Agent skill

Geiss Port

Implementation reference for NullPlayer's Geiss visualization engine — the BSD-3-Clause port of Ryan Geiss's Win32/DirectDraw/Winamp-2 visualizer onto macOS as a ProjectM-peer engine.

Custom licenceAuto-check passedMobile

Install Geiss Port

skills CLI

$ npx skills add ad-repo/nullplayer --skill geiss-port -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install ad-repo/nullplayer geiss-port --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/ad-repo/nullplayer.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/geiss-port .claude/skills/geiss-port && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "geiss-port" agent skill from https://github.com/ad-repo/nullplayer/tree/main/skills/geiss-port into .claude/skills/geiss-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "geiss-port", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/ad-repo/nullplayer/tree/main/skills/geiss-port

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add ad-repo/nullplayer --skill geiss-port -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install ad-repo/nullplayer geiss-port --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/ad-repo/nullplayer.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/geiss-port .agents/skills/geiss-port && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "geiss-port" agent skill from https://github.com/ad-repo/nullplayer/tree/main/skills/geiss-port into .agents/skills/geiss-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "geiss-port", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add ad-repo/nullplayer --skill geiss-port -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install ad-repo/nullplayer geiss-port --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/ad-repo/nullplayer.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/geiss-port .cursor/skills/geiss-port && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "geiss-port" agent skill from https://github.com/ad-repo/nullplayer/tree/main/skills/geiss-port into .cursor/skills/geiss-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "geiss-port", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/ad-repo/nullplayer.git --path skills/geiss-port

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add ad-repo/nullplayer --skill geiss-port -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install ad-repo/nullplayer geiss-port --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/ad-repo/nullplayer.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/geiss-port .gemini/skills/geiss-port && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "geiss-port" agent skill from https://github.com/ad-repo/nullplayer/tree/main/skills/geiss-port into .gemini/skills/geiss-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "geiss-port", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install ad-repo/nullplayer geiss-port

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add ad-repo/nullplayer --skill geiss-port -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/ad-repo/nullplayer.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/geiss-port .github/skills/geiss-port && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "geiss-port" agent skill from https://github.com/ad-repo/nullplayer/tree/main/skills/geiss-port into .github/skills/geiss-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "geiss-port", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add ad-repo/nullplayer --skill geiss-port -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install ad-repo/nullplayer geiss-port --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/ad-repo/nullplayer.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/geiss-port .opencode/skills/geiss-port && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "geiss-port" agent skill from https://github.com/ad-repo/nullplayer/tree/main/skills/geiss-port into .opencode/skills/geiss-port/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "geiss-port", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: geiss-port
GitHub stars: 158
Token cost: ~5.3k tokens
SKILL.md length: 2,188 words
Files: 1
Skills in repo: 40
Repo updated: Oct 10, 2026
First seen: Oct 7, 2026
Licence: Custom licence

At a glance

Implementation reference for NullPlayer's Geiss visualization engine — the BSD-3-Clause port of Ryan Geiss's Win32/DirectDraw/Winamp-2 visualizer onto macOS as a ProjectM-peer engine.

Works in 8 steps: RenderFX() — effect overlays into VS1 → Process_Map(VS1, VS2) — bilinear-blend… → GetWaveData() — populate g_power[] /… → …
Modifying anything under Sources/CGeissCore/
SKILL.md covers File Layout, Architectural deviation:…, Render Pipeline and Audio path, plus 9 more sections
Reaches github.com

What it does

Geiss Port is an agent skill from ad-repo/nullplayer. Implementation reference for NullPlayer's Geiss visualization engine — the BSD-3-Clause port of Ryan Geiss's Win32/DirectDraw/Winamp-2 visualizer onto macOS as a ProjectM-peer engine. Covers the CGeissCore C ABI, upstream-vs-port file split, indexed-framebuffer + palette-LUT render pipeline, Accelerate-based spectrum push, threading model, persistence, and the architectural deviation around upstream/main.cpp. Use when modifying anything under Sources/CGeissCore/, GeissEngine.swift, the spectrum/PCM path in…

Its SKILL.md is about 5.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Mobile, covering iOS development. It works with C++, Windows and macOS. The repository describes itself as: nullPlayer is a free open source macOS media player with some unique features.

When your agent uses it

Modifying anything under Sources/CGeissCore/
GeissEngine.swift
The spectrum/PCM path in VisualizationGLView for Geiss
The engine-conditional Geiss menu in ModernProjectMView

Example prompts

“s Geiss visualization engine — the BSD-3-Clause port of Ryan Geiss”
“/geiss-port”

Workflow steps

8 steps, taken from the first numbered list in SKILL.md.

RenderFX() — effect overlays into VS1
Process_Map(VS1, VS2) — bilinear-blend warp through DATA_FX (portable C; the upstream MSVC __asm dispatcher in proc_map.cpp is gated #if 0)
GetWaveData() — populate g_power[] / g_power_smoothed[], beat-detect, smoothing, centroid
RenderDots(VS2) — audio-driven dot bursts (NUCLIDE)
RenderWave(VS2) — 7 waveform-render modes + beat detect + slide-shift
Swap VS1 ↔ VS2
memcpy(indexBuf, VS1, FXW*FXH) — copy to caller buffer
GenerateChunkOfNewMap(false, 0) — advance warp-map generation by one row of pixels; when chunk completes (y_map_pos returns to -1), call…

What it can do on your machine

Read from SKILL.md and the folder at commit 3d87ce1. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
- github.com
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Geiss Port loads about 5.3k tokens when it runs. Until then it costs about 153 tokens; SKILL.md has 2,188 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~153
When it runs · the whole SKILL.md, loaded when a task matches: ~5.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 2,188 words (~5,267 tokens).

“Geiss is a second visualization engine in NullPlayer's modern visualizer window, switchable from the right-click Visualization Engine submenu alongside ProjectM. It is a port of the BSD-3-Clause upstream at https://github.com/geissomatik/geiss (HEAD pinned at 816f3f6a5ca70592da7583be70c06f6e3425d306).”

— opening of SKILL.md by ad-repo, Custom licence

name: geiss-port

Outline of SKILL.md

Geiss Port Guide
File Layout
Sources/CGeissCore/
Compiled vs excluded
Architectural deviation: upstream/main.cpp
Render Pipeline
Per-frame sequence (GeissCore_render)
Swift side (GeissEngine)
Audio path
PCM (waveform)
Spectrum
Threading model
Effect catalog
Hidden modes in upstream
Palette pipeline
Persistence
Engine-conditional UI
Diagnostic accessor
Licensing
Gotchas
Key files
Configuration Levers (Phase 1)
C ABI surface
Port edits (§0)
Upstream symbol mapping
UserDefaults keys
Menu surface
Deferred to future phases

Read the full SKILL.md on GitHub

Files

Just SKILL.md in skills/geiss-port of ad-repo/nullplayer.

Open the folder on GitHubat commit 3d87ce1

Compare with similar skills

Geiss Port next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Geiss Port compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Geiss Port this skillad-repo/nullplayer	158	—	~5.3k	Automated safety check: Pass	Custom licence	yesterday
Bump Swift Versionjamesmontemagno/tiny-clips	121	—	~695	Automated safety check: Pass	MIT	yesterday
Build CmakeiPlug2/iPlug2OOS	158	—	~1.2k	Automated safety check: Pass	None	26 days ago
Lldbmohitmishra786/low-level-dev-skills	252	—	~1.4k	Automated safety check: Pass	MIT	3 mo ago
Windows Parityn1m21n/Infinite	271	—	~4.6k	Automated safety check: Pass	Custom licence	yesterday
macOS Spm App PackagingDimillian/Skills	4k	5 repos	~1.2k	Automated safety check: Pass	MIT	6 mo ago

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Questions about Geiss Port

What does Geiss Port do?

Implementation reference for NullPlayer's Geiss visualization engine — the BSD-3-Clause port of Ryan Geiss's Win32/DirectDraw/Winamp-2 visualizer onto macOS as a ProjectM-peer engine. Geiss Port is an agent skill from ad-repo/nullplayer. Implementation reference for NullPlayer's Geiss visualization engine — the BSD-3-Clause port of Ryan Geiss's Win32/DirectDraw/Winamp-2 visualizer onto macOS as a ProjectM-peer engine.

When should I use Geiss Port?

Geiss Port fits situations like: modifying anything under Sources/CGeissCore/; geissEngine.swift; the spectrum/PCM path in VisualizationGLView for Geiss; the engine-conditional Geiss menu in ModernProjectMView.

How do I install Geiss Port in Claude Code?

Run `npx skills add ad-repo/nullplayer --skill geiss-port -a claude-code`. Or copy the skill folder (skills/geiss-port in ad-repo/nullplayer) into .claude/skills/geiss-port in your project. Claude Code loads it when a task matches its description.

How do I install Geiss Port in Codex?

Run `npx skills add ad-repo/nullplayer --skill geiss-port -a codex`. Or copy the skill folder (skills/geiss-port in ad-repo/nullplayer) into .agents/skills/geiss-port in your project. Codex loads it when a task matches its description.

Can I use Geiss Port in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add ad-repo/nullplayer --skill geiss-port -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/geiss-port, .gemini/skills/geiss-port, .github/skills/geiss-port and .opencode/skills/geiss-port in your project.

What does Geiss Port need to run?

SKILL.md names no scripts, command-line tools or credentials: Geiss Port is instructions for the agent only.

Does Geiss Port access the network?

SKILL.md names 1 domain. In commands or code: github.com; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.

Is Geiss Port safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Geiss Port use?

Geiss Port has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.

How many tokens does Geiss Port use?

About 5.3k tokens (SKILL.md is roughly 21k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Geiss Port?

Skills that share tags, products or a category with Geiss Port: Bump Swift Version (jamesmontemagno/tiny-clips, 121 stars), Build Cmake (iPlug2/iPlug2OOS, 158 stars), Lldb (mohitmishra786/low-level-dev-skills, 252 stars) and Windows Parity (n1m21n/Infinite, 271 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Geiss Port?

ad-repo (a GitHub user) maintains it in ad-repo/nullplayer, which has 158 GitHub stars. The repository holds 40 skills in this directory. The repository was last updated on October 10, 2026.

Source: ad-repo/nullplayer on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Geiss Port

Install Geiss Port

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Files

Compare with similar skills

Similar skills

Bump Swift Version

Build Cmake

Lldb

Windows Parity

macOS Spm App Packaging

Orca iOS Simulator Control

More from ad-repo/nullplayer

Skin Screenshots

Vis Classic Guide

App Control

Chromecast Casting

Emby Integration

Live UI Testing

Questions about Geiss Port

Install Geiss Port

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Files

Compare with similar skills

Similar skills

More from ad-repo/nullplayer

Related

Questions about Geiss Port