video-edit

name	video-edit
description	Edit talking-head videos by removing silences with neural VAD and adding 3D swivel teaser transitions. Use when user asks to edit video, remove silences, add jump cuts, or create video teasers.
allowed-tools	Bash, Read, Write, Edit, Glob, Grep

Video Editing

Goal

Automatically edit talking-head videos: remove silences via neural VAD, add swivel teaser preview.

Scripts

• ./scripts/jump_cut_vad_singlepass.py - VAD silence removal
• ./scripts/insert_3d_transition.py - Swivel teaser insertion
• ./scripts/simple_video_edit.py - Basic FFmpeg editing

Quick Start

# Step 1: Remove silences
python3 ./scripts/jump_cut_vad_singlepass.py input.mp4 .tmp/edited.mp4

# Step 2: Add swivel teaser
python3 ./scripts/insert_3d_transition.py .tmp/edited.mp4 output.mp4 --bg-image .tmp/bg.png

# One-liner
python3 ./scripts/jump_cut_vad_singlepass.py input.mp4 .tmp/edited.mp4 && \
python3 ./scripts/insert_3d_transition.py .tmp/edited.mp4 output.mp4 --bg-image .tmp/bg.png

Step 1: VAD Silence Removal

How It Works

1. Extracts audio as WAV (16kHz mono)
2. Runs Silero VAD to detect speech segments
3. Merges close segments, adds padding
4. Uses FFmpeg trim+concat to join segments in single pass
5. Hardware encodes with hevc_videotoolbox (H.265, 17Mbps, 30fps)

CLI Arguments

Argument	Default	Description
--min-silence	0.5	Min silence duration to cut (seconds)
--min-speech	0.25	Min speech duration to keep (seconds)
--padding	100	Padding around speech (ms)
--merge-gap	0.3	Merge segments closer than this (seconds)
--keep-start	true	Always start from 0:00

Step 2: Swivel Teaser

How It Works

1. Extracts frames from later in video (default: 60s onwards)
2. Creates 3D rotating "swivel" animation
3. Splits video: intro, transition, main content
4. Re-encodes and concatenates with audio preserved

CLI Arguments

Argument	Default	Description
--insert-at	3	Where to insert teaser (seconds)
--duration	5	Teaser duration (seconds)
--teaser-start	60	Where to sample content from (seconds)
--bg-image	none	Background image for 3D effect

Final Timeline

[0-3s intro] [3-8s swivel teaser @ 100x] [8s onwards: edited content]
Audio: Original audio plays continuously

Processing Time (49-min 4K video)

• Step 1 (VAD + encode): ~8 minutes
• Step 2 (swivel teaser): ~3 minutes
• Total: ~11 minutes

Troubleshooting

Issue	Solution
Cuts feel abrupt	--padding 200
Too much cut	--min-silence 1.0
Too little cut	--min-speech 0.1
Won't play in QuickTime	Ensure hvc1 codec tag
Swivel has blank frames	Extract 300 frames for 5s teaser

Dependencies

pip install torch  # For Silero VAD
brew install ffmpeg node  # macOS
cd video_effects && npm install  # For 3D rendering

Technical Details

• macOS: Hardware encoding (hevc_videotoolbox) H.265 at 17Mbps
• Fallback: libx265 CRF 18
• Audio: AAC 192kbps
• Uses hvc1 codec tag for QuickTime compatibility