Web Audio Player

1. Project Overview

This project aims to create a browser-based audio player that works offline, supports playlists, and provides an improved user experience using waveform visualization and local caching.

Problem Statement (In Simple Words)

Most audio players require internet connectivity or backend support. This project solves that problem by creating a fully frontend-powered music player that:

• Works offline
• Manages playlists
• Visualizes audio waveforms
• Saves user preferences locally

2. Functional Scope

Must-Have Features

• Play, pause, skip, repeat and seek through songs
• Waveform scrubber using Canvas API
• Playlist management (Add/Remove tracks, sorting, pagination)
• Responsive UI (Mobile + Desktop)

Stretch Goals

• Undo/Redo with toast notifications
• Theme switcher (Dark/Light)
• Playback speed & volume controls
• Export/Import playlists as JSON

3. Tech Stack

Frontend

• HTML5
• CSS3 (Flexbox, Grid, Animations)
• JavaScript (ES6+ modules)
• Canvas API – Waveform drawing
• Web Audio API – Playback + Visualization
• ARIA roles + keyboard navigation

Backend (Optional / Final Choice)

• Node.js + Express + JSON file database

Tools used

• Multer (file upload)
• Helmet + CORS (security)
• Postman (API testing)

Browser Storage

• IndexedDB → Cache playlists, metadata, waveforms
• localStorage → UI preferences
• Cache API → Offline assets

Offline Support

• Service Worker (PWA-like behavior)

Dev Tools

• Lighthouse
• GitHub
• Vercel / Netlify / GitHub Pages

4. System Flow

1. User Input (Search / Play / Select)
2. Fetch or Load Playlist JSON
3. Decode Audio via Web Audio API
4. Render Waveform on Canvas
5. Playback Controls (Play/Pause/Seek)
6. Save Data to IndexedDB / localStorage
7. Output: Offline-ready responsive audio player

5. Key Data Structures & Algorithms

• Arrays & Objects for track + playlist storage
• IndexedDB for waveform & metadata caching
• Debounce technique for search optimization
• Pub-Sub architecture for modular event flow

6. Testing Strategy

Functional Testing

• Play / Pause / Skip
• Playlist CRUD
• Waveform scrubber
• Search, sort, pagination

Performance Testing

• Lighthouse
• Waveform rendering speed
• Bundle size optimization

Accessibility Testing

• ARIA labels
• Screen-reader support
• Keyboard navigation

Offline Testing

• Disable WiFi → Player should still:
  • Load pages
  • Load IndexedDB playlist
  • Serve cached files via Service Worker

Cross-Browser Tests

• Chrome, Firefox, Edge, Safari

7. Folder Structure

/project-root
│
├── frontend/
│   ├── index.html
│   ├── assets/
│   ├── js/
│   ├── css/
│
├── server/
│   ├── server.js
│   ├── db.json
│   ├── routes/
│   │     ├── playlists.js
│   │     └── tracks.js
│   ├── uploads/
│   ├── package.json
│   └── README-backend.md
│
└── README.md