Returns 0 if this format is invalid.
[static constexpr] QAudioFormat::ChannelConfig QAudioFormat::channelConfig(Args... channels)▲
Returns the current channel configuration for the given channels.
See Also▲
See also setChannelConfig()
[constexpr] QAudioFormat::ChannelConfig QAudioFormat::channelConfig() const▲
Returns the current channel configuration.
[constexpr] int QAudioFormat::channelCount() const▲
int QAudioFormat::channelOffset(QAudioFormat::AudioChannelPosition channel) const▲
Returns the position of a certain audio channel inside an audio frame for the given format. Returns -1 if the channel does not exist for this format or the channel configuration is unknown.
[static] QAudioFormat::ChannelConfig QAudioFormat::defaultChannelConfigForChannelCount(int channelCount)▲
Returns a default channel configuration for channelCount.
Default configurations are defined for up to 8 channels, and correspond to standard Mono, Stereo and Surround configurations. For higher channel counts, this simply uses the first channelCount audio channels defined in QAudioFormat::AudioChannelPosition.
qint64 QAudioFormat::durationForBytes(qint32 bytes) const▲
Returns the number of microseconds represented by bytes in this format.
Returns 0 if this format is not valid.
Note that some rounding may occur if bytes is not an exact multiple of the number of bytes per frame.
See Also▲
See also bytesForDuration()
qint64 QAudioFormat::durationForFrames(qint32 frameCount) const▲
Return the number of microseconds represented by frameCount frames in this format.
qint32 QAudioFormat::framesForBytes(qint32 byteCount) const▲
Returns the number of frames represented by byteCount in this format.
Note that some rounding may occur if byteCount is not an exact multiple of the number of bytes per frame.
Each frame has one sample per channel.
See Also▲
See also framesForDuration()
qint32 QAudioFormat::framesForDuration(qint64 microseconds) const▲
Returns the number of frames required to represent microseconds in this format.
Note that some rounding may occur if microseconds is not an exact fraction of the sampleRate().
[constexpr] bool QAudioFormat::isValid() const▲
Returns true if all of the parameters are valid.
float QAudioFormat::normalizedSampleValue(const void *sample) const▲
Normalizes the sample value to a number between -1 and 1. The method depends on the QaudioFormat.
[constexpr] QAudioFormat::SampleFormat QAudioFormat::sampleFormat() const▲
[constexpr] int QAudioFormat::sampleRate() const▲
void QAudioFormat::setChannelConfig(QAudioFormat::ChannelConfig config)▲
Sets the channel configuration to config.
Sets the channel configuration of the audio format to one of the standard audio channel configurations.
that this will also modify the channel count.
See Also▲
See also channelConfig()
[constexpr] void QAudioFormat::setChannelCount(int channels)▲
Sets the channel count to channels. Setting this also sets the channel config to ChannelConfigUnknown.
See Also▲
See also channelCount()