Fix QThread

[MAX001]

Please help me understand why nothing is happening, no errors are displayed, and the video is not displayed (((
I have two files, it seems to me that in video.py, since I only run the constructor, it builds and exits and nothing happens.
But how can I start a Thread from another file.

video.py

from object_detection.video_detector import *
import os

videoPath = ""

def main_video_obj(videoPath, grid_video_detect, video_play_btn, video_stop_btn):
    rootDirectory = os.path.dirname(__file__)
   
    configPath = os.path.join(rootDirectory, "data", "ssd_mobilenet_v3_large_coco_2020_01_14.pbtxt")
    modelPath = os.path.join(rootDirectory, "data", "frozen_inference_graph.pb")
    classesPath = os.path.join(rootDirectory, "data", "coco.names")

    Video_Detector_obj(videoPath[0], configPath, modelPath, classesPath, grid_video_detect, video_play_btn, video_stop_btn)

if __name__== '__main__':
    main_video_obj()

video_detector.py

class Video_Detector_obj(QWidget): 
    def __init__(self, videoPath, configPath, modelPath, classesPath, grid_video_detect, video_play_btn, video_stop_btn):
        super().__init__()
        self.videoPath = videoPath
        self.configPath = configPath
        self.modelPath = modelPath
        self.classesPath = classesPath
        self.video_play_btn = video_play_btn
        self.video_stop_btn = video_stop_btn



        self.load_video = QLabel()

        self.th = Thread()
        self.th.finished.connect(self.close)
        self.th.updateFrame.connect(self.setImage)

        
        grid_video_detect.addWidget(self.load_video, 0, 1)


        video_play_btn.clicked.connect(self.start)
        video_stop_btn.clicked.connect(self.kill_thread)
        video_stop_btn.setEnabled(False)



    @Slot()
    def kill_thread(self):
        print("Finishing...")
        self.video_play_btn.setEnabled(True)
        self.video_stop_btn.setEnabled(False)
        self.th.cap.release()
        cv2.destroyAllWindows()
        self.status = False
        self.th.terminate()
        time.sleep(1)

    @Slot()
    def start(self):
        print("Starting...")
        self.video_play_btn.setEnabled(False)
        self.video_stop_btn.setEnabled(True)
        self.th.set_files(self.videoPath, self.configPath, self.modelPath, self.classesPath)
        self.th.start()

    @Slot(QImage)
    def setImage(self, image):
        self.load_video.setPixmap(QPixmap.fromImage(image))





class Thread(QThread):
    updateFrame = Signal(QImage)

    def __init__(self, parent = None):
        QThread.__init__(self, parent)
        #self.trained_file = None
        self.status = True
        self.cap = True
        self.videoPath = None
        self.configPath = None
        self.modelPath = None
        self.classesPath = None



    def set_files(self, videoPath, configPath, modelPath, classesPath):
        self.videoPath = videoPath
        self.configPath = configPath
        self.modelPath = modelPath
        self.classesPath = classesPath

        self.net = cv2.dnn_DetectionModel(self.modelPath, self.configPath)
        self.net.setInputSize(320, 320)
        self.net.setInputScale(1.0/127.5)
        self.net.setInputMean((127.5, 127.5, 127.5))
        self.net.setInputSwapRB(True)

        self.readClasses()

    def readClasses(self):
        with open(self.classesPath, 'r') as f:
            self.classesList = f.read().splitlines()
        
        self.classesList.insert(0, '__Background__')

        self.colorList = np.random.uniform(low=0, high=255, size=(len(self.classesList), 3))
        
        print(self.classesList)


    def run(self):
        self.cap = cv2.VideoCapture(self.videoPath)
        if (self.cap.isOpened()==False):
            print("Error opening file...")
            return

        startTime = 0
        while self.status:
            ret, frame = self.cap.read()
            if not ret:
                continue

            currentTime = time.time()
            fps = 1/(currentTime - startTime)
            startTime = currentTime
            classLabelIDs, confidences, bboxs =  self.net.detect(frame, confThreshold = 0.5)

            bboxs = list(bboxs)
            confidences = list(np.array(confidences).reshape(1,-1)[0])
            confidences = list(map(float, confidences))

            bboxIdx = cv2.dnn.NMSBoxes(bboxs, confidences, score_threshold = 0.5, nms_threshold = 0.2)

            if len(bboxIdx) != 0:
                    for i in range(0, len(bboxIdx)):

                        bbox = bboxs[np.squeeze(bboxIdx[i])]
                        classConfidence = confidences[np.squeeze(bboxIdx[i])]
                        classLabelID = np.squeeze(classLabelIDs[np.squeeze(bboxIdx[i])])
                        classLabel = self.classesList[classLabelID]
                        classColor = [int(c) for c in self.colorList[classLabelID]]

                        displayText = "{}:{:.2f}".format(classLabel, classConfidence)

                        x,y,w,h = bbox

                        cv2.rectangle(frame, (x,y), (x+w, y+h), color=classColor, thickness=1)
                        cv2.putText(frame, displayText, (x, y-10), cv2.FONT_HERSHEY_PLAIN, 1, classColor, 2)

            cv2.putText(frame, "FPS: " + str(int(fps)), (20, 70), cv2.FONT_HERSHEY_PLAIN, 2, (0, 255, 0), 2)
            #cv2.imshow("Result", image)

            color_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)

            
            color_frame = imutils.resize(frame, width = 1500)
            h, w, ch = color_frame.shape
            image = QImage(color_frame.data, w, h, ch * w, QImage.Format_RGB888)

            self.updateFrame.emit(image)
        cv2.destroyAllWindows()
        sys.exit(-1)

[SGaist]

Hi,

You don't create a QApplication object, you don't start the main event loop, you don't show your widget.

[MAX001]

@SGaist I have them in the separate file. From that file I pass buttons and grid_video_detect to video.py and video_detector.py files.

[SGaist]

What other file ?

[MAX001]

@SGaist All ui functionality.

[SGaist]

Please make a minimal script that uses your custom thread and a label so it can be checked and tested.

[JonB]

@MAX001
Confirm that setImage(self, image) is indeed called, and with correct image converted to QPixmap?

[MAX001]

@SGaist
video.py file

from object_detection.video_detector import *
import os

videoPath = ""

def main_video_obj(videoPath, grid_video_detect, video_play_btn, video_stop_btn):
    rootDirectory = os.path.dirname(__file__)
    
    configPath = os.path.join(rootDirectory, "data", "ssd_mobilenet_v3_large_coco_2020_01_14.pbtxt")
    modelPath = os.path.join(rootDirectory, "data", "frozen_inference_graph.pb")
    classesPath = os.path.join(rootDirectory, "data", "coco.names")

    Video_Detector_obj(videoPath[0], configPath, modelPath, classesPath, grid_video_detect, video_play_btn, video_stop_btn)
    #detector.onVideo(grid_video_detect)

if __name__== '__main__':
    main_video_obj()

video_detector.py file

class Video_Detector_obj(QWidget): 
    def __init__(self, videoPath, configPath, modelPath, classesPath, grid_video_detect, video_play_btn, video_stop_btn):
        super().__init__()
        self.videoPath = videoPath
        self.configPath = configPath
        self.modelPath = modelPath
        self.classesPath = classesPath



        self.load_video = QLabel()

        self.th = Thread()
        self.th.finished.connect(self.close)
        self.th.updateFrame.connect(self.setImage)

        
        grid_video_detect.addWidget(self.load_video, 0, 1)


        video_play_btn.clicked.connect(self.start)
        video_stop_btn.clicked.connect(self.kill_thread)
        video_stop_btn.setEnabled(False)



    @Slot()
    def kill_thread(self):
        print("Finishing...")
        self.video_play_btn.setEnabled(True)
        self.video_stop_btn.setEnabled(False)
        self.th.cap.release()
        cv2.destroyAllWindows()
        self.status = False
        self.th.terminate()
        time.sleep(1)

    @Slot()
    def start(self):
        print("Starting...")
        self.video_play_btn.setEnabled(False)
        self.video_stop_btn.setEnabled(True)
        self.th.set_files(self.videoPath, self.configPath, self.modelPath, self.classesPath)
        self.th.start()

    @Slot(QImage)
    def setImage(self, image):
        self.load_video.setPixmap(QPixmap.fromImage(image))


class Thread(QThread):
    updateFrame = Signal(QImage)

    def __init__(self, parent = None):
        QThread.__init__(self, parent)
        self.status = True
        self.cap = True


    def set_files(self, videoPath, configPath, modelPath, classesPath):
        self.videoPath = videoPath
        self.configPath = configPath
        self.modelPath = modelPath
        self.classesPath = classesPath

    def run(self):
        self.cap = cv2.VideoCapture(0)

        startTime = 0
        while self.status:
            ret, frame = self.cap.read()
            if not ret:
                continue

            currentTime = time.time()
            fps = 1/(currentTime - startTime)
            startTime = currentTime
            classLabelIDs, confidences, bboxs =  self.net.detect(frame, confThreshold = 0.5)

            bboxs = list(bboxs)
            confidences = list(np.array(confidences).reshape(1,-1)[0])
            confidences = list(map(float, confidences))

            bboxIdx = cv2.dnn.NMSBoxes(bboxs, confidences, score_threshold = 0.5, nms_threshold = 0.2)

            if len(bboxIdx) != 0:
                    for i in range(0, len(bboxIdx)):

                        bbox = bboxs[np.squeeze(bboxIdx[i])]
                        classConfidence = confidences[np.squeeze(bboxIdx[i])]
                        classLabelID = np.squeeze(classLabelIDs[np.squeeze(bboxIdx[i])])
                        classLabel = self.classesList[classLabelID]
                        classColor = [int(c) for c in self.colorList[classLabelID]]

                        displayText = "{}:{:.2f}".format(classLabel, classConfidence)

            #cv2.imshow("Result", image)

            color_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)

            h, w, ch = color_frame.shape
            image = QImage(color_frame.data, w, h, ch * w, QImage.Format_RGB888)

            self.updateFrame.emit(image)
        sys.exit(-1)

Something like that, there may be errors with object class files.
If they interfere, you can remove them. It will be great if you can run class Thread in video.py.
It is possible without a detector, the main thing is that the camera appears
Later I will add those object class files to the run function.

[MAX001]

This post is deleted!

[ChrisW67]

You are calling main_video_obj() without arguments, and passing the missing arguments on to the Video_Detector_obj() constructor. I guess in Python this makes the arguments None.

[MAX001]

@SGaist Thanks, I already solved the issue, a stupid mistake was enough, I didn’t pass a button from ui, but self.button, so the Qthread didn’t start.
But now it remembers previous video witch I import, and starts also a new one.
Maybe I need Qt.ConnectionType.SingleShotConnection but where to write it )))
Or somehow reload QLabel or clear previous video

[SGaist]

I don't see a reason for a single shot connection.

Implement proper clearing of the label, configuration of your detector, etc.

You really should write down the various workflows of your application.