python - PyQt5 setPlaybackRate

Question

from PyQt5 import QtCore, QtGui, QtWidgets, QtMultimedia
from PyQt5.QtCore import QByteArray
from PyQt5.QtMultimedia import QAudioDecoder

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(246, 134)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
        
        self.start_mp3(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        
    def start_mp3(self,MainWindow):
        self.output_devices_qt = QtMultimedia.QAudioDeviceInfo.availableDevices(QtMultimedia.QAudio.AudioOutput)
        file_path = r"C:\Users\Χρήστος\Desktop\Papinhio player\project\disket box\mp3 files\ΑΓΙΑ ΚΥΡΙΑΚΗ.mp3"
        self.decode_test_sound(file_path,MainWindow)

    def decode_test_sound(self,file_path,MainWindow):
        self.desiredFormat = QtMultimedia.QAudioFormat()
        self.desiredFormat.setCodec("audio/pcm")
        self.desiredFormat.setSampleRate(44100)
        self.desiredFormat.setChannelCount(1)
        self.desiredFormat.setSampleSize(16)
        self.desiredFormat.setByteOrder(QtMultimedia.QAudioFormat.LittleEndian)
        self.desiredFormat.setSampleType(QtMultimedia.QAudioFormat.SignedInt)
        
        self.m_buffer = QByteArray()
        self.m_buffer_copy = QByteArray()
        
        self.decoder = QAudioDecoder()
        self.decoder.bufferReady.connect(lambda:self.readBuffer(MainWindow))
        self.decoder.setAudioFormat(self.desiredFormat)
        self.decoder.setSourceFilename(file_path)   
        self.decoder.start()
        
        self.play_status = 0
        
    def readBuffer(self,MainWindow):
        buffer = self.decoder.read()
        count = buffer.byteCount()
        if(count>0):
            buffer_data = buffer.constData().asstring(count)
            self.m_buffer.append(buffer_data)
            if(self.play_status!=1):
                self.start_player(MainWindow)
                self.play_status = 1
        else:
            return 1
            
    def timeToSize_1(self):
        return ((self.desiredFormat.channelCount() * (self.desiredFormat.sampleSize() / 8) * self.desiredFormat.sampleRate()) * self.m_time_to_buffer / 1000)
    
    def timeToSize_2(self):

        return ((self.desiredFormat.channelCount() * (self.desiredFormat.sampleSize() / 8) * self.desiredFormat.sampleRate()) * self.MAX_BUFFERED_TIME / 1000)
    
            
    def preplay(self,MainWindow):
        if(self.play_status!=0):
            if(self.m_play_called==False):
                self.m_play_called = True
                self.timer = QtCore.QTimer(MainWindow)
                self.timer.setSingleShot(True)
                self.timer.singleShot(0,lambda:self.sound_mp3(MainWindow))
            
    def sound_mp3(self,MainWindow):
        if(self.play_status!=0):
            self.m_play_called = False
            if self.m_buffer.isEmpty():
                self.stop_player(MainWindow)
                self.m_buffer_requested = True
                return
            elif self.m_buffer.size() < self.m_size_to_buffer:
                if self.m_buffer_requested:
                    return
            else:
                self.m_buffer_requested = False
                
            readlen = int(self.m_audio_output.periodSize())
            chunks = int(self.m_audio_output.bytesFree() / readlen)
            
            
            while (chunks>0):
                samples = self.m_buffer.mid(0, readlen)
                len = samples.size()
                self.m_buffer.remove(0, len)
                if (len>0):
                    if(self.m_audio_output.state()!=2):
                        self.m_output_device.write(samples)
                    else:
                        return 1

                if (len != readlen):
                    break

                chunks = chunks - 1
    
    def start_player(self,MainWindow):
        self.m_play_called = False
        self.m_buffer_requested = True
        self.m_time_to_buffer = 50
        self.MAX_BUFFERED_TIME = 100
        
        if (self.desiredFormat.sampleRate() >= 44100):
            self.internal_buffer_size = (1024 * 10) * self.desiredFormat.channelCount()
        elif (self.desiredFormat.sampleRate() >= 24000):
            self.internal_buffer_size = (1024 * 6) * self.desiredFormat.channelCount()
        else:
            self.internal_buffer_size = (1024 * 4) * self.desiredFormat.channelCount()
            
        #self.m_audio_output = QtMultimedia.QAudioOutput(self.output_devices_qt[self.output_device_index], self.desiredFormat)
        self.m_audio_output = QtMultimedia.QAudioOutput(self.output_devices_qt[0], self.desiredFormat)
        self.m_audio_output.setBufferSize(self.internal_buffer_size)
        
        self.m_size_to_buffer = int(self.timeToSize_1())
        
        self.m_max_size_to_buffer = self.m_size_to_buffer + int(self.timeToSize_2())
        
        self.m_output_device = self.m_audio_output.start()
        
        self.timer_play = QtCore.QTimer(MainWindow)
        self.timer_play.setTimerType(QtCore.Qt.PreciseTimer)
        self.timer_play.timeout.connect(lambda:self.preplay(MainWindow))
        self.timer_play.start(10)
        
    def stop_player(self,MainWindow):
        self.play_status = 0
        self.m_audio_output.stop()
        self.timer_play.stop()

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    app.addLibraryPath(r"C:/Users/Χρήστος/AppData/Local/Programs/Python/Python38/Lib/site-packages/pyqt5_tools/Qt/plugins")
    app.addLibraryPath(r"C:/Users/Χρήστος/AppData/Local/Programs/Python/Python38/lib/site-packages/PyQt5/Qt/plugins")   
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

上面的代码运行良好。 要运行代码，您必须更改 3 行：24,143 和 144。 我想要：

1. 设置播放率我搜索类似的东西QtMultimedia.QMediaPlayer().setPlaybackRate(QReal)
2. 通知 i 函数以更改 QSlider（计时器）

我该怎么做1和2？

我正在尝试在我选择的输出设备中播放 mp3 文件。然后我希望能够管理音量、声速和声音位置（实时）。最后，我想为无线电流混合一些 mp3 QByteArray

我认为上述方法是正确的，因为我想为广播流混合一些 mp3 文件。

标签： pythonpyqt5