How to add a meme caption bar with Claude

Turn input.mp4 (540x960) into a meme-format video: a pure white (255, 255, 255) bar across the top 240 pixels holds the caption "Me after one week of using this serum" in black Arial Bold at 43 px, centered and wrapped to fit within 32 px of each side, with lines 1.2x the text size apart and the block centered in the bar. Below the bar, show the middle 540x720 of the video (crop 120 pixels off its top and bottom) so nothing is hidden behind the bar. Keep it at 540x960, 30fps, on screen the whole 6 seconds. Use Python with Pillow to draw the bar and ffmpeg to stack 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
"""Meme caption bar: a white bar across the top holds a black meme caption, with the video cropped to fit underneath.

Usage: python3 meme-caption-bar.py input.mp4 output.mp4
Needs ffmpeg and Pillow (pip install pillow).
"""
import subprocess
import sys
import tempfile
from pathlib import Path

from PIL import Image, ImageDraw, ImageFont

TEXT = "Me after one week of using this serum"
BAR = 0.25           # bar height as a share of the frame height
SIZE = 0.08          # text height as a share of the frame width
PAD = 0.06           # space either side of the text, as a share of the frame width
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 wrap(text, font, width):
    lines, line = [], ""
    for word in text.split():
        trial = f"{line} {word}".strip()
        if font.getlength(trial) <= width or not line:
            line = trial
        else:
            lines.append(line)
            line = word
    return lines + [line]


def caption_bar(w, bar_h):
    """The white bar with the caption centered in it, black text, lines 1.2x the text size apart."""
    font = ImageFont.truetype(FONT_FILE, round(w * SIZE))
    lines = wrap(TEXT, font, w - 2 * round(w * PAD))
    step = round(font.size * 1.2)
    top = (bar_h - step * len(lines)) / 2
    img = Image.new("RGB", (w, bar_h), "white")
    draw = ImageDraw.Draw(img)
    for i, line in enumerate(lines):
        draw.text((w / 2, top + step * i + step / 2), line, font=font, anchor="mm", fill="black")
    return img


src, out = sys.argv[1:3]
w, h = map(int, subprocess.check_output(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries",
                                         "stream=width,height", "-of", "csv=p=0", src]).decode().split(","))
bar_h = round(h * BAR) // 2 * 2
with tempfile.TemporaryDirectory() as tmp:
    bar_png = f"{tmp}/bar.png"
    caption_bar(w, bar_h).save(bar_png)
    # Crop the middle of the video to the height left under the bar, then stack the bar on top.
    subprocess.run(["ffmpeg", "-y", "-v", "error", "-i", src, "-loop", "1", "-i", bar_png, "-filter_complex",
                    f"[0:v]crop={w}:{h - bar_h}[clip];[1:v][clip]vstack=shortest=1,fps=30,format=yuv420p[v]",
                    "-map", "[v]", "-map", "0:a?", "-c:v", "libx264", "-crf", "18", "-c:a", "copy", out], check=True)