Viral Reels Creator

Full-featured viral Reels creator and editor powered by ffmpeg. Use this skill whenever the user wants to create, edit, find, or produce viral Instagram Reel...

Security Scan

The skill appears to be a genuine ffmpeg-based reels editor, but its metadata, runtime instructions, and included scripts request elevated local operations (apt-get, pip installs, filesystem access, shell execution) that are not declared in the registry metadata — review and sandbox before use.

Purpose & Capability

The name, description, and included files (ffmpeg commands, caption templates, color grades, beat/scene detection scripts) are coherent with a viral Reels creator. However the metadata claims no required binaries or env vars while the SKILL.md explicitly instructs installation/use of ffmpeg and Python packages (opencv, librosa, etc.). The registry should have declared ffmpeg and Python dependencies; the mismatch is a notable inconsistency.

Instruction Scope

SKILL.md tells the agent to run system package installs (apt-get), pip installs (including --break-system-packages), run Python scripts and ffmpeg commands, inspect /mnt/user-data/uploads/, copy assets to /home/claude/, and write outputs to /mnt/user-data/outputs/. Those are valid for a local video tool, but they grant broad filesystem and package-management access and include example Python code that calls subprocess.run(..., shell=True). The instructions also assume host filesystem layout (paths like /mnt/user-data) which may be outside a user's expectations — this increases the potential impact if the agent runs autonomously.

Install Mechanism

There is no formal install spec in the registry, but SKILL.md instructs using apt-get and pip to install runtime dependencies. Because install steps are provided only as freeform instructions (not a vetted package spec), they rely on executing arbitrary system commands on the host. The pip install list (opencv-python, librosa, soundfile) and apt-get of ffmpeg are reasonable for functionality but should be run intentionally by the user in a controlled environment.

Credentials

The skill does not request environment variables, credentials, or external service tokens. All operations are local (ffmpeg, Python libs, file I/O). No declared need for secrets — that aligns with the stated purpose.

Persistence & Privilege

always:false (no forced inclusion) and model invocation is allowed (default). That means the agent could autonomously run the skill when eligible. Combined with the ability to run system commands and access host paths, autonomous invocation increases blast radius; however this is platform-default behavior and not unique to this skill.

What to consider before installing

This skill looks like a genuine ffmpeg-based reels editor, but it asks you (via SKILL.md) to run system package installs, run Python scripts that themselves may execute shell commands, and access host filesystem paths (/mnt/user-data, /home/claude). Before installing or allowing autonomous use: 1) Verify you trust the skill source (homepage unknown). 2) Inspect the full contents of the three scripts (scripts/*.py, batch-export.sh) for any network calls, unexpected shell exec, or writes outside intended output folders. 3) Run any apt-get/pip installs manually in a sandbox or container (not on a production host). 4) If you allow the agent to run this skill, restrict its runtime environment (chroot/container, limited filesystem mounts) so it only reads/uploads the folders you expect. If you want, I can review the contents of the scripts (full source) and flag any suspicious network or credential usage in them.

Viral Reels Creator — Full Video Production Suite

A comprehensive ffmpeg-based skill for creating viral Instagram Reels, TikTok videos, and YouTube Shorts — including finding the best moments in raw footage, beat-synced editing, multi-platform export, and viral content strategy.

---

Quick Start — Read Before Doing Anything

1. Install dependencies if not available:

   apt-get update && apt-get install -y ffmpeg fonts-noto fonts-noto-color-emoji fontconfig
   # For scene detection + beat sync:
   pip install --break-system-packages opencv-python numpy librosa soundfile
   

2. Check uploaded files: Look in /mnt/user-data/uploads/ for user assets.
3. Copy assets to /home/claude/ before processing.
4. Output all final videos to /mnt/user-data/outputs/ and present to user.

---

Platform Specs (Primary: Instagram Reels)

Property	Instagram / TikTok / YT Shorts
Resolution	1080×1920 (9:16 portrait)
FPS	30 fps (60fps for YouTube Shorts)
Max Duration	90s (IG/FB) · 60s (TikTok/YT/Snap)
Codec	H.264 (libx264)
Audio Codec	AAC, 44100 Hz, stereo
Pixel Format	yuv420p
Container	.mp4

Base output flags (always use):

-c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -r 30 -c:a aac -ar 44100 -ac 2 -movflags +faststart

For full platform-specific specs and export commands → references/platform-specs.md

---

Workflow Decision Tree

User Request
├── "Find best moments / highlights"?
│   └── Run scripts/scene-detect.py → get timestamps → trim clips
├── "Make it viral" / "viral hook"?
│   └── Load references/viral-hooks.md → apply hook formula
├── Single video input?
│   ├── Trim/Cut           → Section: TRIMMING
│   ├── Add captions       → load references/caption-templates.md
│   ├── Add music          → Section: AUDIO MIXING
│   ├── Sync cuts to beats → load references/beat-sync.md + scripts/beat-detect.py
│   ├── Color grade        → load references/color-grading.md
│   ├── Speed change       → Section: SPEED RAMP
│   ├── Add effects/anim   → load references/animations.md
│   └── Resize only        → Section: RESIZING
├── Multiple video inputs?
│   └── Merge with transitions → load references/transitions.md
├── Images input (slideshow)?
│   └── Ken Burns / Slideshow → Section: SLIDESHOW
├── Export for multiple platforms?
│   └── Run scripts/batch-export.sh → exports all platforms at once
├── Full reel from scratch?
│   └── Combine all: scene detect → hook → content → beat sync → captions + music
└── "Make it look good" / generic?
    └── Auto-resize + color grade (Golden Hour or Clarendon) + caption template + fade transitions

IMPORTANT: For captions, animations, color grading, transitions, viral strategy, beat sync, and platform specs — always read the corresponding reference file before generating ffmpeg commands.

---

FINDING THE BEST MOMENTS (Scene Detection)

When the user has raw footage and wants the best clips extracted:

# Find top 10 most visually interesting moments
python scripts/scene-detect.py raw_footage.mp4 --top 10 --thumbnail

# Extract a specific number of clips for a 30s reel (5s each = 6 clips)
python scripts/scene-detect.py raw_footage.mp4 --top 6 --clip-duration 5 --thumbnail

# For fast-paced content with many scene changes
python scripts/scene-detect.py video.mp4 --threshold 0.2 --top 15

# Output as JSON for further processing
python scripts/scene-detect.py video.mp4 --json > moments.json

Then trim each moment using the generated ffmpeg commands from the script output.

---

VIRAL STRATEGY — Quick Reference

Load references/viral-hooks.md for the full strategy. Core principles:

1. Hook in 3 seconds — pattern interrupt, bold claim, or curiosity gap in text overlay
2. Retention triggers at 7s, 12s, 20s, 25s to fight viewer drop-off
3. Beat-sync all cuts — biggest single factor in watch time and shares
4. End with a loop — last frame should nearly match first frame so viewers rewatch
5. On-screen text always — 85% of viewers watch without sound

The viral reel formula:

[0–3s]  HOOK     → Bold text claim or pattern interrupt
[3–7s]  SETUP    → Context, "here's what you'll see"
[7–20s] CONTENT  → Core value, fast cuts, visual variety
[20–25s] PAYOFF  → Reveal, transformation, punchline
[25–30s] CTA     → "Save this", "Comment X for part 2"

---

BEAT-SYNCED EDITING — Quick Reference

Load references/beat-sync.md for the full workflow.

# Step 1: Detect beats
python scripts/beat-detect.py music.mp3
# → outputs timestamps like: 0.469, 0.938, 1.407, 1.876...

# Step 2: Use beat timestamps as cut points
# (see beat-sync.md for full ffmpeg multi-clip assembly)

# Step 3: Add zoom pulse on every beat (120 BPM = 2Hz)
ffmpeg -i video.mp4 -filter_complex "
  zoompan=z='1+0.05*abs(sin(PI*t*2))':
    x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=1:s=1080x1920:fps=30
" OUTPUT_FLAGS zoom_pulse.mp4

---

Core Operations

RESIZING — Fit Any Video to 9:16

# Scale + crop (fill frame — preferred for Reels)
ffmpeg -i input.mp4 -vf "scale=1080:1920:force_original_aspect_ratio=increase,crop=1080:1920" OUTPUT_FLAGS output.mp4

# Blurred background fill (cinematic — best for landscape source)
ffmpeg -i input.mp4 -filter_complex "
[0:v]scale=1080:1920:force_original_aspect_ratio=increase,crop=1080:1920,boxblur=20:5[bg];
[0:v]scale=1080:1920:force_original_aspect_ratio=decrease[fg];
[bg][fg]overlay=(W-w)/2:(H-h)/2
" OUTPUT_FLAGS output.mp4

TRIMMING — Cut Clips

# Fast trim (copy — no re-encode)
ffmpeg -ss 00:00:05 -i input.mp4 -t 00:00:30 -c copy trimmed.mp4

# Precise trim (re-encode for frame accuracy)
ffmpeg -i input.mp4 -ss 00:00:05 -to 00:00:35 OUTPUT_FLAGS trimmed.mp4

SPEED RAMP — Slow Motion & Fast Forward

# 0.5x slow motion
ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" -map "[v]" -map "[a]" OUTPUT_FLAGS slow.mp4

# 2x speed
ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" OUTPUT_FLAGS fast.mp4

# Speed ramp: normal → slow → normal
ffmpeg -i input.mp4 -filter_complex "
[0:v]trim=0:3,setpts=PTS-STARTPTS[v1];
[0:v]trim=3:6,setpts=2*(PTS-STARTPTS)[v2];
[0:v]trim=6:10,setpts=PTS-STARTPTS[v3];
[v1][v2][v3]concat=n=3:v=1:a=0[v]
" -map "[v]" OUTPUT_FLAGS ramp.mp4

AUDIO MIXING — Add Background Music

# Mix original audio + music (music at 30% volume)
ffmpeg -i video.mp4 -i music.mp3 -filter_complex "
[0:a]volume=1.0[voice];
[1:a]volume=0.3[music];
[voice][music]amix=inputs=2:duration=shortest
" -map 0:v OUTPUT_FLAGS output.mp4

# Fade music in/out
ffmpeg -i video.mp4 -i music.mp3 -filter_complex "
[1:a]afade=t=in:st=0:d=3,afade=t=out:st=27:d=3,volume=0.3[music];
[0:a]volume=1.0[voice];
[voice][music]amix=inputs=2:duration=shortest
" -map 0:v OUTPUT_FLAGS output.mp4

SLIDESHOW — Images to Video

# Ken Burns (zoom + pan)
ffmpeg -loop 1 -i image.jpg -vf "
scale=2160:3840,
zoompan=z='min(zoom+0.001,1.5)':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=150:s=1080x1920:fps=30
" -t 5 OUTPUT_FLAGS kenburns.mp4

---

Advanced Features — Reference Files

Always read the reference file before generating ffmpeg commands for these features.

Feature	Reference File	What's Inside
Viral strategy & hooks	references/viral-hooks.md	Hook formulas, formats, retention tactics, CTAs
Beat-synced editing	references/beat-sync.md	Beat assembly, zoom pulse, drop effects
Multi-platform export	references/platform-specs.md	Specs, safe zones, aspect ratio variants
Caption Templates	references/caption-templates.md	10 Instagram-style caption designs
Animations (50+)	references/animations.md	50 text/video animations: bounce, typewriter, etc.
Color Grading	references/color-grading.md	20 LUT-free color grades and Instagram filters
Transitions	references/transitions.md	12+ transitions: fade, wipe, zoom, glitch, etc.

---

Scripts

Script	Purpose
scripts/scene-detect.py	Find best/most viral-worthy moments in raw footage
scripts/beat-detect.py	Detect beat timestamps for sync-cut editing
scripts/batch-export.sh	Export one reel to Instagram, TikTok, YouTube, etc.

---

Combining Multiple Effects

Stack effects in a single -filter_complex. Order matters:

1. Scale/crop to 1080x1920
2. Apply color grading
3. Apply speed changes
4. Apply animations/effects
5. Overlay captions/text
6. Add transitions (for multi-clip)

Example: Full viral reel pipeline

ffmpeg -i clip1.mp4 -i music.mp3 -filter_complex "
[0:v]scale=1080:1920:force_original_aspect_ratio=increase,crop=1080:1920,
eq=brightness=0.06:saturation=1.4:contrast=1.05,
vignette=PI/5,
drawtext=text='Wait for it...':fontfile=/usr/share/fonts/truetype/noto/NotoSans-Bold.ttf:
  fontsize=72:fontcolor=white:borderw=4:bordercolor=black:
  x=(w-tw)/2:y=(h-th)/2:enable='between(t,0,3)',
drawtext=text='Your Caption Here':fontfile=/usr/share/fonts/truetype/noto/NotoSans-Bold.ttf:
  fontsize=56:fontcolor=white:borderw=3:bordercolor=black:
  x=(w-tw)/2:y=h-th-250:enable='between(t,3,28)',
drawtext=text='Save this!':fontfile=/usr/share/fonts/truetype/noto/NotoSans-Bold.ttf:
  fontsize=40:fontcolor=yellow:borderw=3:bordercolor=black:
  x=(w-tw)/2:y=h-th-120:enable='between(t,25,30)',
fade=t=in:st=0:d=1,fade=t=out:st=28:d=2[v];
[1:a]afade=t=in:st=0:d=2,afade=t=out:st=27:d=3,volume=0.4[a]
" -map "[v]" -map "[a]" -t 30 \
-c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -r 30 \
-c:a aac -ar 44100 -ac 2 -movflags +faststart \
/mnt/user-data/outputs/reel_final.mp4

---

Multi-Platform Export

After finishing the reel, export for all platforms at once:

bash scripts/batch-export.sh /mnt/user-data/outputs/reel_final.mp4 my_reel all
# Creates: my_reel_instagram.mp4, my_reel_tiktok.mp4, my_reel_youtube_shorts.mp4,
#          my_reel_facebook.mp4, my_reel_snapchat.mp4, my_reel_pinterest.mp4

Or export to specific platforms:

bash scripts/batch-export.sh reel.mp4 cooking_video instagram,tiktok,youtube

---

Watermark / Logo Overlay

# Animated logo (fade in, semi-transparent)
ffmpeg -i video.mp4 -i logo.png -filter_complex "
[1:v]scale=120:-1,format=rgba,colorchannelmixer=aa=0.7[logo];
[0:v][logo]overlay=W-w-30:H-h-30
" OUTPUT_FLAGS output.mp4

---

Auto-Captions from Audio (Whisper)

pip install --break-system-packages openai-whisper pysrt

import whisper

model = whisper.load_model("base")
result = model.transcribe("audio.mp3", word_timestamps=True)

with open("captions.srt", "w") as f:
    for i, seg in enumerate(result["segments"], 1):
        start = seg["start"]
        end = seg["end"]
        text = seg["text"].strip()
        f.write(f"{i}\n")
        f.write(f"{int(start//3600):02}:{int(start%3600//60):02}:{start%60:06.3f} --> ")
        f.write(f"{int(end//3600):02}:{int(end%3600//60):02}:{end%60:06.3f}\n")
        f.write(f"{text}\n\n")

Then burn captions (see references/caption-templates.md for styled options):

ffmpeg -i video.mp4 -vf "subtitles=captions.srt:force_style='FontSize=22,PrimaryColour=&Hffffff,OutlineColour=&H000000,Outline=2,Alignment=2'" OUTPUT_FLAGS output.mp4

---

Error Handling & Tips

• Check for audio: ffprobe -i input.mp4 -show_streams -select_streams a
• Silent video? Add -an or generate silent audio: -f lavfi -i anullsrc
• Fonts missing? apt-get install -y fonts-noto fonts-liberation
• Preview fast: Add -t 5 -preset ultrafast to render only 5 seconds
• Emoji in text? Use fontfile=/usr/share/fonts/truetype/noto/NotoColorEmoji.ttf
• Always use -movflags +faststart for web/mobile playback
• Duration limits: 90s Instagram/Facebook · 60s TikTok/YouTube Shorts/Snapchat

---

Output Checklist

Before delivering the final video:

• Resolution is 1080×1920
• Duration within platform limit (90s Instagram, 60s TikTok/Shorts)
• FPS is 30 (or 60 for YouTube Shorts)
• Has audio track (even if silent)
• Uses H.264 + AAC codecs
• Hook text visible in first 3 seconds
• CTA text visible in last 5 seconds
• File is in /mnt/user-data/outputs/
• Platform variants exported via batch-export.sh if needed