Building a Screen Recorder with Python: Capture Desktop Activities

In this blog post, we will explore the exciting world of screen recording and learn how to build a screen recorder using Python. Screen recording is a valuable tool for various purposes, including creating tutorials, demonstrating software functionality, capturing gameplay, and more. Python, with its powerful libraries and ease of use, makes it a great choice for developing such applications. By the end of this tutorial, you will have a functional screen recorder that captures your desktop activities in real-time.

Prerequisites

Before we dive into the coding process, make sure you have the following prerequisites installed on your system 

1. Python (version 3.x)
2. Required Python libraries: pyautogui, opencv-python, and numpy

You can install the necessary libraries using pip:pip install pyautogui opencv-python numpy

Understanding the Process

Before we begin writing code, let's understand the basic steps involved in building our screen recorder

• Import the required libraries.
• Set up the necessary configurations, such as screen resolution and frame rate.
• Capture the screen at regular intervals to record the desktop activities.
• Save the captured frames as a video file.

With this plan in mind, let's start coding!

Import Libraries

First, create a new Python file, e.g., screen_recorder.py, and import the required libraries

import cv2
import numpy as np
import pyautogui
import screeninfo

cv2 (OpenCV) is a popular computer vision library used for image and video processing.
numpy is a powerful library for numerical computations.
pyautogui is a library that allows us to control the mouse and keyboard, and we'll use it to capture the screen.

Set Up Configurations

Now, let's define some configurations for our screen recorder

# Set the resolution of the screen (width, height)
screen_width, screen_height = pyautogui.size()

# Set the output video filename and frame rate
output_filename = "screen_recording.mp4"
frame_rate = 30.0

# Define the codec and create a VideoWriter object
fourcc = cv2.VideoWriter_fourcc(*"mp4v")
out = cv2.VideoWriter(output_filename, fourcc, frame_rate, (screen_width, screen_height))

Capture Desktop Activities

In this step, we'll capture the desktop activities and write them to the output video file

# Get the number of milliseconds between each frame capture based on the frame rate
frame_interval = int(1000 / frame_rate)

try:
    while True:
        # Capture the screen and convert the RGB image to BGR format (required by OpenCV)
        screen = pyautogui.screenshot()
        frame = np.array(screen)
        frame = cv2.cvtColor(frame, cv2.COLOR_RGB2BGR)

        # Write the frame to the output video file
        out.write(frame)

        # Wait for the specified interval before capturing the next frame
        cv2.waitKey(frame_interval)

        # Stop the screen recording when the user presses the 'q' key
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break

except KeyboardInterrupt:
    # Stop the screen recording if the user interrupts the process (Ctrl+C)
    pass

# Release the VideoWriter and destroy all OpenCV windows
out.release()
cv2.destroyAllWindows()

Run the Screen Recorder

Save the Python file, and you are now ready to run your screen recorder! Open a terminal or command prompt, navigate to the directory where you saved screen_recorder.py, and run the following command

python screen_recorder.py
During the execution, the screen recorder will continuously capture your desktop activities and save them to the specified output video file. To stop the recording, press the q key, and the recording will be saved.

Conclusion

Congratulations! You have successfully built a screen recorder using Python, capable of capturing desktop activities and saving them as a video file. With this basic implementation, you can further enhance the screen recorder by adding features like audio recording, video compression, or a graphical user interface (GUI) for user interaction.

Screen recording is a valuable tool for various purposes, including creating educational content, software testing, and content creation for social media. By combining Python's simplicity and powerful libraries like OpenCV, you can create a wide range of applications that leverage screen recording capabilities.

I hope you found this tutorial helpful and that it sparked your creativity to explore more possibilities with screen recording using Python. Happy coding!