macOS Picture in Picture

Always on top window preview with AirPlay receiver support (if on macOS 12+, turn-off built-in AirPlay receiver from system preferences)

Code Info

• Nibless cocoa app
• OpenGL/Metal renderer with HiDPI support
• CoreGraphics based capturer (looking for alternative)
• No third party dependency
• Uses private framework for native pip support
• AirPlay backend from https://github.com/FDH2/UxPlay and https://github.com/KqSMea8/AirplayServer

Features

• Clone any visibile window
• Clone multiple active display
• Camera preview with audio monitoring
• HLS live streaming of any preview (window, display, or camera)
• Airplay sender (unstable)
• Crop the preview
• Auto and manual resize preserving the aspect ratio
• Multiple window preview from same process, cmd+n to open and cmd+w to close
• Pinch to zoom
• Native picture in picture support cmd+p
• Transparency/opacity control (slider in right click menu)
• Minimal modern UI
• Upto 10 parallel airplay sessions (soft limit)

Live Streaming

PiP can stream any preview window over your local network using HLS (HTTP Live Streaming). Any device with a web browser on the same network can watch the live feed.

How to use

1. Right-click any active preview window and select Stream > Start Streaming
2. The stream URL (e.g. http://192.168.1.42:8080) appears at the bottom of the Stream menu
3. Open that URL on any device's browser to watch the live stream
4. Use Copy URL or Open in Browser for quick access

Quality presets

Preset	Resolution	Bitrate	FPS
Low	720p	1.5 Mbps	24
Medium	1080p	3 Mbps	30
High	Native	6 Mbps	30

Change quality on the fly via Stream > Quality.

Architecture

The streaming pipeline is fully self-contained with no third-party dependencies:

Frame Capture → H.264 Video Encoder → MPEG-TS Muxer → HLS Writer → HTTP Server
                                             ↑
                                       Audio Capture

• Frame Capture – grabs RGBA frames from the preview's OpenGL/Metal renderer
• Video Encoder – hardware-accelerated H.264 encoding via VideoToolbox
• TS Muxer – multiplexes video (and optional audio) into MPEG-TS segments
• HLS Writer – manages a ring buffer of .ts segments and generates the .m3u8 playlist
• HTTP Server – lightweight embedded server that serves the playlist, segments, and a built-in web viewer with hls.js

Installation

Manual download

Download and install via Homebrew

brew install --cask amitv87-pip

Build from source and run

# checkout code
git clone https://github.com/amitv87/PiP.git
cd pip

# build using xcode
xcodebuild -alltargets
open build/Release/PiP.app

# or simply
./run.sh