zoomcutter 0.1.0

Automatically process Zoom recordings to switch between speaker-only and side-by-side views based on screen sharing chapters

ZoomCutter

Automatically process Zoom recordings to switch between speaker-only and side-by-side views based on screen sharing chapters.

What it does

ZoomCutter intelligently combines your Zoom camera and screen sharing recordings into a single video that:

• Shows speaker-only view when you're not sharing your screen
• Switches to side-by-side view (slides + camera) when screen sharing is detected
• Maintains camera's native resolution for optimal performance
• Uses Zoom's built-in chapter markers to detect sharing automatically

Perfect for creating professional-looking recordings of presentations, lectures, or meetings!

Features

• Automatic switching: Reads Zoom chapter markers to detect when screen sharing starts/stops
• Smart resolution handling: Uses camera's native resolution (no unnecessary upscaling)
• Trim support: Cut your video to specific start/end times
• Fast processing: Optimized ffmpeg settings for quick encoding
• Dry-run mode: Preview the ffmpeg command before processing

Installation

pip install zoomcutter

Requirements

ZoomCutter requires ffmpeg to be installed on your system:

macOS:

brew install ffmpeg

Ubuntu/Debian:

sudo apt install ffmpeg

Windows: Download from ffmpeg.org or use Chocolatey:

choco install ffmpeg

Usage

Basic Usage

zoomcutter camera_file.mp4 slides_file.mp4 output.mp4

Where:

• camera_file.mp4 - Your Zoom camera recording (usually named *_avo_*.mp4)
• slides_file.mp4 - Your Zoom screen sharing recording (usually named *_as_*.mp4)
• output.mp4 - The output filename

Trim Video

Cut your video to a specific time range:

# Start at 2 minutes, end at 45 minutes
zoomcutter camera.mp4 slides.mp4 output.mp4 --start 00:02:00 --end 00:45:00

# Using short options
zoomcutter camera.mp4 slides.mp4 output.mp4 -ss 00:02:00 -to 00:45:00

Dry Run

Preview the ffmpeg command without processing:

zoomcutter camera.mp4 slides.mp4 output.mp4 --dry-run

How It Works

1. Reads chapter markers: ZoomCutter analyzes the screen sharing video file to find "Sharing Started" and "Sharing Stopped" chapter markers that Zoom automatically adds
2. Detects camera resolution: Uses the camera feed's native resolution for optimal quality
3. Builds filter: Creates an ffmpeg filter that:
   • Shows camera at full resolution when not sharing
   • Switches to side-by-side (slides on left, camera on right) during sharing
4. Processes video: Runs ffmpeg with optimized settings for fast, high-quality output

Output Quality

• Video codec: H.264 with CRF 18 (high quality)
• Preset: veryfast (good balance of speed and compression)
• Audio: Copied directly from camera feed (no re-encoding)
• Resolution: Matches camera's native resolution

Example

# Process a 1-hour Zoom recording
$ zoomcutter zoom_0.mp4 zoom_share.mp4 final.mp4

Processing Zoom recordings...
  Camera: zoom_0.mp4
  Slides: zoom_share.mp4
  Output: final.mp4

Camera resolution: 1920x1080

Found 12 chapters
Found 3 screen sharing intervals:
  1. 120.50s - 850.30s
  2. 1200.00s - 2400.50s
  3. 2800.00s - end

Output resolution: 1920x1080 (camera native)
  - Speaker-only mode: No scaling (maximum performance!)
  - Side-by-side mode: Only scales slides down

Running ffmpeg...

 Successfully created: final.mp4

Troubleshooting

Error: "Could not detect camera resolution"

• Make sure the camera file is a valid video file
• Try running ffprobe camera_file.mp4 to verify

Error: "Error running ffprobe"

• Ensure ffmpeg (which includes ffprobe) is installed and in your PATH

No chapters found

• Verify you're using the screen sharing file (*_as_*.mp4) for chapter detection
• Some older Zoom versions may not include chapters

Development

Setup

git clone https://github.com/weltonrodrigo/zoomcutter.git
cd zoomcutter
uv pip install -e .

Run locally

python main.py camera.mp4 slides.mp4 output.mp4

License

MIT License - see LICENSE file for details

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.