Multiviewer

A hardware-accelerated, multi-protocol video multiviewer built in Rust. Drag, resize, and snap video sources on an interactive canvas with real-time compositing.

📖 Full Documentation

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🌟 Features

• Multi-Protocol Video Sources — ingest from many video protocols or test patterns.
• Hardware-Accelerated Compositor — wgpu-based pipeline with YUV→RGB conversion on the GPU, minimal CPU↔GPU copies.
• Interactive Canvas — drag, resize, snap, and zoom layers intuitively.
• Per-Source Settings — configure each source individually with persistent session state.
• Real-Time Output — broadcast the composed view.
• Cross-Platform — native desktop applications for macOS, Windows, and Linux.

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🎥 Supported Protocols

Protocol	Source	Output	Platforms	Notes
Test Patterns	✅	—	macOS, Windows, Linux	SMPTE color bars and generative patterns
NDI	✅	✅	macOS, Windows, Linux
OMT	✅	✅	macOS, Windows, Linux	Open Media Transport
Blackmagic DeckLink	✅	✅	macOS, Windows, Linux	Requires DeckLink Desktop Video installed
Syphon	✅	✅	macOS only	GPU-only, zero-copy texture sharing
Spout	✅	✅	Windows only	GPU-only, zero-copy texture sharing
AVFoundation	✅	—	macOS only	Webcams and capture devices
MediaFoundation	✅	—	Windows only	Webcams and capture devices
DirectShow	✅	—	Windows only	Webcams and WDM capture devices
macOS Screen Capture	✅	—	macOS only	Display and window screen capture
Windows Screen Capture	✅	—	Windows only	Display and window screen capture
VNC	✅	—	macOS, Windows, Linux	Remote Desktop over VNC/RFB
RDP	✅	—	macOS, Windows, Linux	Microsoft Remote Desktop

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🛠️ Built Upon

Multiviewer is built with:

• Rust (Edition 2024) — systems programming language with fearless concurrency
• egui / eframe — immediate-mode GUI toolkit
• wgpu — safe, portable WebGPU implementation for GPU compute and rendering

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📦 Installation

Precompiled Binaries (Recommended)

Download ready-to-use binaries for macOS, Windows, and Linux from the Releases page.

Homebrew (macOS)

brew install patopesto/tap/multiviewer

Build from Source

git clone https://gitlab.com/patopest/multiviewer.git
cd multiviewer
cargo build --release

Note: The NDI SDK is required for NDI support. Run Setup environment first; the build uses the project-local SDK and fails if it is missing.

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🚀 Development

Using go-task

Setup environment

task setup

Note: This downloads the NDI SDK to a local project directory (vendor/ndi/<os>/sdk), which is the only SDK the build uses; the build fails if it is missing. Get the SDK itself from NDI's website

Run the App

task run

Build the App

task package

Test

cargo test

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📘 How It Works

Multiviewer ingests video from multiple protocols, composites them on a shared GPU canvas, and can broadcast the result back out over NDI, DeckLink, or Syphon.

1. Source Threads — each protocol runs on its own thread, decoding frames and handing them off to the main thread via lock-free Arc swaps.
2. GPU Compositing — a single WGSL shader handles passthrough (RGBA/BGRA) and UYVY→RGB conversion (BT.601 for SD, BT.709 for HD) directly on the GPU.
3. Zero-Copy Paths — Syphon/Spout sources feed GPU textures directly with no CPU copy; NDI and DeckLink use shared CPU buffers uploaded via queue.write_texture().
4. Interactive UI — the egui canvas lets you arrange sources freely, with snap-to-grid, zoom, and per-layer controls.

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📚 References & Specifications

• NDI SDK — NDI, proprietary with attribution requirements
• Blackmagic DeckLink SDK — BSD-style license (see header files)
• Syphon — BSD 3-clause
• Spout — BSD 2-clause

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🐛 Contributing

Contributions are welcome! Whether it's bug reports, feature requests, or code contributions:

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Open a Pull Request

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📄 License

This project is licensed under the MIT License. See the LICENSE file for details.

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Made with ❤️ for live video production