audio.py

"""PySide6 port of the charts/audio example from Qt v5.x"""

import sys
from PySide6.QtCharts import QChart, QChartView, QLineSeries, QValueAxis
from PySide6.QtCore import QPointF
from PySide6.QtMultimedia import (QAudioDeviceInfo, QAudioFormat,
        QAudioInput)
from PySide6.QtWidgets import QApplication, QMainWindow, QMessageBox

sampleCount = 2000
resolution = 4

class MainWindow(QMainWindow):
    def __init__(self, device):
        super(MainWindow, self).__init__()

        self.series = QLineSeries()
        self.chart = QChart()
        self.chart.addSeries(self.series)
        self.axisX = QValueAxis()
        self.axisX.setRange(0, sampleCount)
        self.axisX.setLabelFormat("%g")
        self.axisX.setTitleText("Samples")
        self.axisY = QValueAxis()
        self.axisY.setRange(-1, 1)
        self.axisY.setTitleText("Audio level")
        self.chart.setAxisX(self.axisX, self.series)
        self.chart.setAxisY(self.axisY, self.series)
        self.chart.legend().hide()
        self.chart.setTitle("Data from the microphone ({})".format(device.deviceName()))

        formatAudio = QAudioFormat()
        formatAudio.setSampleRate(8000)
        formatAudio.setChannelCount(1)
        formatAudio.setSampleSize(8)
        formatAudio.setCodec("audio/pcm")
        formatAudio.setByteOrder(QAudioFormat.LittleEndian)
        formatAudio.setSampleType(QAudioFormat.UnSignedInt)

        self.audioInput = QAudioInput(device, formatAudio, self)
        self.ioDevice = self.audioInput.start()
        self.ioDevice.readyRead.connect(self._readyRead)

        self.chartView = QChartView(self.chart)
        self.setCentralWidget(self.chartView)

        self.buffer = [QPointF(x, 0) for x in range(sampleCount)]
        self.series.append(self.buffer)

    def closeEvent(self, event):
        if self.audioInput is not None:
            self.audioInput.stop()
        event.accept()

    def _readyRead(self):
        data = self.ioDevice.readAll()
        availableSamples = data.size() // resolution
        start = 0
        if (availableSamples < sampleCount):
            start = sampleCount - availableSamples
            for s in range(start):
                self.buffer[s].setY(self.buffer[s + availableSamples].y())

        dataIndex = 0
        for s in range(start, sampleCount):
            value = (ord(data[dataIndex]) - 128) / 128
            self.buffer[s].setY(value)
            dataIndex = dataIndex + resolution
        self.series.replace(self.buffer)

if __name__ == '__main__':
    app = QApplication(sys.argv)

    inputDevice = QAudioDeviceInfo.defaultInputDevice()
    if (inputDevice.isNull()):
        QMessageBox.warning(None, "audio", "There is no audio input device available.")
        sys.exit(-1)

    mainWin = MainWindow(inputDevice)
    mainWin.setWindowTitle("audio")
    availableGeometry = app.desktop().availableGeometry(mainWin)
    size = availableGeometry.height() * 3 / 4
    mainWin.resize(size, size)
    mainWin.show()
    sys.exit(app.exec_())