class QAudioBuffer#

The QAudioBuffer class represents a collection of audio samples with a specific format and sample rate. More…

Synopsis#

Methods#

def __init__()
def byteCount()
def duration()
def format()
def frameCount()
def isValid()
def sampleCount()
def startTime()
def swap()

Note

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Detailed Description#

QAudioBuffer is used by the QAudioDecoder class to hand decoded audio data over to the application. An audio buffer contains data in a certain QAudioFormat that can be queried using format() . It is also tagged with timing and duration information.

To access the data stored inside the buffer, use the data() or constData() methods.

Audio buffers are explicitly shared, in most cases, you should call detach() before modifying the data.

__init__()#

Create a new, empty, invalid buffer.

__init__(other)

Parameters:: other – QAudioBuffer

Creates a new audio buffer from other. Audio buffers are explicitly shared, you should call detach() on the buffer to make a copy that can then be modified.

__init__(data, format[, startTime=-1])

Parameters:

data – QByteArray
format – QAudioFormat
startTime – int

Creates a new audio buffer from the supplied data, in the given format. The format will determine how the number and sizes of the samples are interpreted from the data.

If the supplied data is not an integer multiple of the calculated frame size, the excess data will not be used.

This audio buffer will copy the contents of data.

startTime (in microseconds) indicates when this buffer starts in the stream. If this buffer is not part of a stream, set it to -1.

__init__(numFrames, format[, startTime=-1])

Parameters:

numFrames – int
format – QAudioFormat
startTime – int

Creates a new audio buffer with space for numFrames frames of the given format. The individual samples will be initialized to the default for the format.

startTime (in microseconds) indicates when this buffer starts in the stream. If this buffer is not part of a stream, set it to -1.

byteCount()#

Return type:: int

Returns the size of this buffer, in bytes.

duration()#

Return type:: int

Returns the duration of audio in this buffer, in microseconds.

This depends on the format() , and the frameCount() .

format()#

Return type:: QAudioFormat

Returns the format of this buffer.

Several properties of this format influence how the duration() or byteCount() are calculated from the frameCount() .

frameCount()#

Return type:: int

Returns the number of complete audio frames in this buffer.

An audio frame is an interleaved set of one sample per channel for the same instant in time.

isValid()#

Return type:: bool

Returns true if this is a valid buffer. A valid buffer has more than zero frames in it and a valid format.

sampleCount()#

Return type:: int

Returns the number of samples in this buffer.

If the format of this buffer has multiple channels, then this count includes all channels. This means that a stereo buffer with 1000 samples in total will have 500 left samples and 500 right samples (interleaved), and this function will return 1000.

See also

frameCount()

startTime()#

Return type:: int

Returns the time in a stream that this buffer starts at (in microseconds).

If this buffer is not part of a stream, this will return -1.

swap(other)#

Parameters:: other – QAudioBuffer

Swaps the audio buffer with other.