How to add a LED screen with Claude

Turn input.mp4 (540x960, 30fps) into an LED screen from 1.0 seconds to the end, using Python with numpy and ffmpeg. Before 1.0 seconds leave the frames untouched. From 1.0 seconds on, split each frame into a grid of 15x15 pixel cells (36 across, 64 down) and average each cell's color. Push that color away from its own gray by 1.8x for richer color and multiply it by 1.1, clipped to 0-255. Then redraw the frame on black: in the center of each cell draw one round LED of radius 5.7 pixels (0.38 of the cell) in that cell's color, with a softly anti-aliased edge and a faint halo at 20% brightness fading out toward the cell edge, so dark gaps show between the dots. Keep the size, 30fps, the 6 second length and the audio. There's no text to draw, but if you add any, draw it with Pillow, not ffmpeg's drawtext. Save it as output.mp4.

#!/usr/bin/env python3
"""LED screen: at one second the shot is rebuilt from glowing round LED dots on a black panel, like a stadium screen.

Usage: python3 led-screen.py input.mp4 output.mp4
Needs ffmpeg and numpy (pip install numpy).
"""
import json
import subprocess
import sys

import numpy as np

START = 1.0      # second the picture switches to LEDs
PITCH = 15       # pixels from one LED's center to the next (540 / 15 = 36 LEDs across)
DOT = 0.38       # LED radius as a share of PITCH
GAIN = 1.1       # how much brighter each LED glows than the average color it stands for
SATURATION = 1.8 # how much richer each LED's color is than the footage's (1 = unchanged)
GLOW = 0.2       # strength of the soft halo around each LED


def led_cell():
    """One LED as brightness 0-1 over a PITCH x PITCH cell: a bright round core fading into a soft halo."""
    y, x = np.mgrid[0:PITCH, 0:PITCH] + 0.5 - PITCH / 2
    r = np.hypot(x, y) / (DOT * PITCH)
    core = np.clip((1.15 - r) * 4, 0, 1)
    halo = GLOW * np.exp(-((r - 1).clip(0) ** 2) * 2.5)
    return np.maximum(core, halo).astype(np.float32)


def led_frame(img):
    """Average each PITCH x PITCH cell's color, make it richer, then light that cell's LED in it."""
    cells = img[:rows * PITCH, :cols * PITCH].reshape(rows, PITCH, cols, PITCH, 3).mean(axis=(1, 3))
    gray = cells.mean(axis=2, keepdims=True)
    cells = np.clip((gray + (cells - gray) * SATURATION) * GAIN, 0, 255)
    pic = cell[None, :, None, :, None] * cells[:, None, :, None, :]
    out = np.zeros_like(img)
    out[:rows * PITCH, :cols * PITCH] = pic.reshape(rows * PITCH, cols * PITCH, 3)
    return out


def probe(path):
    info = json.loads(subprocess.check_output(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries",
                                               "stream=width,height,r_frame_rate", "-of", "json", path]))
    s = info["streams"][0]
    num, den = s["r_frame_rate"].split("/")
    return s["width"], s["height"], s["r_frame_rate"], float(num) / float(den)


src, out = sys.argv[1:3]
w, h, rate, fps = probe(src)
cols, rows = w // PITCH, h // PITCH
cell = led_cell()

reader = subprocess.Popen(["ffmpeg", "-v", "error", "-i", src, "-f", "rawvideo", "-pix_fmt", "rgb24", "-"],
                          stdout=subprocess.PIPE)
writer = subprocess.Popen(["ffmpeg", "-y", "-v", "error", "-f", "rawvideo", "-pix_fmt", "rgb24", "-s", f"{w}x{h}",
                           "-r", rate, "-i", "-", "-i", src, "-map", "0:v", "-map", "1:a?",
                           "-c:v", "libx264", "-crf", "18", "-pix_fmt", "yuv420p", "-c:a", "copy", "-shortest", out],
                          stdin=subprocess.PIPE)
i = 0
while raw := reader.stdout.read(w * h * 3):
    img = np.frombuffer(raw, np.uint8).reshape(h, w, 3).astype(np.float32)
    if i / fps >= START:
        img = led_frame(img)
    writer.stdin.write(np.clip(img, 0, 255).astype(np.uint8).tobytes())
    i += 1
writer.stdin.close()
if reader.wait() or writer.wait():
    sys.exit("ffmpeg failed")