How to add a number counter with Claude

Add a number counter to input.mp4: from 0.5 seconds, a black box at 69% opacity with rounded corners, 85% of the frame width wide and centered across, with its center about 70% down the frame. In it, a yellow (255, 214, 0) bold number 20% of the frame width tall counts up from 0 to 50,000 with comma separators over 2 seconds, easing out (value = 50000 * (1 - (1 - p)^3), p going 0 to 1), and gains a "+" ("50,000+") once it lands at 2.5 seconds; under it "HAPPY CUSTOMERS" in white, 6.5% of the frame width tall. Nothing shows before 0.5 seconds, and the counter stays until the end. Use Python with Pillow to draw it and ffmpeg to put it on the video (don't rely on ffmpeg's drawtext filter), keep the audio, and save it as output.mp4.

#!/usr/bin/env python3
"""Number counter: a big yellow number counts up from 0, slowing as it lands on "50,000+" above "HAPPY CUSTOMERS".

Usage: python3 number-counter.py input.mp4 output.mp4
Needs ffmpeg and Pillow (pip install pillow).
"""
import json
import math
import subprocess
import sys
from pathlib import Path

from PIL import Image, ImageDraw, ImageFont

TARGET = 50000             # the number it lands on
SUFFIX = "+"               # added after the number once it lands
LABEL = "HAPPY CUSTOMERS"  # the line under the number
START = 0.5                # second the counter appears and starts at 0
COUNT = 2.0                # seconds the count takes
Y = 0.70                   # where the counter's center sits (0 = top, 1 = bottom)
COLOR = (255, 214, 0)      # number color
FONTS = ["/System/Library/Fonts/Supplemental/Arial Bold.ttf",     # macOS
         "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf",  # Linux
         "C:/Windows/Fonts/arialbd.ttf"]                          # Windows
FONT_FILE = next((f for f in FONTS if Path(f).exists()), None) or sys.exit("No bold font found: add one to FONTS")


def value(t):
    """The number shown at t: fast at first, easing out (cubic) as it reaches TARGET."""
    p = min(max((t - START) / COUNT, 0), 1)
    shown = f"{round(TARGET * (1 - (1 - p) ** 3)):,}"
    return shown + SUFFIX if p == 1 else shown


def overlay(t):
    img = Image.new("RGBA", (w, h))
    if t < START:
        return img
    draw = ImageDraw.Draw(img)
    number_y, label_y = h * Y - label.size * 0.6, h * Y + digits.size * 0.5
    x0, _, x1, _ = draw.textbbox((w / 2, number_y), f"{TARGET:,}{SUFFIX}", font=digits, anchor="mm")
    pad = w * 0.06
    draw.rounded_rectangle([x0 - pad, number_y - digits.size * 0.75, x1 + pad, label_y + label.size * 1.1],
                           radius=pad, fill=(0, 0, 0, 175))
    draw.text((w / 2, number_y), value(t), font=digits, anchor="mm", fill=COLOR)
    draw.text((w / 2, label_y), LABEL, font=label, anchor="mm", fill="white")
    return img


def probe(path):
    info = json.loads(subprocess.check_output(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries",
                                               "stream=width,height,r_frame_rate:format=duration", "-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), float(info["format"]["duration"])


def render(src, out):
    """Draw overlay(t) on every frame of src and save to out, keeping the audio."""
    ff = subprocess.Popen(["ffmpeg", "-y", "-v", "error", "-i", src,
                           "-f", "rawvideo", "-pix_fmt", "rgba", "-s", f"{w}x{h}", "-r", rate, "-i", "-",
                           "-filter_complex", "[0:v][1:v]overlay=shortest=1,format=yuv420p[v]",
                           "-map", "[v]", "-map", "0:a?", "-c:v", "libx264", "-crf", "18", "-c:a", "copy", out],
                          stdin=subprocess.PIPE)
    for i in range(math.ceil(duration * fps)):
        ff.stdin.write(overlay(i / fps).tobytes())
    ff.stdin.close()
    if ff.wait():
        sys.exit("ffmpeg failed")


src, out = sys.argv[1:3]
w, h, rate, fps, duration = probe(src)
digits = ImageFont.truetype(FONT_FILE, round(w * 0.20))
label = ImageFont.truetype(FONT_FILE, round(w * 0.065))
render(src, out)