Captr

The Problem

Capture card software is one of those things streamers and content creators expect to "just work" — but a lot of the existing tools feel like they were designed in 2008. Big chunky buttons, dated chrome, settings buried in three levels of menus. The original VideoGameCapture by ImmerNochNoah did the hard part — actually pulling a clean video and audio signal from a USB capture card — but the UI hadn't aged well.

I wanted a modern, dark, keyboard-driven rewrite. Something a creator could pop open on a second monitor, see at a glance, and drive without taking their hands off the keyboard.

What I Built

Captr is a focused, modern UI rewrite of VideoGameCapture, built on Unity 2022.3.62f3. It keeps the capture pipeline that worked and replaces the entire presentation layer with a clean, shadcn/ui-inspired dark theme built in Unity's UI Toolkit (UXML/USS), plus a full keyboard shortcut model for hands-off operation.

A full disclosure: I'm new to Unity, and this project was built with significant AI assistance. Treat it as a case study in how far you can get in an unfamiliar engine with a fast pair-programmer, a clear reference design, and a willingness to read the docs.

How It Works

The app boots into a single scene (MainScene.unity) that hosts a fullscreen video surface plus two slide-in panels — a settings panel on the left and a keyboard shortcut reference on the right. The capture pipeline runs in three managers:

• VideoCaptureManager — wraps Unity's WebCamTexture API, handles device enumeration, resolution/FPS selection, and aspect-ratio fit modes. A live FPS counter overlays the preview.
• AudioCaptureManager — captures audio from the selected capture card device, exposes volume + mute, and runs an auto-sync loop that re-aligns the audio stream to the video clock on a configurable interval (1–15 minutes). The R key triggers an on-demand sync for instant fixes.
• SettingsManager — serialises the full configuration (capture card, resolution, FPS, aspect mode, audio device, volume, sync frequency) to Application.persistentDataPath/CaptureSettings.json on change.

UI lives in Assets/UI/ as UXML + USS pairs — SettingsPanel, KeymapsPanel, VolumeIndicator — sharing a Common.uss stylesheet that defines the zinc palette and the 300ms slide animation tokens.

Key Design Decisions

UI Toolkit over uGUI

Most Unity tutorials still teach uGUI, but for a settings-heavy desktop app UI Toolkit is the better tool. UXML is a declarative layout format, USS is a real stylesheet with selectors and variables, and the panel-based architecture maps cleanly onto slide-in side panels. The whole UI re-themes from one file.

Auto audio sync, not just manual

Audio drift over USB capture cards is real and gradual — by the time you notice, you're 30 seconds out of sync. A single "press R to fix" key was the original design, but I added a configurable auto-sync on top: every N minutes (default 5), the audio stream re-aligns to the video clock. The R key still exists for the impatient.

Shadcn/ui dark, not game-dark

"Dark theme" in a game engine usually means jet black with neon accents. Captr goes the other way — a zinc/neutral grey palette with subtle borders and a single accent colour, straight out of the shadcn/ui playbook. It looks like a developer tool, not a game menu, which is the point.

Resolutions and FPS as first-class settings

1080p30, 1080p60, 1080p120, 1440p60, 4K30, 4K60 — the device dropdowns only show combinations the capture card actually supports, and the FPS counter in the corner confirms what you're actually getting. If a target is too aggressive for the hardware, the counter tells you before the recording does.

Features

Building It Yourself

The project targets Unity 2022.3.62f3 and Windows. To run from source:

1. Clone and open in Unity Hub with the 2022.3.62f3 editor.
2. Open Assets/Scenes/MainScene.unity.
3. Press ESC to open the settings panel, pick your capture card and audio device, choose resolution and FPS, then Save Preferences.
4. Build via File → Build Settings → Windows → x86_64.

For distribution, the README documents packaging the built executable into a Windows installer with Inno Setup.

Links

• GitHub: imsudip/captr
• Original project: ImmerNochNoah/VideoGameCapture
• License: MIT

Timeline

Built in a focused two-day session as a modern UI rewrite of an existing capture card tool.

• Jan 2026 — Initial development: Unity WebCamTexture video capture pipeline, audio capture with volume/mute controls, UI Toolkit dark theme interface
• Jan 2026 — Final commit: auto audio sync feature, keyboard shortcuts, persistent JSON settings, documentation