NovaCut

A professional Android video editor built with Kotlin and Jetpack Compose. Open alternative to CapCut, PowerDirector, and DaVinci Resolve — with on-device AI, GPU-accelerated effects, and desktop NLE interoperability.

NovaCut PREMIUM MOBILE VIDEO EDITING

See CHANGELOG.md for full release history.

Project planning

• ROADMAP.md tracks active and future work.
• COMPLETED.md summarizes shipped roadmap work.
• RESEARCH_REPORT.md summarizes product, platform, and ecosystem research.
• Historical roadmap and research inputs live under docs/archive.

Features

Timeline Editing

• Multi-track timeline with video, audio, overlay, text, and adjustment layers
• Trim, split, merge, crop, rotate with visual handles
• Slip/slide editing — drag clip body to slide (reposition) or slip (shift source window)
• Magnetic snapping — clips snap to edges, playhead, and markers (8dp threshold with diamond indicators)
• Clip grouping — select multiple clips, group/ungroup, move as a unit
• Speed control (0.1x-16x) with bezier speed ramping curves and presets
• Keyframe animation for position, scale, rotation, opacity, volume with 12 easing types (linear, ease in/out, spring, bounce, elastic, back, circular, expo, sine, cubic)
• 14 speed presets including time freeze, film reel, heartbeat, crescendo
• Undo/redo (50 levels) with full state restoration + command-based undo foundation
• Long-press multi-select for batch operations
• Pinch-to-zoom + zoom in/out/fit buttons
• Timeline scrubbing with frame-accurate seeking
• Colored timeline markers — 6 colors (red/orange/yellow/green/blue/purple) with labels, notes, and jump navigation
• Sticker/GIF/image overlays — position, scale, rotate, opacity with timeline placement
• Favorites & recent effects — mark effects as favorites, track recently used for quick access
• Multi-cam sync — audio-based clip synchronization across tracks
• Clip reorder & move — reorder clips within a track or move between tracks
• Haptic feedback — tactile response on trim handle grab and magnetic snap
• Waveform caching — LRU cache avoids redundant audio decoding on timeline recomposition
• Clip color labels — 7 Catppuccin colors (red, peach, green, blue, mauve, yellow, none) with colored top border on Timeline
• Track collapse/expand — Per-track chevron + collapse/expand all toggle, collapsed tracks show thin 24dp colored bars
• Track height cycling — Long-press track type icon to cycle 48→64→80→96dp
• Keyboard shortcuts — Space, Ctrl+Z/Y, arrow keys, M, S, +/-, Delete, Ctrl+S, Ctrl+C/V for external keyboard editing
• Snap-to-beat/marker — Beat markers and timeline markers as additional snap targets (settings-driven)
• Marker list panel — Searchable, filterable marker list with color chips, inline label editing, jump-to-time

Effects & Transitions

• 37 GPU-accelerated GLSL transitions with unique Material icons per type — dissolve, wipe, zoom, spin, flip, cube, ripple, pixelate, morph, glitch, swirl, heart, dreamy, plus 12 new: door open, burn, radial wipe, mosaic reveal, bounce, lens flare, page curl, cross warp, angular, kaleidoscope, squares wire, color phase
• 40+ video effects — brightness, contrast, saturation, hue, sharpen, vignette, mosaic, fisheye, wave, chromatic aberration, radial blur, motion blur, tilt shift
• Film grain — perceptual-aware (more in shadows, less in highlights), animated blue noise pattern
• VHS/Retro — scanlines, chroma bleeding, tracking distortion, posterized color depth
• Glitch — RGB channel splitting, 8x8 block corruption, horizontal line displacement
• Light leak — procedural animated warm gradient with screen blend mode
• 9-tap Gaussian blur — separable kernel with proper sigma-based weights
• 18 blend modes (normal, multiply, screen, overlay, soft light, hard light, difference, exclusion, etc.)
• Freehand/rectangle/ellipse/gradient masks with feather, expansion, and motion tracking
• Professional chroma key — YCbCr color space keying with smoothstep feathering and green/blue spill suppression

Color Grading

• Lift/gamma/gain color wheels with continuous control
• RGB curves and HSL qualifier
• LUT import (.cube/.3dl) with file picker and intensity control
• Color matching — per-channel gamma correction between reference and target clips
• Video scopes — histogram, waveform, vectorscope with animated overlay (GPU compute shader ready for ES 3.1+)

Audio

• Full audio mixer with per-track volume faders, pan slider, mute/solo, smoothed VU meters (ballistic attack/decay)
• 15 DSP effects — parametric EQ, compressor (corrected attack/release), limiter, delay, chorus, de-esser, pitch shift, noise gate
• Waveform visualization with fade envelope overlay
• Beat detection — spectral flux onset detection with adaptive thresholding and BPM estimation (aubio NDK ready)
• Auto-duck — speech-aware volume keyframing (analyzes voice track, creates keyframes on music track)
• EBU R128 loudness normalization — K-weighted measurement with 6 platform presets:
  • YouTube/Spotify (-14 LUFS), TikTok (-14 LUFS), Podcast/Apple (-16 LUFS), Broadcast EBU R128 (-23 LUFS), Cinema (-24 LUFS), Loud (-9 LUFS)
• True-peak limiting to prevent clipping
• Voiceover recording with automatic timeline placement
• Fade overlap protection — fade in + fade out constrained to clip duration
• Noise reduction — Spectral gate heuristic (5 modes: off/light/moderate/aggressive/spectral gate). DeepFilterNet ML path planned

AI Tools

Text & Titles

• Rich text overlays with 10+ animation styles
• Static templates — lower thirds, title cards, end screens, CTAs
• Animated Lottie templates — 10 built-in (slide-in lower third, bounce title, typewriter, glitch reveal, neon glow, fade subtitle, circle logo reveal, countdown, subscribe button). Render frame-by-frame for export via LottieDrawable
• Caption editor with start/end time sliders (mutually constrained)
• Caption style gallery with karaoke, word-pop, bounce, typewriter, minimal styles
• Continuous caption positioning via BiasAlignment (not 3-zone snap)
• Text on path (straight, curved, circular, wave)
• Shadow, glow, letter spacing, line height controls

Text-to-Speech

• System TTS — Android built-in voices with mutex-protected synthesis
• Piper TTS (planned) — near-human quality VITS voices via Sherpa-ONNX (stub, requires dependency integration)
  • 10 voice profiles defined: Amy (US), Ryan (US), Alba (UK), Thorsten (DE), Dave (ES), Siwis (FR), Takumi (JP), Huayan (CN), Sunhi (KR), Faber (BR)
  • Currently falls back to Android System TTS
• System/Piper engine toggle in TTS panel

Export

• GIF export — Self-contained GIF89a encoder with LZW compression, configurable frame rate (10/15/20fps) and max width (320/480/640px)
• Frame capture — PNG/JPEG single-frame export from current playhead position
• 480p to 4K Ultra HD
• 4 codecs — H.264, H.265 (HEVC), AV1, VP9 with hardware capability detection via MediaCodecList
• HDR export confidence — HEVC, AV1, and VP9 preflight reports HDR10+, Dolby Vision Profile 10, Ultra HDR source gain maps, and device-tier hardware encode support before render
• One-tap platform presets — YouTube 1080p, YouTube 4K, TikTok, Instagram Reels, Instagram Square, Threads
• Multi-sequence Media3 Composition export for visible video and overlay tracks, with dedicated audio-track mixdown
• Batch export with multiple presets simultaneously
• Background export with progress notification, ETA display, and cancel
• Timeline interchange — OTIO (OpenTimelineIO) JSON export/import + FCPXML export for desktop NLE round-tripping (DaVinci Resolve, Premiere Pro, Final Cut Pro)
• EDL export (CMX 3600) with sanitized reel names and proper timecodes
• Chapter markers and subtitle export (SRT, VTT with word-level cues, ASS/SSA with full styling)
• Burned-in subtitle rendering — Canvas-based with ASS/SSA file generation for FFmpeg integration
• Audio-only and stems export modes
• Export error cleanup — partial output files deleted on failure/timeout

Effect Library

• Copy/paste effects between clips
• Export effects to .ncfx file for sharing
• Import effects from .ncfx with portable LUT references (filename-based, not absolute paths)

Project Management

• User template system (save/load/delete project templates, preserves non-media track clips)
• Project snapshots with version history and auto-generated default names
• Project archive (ZIP export)
• Auto-save with configurable interval, format versioning, rotating backups
  • Full serialization: all clip fields, compound clips, 9 caption style properties, mask bezier handles, clip group IDs
• Command-based undo/redo foundation — sealed class with AddClip, RemoveClip, TrimClip, MoveClip, SetClipSpeed, ApplyEffect, CompoundCommand
• 3-tier proxy workflow — thumbnail (scrubbing) / proxy (540p editing) / original (export) with auto-switch and storage management
• Cloud backup UI (backend pending)
• First-run tutorial — auto-shows on first launch, dismissable, resettable from Settings

Settings

• Default resolution, frame rate, aspect ratio, export codec
• Auto-save toggle + interval (15-300s)
• Proxy resolution selector
• Reset first-run tutorial
• Show waveforms — Global waveform visibility toggle
• Snap to beat / snap to markers — Timeline snap behavior toggles
• Default track height — 48/64/80/96dp chips
• Confirm before delete — Gate clip deletion dialog
• Thumbnail cache size — 64/128/256 MB
• Default export quality — LOW/MEDIUM/HIGH
• All settings persist via DataStore

Tech Stack

Architecture

com.novacut.editor/
├── ai/                     # AI features (captions, scene detect, stabilize, auto-edit)
├── engine/                 # Core engines (29 injectable singletons)
│   ├── VideoEngine          # Media3 playback + export
│   ├── AudioEngine          # Waveform extraction + PCM processing
│   ├── AudioEffectsEngine   # DSP chain (EQ, compressor, chorus, etc.)
│   ├── ShaderEffect         # GLSL fragment shader pipeline
│   ├── KeyframeEngine       # Bezier/hold interpolation
│   ├── ProjectAutoSave      # JSON serialization with format versioning
│   ├── ExportService        # Foreground service for background export
│   ├── BeatDetectionEngine  # Spectral flux onset + BPM estimation
│   ├── LoudnessEngine       # EBU R128 measurement + normalization
│   ├── NoiseReductionEngine # Spectral gate (DeepFilterNet stub)
│   ├── FrameInterpolationEngine  # RIFE v4.6 slow-motion (stub)
│   ├── InpaintingEngine     # LaMa object removal (ONNX Runtime + NNAPI)
│   ├── UpscaleEngine        # Real-ESRGAN video upscaling (stub)
│   ├── VideoMattingEngine   # RVM AI green screen (stub)
│   ├── StabilizationEngine  # OpenCV optical flow (stub)
│   ├── StyleTransferEngine  # AnimeGAN + Fast NST (stub)
│   ├── SmartReframeEngine   # Subject-tracking auto-crop
│   ├── TapSegmentEngine     # SAM 2.1 / MobileSAM target metadata (stub)
│   ├── PiperTtsEngine       # Piper VITS TTS (stub, system TTS fallback)
│   ├── LottieTemplateEngine # Animated title rendering
│   ├── FFmpegEngine         # FFmpegX fallback encoder (stub)
│   ├── SubtitleRenderEngine # Canvas + ASS subtitle rendering
│   ├── GenerativeVideoPolicy # Cloud-only trust gates for large video generators
│   ├── TimelineExchangeEngine  # OTIO/FCPXML interchange
│   ├── ProxyWorkflowEngine  # 3-tier media management
│   ├── EditCommand          # Command-pattern undo/redo
│   ├── db/ProjectDatabase   # Room database with migrations
│   ├── whisper/WhisperEngine     # Built-in Whisper (ONNX)
│   ├── whisper/SherpaAsrEngine   # Sherpa-ONNX ASR target metadata + fallback
│   └── segmentation/        # MediaPipe selfie segmentation
├── model/                  # Data classes (Project, Clip, Track, Effect, etc.)
├── ui/
│   ├── editor/             # Main editor (EditorScreen, EditorViewModel, 40+ panels)
│   ├── export/             # ExportSheet, BatchExportPanel
│   ├── mediapicker/        # MediaPickerSheet
│   ├── projects/           # ProjectListScreen, ProjectTemplateSheet
│   ├── settings/           # SettingsScreen, SettingsViewModel
│   └── theme/              # Catppuccin Mocha theme
├── MainActivity.kt         # Single activity, Compose navigation, permission handling
└── NovaCutApp.kt           # Application class, notification channels

Build

# Debug build
./gradlew assembleDebug

# Release build (requires keystore.properties or env vars)
./gradlew assembleRelease

# Managed-device startup/editor performance gate
./gradlew :baselineprofile:pixel6Api36BenchmarkReleaseAndroidTest :baselineprofile:collectNonMinifiedReleaseBaselineProfile

Requirements

• Android Studio Ladybug+ (2024.2+)
• AGP 8.7.3, Gradle 8.9, JDK 21
• Android SDK 36

Release Signing

Configure via keystore.properties:

storeFile=path/to/your.jks
storePassword=yourpass
keyAlias=youralias
keyPassword=yourpass

Or via environment variables: NOVACUT_STORE_FILE, NOVACUT_STORE_PASSWORD, NOVACUT_KEY_ALIAS, NOVACUT_KEY_PASSWORD

If release credentials are not configured, assembleRelease falls back to debug signing so CI and local verification can still produce a testable release artifact without relying on an embedded keystore.

Dependencies

Key external dependencies currently in build.gradle.kts:

Supported Devices

• Min SDK: 26 (Android 8.0 Oreo)
• Target SDK: 36 (Android 16)
• Required: OpenGL ES 3.0
• Recommended: 4GB+ RAM, Snapdragon 7-series or better for AI features
• AV1 hardware encoding: Pixel 8+, Snapdragon 8 Gen 3+, Dimensity 9200+

Permissions

Media access uses the system Photo Picker (ActivityResultContracts.PickVisualMedia) and ACTION_OPEN_DOCUMENT exclusively — NovaCut requests no broad READ_MEDIA_VIDEO / READ_MEDIA_IMAGES / READ_MEDIA_AUDIO / READ_EXTERNAL_STORAGE / WRITE_EXTERNAL_STORAGE permissions, so the per-URI grant model survives background kill without the Android 14 Selected Photos compatibility-mode loss.

Known Limitations

• Multi-sequence export now honors track opacity through Media3 compositor settings, and all 18 fallback blend modes render distinctly; true source-over-destination blend math still needs a custom programmable compositor because Media3's public settings only expose alpha/transform
• clip.isReversed works in preview but not in export (Media3 Transformer has no reverse playback support)
• SmartRenderEngine analysis results not used for actual export bypass
• 11 AI/ML engine stubs awaiting dependency integration (see ROADMAP.md)

License

MIT