from PySide2.QtWidgets import QWidget, QLabel, QVBoxLayout, QApplication, QSlider
from PySide2.QtGui import QImage, QPixmap
from PySide2.QtCore import Qt

import mpegCoder
mpegCoder.setGlobal(dumpLevel=0)

class Player(QWidget):
    def __init__(self, parent=None):
        super(Player, self).__init__(parent)
        self._layout = QVBoxLayout(self)
        self.image = QLabel()
        self.slider = QSlider(Qt.Horizontal)
        self.slider.valueChanged.connect(self.extract_frame)
        self._layout.addWidget(self.image)
        self._layout.addWidget(self.slider)
        self.frames = []
        self.open_file()
        
    def close(self):
        self.decoder.clear()
        return super(Player, self).close()
        
    def open_file(self):
        self.decoder = mpegCoder.MpegDecoder()
        self.decoder.setParameter(nthread=4)
        opened = self.decoder.FFmpegSetup(r"30.mp4")
        
        if opened:
            duration = self.decoder.getParameter("duration")
            fps = self.decoder.getParameter("avgFrameRate")
            frameCount = duration*fps
            print("Video frame count is", frameCount)
            self.slider.setRange(0, frameCount-1) # -1 since start from 0
        
        self.extract_frame(0)
    
    def extract_frame(self, frame):
        print(frame)
        p = self.decoder.ExtractFrame(frame, 1)
        
        data = p[0].data
        height = p[0].shape[0]
        width = p[0].shape[1]
        channel = p[0].shape[2]
        pixmap = QPixmap.fromImage(QImage(data, width, height, channel*width, QImage.Format_RGB888))
        self.image.setPixmap(pixmap)
        
        
if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    p = Player()
    p.show()
    app.exec_()