Materials for my answer the StackOverflow question: https://stackoverflow.com/q/70445787/8877692. A direct link to my answer: https://stackoverflow.com/a/70446399/8877692.

OpenCV video capture example.ipynb

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   "source": [
    "# OpenCV video capture example\n",
    "\n",
    "Note: you should run this example on your desktop.\n",
    "\n",
    "Created as part of the answer for [the Stack Overflow question by coreselene](https://stackoverflow.com/q/70445787/8877692). The path definition as in the original question.\n",
    "\n",
    "Source of the MP4 files: https://file-examples.com/index.php/sample-video-files/sample-mp4-files/\n",
    "\n",
    "How to capture (load) files with OpenCV: https://learnopencv.com/read-write-and-display-a-video-using-opencv-cpp-python/\n",
    "\n",
    "See also: https://learnopencv.com/reading-and-writing-videos-using-opencv/"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import cv2\n",
    "import os\n",
    "import numpy as np"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "#SETUP PATHS\n",
    "POS_PATH = os.path.join('data', 'positive')\n",
    "NEG_PATH = os.path.join('data', 'negative')\n",
    "ANC_PATH = os.path.join('data','anchor')\n",
    "\n",
    "\n",
    "#MAKE DIRECTORIES\n",
    "os.makedirs(POS_PATH)\n",
    "os.makedirs(NEG_PATH)\n",
    "os.makedirs(ANC_PATH)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Fill your directories with the files. In this example we will use a file `file_example_MP4_480_1_5MG.mp4` (path: `data/positive/file_example_MP4_480_1_5MG.mp4`). Source of this file is: https://file-examples.com/index.php/sample-video-files/sample-mp4-files/"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Now, if you will use the following command:\n",
    "\n",
    "```\n",
    "os.listdir('positive')\n",
    "\n",
    "```\n",
    "\n",
    "you will get `FileNotFoundError`:\n",
    "\n",
    "```\n",
    "---------------------------------------------------------------------------\n",
    "FileNotFoundError                         Traceback (most recent call last)\n",
    "<ipython-input-6-f6aeca1b018e> in <module>\n",
    "----> 1 os.listdir('positive')\n",
    "\n",
    "FileNotFoundError: [Errno 2] No such file or directory: 'positive'\n",
    "```\n",
    "\n",
    "The reason for that is that the actual location of this directory is:\n",
    "\n",
    "```\n",
    "'data/positive'\n",
    "\n",
    "```\n",
    "\n",
    "See the proper command below:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['file_example_MP4_640_3MG.mp4', 'file_example_MP4_480_1_5MG.mp4']"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.listdir('data/positive')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Frames per second :  30.0 FPS\n"
     ]
    },
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "2021-12-22 09:44:13.013 Python[10065:138219] ApplePersistenceIgnoreState: Existing state will not be touched. New state will be written to /var/folders/8j/8tw8x4sx49384vtn35xcpwn00000gr/T/org.python.python.savedState\n"
     ]
    }
   ],
   "source": [
    "# Create a VideoCapture object and read from input file\n",
    "# If the input is the camera, pass 0 instead of the video file name\n",
    "cap = cv2.VideoCapture('data/positive/file_example_MP4_480_1_5MG.mp4')\n",
    "\n",
    "fps = cap.get(5)\n",
    "print('Frames per second : ', fps,'FPS')\n",
    "\n",
    "\n",
    "# Check if camera opened successfully\n",
    "if (cap.isOpened()== False): \n",
    "  print(\"Error opening video stream or file\")\n",
    "\n",
    "# Read until video is completed\n",
    "while(cap.isOpened()):\n",
    "  # Capture frame-by-frame\n",
    "  ret, frame = cap.read()\n",
    "  if ret == True:\n",
    "\n",
    "    # Display the resulting frame\n",
    "    cv2.imshow('Frame',frame)\n",
    "\n",
    "    # Press Q on keyboard to  exit\n",
    "    if cv2.waitKey(25) & 0xFF == ord('q'):\n",
    "      break\n",
    "\n",
    "  # Break the loop\n",
    "  else: \n",
    "    break\n",
    "\n",
    "# When everything done, release the video capture object\n",
    "cap.release()\n",
    "\n",
    "# Closes all the frames\n",
    "cv2.destroyAllWindows()"
   ]
  }
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Pipfile

[[source]]
url = "https://pypi.org/simple"
verify_ssl = true
name = "pypi"

[packages]
jupyter = "*"
notebook = "*"
opencv-python = "*"

[dev-packages]

[requires]
python_version = "3.9"