在 PyQt 上的 QVideoWidget 容器中，您需要从计算机启动视频，通过 TensorFlow(openCV、cv2)在该视频上搜索对象。问题是，当按下按钮时，视频只显示一帧，没有其他内容。可能是什么问题呢？由 PyCharm、Python 3.7 制成。
from PyQt5 import QtCore, QtGui, QtWidgets, uiс
import os
import cv2
import numpy as np
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QLabel, QVBoxLayout
from PyQt5.QtCore import QThread, pyqtSignal, Qt
from PyQt5.QtGui import QImage, QPixmap
class ThreadOpenCV(QThread):
changePixmap = pyqtSignal(QImage)
def __init__(self, source):
super().__init__()
def run(self):
# MODEL_NAME = 'inference_graph'
VIDEO_NAME = '20201024161726.mp4'
#
# # Grab path to current working directory
CWD_PATH = os.getcwd()
PATH_TO_VIDEO = os.path.join(CWD_PATH, VIDEO_NAME)
cap = cv2.VideoCapture(PATH_TO_VIDEO)
while True:
ret, frame = cap.read()
if ret:
frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
frame_expanded = np.expand_dims(frame_rgb, axis=0)
rgbImage = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
h, w, ch = rgbImage.shape
bytesPerLine = ch * w
convertToQtFormat = QImage(rgbImage.data, w, h, bytesPerLine, QImage.Format_RGB888)
p = convertToQtFormat.scaled(640, 480, Qt.KeepAspectRatio)
self.changePixmap.emit(p)
if cv2.waitKey(1) == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
class Widget(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
uic.loadUi('fire_detection.ui', self)
self.show()
self.label_video = QLabel()
layout = QVBoxLayout()
layout.addWidget(self.label_video)
self.widget.setLayout(layout)
self.thread = ThreadOpenCV('20201024161726.mp4')
self.thread.changePixmap.connect(self.setImage)
self.btn1.clicked.connect(self.playVideo)
def playVideo(self):
self.thread.start()
def setImage(self, image):
self.label_video.setPixmap(QPixmap.fromImage(image))
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
mw = Widget()
mw.show()
sys.exit(app.exec_())
最佳答案
所有问题都是因为您的缩进错误 - 并且您在 while 循环内运行 cap.release() ，因此它在第一帧后释放流。
while True:
ret, frame = cap.read()
if ret:
frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
frame_expanded = np.expand_dims(frame_rgb, axis=0)
rgbImage = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
h, w, ch = rgbImage.shape
bytesPerLine = ch * w
convertToQtFormat = QImage(rgbImage.data, w, h, bytesPerLine, QImage.Format_RGB888)
p = convertToQtFormat.scaled(640, 480, Qt.KeepAspectRatio)
self.changePixmap.emit(p)
# --- after `while` ---
cap.release()
您没有在cv2中创建窗口，因此您也没有cv2.destroyAllWindows()。
并且 cv2.waitKey(1) 也将毫无用处，因为系统仅在显示窗口且该窗口处于事件状态(获得焦点)时才向 cv2 发送键/鼠标事件。
编辑:
完整的工作代码。它使用网络摄像头。
它不需要 UI 文件。
它有启动和停止流媒体的按钮，
它还有切换按钮:RGB <-> 灰度、正常 <-> 模糊。
import os
import sys
import numpy as np
import cv2
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import Qt, QThread, pyqtSignal
from PyQt5.QtWidgets import QLabel, QVBoxLayout, QPushButton, QWidget
from PyQt5.QtGui import QImage, QPixmap
class ThreadOpenCV(QThread):
changePixmap = pyqtSignal(QImage)
def __init__(self, source):
super().__init__()
self.source = source
self.running = True
self.grayscale = False
self.blur = False
def run(self):
print('start')
cap = cv2.VideoCapture(self.source)
self.running = True
while self.running:
ret, frame = cap.read()
if ret:
if self.grayscale:
frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
frame = cv2.cvtColor(frame, cv2.COLOR_GRAY2RGB)
else:
frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
if self.blur:
frame = cv2.blur(frame, (15, 15))
h, w, ch = frame.shape
bytes_per_line = ch * w # PEP8: `lower_case_names` for variables
image = QImage(frame.data, w, h, bytes_per_line, QImage.Format_RGB888)
image = image.scaled(640, 480, Qt.KeepAspectRatio)
self.changePixmap.emit(image)
cap.release()
print('stop')
def stop(self):
self.running = False
class Widget(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
# MODEL_NAME = 'inference_graph'
VIDEO_NAME = '20201024161726.mp4'
CWD_PATH = os.getcwd()
PATH_TO_VIDEO = os.path.join(CWD_PATH, VIDEO_NAME)
# webcam
PATH_TO_VIDEO = 0
self.thread = ThreadOpenCV(PATH_TO_VIDEO)
self.thread.changePixmap.connect(self.setImage)
layout = QVBoxLayout()
self.label_video = QLabel()
layout.addWidget(self.label_video)
self.btn1 = QPushButton("PLAY")
self.btn1.clicked.connect(self.playVideo)
layout.addWidget(self.btn1)
self.btn_stop = QPushButton("STOP")
self.btn_stop.clicked.connect(self.stopVideo)
layout.addWidget(self.btn_stop)
self.btn_gray = QPushButton("RGB <-> GRAYSCALE")
self.btn_gray.clicked.connect(self.grayVideo)
layout.addWidget(self.btn_gray)
self.btn_blur = QPushButton("NORMAL <-> BLURED")
self.btn_blur.clicked.connect(self.blurVideo)
layout.addWidget(self.btn_blur)
self.widget = QWidget()
self.widget.setLayout(layout)
self.setCentralWidget(self.widget)
def playVideo(self):
self.thread.start()
def stopVideo(self):
self.thread.running = False
def grayVideo(self):
self.thread.grayscale = not self.thread.grayscale
def blurVideo(self):
self.thread.blur = not self.thread.blur
def setImage(self, image):
self.label_video.setPixmap(QPixmap.fromImage(image))
if __name__ == '__main__':
app = QtWidgets.QApplication([])
mw = Widget()
mw.show()
app.exec()
RGB，正常:
灰度、模糊:
关于python - 如何在 PyQt 容器中运行视频？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/67488022/