Zureshot

Pixel-perfect screen recording for Mac.
Built with Rust. Powered by Apple Silicon.

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Why Zureshot?

Zero-copy · pure Rust · one shot

The name says it all — Zero + Pure + Shot.

Zero — zero-copy GPU pipeline. The CPU never touches a single pixel. 3% usage while recording. Pure — pure Rust, no Electron bloat. 3.9 MB installer, 11 MB on disk. Nothing wasted. Shot — one shot, instant capture. Click to record, done.

Most screen recorders treat your Mac like a 2015 laptop — copying pixels through CPU, bloating memory, spinning fans.

Zureshot doesn't touch your pixels. Every frame flows through a pure GPU pipeline, from capture to file. The result: recordings that look exactly like your screen, using almost no resources.

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✨ Core Technology

🎯 True Retina Recording

Your Mac renders at 2× or 3× physical pixels. Most tools quietly downscale to save bandwidth. Zureshot records every single physical pixel.

A 3200×2132 Retina display records at 3200×2132. Not 1600×1066. No exceptions.

Text stays razor-sharp. UI elements keep their crisp edges. What you see is what you get — pixel for pixel.

🚀 Zero-Copy GPU Pipeline

The entire recording path lives on the GPU. Pixel data never enters your app's memory.

ScreenCaptureKit → IOSurface (GPU) → VideoToolbox HEVC → MP4
                          ↑                    ↑
                    Zero CPU copy        Hardware encoder

• ScreenCaptureKit captures frames as GPU-resident IOSurfaces
• VideoToolbox hardware-encodes directly from those surfaces
• AVAssetWriter muxes the encoded NALUs into MP4

No memcpy. No Vec<u8>. No frame buffers in RAM. The CPU barely knows a recording is happening.

🧊 Absurdly Low Resource Usage

Metric	Zureshot	Typical Screen Recorder
Extra RAM during recording	~30-50 MB	200-500 MB
CPU usage	< 3%	15-40%
GPU overhead	< 5%	10-25%
Fan noise	Silent	Often audible

Your Mac stays cool. Your battery lasts longer. Your other apps don't stutter.

🎨 Color-Accurate Output

Every recording is tagged with the full BT.709 color pipeline:

• Color Primaries: ITU-R BT.709 — matches sRGB displays
• Transfer Function: BT.709 — correct gamma curve
• YCbCr Matrix: BT.709 — precise luma/chroma separation
• Capture Color Space: sRGB — no implicit P3→709 conversion

Play your recording on any device and the colors will match your screen exactly.

⚡ HEVC (H.265) Hardware Encoding

Zureshot uses HEVC Main profile with Apple Silicon's dedicated media engine:

• 40-50% smaller files than H.264 at equal quality
• Adaptive bitrate — up to 36 Mbps for 4K, tuned for screen content
• Quality-targeted VBR — encoder prioritizes text sharpness over file size
• No frame reordering — minimal latency, instant stop
• 2-second keyframes — smooth seeking in any player

A 60-second Retina recording at 60fps: ~135 MB (vs 200+ MB with H.264).

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🎬 Features

• 📹 Full Screen Recording — native Retina resolution, one click from tray
• 🔲 Region Recording — drag to select any area, pixel-perfect cropping
• ⏸ Pause / Resume — zero-overhead atomic flag, no encoding gaps
• 🔊 System Audio — capture app sounds via ScreenCaptureKit
• 🎤 Microphone — separate AAC track, hardware-encoded
• 🖱 Cursor Capture — rendered by macOS compositor, zero CPU cost
• 🎯 Window Exclusion — automatically hides Zureshot's own UI from recordings
• ⌨️ Keyboard Shortcuts — ⌘⇧R to record, ⌘⇧A for region select
• 🌗 Quality Presets — Standard (30fps) and High (60fps)

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🏗 Architecture

System Overview

┌─────────────────────────────────────────────────────────────────────┐
│                         Zureshot                                    │
├─────────────────┬───────────────────────────────────────────────────┤
│   UI Layer      │              Engine (Rust)                        │
│   Svelte 5      │                                                   │
│                 │  ┌──────────────────────────────────────────────┐ │
│  Tray Menu      │  │           Capture Pipeline                   │ │
│  Region Select  │  │                                              │ │
│  Recording Bar  │  │  SCK ──→ IOSurface ──→ VideoToolbox ──→ MP4  │ │
│  Dim Overlay    │  │  (GPU)    (GPU/VRAM)    (Media Engine)  (SSD) │ │
│                 │  │                                              │ │
│                 │  │  Audio: SCK ──→ CMSampleBuffer ──→ AAC ──┘   │ │
│                 │  └──────────────────────────────────────────────┘ │
│                 │                                                   │
│                 │  ┌─────────┐ ┌──────────┐ ┌───────────────────┐  │
│                 │  │ capture │ │  writer  │ │    commands       │  │
│                 │  │   .rs   │ │   .rs    │ │      .rs          │  │
│                 │  │ SCK API │ │ AVAsset  │ │ Tauri IPC bridge  │  │
│                 │  │ Delegate│ │ Writer   │ │ State management  │  │
│                 │  └─────────┘ └──────────┘ └───────────────────┘  │
├─────────────────┴───────────────────────────────────────────────────┤
│                    Tauri v2 + objc2 FFI                             │
├─────────────────────────────────────────────────────────────────────┤
│  macOS: ScreenCaptureKit │ VideoToolbox │ AVFoundation │ CoreMedia  │
└─────────────────────────────────────────────────────────────────────┘

Data Flow — Zero-Copy Path

                              Apple Silicon SoC
                    ┌───────────────────────────────┐
                    │                               │
  Display Output ───┤  Window Server composites     │
                    │  frame into IOSurface         │
                    │         │                     │
                    │         ▼                     │
                    │  ScreenCaptureKit delivers    │
                    │  CMSampleBuffer (IOSurface    │
                    │  handle — NOT pixel data)     │
                    │         │                     │
                    │         ▼                     │
                    │  VideoToolbox reads IOSurface │
                    │  via Apple Media Engine       │
                    │  (dedicated HEVC hardware)    │
                    │         │                     │
                    │         ▼                     │
                    │  Encoded H.265 NALUs          │
                    │  (tiny compressed packets)    │
                    │                               │
                    └───────────┬───────────────────┘
                                │
                                ▼
                    AVAssetWriter → MP4 file on disk

Key insight: The pixel data (e.g., 3200×2132 × 1.5 bytes/pixel = 10 MB/frame) stays entirely in unified GPU memory. Only the tiny compressed NALUs (50-100 KB/frame) pass through CPU memory on the way to disk.

Source Files

File	Lines	Responsibility
capture.rs	~650	SCK stream setup, SCStreamOutput delegate, frame routing, PTS enforcement
writer.rs	~470	AVAssetWriter creation, HEVC encoding settings, BT.709 color, finalization
commands.rs	~820	Tauri IPC commands, recording state machine, window management
tray.rs	~250	System tray icon, context menu, shortcut handling
lib.rs	~60	App bootstrap, plugin registration

Rust handles all capture, encoding, and file I/O. The UI is a thin Svelte layer (~5 components) for tray menus, region selection, and recording controls. Tauri v2 bridges the two with type-safe IPC.

Tech Stack

Layer	Technology	Why
Capture	ScreenCaptureKit (macOS 12.3+)	Next-gen capture API, GPU-native IOSurface output
Pixel Format	NV12 (420v)	Native format for HEVC encoder — zero color conversion
Color Space	sRGB capture → BT.709 encoding	Lossless metadata match, no implicit conversion
Encoding	VideoToolbox HEVC Main	Apple Media Engine hardware, ~3% CPU
Container	AVAssetWriter → MP4	Native Apple muxer, proper moov atom, instant seek
Audio	AAC 48kHz stereo, 128kbps	System audio + microphone, dual track
FFI	objc2 0.6 + block2 0.6	Type-safe Rust ↔ Objective-C bridge
App Shell	Tauri v2	Lightweight native wrapper, ~3 MB binary
Frontend	Svelte 5 + Vite	Minimal UI for overlays and controls

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🚀 Quick Start

# Prerequisites: Rust, Node.js, pnpm
git clone https://github.com/anxiong2025/zureshot.git
cd zureshot
pnpm install
pnpm tauri dev

First launch: macOS will ask for Screen Recording permission. Grant it in System Settings → Privacy & Security → Screen Recording, then restart the app.

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🔧 Build for Production

pnpm tauri build

The .dmg installer will be in src-tauri/target/release/bundle/dmg/.

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� Compatible Devices

Apple Silicon (Recommended — Full Zero-Copy Pipeline)

Mac	Chips	Capture	Encoding	Notes
MacBook Air	M1 / M2 / M3 / M4	✅ SCK Zero-Copy	✅ Hardware HEVC	Fanless — truly silent recording
MacBook Pro 14" 16"	M1 Pro/Max — M4 Pro/Max	✅ SCK Zero-Copy	✅ Hardware HEVC	Multiple media engines on Pro/Max
Mac mini	M1 / M2 / M2 Pro / M4 / M4 Pro	✅ SCK Zero-Copy	✅ Hardware HEVC	Great for desktop recording setups
iMac	M1 / M3 / M4	✅ SCK Zero-Copy	✅ Hardware HEVC	4.5K/5K Retina fully supported
Mac Studio	M1 Max/Ultra / M2 Max/Ultra / M4 Max	✅ SCK Zero-Copy	✅ Hardware HEVC	Multi-encoder for highest throughput
Mac Pro	M2 Ultra	✅ SCK Zero-Copy	✅ Hardware HEVC	Up to 4 media engines

All M-series chips share the same Apple Media Engine architecture. M1 through M4 (including Pro / Max / Ultra variants) deliver identical zero-copy recording quality. Higher-tier chips simply have more encoder instances for parallel workloads.

Intel Macs (Supported with Limitations)

Configuration	Capture	Encoding	Limitations
Intel + T2 chip (2018-2020 models)	✅ SCK	✅ Hardware HEVC via T2	No unified memory — extra copy between CPU↔GPU
Intel without T2 (pre-2018)	✅ SCK	⚠️ Software HEVC	Higher CPU usage (15-30%), may impact performance

System Requirements

Requirement	Minimum	Recommended
macOS	13.0 Ventura	14.0+ Sonoma
RAM	8 GB	16 GB
Disk	~200 MB/min (Standard)	SSD recommended
Display	Any resolution	Retina (2x) for best quality

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🗺 Roadmap

v0.2 — Trim & Export

• Post-recording preview window
• Drag-to-trim: start/end range slider
• Stream copy export (no re-encoding, instant)
• Optional hardware-accelerated 4K → 1080p transcode

v0.3 — Polish & Quality of Life

• Multi-display selection
• Thumbnail preview on recording stop
• Global settings panel (output path, format, quality)
• Auto-open in Finder after export
• Recording countdown timer (3-2-1)

v0.4 — Export Formats

• GIF export (palette-optimized, max 30fps)
• WebM / VP9 export
• Screenshot mode (full screen / region)
• Copy to clipboard

v0.5 — Annotation & Overlay

• On-screen annotation: arrows, rectangles, text
• Highlight / spotlight effect (dim outside cursor area)
• Webcam overlay (picture-in-picture circle)
• Customizable watermark

v1.0 — Presentation Mode 🎯

• Auto Zoom: camera automatically follows cursor and zooms into the focused area — perfect for tutorials, demos, and walkthroughs
• Click Ripple: visual ripple effect on mouse click to highlight interactions
• Keystroke Overlay: display pressed keys on screen for shortcut demonstrations
• Spotlight Mode: dim everything except a configurable radius around the cursor
• Smooth Pan: cinematic camera movement with configurable easing curves
• Scene Presets: save and switch between zoom levels / focus areas

Vision: Zureshot aims to become the go-to tool for developers and creators who record tutorials, product demos, and technical walkthroughs — combining pixel-perfect capture quality with intelligent presentation features that make every recording look professionally produced.

Future

• Real-time LUT / color filters (Core Image or Metal Compute)
• Auto-upload to cloud (S3, R2, custom endpoint)
• Plugin system for custom post-processing
• Apple Shortcuts integration
• Menu bar recording indicator with live waveform

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📄 License

MIT © Zureshot