Minimal Python example code to display video frames from USB camera using OpenCV, Pygame and OpenGL.

minimal_pygame_opencv_opengl.py

"""
Minimal Python example code to display video frames from USB camera
using OpenCV, Pygame and OPENGL.
Tested with:
Pygame: 1.9.4
OpenCV: 4.5.4
"""

import time

import cv2
import pygame
from OpenGL.GL import *
from OpenGL.GLU import *

CAM_INDEX = 0
WIDTH, HEIGHT = (640, 480)
OPENGL_TEXTURE = glGenTextures(1)
PYGAME_FLAGS = pygame.DOUBLEBUF | pygame.OPENGL


def bilt_frame(frame):
    glTexImage2D(
        GL_TEXTURE_2D,
        0,
        GL_RGB,
        WIDTH,
        HEIGHT,
        0,
        GL_RGB,
        GL_UNSIGNED_BYTE,
        frame,
    )

    glClear(GL_COLOR_BUFFER_BIT)
    glLoadIdentity()
    glBegin(GL_QUADS)

    glTexCoord(0, 0)
    glVertex2f(0, 0)

    glTexCoord(1, 0)
    glVertex2f(WIDTH, 0)

    glTexCoord(1, 1)
    glVertex2f(WIDTH, HEIGHT)

    glTexCoord(0, 1)
    glVertex2f(0, HEIGHT)

    glEnd()

    pygame.display.flip()

    glBindTexture(GL_TEXTURE_2D, 0)


def init_opengl():
    glMatrixMode(GL_PROJECTION)
    gluOrtho2D(0, WIDTH, 0, HEIGHT)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()
    glDisable(GL_DEPTH_TEST)
    glClearColor(0.0, 0.0, 0.0, 0.0)
    glEnable(GL_TEXTURE_2D)
    glBindTexture(GL_TEXTURE_2D, OPENGL_TEXTURE)
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
    glBindTexture(GL_TEXTURE_2D, 0)


def init_pygame():
    pygame.display.set_mode((WIDTH, HEIGHT), PYGAME_FLAGS)


def quit_pygame():
    pygame.display.quit()


if __name__ == "__main__":

    init_pygame()
    init_opengl()

    cap = cv2.VideoCapture(CAM_INDEX, cv2.CAP_V4L2)
    cap.set(cv2.CAP_PROP_FRAME_WIDTH, WIDTH)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT, HEIGHT)

    while True:
        ret, frame = cap.read()
        if ret:
            bilt_frame(frame)

        time.sleep(1 / 25)

    # hit Ctrl + C to exit the program
    quit_pygame()
    cap.release()