Function video

python/inputmodule/inputmodule/ledmatrix.py:144–187

Resize and play back a video

(dev, video_file)

def video(dev, video_file):
    """Resize and play back a video"""
    with serial.Serial(dev.device, 115200) as s:
        import cv2

        capture = cv2.VideoCapture(video_file)
        ret, frame = capture.read()

        scale_y = HEIGHT / frame.shape[0]

        # Scale the video to 34 pixels height
        dim = (HEIGHT, int(round(frame.shape[1] * scale_y)))
        # Find the starting position to crop the width to be centered
        # For very narrow videos, make sure to stay in bounds
        start_x = max(0, int(round(dim[1] / 2 - WIDTH / 2)))
        end_x = min(dim[1], start_x + WIDTH)

        processed = []

        # Pre-process the video into resized, cropped, grayscale frames
        while True:
            ret, frame = capture.read()
            if not ret:
                print("Failed to read video frames")
                break

            gray = cv2.cvtColor(frame, cv2.COLOR_RGB2GRAY)

            resized = cv2.resize(gray, (dim[1], dim[0]))
            cropped = resized[0:HEIGHT, start_x:end_x]

            processed.append(cropped)

        # Write it out to the module one frame at a time
        # TODO: actually control for framerate
        for frame in processed:
            for x in range(0, cropped.shape[1]):
                vals = [0 for _ in range(HEIGHT)]

                for y in range(0, HEIGHT):
                    vals[y] = frame[y, x]

                send_col(dev, s, x, vals)
            commit_cols(dev, s)


def pixel_to_brightness(pixel):