--- title: "How to add a neon edge wipe with Claude (tested prompt and script)" description: "A glowing hot-pink neon line sweeps from right to left, and the next clip is already showing behind it. Install one skill and ask Claude Code, or run the Python script we tested yourself." url: https://www.recharm.com/effects/neon-edge-wipe --- # How to add a neon edge wipe with Claude A glowing hot-pink neon line sweeps from right to left, and the next clip is already showing behind it. Made by the script on this page, from our own test clips. ## Get this effect 1. ### Switch to Code in your [Claude Desktop App](https://claude.com/download) 2. ### Install the skill (once) ``` 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/skills ``` 3. ### Ask for the effect ``` Join clipA.mp4 and clipB.mp4 with a neon edge wipe Length of the transition in seconds: 0.8 Glow color: (255, 40, 200) ``` ## 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. Put a sale badge on **@clip1.mp4**, give **@clip2.mp4** a VHS look, then join them with a neon edge wipe. ## 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 | | ------------ | ----------------- | --------------------------------------------------- | | `D` | `0.8` | Length of the transition in seconds. | | `NEON` | `(255, 40, 200)` | Glow color. | | `CORE` | `(255, 235, 250)` | Color of the bright line in the middle of the glow. | | `CORE_WIDTH` | `6` | Bright line width in pixels. | | `GLOW` | `22` | Glow radius in pixels. | ## Without the skill Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the script itself. ``` Join clipA.mp4 and clipB.mp4 with a 0.8 second neon edge wipe that starts 0.8 seconds before the end of clipA. A straight vertical edge moves from the right side of the frame to the left side at a constant speed, with clipA on the left of the edge and clipB on the right (ffmpeg xfade wipeleft). A neon line rides centered on that edge for the whole 0.8 seconds: a 6 pixel wide, near-white (255, 235, 250) line down the full height, inside a hot-pink (255, 40, 200) glow made by Gaussian-blurring a 24 pixel wide pink bar with a 22 pixel radius in Pillow and stacking the blurred bar twice. No line before or after the transition. Match clipB's size to clipA, output 30fps, crossfade the audio over the same 0.8 seconds, draw the line with Pillow (not ffmpeg's drawtext or drawbox), and save it as output.mp4. ``` ## Run it without Claude This is the exact script we tested. Save it as `neon-edge-wipe.py` and run: ``` python3 neon-edge-wipe.py clipA.mp4 clipB.mp4 output.mp4 ``` ``` #!/usr/bin/env python3 """Neon edge wipe: a glowing pink neon line sweeps right to left over 0.8s, swapping clip A for clip B behind it. Usage: python3 neon-edge-wipe.py clipA.mp4 clipB.mp4 output.mp4 (both clips need an audio track) Needs ffmpeg and Pillow (pip install pillow). """ import json import subprocess import sys import tempfile from PIL import Image, ImageDraw, ImageFilter D = 0.8 # transition length in seconds NEON = (255, 40, 200) # glow color CORE = (255, 235, 250) # color of the bright line at the center of the glow CORE_WIDTH = 6 # bright line width in pixels GLOW = 22 # glow radius (Gaussian blur, in pixels) def probe(path): info = json.loads(subprocess.check_output(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries", "stream=width,height:format=duration", "-of", "json", path])) s = info["streams"][0] return s["width"], s["height"], float(info["format"]["duration"]) def neon_line(h): """A vertical strip: a soft pink glow with a near-white line down its middle, on a transparent background.""" sw = GLOW * 8 glow = Image.new("RGBA", (sw, h), NEON + (0,)) ImageDraw.Draw(glow).rectangle([sw / 2 - CORE_WIDTH * 2, 0, sw / 2 + CORE_WIDTH * 2, h], fill=NEON + (255,)) glow = glow.filter(ImageFilter.GaussianBlur(GLOW)) # stack the glow twice so it stays strong right next to the line strip = Image.alpha_composite(glow, glow) ImageDraw.Draw(strip).rectangle([sw / 2 - CORE_WIDTH / 2, 0, sw / 2 + CORE_WIDTH / 2 - 1, h], fill=CORE + (255,)) return strip a, b, out = sys.argv[1:4] w, h, length = probe(a) offset = length - D with tempfile.NamedTemporaryFile(suffix=".png") as line: neon_line(h).save(line.name) # xfade's wipeleft moves the A/B edge from x = w to x = 0 over D seconds; the line is centered on that edge edge = f"{w}*(1-(t-{offset})/{D})" subprocess.run(["ffmpeg", "-y", "-v", "error", "-i", a, "-i", b, "-loop", "1", "-i", line.name, "-filter_complex", f"[0:v]fps=30,format=yuv420p,setsar=1[a];" f"[1:v]scale={w}:{h}:force_original_aspect_ratio=increase,crop={w}:{h},fps=30,format=yuv420p,setsar=1[b];" f"[a][b]xfade=transition=wipeleft:duration={D}:offset={offset}[wiped];" f"[wiped][2:v]overlay=x='{edge}-w/2':y=0:enable='between(t,{offset},{length})':shortest=1,format=yuv420p[v];" f"[0:a][1:a]acrossfade=d={D}[au]", "-map", "[v]", "-map", "[au]", "-c:v", "libx264", "-crf", "18", "-pix_fmt", "yuv420p", "-c:a", "aac", out], check=True) ``` ## More transitions - [Barn door transition **Barn door transition**](https://www.recharm.com/effects/barn-door) - [Blinds transition **Blinds transition**](https://www.recharm.com/effects/blinds-transition) - [Block dissolve **Block dissolve**](https://www.recharm.com/effects/block-dissolve) - [Blur transition **Blur transition**](https://www.recharm.com/effects/blur-transition) - [Bounce transition **Bounce transition**](https://www.recharm.com/effects/bounce-transition) ## Find 3x _winning ads_ Recharm cuts your ad footage into tagged, searchable clips: hooks, testimonials, product shots. Find the shots that win, add the effect with Claude, and ship 3x more ad edits. [Start 14-day free trial](https://www.recharm.com/get-started)