opencv-cam.py

# options
MAX_CAMS = 4
WIDTH_PIXELS = 1280
HEIGHT_PIXELS = 720
VIDEO_FORMAT = 'MJPG'

# connect to all available webcams
cams = []
for i in range(0, MAX_CAMS):
  next_cam = cv2.VideoCapture(i)
  if next_cam.isOpened():
    cams.append(next_cam)
  else:
    break

# configure camera settings
# (use `v4l2-ctl -d /dev/video0 --list-formats-ext` in shell to see what webcam supports)
for cam in cams:
  # resolution
  cam.set(cv2.CAP_PROP_FRAME_WIDTH, WIDTH_PIXELS)
  cam.set(cv2.CAP_PROP_FRAME_HEIGHT, HEIGHT_PIXELS)
  # format
  cam.set(cv2.CAP_PROP_FOURCC, cv2.VideoWriter_fourcc(*VIDEO_FORMAT))

# read frames
while True:
  for cam in cams:
    _, frame = cam.read()
    # convert from BGR to RGB
    cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
    # TODO: send along to something