python - 如何在 Python VLC MediaPlayer 中使用 QFile
问题描述
我可以wav
使用以下代码简单地从文件中播放文件:
media = vlc.MediaPlayer('c.wav')
media.audio_set_volume(50)
media.play()
我怎样才能对 qrc 资源文件做同样的事情?我尝试了这段代码,但似乎不起作用:
mediafile = QFile(':/sounds/c.wav')
media = vlc.Instance().media_player_new()
media.set_media(mediafile)
media.audio_set_volume(50)
media.play()
解决方案
您需要为此使用vlc.media_new_callbacks,以便您可以包装QFile
并使用其方法。下面是一个演示脚本,展示了如何实现它:
import sys, vlc
from PyQt5.QtCore import QFile, QCoreApplication
@vlc.CallbackDecorators.MediaOpenCb
def open_cb(opaque, data, size):
data.contents.value = opaque
size.value = sys.maxsize
return 0
@vlc.CallbackDecorators.MediaReadCb
def read_cb(opaque, buffer, length):
data = qfile.read(length)
for index, char in enumerate(data):
buffer[index] = char
return len(data)
@vlc.CallbackDecorators.MediaSeekCb
def seek_cb(opaque, offset):
qfile.seek(offset)
return 0
@vlc.CallbackDecorators.MediaCloseCb
def close_cb(opaque):
qfile.close()
if __name__ == '__main__':
import time, signal
signal.signal(signal.SIGINT, signal.SIG_DFL)
print('Press Ctrl+C to Quit')
player = vlc.Instance().media_player_new()
qfile = QFile(sys.argv[1])
qfile.open(QFile.ReadOnly)
player.set_media(vlc.Instance().media_new_callbacks(
open_cb, read_cb, seek_cb, close_cb, None))
player.play()
app = QCoreApplication(sys.argv)
app.exec_()
更新:
在更典型的 PyQt 应用程序中让它正常工作有点棘手,因为回调必须是静态函数。这是一个扩展示例,显示了如何完成:
import sys, ctypes, vlc
from PyQt5 import QtCore, QtWidgets
class VLCPlayer(QtCore.QObject):
def __init__(self, parent=None):
super().__init__()
self._player = vlc.Instance().media_player_new()
@staticmethod
@vlc.CallbackDecorators.MediaOpenCb
def _open_cb(voidptr, data, size):
data.contents.value = voidptr
size.value = sys.maxsize
return 0
@staticmethod
@vlc.CallbackDecorators.MediaReadCb
def _read_cb(voidptr, buffer, length):
stream = ctypes.cast(
voidptr, ctypes.POINTER(ctypes.py_object)).contents.value
data = stream.read(length)
for index, char in enumerate(data):
buffer[index] = char
return len(data)
@staticmethod
@vlc.CallbackDecorators.MediaSeekCb
def _seek_cb(voidptr, offset):
stream = ctypes.cast(
voidptr, ctypes.POINTER(ctypes.py_object)).contents.value
stream.seek(offset)
return 0
@staticmethod
@vlc.CallbackDecorators.MediaCloseCb
def _close_cb(voidptr):
stream = ctypes.cast(
voidptr, ctypes.POINTER(ctypes.py_object)).contents.value
stream.close()
def play(self):
self._player.play()
def stop(self):
self._player.stop()
def load(self, path):
file = QtCore.QFile(path)
file.open(QtCore.QIODevice.ReadOnly)
voidptr = ctypes.cast(ctypes.pointer(
ctypes.py_object(file)), ctypes.c_void_p)
self._player.set_media(vlc.Instance().media_new_callbacks(
self._open_cb, self._read_cb,
self._seek_cb, self._close_cb, voidptr))
class Window(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.buttonPlay = QtWidgets.QPushButton('Play')
self.buttonPlay.clicked.connect(self.handlePlay)
self.buttonStop = QtWidgets.QPushButton('Stop')
self.buttonStop.clicked.connect(self.handleStop)
self.buttonOpen = QtWidgets.QPushButton('Open')
self.buttonOpen.clicked.connect(self.handleOpen)
layout = QtWidgets.QHBoxLayout(self)
layout.addWidget(self.buttonOpen)
layout.addWidget(self.buttonPlay)
layout.addWidget(self.buttonStop)
self.player = VLCPlayer(self)
def handlePlay(self):
self.player.play()
def handleStop(self):
self.player.stop()
def handleOpen(self):
path, ok = QtWidgets.QFileDialog.getOpenFileName(
self, filter='Audio Files (*.wav)')
if ok:
self.player.load(path)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.setWindowTitle('VLC Player')
window.setGeometry(600, 100, 200, 80)
window.show()
sys.exit(app.exec_())
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