nullplayer

Audio engine architecture, local/streaming pipelines, EQ, spectrum analysis, and playback flow. Use when working on audio playback, streaming, equalization, spectrum visualization, BPM detection, or ProjectM integration.

Flow network throughput window — live download/upload meter, interface selection, single-height center-stack docking, classic/modern window controllers, and rendering behavior.

Coordinate systems, scaling architecture, hit testing, skin sprite rendering, window layout, and Compact Mode for NullPlayer's UI. Use when working on window scaling, skin rendering, coordinate transforms, visual layout, compact/status-item windows, or playlist/marquee text rendering.

Index of NullPlayer's visualization systems. Use this to discover which sub-skill covers the specific visualizer you're working on (main window vis, spectrum window, album art, ProjectM/MilkDrop, Geiss, Tripex, Met Museum, vis_classic, Metal mode internals).

ProjectM/MilkDrop preset engine inside the visualization window — preset loading, controls, modes, audio sensitivity, beat sensitivity, drag-suspend behavior. Use when editing the ProjectM wrapper, preset folder logic, or its menu.

Modern skin engine, skin.json schema, element catalog, and custom skin creation. Use when creating or modifying modern skins, working on ModernSkin components, or adding UI elements to the modern system.

The PeppyMeter analog VU meter window — a skinnable needle/bar meter (port of project-owner/PeppyMeter) in classic + modern UI. Covers the meters.txt geometry, the CoreGraphics compositor (needle rotation + linear masks), the stereo-tap level model, meter selection/random, bundled GPL assets, and WindowManager integration. Use when modifying the PeppyMeter window, its renderer, meter templates, or level plumbing.

The classic and modern Audio Analyzer windows — a Friture-style multi-pane analyzer (Scope, Levels, Spectrogram, Octave, Pitch, Delay), the stereo PCM path that feeds them, per-pane consumer gating, and the shared AudioAnalysisDSP module. Use when modifying either analyzer window, its panes, the spectrogram shader, or the stereo/DSP plumbing.

Headless CLI mode for NullPlayer. Use when working on CLI features, arguments, playback control, query commands, source resolution, or terminal display. Covers architecture, all flags, keyboard controls, and source APIs.

User-facing features, menus, keyboard shortcuts, and functionality overview. Use when documenting features, understanding user workflows, or explaining capabilities to users.

UI testing mode, accessibility identifiers, and testing workflows. Use when writing tests, adding testable UI elements, or understanding test structure and philosophy.

Plex API endpoints, authentication, filtering, music radio, and video content. Use when working on Plex integration, library browsing, track queries, radio features, or video playback.

Cross-cutting Metal pitfalls in NullPlayer's visualization code — command encoder ordering, render-to-texture y-flip, shader availability checks, and the AudioEngine spectrum coalescing pattern that fixes Classic/Spectrum bar stuttering. Use when writing Metal pipelines or chasing visualizer jitter/crash bugs.

Sonos UPnP discovery, multi-room casting, coordinator transfer, custom checkbox UI, and protocol quirks. Use when working on Sonos casting, UPnP control, multi-room audio, or group management.

Internet radio (Shoutcast/Icecast), metadata fallback, auto-reconnect, ratings/folder organization, and casting. Also covers Library Browser radio mode for Subsonic, Jellyfin, Emby, Plex, and local library (smart playlist generation, history filtering, history pages). Use when working on radio station playback, streaming metadata, auto-reconnect logic, radio organization UI, radio casting, or library-source radio.

YouTube channel uploads in the Radio tab — browse channels, download audio (FLAC / MP3) or video (720p / 1080p) ad-free, store in a user folder, and play/cast locally. Use when working on YouTube source UI, channel/video listing, downloads, manifest tracking, or format settings.

.cue sheet support — direct-play virtual split (open a .cue or an audio file with a sibling .cue → N playlist rows from one backing file, gapless) and library physical split-on-import (ffmpeg per-track files, off by default). Use when working on cue parsing, the AudioEngine cue boundary detector, in-file offset playback, or CueAlbumSplitter.

Rip a media URL to FLAC/MP3/MP4 via yt-dlp — quality-first format selection, metadata tagging, cover art, metadata-based filenames, .cue from chapters, and the main-window activity band. Use when working on the Stream Ripper, yt-dlp/ffmpeg integration, or the Output → Streaming menu.

Non-Retina display artifact fixes, blue line issues, tile seam corrections, and targeted redraw optimizations. Use when debugging rendering issues on 1x displays or working on skin rendering code.

Per-mode shader and algorithm internals for the GPU visualization modes shared by both the main window and spectrum window — Fire, JWST, Lightning, Matrix, Snow, EKG. Includes Metal pass counts, audio mappings, color schemes, intensity presets, and the shader file names. Use when editing a specific mode's shader or audio response.

The main window's built-in 76×16 (Winamp coordinates) visualization area — eleven display modes, mode switching, persistence, per-mode settings, and the embedded SpectrumAnalyzerView lifecycle. Use when modifying the in-skin visualizer area or its menu.

The dedicated Metal-based spectrum analyzer window — 84-bar mode list, window geometry, docking behavior, the cropped analyzer curve used by Classic/Enhanced/Ultra, vis_classic exact mode and its waveform demand. Use when modifying the spectrum window chrome, mode list, controls, or analyzer curve.

The Library Browser ART-mode visualizer — 30 Core Image GPU effects that transform album artwork based on audio. Use when adding/editing visualizer effects, intensity, keyboard shortcuts, or the ART-mode lifecycle.

The Met Museum Open Access slideshow engine — controls, persistence keys, throttled API client, disk image cache, empty-department handling, audio reactivity hooks. Use when modifying the Met Museum engine, its menu, the API client, or the image cache.

Implementation reference for NullPlayer's Tripex visualization engine — the MIT-licensed port of ben-marsh/tripex (Winamp-era D3D9 3D visualizer, ~25 effects) onto macOS as a ProjectM-peer engine. Covers the CTripexCore C ABI, upstream-vs-port file split, OpenGL 3.2 renderer subclass, audio ring buffer, threading model, persistence, and the architectural deviations from upstream. Use when modifying anything under Sources/CTripexCore/, TripexEngine.swift, TripexMenuBuilder.swift, the Tripex factory branch in VisualizationGLView, or the engine-conditional Tripex menu in ModernProjectMView.

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 VisualizationGLView for Geiss, or the engine-conditional Geiss menu in ModernProjectMView.

Google Cast Protocol v2, message framing, debugging, and test scripts. Use when working on Chromecast casting, debugging Cast protocol issues, or implementing Cast commands.

Emby API, authentication flow, rating scale, streaming, scrobbling, and video playback. Use when working on Emby integration, library browsing, playback reporting, or video casting.

Jellyfin API, authentication flow, rating scale, streaming, scrobbling, and video playback. Use when working on Jellyfin integration, library browsing, playback reporting, or video casting.

Subsonic/Navidrome API, authentication, music folder selection, streaming, and scrobbling. Use when working on Subsonic/Navidrome integration, library browsing, music folder filtering, or playback reporting.

Comprehensive implementation and profile reference for NullPlayer's vis_classic mode (CVisClassicCore, VisClassicBridge, SpectrumAnalyzerView integration, menu/keyboard controls, transparent-background behavior, persistence keys, and bundled INI profiles). Use when modifying vis_classic rendering behavior, profile import/export, assigning profiles to skins, or debugging profile-specific response differences.