Dreydrey9000 Multi-Cam Split Screen Compositor
Composite 2 vertical camera angles + 1 horizontal audio source into split screen layouts at production quality. Built for 3-camera podcast/interview setups (2 close-up iPhones + 1 wide camera).
When User Says "Split Screen", "Multi-Cam", or "Composite These Videos"
- Find the 3 video files (2 vertical + 1 horizontal)
- Identify who is in each vertical (extract frame, look at it)
- ASK which audio to keep and which to silence
- Ask which layout they want (show the menu below)
- ALWAYS export BOTH formats — ProRes master AND H.264 sharing copy:
--format prores→.mov(master quality, ~2-3 GB/min)--format h264→.mp4(sharing quality, ~100-200 MB/min)- Deliver both files to the user's Desktop (or specified location)
- Extract a preview frame — verify faces are visible and within safe zone
- Open the output for review and present both files with sizes
Layout Menu
| Layout | Aspect | Description |
|---|---|---|
top-bottom |
9:16 | Person A on top, Person B on bottom (vertical split) |
side-by-side |
16:9 | Person A on left, Person B on right (horizontal split) |
side-by-side-9x16 |
9:16 | Both people side by side in vertical frame, center-cropped strips |
pip-left |
16:9 | Wide shot with Person A as small picture-in-picture (bottom-left) |
pip-right |
16:9 | Wide shot with Person B as small picture-in-picture (bottom-right) |
wide-only |
16:9 | Just the horizontal camera, no split |
Quick Start
# Vertical split — side by side 9:16 (recommended for TikTok/Reels)
python3 ~/.claude/skills/_youtube-execution/multicam_split.py \
--left "person_A.mov" \
--right "person_B.mov" \
--audio "wide_shot.mov" \
--layout side-by-side-9x16
# Top/bottom vertical split
python3 ~/.claude/skills/_youtube-execution/multicam_split.py \
--left "person_A.mov" \
--right "person_B.mov" \
--audio "wide_shot.mov" \
--layout top-bottom
# Horizontal split — side by side 16:9
python3 ~/.claude/skills/_youtube-execution/multicam_split.py \
--left "person_A.mov" \
--right "person_B.mov" \
--audio "wide_shot.mov" \
--layout side-by-side
# List all layouts
python3 ~/.claude/skills/_youtube-execution/multicam_split.py --list-layouts
CLI Arguments
| Argument | Default | Description |
|---|---|---|
--left, -l |
required | Left/top person video (vertical 9:16) |
--right, -r |
required | Right/bottom person video (vertical 9:16) |
--audio, -a |
required | Main audio source (horizontal 16:9 camera) |
--output, -o |
auto | Output file path (auto-names based on layout) |
--layout |
top-bottom | Layout preset (see menu above) |
--format |
prores | prores (max quality), h264 (hardware), h264-software (fallback) |
--left-crop-y |
auto | Custom vertical crop offset for left/top person |
--right-crop-y |
auto | Custom vertical crop offset for right/bottom person |
--list-layouts |
- | Show available layouts and exit |
Quality Formats
| Format | Codec | Quality | File Size | Use Case |
|---|---|---|---|---|
prores |
ProRes 422 HQ + PCM 24-bit | Lossless-grade | ~2-3 GB/min | Master file, NLE import |
h264 |
H.264 VideoToolbox 15Mbps + AAC 320k | Very high | ~100-150 MB/min | Sharing, direct upload |
h264-software |
libx264 CRF 12 + AAC 320k | Very high | ~80-120 MB/min | Fallback if no Apple Silicon |
Default is prores — always export masters at max quality, compress later.
Workflow
Standard 3-Camera Setup
Equipment:
- Camera 1 (vertical): iPhone on Person A — close-up
- Camera 2 (vertical): iPhone on Person B — close-up
- Camera 3 (horizontal): Main camera — wide shot, best audio (lav mic or shotgun)
File naming convention from DaVinci Resolve:
*_V1-*.mov— horizontal (wide shot, main audio)*_V2-*.mov— vertical (Person A)*_V3-*.mov— vertical (Person B)
Post-Production
- Ask about audio — which track to use, which to silence
- Run this script to composite desired layout
- Verify safe zone — extract frame, overlay template, check faces
- Import the ProRes output into CapCut/Premiere/DaVinci
- Add text overlays, transitions, effects
- Export final
Crop Tuning
If a person's head is cut off or framing is wrong, adjust the Y crop offset:
# Move Person A's crop down (show more of their body, less ceiling)
python3 ~/.claude/skills/_youtube-execution/multicam_split.py \
--left A.mov --right B.mov --audio main.mov \
--layout top-bottom \
--left-crop-y 350
# Move Person B's crop up (show more headroom)
python3 ~/.claude/skills/_youtube-execution/multicam_split.py \
--left A.mov --right B.mov --audio main.mov \
--layout top-bottom \
--right-crop-y 100
Default crop values are tuned for standard seated interview framing.
Output
- Deliverable: Composited video at specified output path
- Default location:
~/.tmp/{filename}_split_{layout}.mov - Format: ProRes 422 HQ (.mov) or H.264 (.mp4)
- Audio: From whichever source the user specifies (always ask first)
- Resolution: Matches layout (1080x1920 for 9:16, 1920x1080 for 16:9)
- FPS: Matches source (typically 30fps)
Dependencies
brew install ffmpeg # macOS (already installed)
No Python packages required — uses only ffmpeg and ffprobe via subprocess. Pillow required only for safe zone overlay generation (already installed).
Troubleshooting
Videos not synced
All 3 cameras must be synced before running this script. If shot on DaVinci Resolve multicam, they're already synced. If not, sync in your NLE first or use matching timecodes.
Person's head cut off
Adjust --left-crop-y or --right-crop-y to shift the crop window up (lower value) or down (higher value). Always verify with a preview frame before accepting.
Face in TikTok danger zone
If a face sits behind the like/comment buttons or under the caption area, adjust crop offsets to move the face into the safe rectangle.
File too large
ProRes is meant to be large — it's a production format. Use --format h264 for smaller files when you don't need master quality.
Hardware encoding fails
Use --format h264-software as fallback.
Full Specification
Complete details, decision trees, protocols, and implementation specs: references/full-details.md