📺 CRT Scanline Plugin for VLC

The first native CRT scanline video filter ever made for VLC media player.

VLC has over 4 billion downloads and is the world's most popular open-source media player, yet somehow it has never had a working native CRT shader plugin. Emulation communities have long enjoyed CRT simulation through RetroArch and mpv shader stacks, but VLC's difficult plugin architecture made this a gap no one filled — until now. This plugin is designed with ease of use in mind, with an included smart installer script. It's designed to be a permanent improvement to VLC, simply toggle off in menu for zero overhead and it will not turn back on until you enable it, even between opening and closing the app or switching media.

This addon will be perfect for DIY retro TV projects, scanlines can be adjusted as dark as you'd like to match your desired aesthetic.

However, the purpose in making this effect is that it is especially beneficial for 80s–90s era anime and broadcast-era video, which were created with CRT display characteristics in mind. These works assumed phosphor bloom, scanline structure, and NTSC/PAL signal blending as part of the final image formation. Color choices, shading, and even dithering patterns were designed to integrate across scanlines and soften through analog display behavior.

When viewed on modern displays, these assumptions are lost. Deinterlacing and pixel-perfect rendering remove the vertical integration and luminance blending the content relied on, often leaving the image looking flat, harsh, overly bright and artificially noisy.

This filter restores that missing layer by reintroducing controlled scanline-based luminance modulation. The result is improved gradient reconstruction, reduced aliasing, and more natural color fusion—closer to how the content was originally intended to be seen. The effect is fully adjustable, allowing subtle correction or more pronounced CRT-style presentation depending on preference. As you'll see by the screenshots below, it can also add a pleasant retro look to modern media as well.

To install, simply right click install.bat and run as administrator. The bat file will automatically close VLC if open, checks for requirements and installs the video plugin and LUA menu extension. Open VLC and enable the video filter in Preferences, restart the app and you're good to go.

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📸 Screenshots

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Before / After Comparisons

🔴 Filter OFF	🟢 Filter ON

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🎚️ Intensity Comparison — Low vs High

🔴 Filter OFF	🟡 Low Intensity	🔵 High Intensity

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✨ Features

🎛️ Authentic CRT scanline simulation — cosine-wave brightness modulation on the luma plane mimics the gaussian beam profile of real CRT phosphor lines.

📐 Resolution-aware auto-scaling — scanline spacing scales relative to 480p (NTSC reference), and darkness scales relative to 1080p. A 360p video gets fine, subtle lines; a 1080p video gets the full effect. The visual density stays consistent regardless of source resolution.

⚡ Zero-cost bypass — Simply turn it on or off in the view menu - Off short-circuits the filter entirely, passing frames through with no processing overhead.

🎚️ Live adjustment via Lua extension — a companion control panel (View → CRT Scanline Controller) lets you adjust darkness, spacing, and blend mode in real time during playback without restarting VLC.

🎬 Presets — Subtle, Classic, and Heavy presets for quick switching between looks.

🔘 Smooth and hard modes — smooth blend uses a cosine wave for natural phosphor falloff; hard mode produces sharp alternating bright/dark bands.

✅ Works with hardware acceleration — tested and confirmed working with Direct3D11 hardware-accelerated decoding enabled. No need to change default VLC settings.

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📊 Parameters

Parameter	Range	Default	Description
crtscanline-darkness	0–100	35	🌑 Scanline intensity at 1080p reference (auto-reduced for lower res)
crtscanline-spacing	1–20	2	📏 Scanline period in pixels at 480p reference (auto-scaled to video res)
crtscanline-blend	on/off	on	🌊 Smooth cosine-wave blending vs hard alternating lines

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🔧 Build

Prerequisites: Visual Studio 2022/2026 with "Desktop development with C++" workload, and the VLC 3.0.x SDK extracted to C:\vlc-sdk\

:: Open "x64 Native Tools Command Prompt for VS" from Start Menu
cd C:\crt-scanline-plugin
build.bat

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📦 Install

Option A — Automated:

:: Right-click > Run as administrator
install.bat

Option B — Manual:

1. 📁 Copy build\libcrt_scanline_plugin.dll → C:\Program Files\VideoLAN\VLC\plugins\video_filter\
2. 📁 Copy lua\crt_scanline_controller.lua → C:\Program Files\VideoLAN\VLC\lua\extensions\
3. 🔄 Run vlc-cache-gen.exe or delete plugins.dat to refresh the plugin cache

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🚀 Enable

1. Open VLC → Tools → Preferences → Show settings: All
2. Navigate to Video → Filters → ☑️ check "CRT Scanline video filter"
3. Click Save, restart VLC
4. View → CRT Scanline Controller for live adjustments 🎛️

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💻 Command Line Usage

Basic:

vlc --video-filter=crtscanline video.mp4

Custom settings:

vlc --video-filter=crtscanline --crtscanline-darkness=50 --crtscanline-spacing=3 --no-crtscanline-blend video.mp4

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🔍 Troubleshooting

⚠️ If the scanline effect does not appear, try disabling hardware-accelerated decoding:

Tools → Preferences → Input/Codecs → Hardware-accelerated decoding → Disable

This forces VLC to use software decoding, which guarantees planar YUV frames reach the filter. In most configurations this is not necessary — the plugin has been tested and works with Direct3D11 hardware acceleration enabled.

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🛠️ Technical Details

Architecture	Native VLC video filter module (C99), compiled as a standalone DLL
Processing	Operates on planar YUV frames (I420, J420, YV12, I422, etc.) — modulates Y plane per-row; chroma passes through unchanged
Compatibility	VLC 3.0.x on Windows 64-bit — SDK from 3.0.23, ABI-compatible with any 3.0.x install
Compiler	MSVC with /std:c11 (C11 required for VLC header compatibility)

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📄 License

LGPL v2.1+ (same as VLC)

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👤 Author

Created by Jules Lazaro