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Install the skill (once)
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Install the Recharm video effects skill: download https://recharm-growth-staging.s3.us-east-2.amazonaws.com/website/downloads/recharm-video-effects.zip and unzip it into ~/.claude/skillsAsk for the effect
Add a text highlight marker to input.mp4 Text: Clears dark spots Mark: dark spots
Several videos, several effects, one ask
Put your clips in the folder, mention them with @, and ask for everything at once. Claude runs one tested script after another on each clip, then joins them.
Add a text highlight marker to @clip1.mp4, put a sale badge on @clip2.mp4, give @clip3.mp4 a VHS look, then join all three with crossfades.
Settings you can change
Ask Claude to change any of these, or edit them at the top of the script.
| Setting | Default | What it does |
|---|---|---|
TEXT | Clears dark spots | The headline. |
MARK | dark spots | The words that get highlighted. |
START | 0.6 | Second the marker starts. |
SWIPE | 0.4 | Seconds the marker takes. |
In other editors
From each editor’s own help pages, in our words. We haven’t run these ourselves.
Closest built-in: Highlight
- Double-click the text, or click Edit at the top, to open the text panel.
- Select the key words and click the highlight pop-up.
- Change the highlight color with the Text color option.
Page covers highlighting selected words with a color; no animated marker swipe is mentioned.
Source: How to highlight a text and change its color and font style? | Support (InVideo), checked October 22, 2026.
Without the skill
Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the script itself.
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Add a highlighted headline to input.mp4: "Clears dark spots" in black bold, centered 20% of the way down, and starting at 0.6 seconds a yellow marker rectangle swipes left to right behind "dark spots" over 0.4 seconds and stays. 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.Run it without Claude
This is the exact script we tested. Save it as text-highlight-marker.py and run:
python3 text-highlight-marker.py input.mp4 output.mp4Show the script
#!/usr/bin/env python3
"""Text highlight marker: a yellow marker stroke swipes in behind the key words of a headline.
Usage: python3 text-highlight-marker.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
TEXT = "Clears dark spots"
MARK = "dark spots" # the words that get highlighted (must be part of TEXT)
START = 0.6 # second the marker starts
SWIPE = 0.4 # seconds the marker takes to cross the words
SIZE = 0.09 # text height as a share of the frame width
Y = 0.20 # where the text's center sits (0 = top, 1 = bottom)
MARKER = (255, 214, 0, 235) # marker color (last number is opacity, 0-255)
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 overlay(t):
img = Image.new("RGBA", (w, h))
draw = ImageDraw.Draw(img)
x0, y0, x1, y1 = draw.textbbox((w / 2, h * Y), TEXT, font=font, anchor="mm")
start = x0 + font.getlength(TEXT[:TEXT.index(MARK)])
end = start + font.getlength(MARK)
if t >= START:
p = min(1, (t - START) / SWIPE)
pad = font.size * 0.12
draw.rectangle([start - pad, y0 - pad, start - pad + (end - start + 2 * pad) * p, y1 + pad], fill=MARKER)
draw.text((w / 2, h * Y), TEXT, font=font, anchor="mm", fill="black")
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)
font = ImageFont.truetype(FONT_FILE, round(w * SIZE))
render(src, out)
