QAudioFormat

The QAudioFormat class stores audio stream parameter information. More

Inheritance diagram of PySide2.QtMultimedia.QAudioFormat

Synopsis

Functions

Detailed Description

An audio format specifies how data in an audio stream is arranged, i.e, how the stream is to be interpreted. The encoding itself is specified by the codec() used for the stream.

In addition to the encoding, QAudioFormat contains other parameters that further specify how the audio sample data is arranged. These are the frequency, the number of channels, the sample size, the sample type, and the byte order. 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)

Sample size

How much data is stored in each sample (typically 8 or 16 bits)

Sample type

Numerical representation of sample (typically signed integer, unsigned integer or float)

Byte order

Byte ordering of sample (typically little endian, big endian)

This class is typically used in conjunction with QAudioInput or QAudioOutput 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 QAudioDeviceInfo . This class also lets you query available parameter values for a device, so that you can set the parameters yourself. See the QAudioDeviceInfo class description for details. You need to know the format of the audio streams you wish to play or record.

In the common case of interleaved linear PCM data, the codec will be “audio/pcm”, and the 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).

class PySide2.QtMultimedia.QAudioFormat

PySide2.QtMultimedia.QAudioFormat(other)

param other

PySide2.QtMultimedia.QAudioFormat

Construct a new audio format.

Values are initialized as follows:

Construct a new audio format using other .

PySide2.QtMultimedia.QAudioFormat.SampleType

Constant

Description

QAudioFormat.Unknown

Not Set

QAudioFormat.SignedInt

Samples are signed integers

QAudioFormat.UnSignedInt

Samples are unsigned intergers

QAudioFormat.Float

Samples are floats

PySide2.QtMultimedia.QAudioFormat.Endian

Constant

Description

QAudioFormat.BigEndian

Samples are big endian byte order

QAudioFormat.LittleEndian

Samples are little endian byte order

PySide2.QtMultimedia.QAudioFormat.byteOrder()
Return type

Endian

Returns the current value.

See also

setByteOrder()

PySide2.QtMultimedia.QAudioFormat.bytesForDuration(duration)
Parameters

duration – int

Return type

qint32

Returns the number of bytes required for this audio format for duration microseconds.

Returns 0 if this format is not valid.

Note that some rounding may occur if duration is not an exact fraction of the sampleRate() .

PySide2.QtMultimedia.QAudioFormat.bytesForFrames(frameCount)
Parameters

frameCountqint32

Return type

qint32

Returns the number of bytes required for frameCount frames of this format.

Returns 0 if this format is not valid.

PySide2.QtMultimedia.QAudioFormat.bytesPerFrame()
Return type

int

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.

PySide2.QtMultimedia.QAudioFormat.channelCount()
Return type

int

Returns the current channel count value.

PySide2.QtMultimedia.QAudioFormat.codec()
Return type

str

Returns the current codec identifier.

PySide2.QtMultimedia.QAudioFormat.durationForBytes(byteCount)
Parameters

byteCountqint32

Return type

int

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.

PySide2.QtMultimedia.QAudioFormat.durationForFrames(frameCount)
Parameters

frameCountqint32

Return type

int

Return the number of microseconds represented by frameCount frames in this format.

PySide2.QtMultimedia.QAudioFormat.framesForBytes(byteCount)
Parameters

byteCountqint32

Return type

qint32

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.

PySide2.QtMultimedia.QAudioFormat.framesForDuration(duration)
Parameters

duration – int

Return type

qint32

Returns the number of frames required to represent duration microseconds in this format.

Note that some rounding may occur if duration is not an exact fraction of the sampleRate() .

PySide2.QtMultimedia.QAudioFormat.isValid()
Return type

bool

Returns true if all of the parameters are valid.

PySide2.QtMultimedia.QAudioFormat.__ne__(other)
Parameters

otherPySide2.QtMultimedia.QAudioFormat

Return type

bool

Returns true if this QAudioFormat is not equal to the other QAudioFormat ; otherwise returns false.

All elements of QAudioFormat are used for the comparison.

PySide2.QtMultimedia.QAudioFormat.__eq__(other)
Parameters

otherPySide2.QtMultimedia.QAudioFormat

Return type

bool

Returns true if this QAudioFormat is equal to the other QAudioFormat ; otherwise returns false.

All elements of QAudioFormat are used for the comparison.

PySide2.QtMultimedia.QAudioFormat.sampleRate()
Return type

int

Returns the current sample rate in Hertz.

See also

setSampleRate()

PySide2.QtMultimedia.QAudioFormat.sampleSize()
Return type

int

Returns the current sample size value, in bits.

PySide2.QtMultimedia.QAudioFormat.sampleType()
Return type

SampleType

Returns the current SampleType value.

See also

setSampleType()

PySide2.QtMultimedia.QAudioFormat.setByteOrder(byteOrder)
Parameters

byteOrderEndian

Sets the byteOrder to byteOrder .

See also

byteOrder()

PySide2.QtMultimedia.QAudioFormat.setChannelCount(channelCount)
Parameters

channelCount – int

Sets the channel count to channels .

See also

channelCount()

PySide2.QtMultimedia.QAudioFormat.setCodec(codec)
Parameters

codec – str

Sets the codec to codec .

The parameter to this function should be one of the types reported by the supportedCodecs() function for the audio device you are working with.

PySide2.QtMultimedia.QAudioFormat.setSampleRate(sampleRate)
Parameters

sampleRate – int

Sets the sample rate to samplerate Hertz.

See also

sampleRate()

PySide2.QtMultimedia.QAudioFormat.setSampleSize(sampleSize)
Parameters

sampleSize – int

Sets the sample size to the sampleSize specified, in bits.

This is typically 8 or 16, but some systems may support higher sample sizes.

See also

sampleSize()

PySide2.QtMultimedia.QAudioFormat.setSampleType(sampleType)
Parameters

sampleTypeSampleType

Sets the sampleType to sampleType .

See also

sampleType()