Changelog

LUFS Stack

• NEW: LUFS Stack analysis panel — dedicated collapsible panel with Meter (M/S/I bars), Target Validator (I/LRA/TP modes with delta display), and scrolling Histogram (momentary green, short-term blue)
• NEW: LRA (Loudness Range) computation from short-term loudness distribution
• NEW: Target Validator inherits target from active compliance preset automatically
• NEW: Histogram modes — SCROLL (10-second window) and FIT (full analysis history)
• NEW: Explicit Analyze start/stop toggle and Reset button for LUFS measurements
• CHANGED: LUFS Stack restyled with card treatment, CSS variables, SVG lock icons for tier-locked features
• NEW: LUFS locked upgrade prompt for free-tier users

Independent L/R Stereo Meters

• NEW: Independent left/right stereo meters for both IN and OUT level meters
• NEW: Parallel dead-end ChannelSplitter + dual AnalyserNode taps at input and output stages
• NEW: Per-channel peak and RMS readings (inputPeakL/R, inputRmsL/R, peakL/R, rmsL/R)

File-Based Preset Import/Export

• NEW: Export presets as .tabdsp files (downloads to your Downloads folder)
• NEW: Import presets via file picker (.tabdsp or .json files) or drag-and-drop

UI/UX Refinements

• CHANGED: Compact toolbar with popovers for presets and settings
• CHANGED: Module strip and canvas layout refined
• CHANGED: Module glow refined to perimeter-only; improved locked module readability
• CHANGED: Toolbar title/badge enlarged, branding centered
• CHANGED: Band panel auto-hide with fade timing, canvas-leave detection, auto-dismiss

Limiter UI Refinements

• CHANGED: True Peak/Sample Peak cycle button replaces previous toggle
• CHANGED: Both sample peak and true peak bars always visible in True Peak mode
• CHANGED: Limiter meter redesign

Bug Fixes

• FIXED: Firefox standalone window resize freeze
• FIXED: Enable onboarding overlay for sidebar/window modes
• FIXED: tabCapture tier enforcement — harmonized bypass with state flag tracking
• FIXED: E2E smoke test selectors for unified toolbar rename (.title to .toolbar-title)

Documentation

• FIXED: Signal flow accuracy, test counts, post-dynamics analyser references, version strings
• FIXED: Outdated documentation — node counts, version refs, false claims corrected
• REMOVED: Firefox resize freeze from Known Bugs (resolved)

Testing

• NEW: Test suite expanded to 978 tests (698 Vitest unit + 238 Chrome E2E + 42 Firefox E2E)

Bug Fixes

• FIXED: Stale Delete/Export button states after sidebar retarget, window retarget, cross-mode sync, A/B toggle, undo, and redo

UI Improvements

• CHANGED: Preset import toast restyled — larger, green gradient, centered over preset bar
• NEW: Preset placeholder reload — click active preset name in dropdown to reload it

Audio Engine

• NEW: Late-created AudioContext destination chain building — contexts created after enable automatically get DSP chains

Testing

• FIXED: Undo-redo test timing adjusted for debounce accommodation
• NEW: E2E test for late-created AudioContext chain building

Sidebar-First UI

• NEW: Sidebar and standalone window are now the primary UI — popup panel removed as default
• NEW: Dynamic tab retargeting — sidebar follows active tab, re-targets on tab switch
• NEW: Header redesign with state-aware source dot and prominent Enable checkbox
• NEW: Onboarding overlay for first-time users

Per-Hostname State

• NEW: EQ, compressor, limiter, multiband, and gain parameters persist per hostname
• NEW: A/B comparison, undo/redo history, Auto-Enable, and CORS settings are per-hostname
• NEW: Delta undo system — only changed parameters are stored per undo step

Auto-Enable & DRM Detection

• NEW: Auto-enable on page interaction — deferred DSP activation triggered by user gesture
• NEW: DRM detection push mechanism (A+C) — proactive notification + storage persistence for reliable tabCapture fallback

Bug Fixes

• FIXED: Chrome 146 browser detection — uses Firefox-only API for reliable detection
• FIXED: ENABLE registration — announcement pattern ensures engine registration before activation
• FIXED: GET_TAB_STATUS retry-failure response missing fields
• FIXED: tabCapture spectrum — blocky display, level offset, and flashing resolved
• FIXED: DRM detection timing — passive flag + immediate push + storage persistence
• FIXED: Post-dynamics spectrum tap — multiband output only
• FIXED: Chrome Side Panel open/close
• FIXED: 3 redundant browser detection guards replaced with feature detection

Testing

• NEW: Test suite expanded from 415 to 909 tests (+119%)
• NEW: Istanbul coverage instrumentation — worklet coverage 99.68% statements
• NEW: Professional measurement-based validation with ITU-R BS.1770-4 compliance
• IMPROVED: DSP test tolerances tightened to professional standards

Bug Fixes

• FIXED: Multiband crossover hover cursor blocked by inline style specificity
• FIXED: Compressor/limiter threshold drag not working without active audio
• FIXED: Bypass arc rendering for consecutive modules

UI Improvements

• CHANGED: Tier badge eye icon replaced with key icon
• NEW: Free tier green pulse animation on tier badge
• NEW: Limiter ceiling line hover cursor feedback

Documentation

• NEW: Terms of Service, Privacy Policy, and Refund Policy pages
• NEW: Licensing nav link, Lemon Squeezy checkout overlay, store CTAs
• FIXED: Docs/v2 audit — DSP accuracy fixes, content gaps, a11y, UI overview zones
• FIXED: Documentation drift from project audit (5 items)

Development Tooling

• NEW: Automated test suite — 415 tests (294 Vitest + 121 Playwright E2E)
• NEW: ESLint v9, GitHub Actions CI, Claude hooks and skills
• NEW: V8 coverage reporting

Freemium Tier System

• NEW: Three-tier feature gating — Free (EQ + spectrum + RMS + linear phase + M/S), Enthusiast (+ compressor + module reorder), Professional (+ multiband + limiter + LUFS + all presets)
• NEW: Defense-in-depth enforcement — popup UI gating + DSP-level force-bypass + LUFS suppression
• NEW: License panel — key input, tier badge in header, upgrade prompt overlay, locked module states
• NEW: Lemon Squeezy server-side license validation — activate/validate/deactivate API, subscription + perpetual license types
• NEW: Device limiting — 6 activations per key, activation count display
• NEW: Offline grace periods — 7 days (subscription), 90 days (perpetual), automatic downgrade when expired
• NEW: Background re-validation via chrome.alarms (24-hour interval)
• NEW: Cross-mode license sync via storage.onChanged
• NEW: Uninstall deactivation page — automatically frees activation slot on extension removal
• NEW: Grandfather clause — existing users auto-granted permanent Professional on upgrade
• NEW: Preset lock indicators for presets using tier-locked features

Background Tab Overlay & Sidebar Robustness

• NEW: "Visualization Paused" overlay when target tab is in background
• NEW: Auto-retarget on target tab close — sidebar queries newly active tab
• NEW: Sidebar re-targeting via storage.onChanged
• NEW: Standalone window retargets via URL update
• NEW: Popup storage isolation — popup always targets current active tab
• NEW: Firefox user gesture preservation — sidebarAction.open() called synchronously
• NEW: Stale tab ID validation — checks window membership
• NEW: Navigation re-initialization on tabs.onUpdated for per-tab reattachment

Canvas Render Dispatch Fix

• FIXED: COMP/LIMIT canvases not rendering on module switch when no audio playing

Documentation

• NEW: Licensing & Tiers page with feature comparison and activation guide
• UPDATED: Privacy disclosure — accurate LS API call documentation
• UPDATED: Permissions table — added alarms, tabCapture, offscreen, declarativeNetRequest
• FIXED: quick-start.html DRM note — Chrome tabCapture documented accurately
• FIXED: signal-flow.html post-dynamics analyser — "after last dynamics module" not "after Multiband only"
• NEW: Display Modes section in UI overview

Compatibility Audit

• NEW: Silence detection on media element chains — monitors post-capture audio, reports to popup after 2 seconds of silence
• NEW: Opt-in CORS expansion for cross-origin audio — crossorigin attribute injection + declarativeNetRequest CORS headers for allowlisted CDN domains
• NEW: Chrome tabCapture fallback for DRM-protected content — offscreen document with full DSP chain via chrome.tabCapture
• NEW: WebRTC detection — observational createMediaStreamSource counting with popup status display
• FIXED: Offscreen document module reorder now uses 50ms crossfade (parity with other chain types)
• CHANGED: Safari and Edge moved to future browser targets
• REMOVED: Linear phase EQ zippering from Known Bugs (resolved)

Chrome MV3 Support

• NEW: Unified manifest.json for both Firefox and Chrome — includes both background.scripts and background.service_worker
• NEW: CSP-immune worklet URL injection adapted to each browser's messaging requirements
• NEW: Persistent background state via chrome.storage.session
• FIXED: Chrome compressor/limiter canvas waveforms not displaying — Chrome's message bus uses JSON serialization (not structured clone), breaking Float32Array history buffers; now serialized transparently
• FIXED: Worklet loading permanently cached failure when URLs not yet available via async messaging
• FIXED: Async response pattern for Chrome compatibility
• CHANGED: Firefox minimum version bumped from 112.0 to 121.0

Performance Optimization

• IMPROVED: Total estimated CPU usage reduced from ~5.1% to ~3.8% (all features enabled), ~2.7% typical
• IMPROVED: Linear Phase EQ rewritten with FFT overlap-add (1024-pt radix-2 Cooley-Tukey) — ~4x faster
• IMPROVED: Limiter lookahead uses monotone deque sliding window maximum — O(1) amortized
• IMPROVED: Compressor/limiter worklet postMessage uses Transferable arrays (zero-copy)
• IMPROVED: LUFS meter circular buffer with O(1) running sums for absolute gate
• IMPROVED: Multiband compressor pre-allocated buffers and hoisted coefficients
• IMPROVED: Conditional meter payload, spectrum pre-pass, visibility-gated metering, cached DOM queries

Documentation

• FIXED: Stale CQT/Goertzel spectrum references corrected to FFT 8192 + constant-Q power summation across 11 pages
• FIXED: Linear phase EQ performance numbers updated

Bug Fixes

• FIXED: GPU usage scaling linearly with bypassed module count (87% to 220% in Firefox Process Manager) — removed filter: drop-shadow() from bypass arc SVG path and arrow elements that forced per-frame Gaussian blur re-computation at 60fps per bypassed module

Accessibility (Phase 6)

• NEW: ARIA roles and labels on all interactive controls (knobs, bypass buttons, toggles, meters)
• NEW: Full keyboard navigation — Arrow/PageUp/PageDown/Home/End on all knobs and sliders
• NEW: Module reorder buttons with screen reader live region announcements
• NEW: Focus management for floating panels and confirm dialogs
• NEW: 1Hz throttled ARIA meter updates (separate from 60fps visual loop)

New Features

• NEW: Permission revocation detection with actionable user messaging
• NEW: CSP-immune worklet URL injection for improved site compatibility
• NEW: DRM/unprocessable audio notification when audio cannot be intercepted
• NEW: Compliance warning indicator in limiter panel (caution/warning severity)

Bug Fixes

• FIXED: -12dB HF rolloff in digital mode caused by WaveShaper anti-aliasing filter
• FIXED: Metering bugs at 0 dBFS (history buffers, scalar fallbacks)
• FIXED: GET_STATUS race condition on first popup open
• FIXED: Keyboard shortcuts (E, D, L, M) now properly propagate DSP state changes

Cleanup

• REMOVED: ~1350 lines of legacy DOM code (HTML, CSS, JS)
• REMOVED: Orphaned CQT analyzer worklet file

Bug Fixes

• FIXED: Sidebar no longer auto-opens on extension install
• FIXED: Source count on YouTube showing "2" on first enable — now filters closed AudioContexts and reports combined total
• FIXED: Destination chain sidechain HP filter stuck at 20Hz (wrong parameter name)
• FIXED: A/B bypass now toggles processing on destination chains (YouTube, SoundCloud)
• FIXED: LUFS meter reset now works on destination chains
• FIXED: Compressor meter 0 dBFS no longer misread as -96 dB

New Features

• NEW: Install/update badge notification on extension icon — clears on first popup open
• NEW: Standalone window closes automatically when its associated tab is closed
• NEW: Standalone window reloads when its associated tab refreshes
• NEW: Status notification banner when audio processing is restricted or no sources detected

UI Improvements

• NEW: Collapsible preset section with chevron toggle; undo/redo buttons relocated to header controls row
• NEW: Info icon in header linking to documentation modules page
• FIXED: Multiband crossover lines now have visible grab handles (hover/drag highlight)
• FIXED: Slider/knob sensitivity — input/output gain, EQ, and multiband knobs had too-coarse sensitivity
• FIXED: Factory presets V1-to-V2 migration bug; all 8 presets now differentiated with unique multiband settings

Hybrid Audio Interception

• NEW: Destination-level audio interception via AudioNode.prototype.connect patching
• NEW: Works on sites that use Web Audio API directly (e.g., SoundCloud) without <audio>/<video> elements
• NEW: Cross-origin media element detection prevents audio silence on sites like Bandcamp
• NEW: Full DSP parity for destination chains: bypass, enable/disable, metering, multiband, spectrum analysis

M/S Processing & Linear Phase EQ

• NEW: M/S (Mid/Side) processing mode for destination chains with separate Mid and Side EQ
• NEW: Linear Phase EQ (511-tap FIR) for destination chains
• NEW: M/S solo monitoring (Mid Solo / Side Solo) for destination chains
• IMPROVED: Linear phase FIR zippering reduced via fingerprint dedup, crossfade snapshot, and throttled FIR regeneration

Bug Fixes

• FIXED: Background audio artifacts when tab is hidden (suspend/resume analysis nodes on visibility change)
• FIXED: Compressor makeup gain visualization (set worklet parameter instead of external GainNode)
• FIXED: Cross-origin media elements no longer cause audio silence (Bandcamp, CDN-hosted media)

Distribution

• CHANGED: Downloads moved to dedicated releases page on GitHub Pages
• NEW: Public feedback repository for bug reports and feature requests
• CHANGED: Auto-update manifest now uses GitHub Pages URLs

Documentation

• NEW: V2 documentation site deployed to GitHub Pages
• 10 comprehensive pages with dual-audience approach (Essential + Gear Head Details)
• Dark/light theme toggle with system preference detection
• Search modal with keyboard shortcut (Cmd/Ctrl + K)
• Responsive design for desktop, tablet, and mobile
• Complete module reference (EQ, Compressor, Multiband, Limiter)
• 35+ glossary terms with technical deep-dives
• Signal flow diagrams and use case examples

Code Quality & Stability

• FIXED: Extension disconnection handling (logs warning, stops meter updates)
• FIXED: RMS sum drift prevention in compressor/multiband/LUFS worklets (periodic recalculation)
• FIXED: GC pressure reduction (~160k fewer allocations/sec via Float32Array meter messages)
• FIXED: Concurrent injection race condition in the background layer (pending-injection tracking map)
• FIXED: Denormal protection in compressor, multiband, LUFS meter worklets
• FIXED: Coefficient smoothing for HP filter and crossovers (prevents clicks)
• FIXED: FIR coefficient crossfade in linear-phase-eq (prevents glitches)
• FIXED: AudioContext memory leak on page navigation (page-unload cleanup)
• FIXED: Firefox scrollbar styling in popup
• REMOVED: ~135 lines of dead CSS (legacy multiband meters, unused selectors)
• REMOVED: Dead message handlers in the audio engine (SET_INPUT_GAIN/SET_MASTER_GAIN)
• REMOVED: Dead code in the UI layer (empty stubs, unused variables)
• REMOVED: Legacy signal chain nodes (dynDry/dynWet/dynSum)

Browser Compatibility

• FIXED: roundRect polyfill for older browsers without Canvas roundRect support
• FIXED: CSS undefined variables (4 variables fixed)

Initial pre-beta release. First signed and self-distributed version.

Core Features

• 8-Band Parametric EQ with real-time spectrum visualization (CQT analyzer)
• Linear Phase Mode (511-tap FIR) for transparent phase-coherent processing
• M/S Processing with separate Mid and Side EQ, solo monitoring
• Single-Band Compressor with RMS/Peak detection, sidechain HP filter
• Multiband Compressor (3-band/4-band) with LR4 crossovers
• True Peak Limiter with 4x oversampling (ITU-R BS.1770-4 compliant)
• LUFS Metering (Momentary, Short-term, Integrated)
• Input/Master Gain Controls (-24 to +24 dB)

UI/UX Features

• Modular UI Design with module blocks and canvas switching
• Drag-and-Drop Module Reordering with glitch-free crossfade
• Interactive Canvases: EQ spectrum, compressor waveforms, limiter stereo meters
• Global Meter Section showing all module levels (IN/EQ/MB/COMP/LIM/OUT)
• Floating Control Panels for EQ bands and multiband bands
• A/B Comparison with keyboard shortcut (A key)
• Preset Management: 8 factory presets, 15 compliance presets, custom preset save/load/export/import
• Site Override for per-domain settings
• Bypass Visualization with orange routing arcs and consecutive bypass spanning

Audio Quality

• CQT Spectrum Analyzer: 60 bins (6 per octave), Q = 8.65, Goertzel-based
• Higher-Order Filters: 12/24/36/48 dB/oct with Butterworth and Linkwitz-Riley options
• True Sidechain HP Filtering: Detection path only, preserves output bass
• Soft Knee Compression: Smooth transition region around threshold
• True Peak Detection: 4x polyphase FIR oversampling with ITU/Kaiser modes
• Silent Enable/Disable: No clicks, pops, or stutters when toggling processing

Performance

• CPU Usage: 2-5% typical (modern systems), <5% target achieved
• Efficient Rendering: document.hidden check prevents background rendering
• Optimized Message Passing: Float32Array meter data, debounced updates

Distribution

• Firefox Self-Distribution: Signed via AMO, hosted on GitHub Pages
• Auto-Updates: Update manifest at tabdsp.com/updates.json
• Downloads: tabdsp.com/releases/

Planned Features

These features are under consideration for future releases.

Accessibility

• High Contrast Mode: WCAG AAA compliance

Advanced Features

• Dynamic EQ: Frequency-dependent compression (soothe2-style)
• Spectral Processing: FFT-based noise reduction, de-essing
• Convolution Reverb: Impulse response-based room simulation
• Auto-Gain: Automatic makeup gain calculation for compressors

UI/UX Improvements

• Preset Browser: Categorized preset library with search
• Visual EQ Matching: Drag target curve, auto-calculate band parameters
• Waveform Display: Full audio waveform with zoom/pan
• Customizable Themes: User-defined color schemes