iShareScreen

Cross-platform Python client for Apple's macOS Screen Sharing High Performance mode (HEVC RExt 4:4:4 over UDP/SRTP). Renders the host Mac's screen in a native wgpu window with hardware decode where available.

Setup

On the host Mac (the target you want to view)

1. Any modern macOS that supports the Screen Sharing app's High Performance mode (Apple Silicon, recent macOS).
2. System Settings → General → Sharing → Screen Sharing → toggle on.

On the viewing machine

macOS

1. Install Python 3.10 or later (from python.org, brew install python, or uv python install 3.13).
2. Install iShareScreen:

   pip install git+https://github.com/renegadelink/iShareScreen.git
   

Windows

1. Install Python 3.10 or later from python.org (the installer includes pip; check "Add python.exe to PATH" during install).

2. Open PowerShell or cmd and run:

   pip install git+https://github.com/renegadelink/iShareScreen.git
   

3. (Optional, only if you want audio) install libfdk-aac — Apple's PT=101 audio uses AAC-ELD-SBR, which Windows Media Foundation can't decode. The cleanest source is MSYS2:

   pacman -Sy --noconfirm mingw-w64-x86_64-fdk-aac
   

   This drops libfdk-aac-2.dll at C:\msys64\mingw64\bin\, which iss searches automatically. If you already have scoop, scoop install msys2 followed by the same pacman command also works — iss looks under %USERPROFILE%\scoop\apps\msys2\current\mingw64\bin too. Without libfdk-aac, video works as normal and audio is silently skipped.

Linux (Debian / Ubuntu)

1. Install Python and the system libraries that the GPU + window stack need (Vulkan loader, OpenGL, X11 / Wayland surfaces, PortAudio, AAC-ELD-SBR audio decoder):

   sudo apt install python3 python3-pip python3-venv \
       libvulkan1 libgl1 libegl1 \
       libxrandr2 libxinerama1 libxcursor1 libxi6 \
       libportaudio2 libfdk-aac2 \
       xclip
   

   libfdk-aac2 is only used for audio; if you skip it, video still works and audio is silently disabled.

   xclip enables bidirectional clipboard sync with the macOS host. On Wayland desktops use wl-clipboard instead. If neither is installed iss logs a one-line warning at startup and runs without clipboard sync — everything else still works.

2. (Optional, for hardware HEVC decode on Intel GPUs) install vaapi:

   sudo apt install vainfo intel-media-va-driver-non-free
   

   For AMD, swap the driver: sudo apt install mesa-va-drivers.

3. Install iShareScreen (in a venv recommended):

   python3 -m venv ~/.venvs/iss
   ~/.venvs/iss/bin/pip install git+https://github.com/renegadelink/iShareScreen.git
   ~/.venvs/iss/bin/iss     # or symlink to ~/.local/bin
   

For Fedora / Arch / openSUSE, translate the apt package names with your distro's package manager (most are named the same or very close).

Firewall

iss connects to the host Mac over TCP 5900 (control) plus two UDP flows: 5900 (audio + RTCP) and 5901 (video). It sends from both UDP ports during connect. If a firewall still blocks the stream, allow UDP 5900–5901 inbound.

Usage

iss

Opens the terminal UI: a connect form for host / username / password (masked) and resolution, then a live session view with per-tile fps and loss, throughput, UDP queue health, and a log tail. The actual screen streams in a separate window. Last-session values pre-fill the form on the next launch; passwords are never persisted.

Any flag accepted by iss --headless also pre-fills the form, so launchers can do:

iss --host mac.local -u me --advertise 1920x1080 --no-curtain

Useful keys in the live session: f force IDR refresh (fixes the rare gray patch the auto-recovery doesn't catch), r reconnect, d disconnect, Ctrl-B save a bug-report snapshot, q quit.

For CI / scripted use:

echo "$PASSWORD" | iss --headless --host mac.local -u me --password-stdin --auto-quit-secs 30

License

AGPL-3.0-or-later. See LICENSE.

This is an independent reverse-engineering of a publicly-documented network protocol. No Apple source code, headers, or symbols are included.