QAudioFormat

The QAudioFormat class stores audio stream parameter information. More…

Synopsis

Functions

• def __eq__ (other)

• def __ne__ (other)

• def byteOrder ()

• def bytesForDuration (duration)

• def bytesForFrames (frameCount)

• def bytesPerFrame ()

• def channelCount ()

• def codec ()

• def durationForBytes (byteCount)

• def durationForFrames (frameCount)

• def framesForBytes (byteCount)

• def framesForDuration (duration)

• def isValid ()

• def sampleRate ()

• def sampleSize ()

• def sampleType ()

• def setByteOrder (byteOrder)

• def setChannelCount (channelCount)

• def setCodec (codec)

• def setSampleRate (sampleRate)

• def setSampleSize (sampleSize)

• def setSampleType (sampleType)

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:

• sampleRate() = -1

• channelCount() = -1

• sampleSize() = -1

• byteOrder() = Endian ( ByteOrder )

• sampleType() = Unknown codec() = “”

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() .

See also

durationForBytes()

PySide2.QtMultimedia.QAudioFormat.bytesForFrames(frameCount)

Parameters:

frameCount – qint32

Return type:

qint32

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

Returns 0 if this format is not valid.

See also

bytesForDuration()

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.

See also

setChannelCount()

PySide2.QtMultimedia.QAudioFormat.codec()

Return type:

str

Returns the current codec identifier.

See also

setCodec() supportedCodecs()

PySide2.QtMultimedia.QAudioFormat.durationForBytes(byteCount)

Parameters:

byteCount – qint32

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.

See also

bytesForDuration()

PySide2.QtMultimedia.QAudioFormat.durationForFrames(frameCount)

Parameters:

frameCount – qint32

Return type:

int

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

PySide2.QtMultimedia.QAudioFormat.framesForBytes(byteCount)

Parameters:

byteCount – qint32

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.

See also

framesForDuration()

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:

other – PySide2.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:

other – PySide2.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.

See also

setSampleSize() bytesPerFrame()

PySide2.QtMultimedia.QAudioFormat.sampleType()

Return type:

SampleType

Returns the current SampleType value.

See also

setSampleType()

PySide2.QtMultimedia.QAudioFormat.setByteOrder(byteOrder)

Parameters:

byteOrder – Endian

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.

See also

codec() supportedCodecs()

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:

sampleType – SampleType

Sets the sampleType to sampleType .

See also

sampleType()