from math import pi, sin
import struct, sys
from PyQt4.QtCore import QBuffer, QByteArray, QIODevice, Qt
from PyQt4.QtGui import QApplication, QFormLayout, QLineEdit, QHBoxLayout, \
QPushButton, QSlider, QVBoxLayout, QWidget
from PyQt4.QtMultimedia import QAudio, QAudioDeviceInfo, QAudioFormat, QAudioOutput
class Window(QWidget):
def __init__(self, parent = None):
QWidget.__init__(self, parent)
format = QAudioFormat()#存储音频信息
format.setChannels(1)#通道
format.setFrequency(22050)#采样率赫兹
format.setSampleSize(16)#采样大小
format.setCodec("audio/pcm")#设置编解码器的编解码器
format.setByteOrder(QAudioFormat.LittleEndian)
format.setSampleType(QAudioFormat.SignedInt)
self.output = QAudioOutput(format, self)
self.frequency = 440
self.volume = 0
self.buffer = QBuffer()
self.data = QByteArray()
self.deviceLineEdit = QLineEdit()
self.deviceLineEdit.setReadOnly(True)
self.deviceLineEdit.setText(QAudioDeviceInfo.defaultOutputDevice().deviceName())
self.pitchSlider = QSlider(Qt.Horizontal)
self.pitchSlider.setMaximum(100)
self.volumeSlider = QSlider(Qt.Horizontal)
self.volumeSlider.setMaximum(32767)
self.volumeSlider.setPageStep(1024)
self.playButton = QPushButton(self.tr("&Play"))
self.pitchSlider.valueChanged.connect(self.changeFrequency)
self.volumeSlider.valueChanged.connect(self.changeVolume)
self.playButton.clicked.connect(self.play)
formLayout = QFormLayout()
formLayout.addRow(self.tr("Device:"), self.deviceLineEdit)
formLayout.addRow(self.tr("P&itch:"), self.pitchSlider)
formLayout.addRow(self.tr("&Volume:"), self.volumeSlider)
buttonLayout = QVBoxLayout()
buttonLayout.addWidget(self.playButton)
buttonLayout.addStretch()
horizontalLayout = QHBoxLayout(self)
horizontalLayout.addLayout(formLayout)
horizontalLayout.addLayout(buttonLayout)
def changeFrequency(self, value):
self.frequency = 440 + (value * 2)
def play(self):
if self.output.state() == QAudio.ActiveState:
self.output.stop()
if self.buffer.isOpen():
self.buffer.close()
self.createData()
self.buffer.setData(self.data)
self.buffer.open(QIODevice.ReadOnly)
self.buffer.seek(0)
self.output.start(self.buffer)
def changeVolume(self, value):
self.volume = value
def createData(self):
# Create 2 seconds of data with 22050 samples per second, each sample
# being 16 bits (2 bytes).
self.data.clear()
for i in xrange(2 * 22050):
t = i / 22050.0
value = int(self.volume * sin(2 * pi * self.frequency * t))
self.data.append(struct.pack("<h", value))
if __name__ == "__main__":
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
