我有一个应用程序，旨在帮助同步实验视频和数据信号。该应用程序有一个视频小部件和一个滑块，可以设置视频的时间位置。然而，QMediaPlayer 只会以 500 毫秒/1000 毫秒的间隔设置位置（在我的应用程序中为 500 毫秒/在设计的应用程序中为 1000 毫秒），而视频以 50 fps 拍摄，意味着 20 毫秒的间隔。这使得同步变得毫无用处。我添加了位置更改之前和之后位置的输出。
任何帮助，将不胜感激。
这是更改滑块时的输出：
New slider position 326
Media player updated position 0
New slider position 816
Media player updated position 0
New slider position 1306
Media player updated position 0
New slider position 1632
Media player updated position 1000
New slider position 1959
Media player updated position 1000
New slider position 2449
Media player updated position 2000
New slider position 2938
Media player updated position 2000
New slider position 3428
Media player updated position 2000
New slider position 3755
Media player updated position 3000
New slider position 4081
Media player updated position 3000
New slider position 4571
Media player updated position 4000
New slider position 4897
Media player updated position 4000
New slider position 5224
Media player updated position 4000
New slider position 5550
Media player updated position 5000
New slider position 5714
Media player updated position 5000
New slider position 6040
Media player updated position 5000
New slider position 6203
Media player updated position 6000
New slider position 6530
我还尝试设置从 mediaPlayer.position () 检索到的特定位置，但无济于事。
这是设计的应用程序：
import sys
from PyQt5 import QtWidgets
from PyQt5.QtCore import QSize, Qt, QUrl
from PyQt5.QtMultimedia import QMediaContent, QMediaPlayer
from PyQt5.QtMultimediaWidgets import QVideoWidget
from PyQt5.QtWidgets import QMainWindow, QLabel, QWidget, QSlider
from PyQt5.QtWidgets import QVBoxLayout, QHBoxLayout
#
# Reference https://pythonprogramminglanguage.com/pyqt5-video-widget/
#
class MainWindow (QMainWindow):
def __init__ (self, parent=None):
super (QMainWindow, self).__init__ (parent)
#
# Set the filename here
#
filename = '/Users/yuval/src/lab/S4560001.MP4'
self.setMinimumSize (QSize (640, 480))
self.setWindowTitle ('Video & Data Viewer and Annotator')
self.mediaPlayer = QMediaPlayer (None, QMediaPlayer.VideoSurface)
videoWidget = QVideoWidget ()
videoWidget.setMinimumSize (640,200)
#
# Position Slider
#
self.positionSlider = QSlider (Qt.Horizontal)
self.positionSlider.setRange (0, 0)
self.positionSlider.sliderMoved.connect (self.setPosition)
#
# Position Label
#
self.positionLabel = QLabel ('00:00:000')
centralWidget = QWidget (self)
self.setCentralWidget (centralWidget)
#
# Layout the Control Widgets
#
ctlLayout = QHBoxLayout ()
ctlLayout.setContentsMargins (0, 0, 0, 0)
ctlLayout.addWidget (self.positionSlider)
ctlLayout.addWidget (self.positionLabel)
#
# Layout the Window
#
layout = QVBoxLayout ()
layout.addWidget (videoWidget)
layout.addLayout (ctlLayout)
centralWidget.setLayout (layout)
self.mediaPlayer.setVideoOutput (videoWidget)
self.mediaPlayer.positionChanged.connect (self.positionChanged)
self.mediaPlayer.durationChanged.connect (self.durationChanged)
self.mediaPlayer.error.connect (self.handleError)
self.mediaPlayer.setNotifyInterval (100)
self.mediaPlayer.setMuted (True)
print (filename)
if filename != '':
self.mediaPlayer.setMedia (
QMediaContent (QUrl.fromLocalFile (filename)))
def positionChanged (self, position):
self.positionSlider.setValue (position)
def durationChanged (self, duration):
self.positionSlider.setRange (0, duration)
def setPosition (self, position):
print (f'New slider position {position}')
self.mediaPlayer.setPosition (position)
print (f'Media player updated position {self.mediaPlayer.position ()}')
def handleError (self):
print ('Error: ' + self.mediaPlayer.errorString ())
if __name__ == '__main__':
app = QtWidgets.QApplication (sys.argv)
mainWin = MainWindow ()
mainWin.show ()
sys.exit (app.exec_ ())
我在 MacOS 10.14.16 (Mojave) 上运行。
Python 3.7.4
Python 包：
PyQt5==5.13.0
PyQt5-sip==4.19.18
端口包：
py37-pyqt5 @5.12.2_0（活动）
qt5 @5.12.4_0（活动）
