musikcube is a cross-platform, terminal-based music player and streaming server written in C++. It consists of a core library (`musikcore`) with a plugin-based architecture for decoders, encoders, audio outputs, DSP, and data streams. The project includes three distinct front-ends: a terminal UI (`musikcube`) built on a custom curses++ framework, a native Windows UI (`musikwin`) using a custom Win32 wrapper, and an Android remote client (`musikdroid`) written in Kotlin. The server plugin enables remote control and audio streaming via WebSocket and HTTP. The core manages a SQLite-backed music library with indexing, metadata extraction (via TagLib), and playlist management. Audio playback supports gapless and crossfade transitions, visualizers, and an equalizer. The system is designed for extensibility through a well-defined SDK interface set, allowing third-party plugins for decoders, outputs, and DSP. The codebase is mature (copyright 2004-2023) and shows signs of organic growth, with heavy vendored third-party dependencies and platform-specific code. While not architecturally pristine, it demonstrates solid engineering, a clean plugin API, and reusable UI frameworks.
Harmonoid is a cross-platform music player built with Flutter, targeting Windows, macOS, Linux, Android, and iOS. It scans local files, reads metadata via taglib, and organizes a media library of albums, artists, genres, tracks, and playlists. Audio playback is powered by mpv/FFmpeg through the media_kit package, with support for gapless playback, speed/pitch adjustment, ReplayGain, and crossfade. The app integrates Last.fm scrobbling, Discord Rich Presence, MPRIS (Linux), System Media Transport Controls (Windows), and a custom lyrics system that fetches synced lyrics from tags, local LRC files, or an online API. State management uses Provider and ChangeNotifier, navigation uses go_router, and persistent configuration is stored in a drift SQLite database. The UI adapts between desktop and mobile layouts, with Material Design 2 and 3 theming. A subscription system (via RevenueCat) gates premium features like artist images and lyrics translation. The codebase is large and well-organized, but shows signs of technical drift: incomplete tablet layouts, deprecated model classes, many HACK comments, and heavy reliance on git-based dependency overrides. Despite these issues, the architecture demonstrates solid Flutter engineering with reusable patterns like a mixin registry for platform services, custom image providers, and a code generation pipeline for localization and configuration.