Video.py

# Filename: Video.py
# Author: Jason Grant, Middlebury College
# Date Created: 3/12/2020
# Open a video source with OpenCV

import cv2
import argparse
import numpy as np
import sys
import random

def take_pic(frame):
    global imgno
    text = opt.output + "/img" + str(imgno) + ".png"
    cv2.imwrite(text, frame)
    print("file saved to", text)
    

if __name__ == "__main__":
    start = False

    parser = argparse.ArgumentParser()

    # Frequently used
    parser.add_argument('-s', '--source', type=str, default='/home/scott/MiddballHam.mp4', help='source')  # file/folder, 0 for webcam
    parser.add_argument('-o', '--output', type=str, default='/home/scott/summer2020/data/', help='output folder')  # output folder
    parser.add_argument('-n', '--number', type=int, required=True, help='what number to start images at')

    opt = parser.parse_args()

    # The default capture device is the default video source.
    source = 0
    if len(sys.argv) > 1:
        source = opt.source

        # If the source is a peripheral device, it will
        # be a number. Change the string into a number.
        # If the source beingg passed is a filename, this
        # will throw an exception. Ignore the conversion
        try:
            source = int(source)
        except:
            pass

    cap = cv2.VideoCapture(source)
    imgno = opt.number
    x = random.randint(1,200)
    print(x)

    while(True):
        ret, frame = cap.read()
        if not ret:
            sys.exit()

        cv2.imshow("frame",frame)

        if start:
            if x < 1:
                take_pic(frame)
                x = random.randint(1,200)
                imgno += 1
            else:
                x -= 1

        # If the q key is pressed, the loop will exit
        k = cv2.waitKey(20)
        if k & 0xFF == ord('q'):
                break
        elif k & 0xFF == ord('s'):
            start = not start

    cv2.destroyAllWindows()