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+# 8-cut
+
+A desktop tool for cutting 8-second clips from video files, designed for building [SELVA](https://github.com/google-deepmind/selva) datasets.
+
+## Overview
+
+8-cut lets you scrub through a video, mark a cut point, and export a fixed 8-second clip with one keypress. It tracks every export in a local SQLite database so you can resume a session or switch between resolution variants of the same source without duplicating work.
+
+All clips are exactly 8 seconds — this is a hard constraint of the SELVA format.
+
+## Features
+
+- **Frame-accurate scrubbing** — click or drag the timeline; arrow keys and J/K/L for frame-by-frame stepping
+- **Keyboard shortcuts** — J/L step one frame, Shift+J/L step one second, Space/P play/pause, K pause and return to cursor, E export, M jump to next marker
+- **Two export formats** — H.264/AAC MP4 or lossless WebP image sequence (frames + `.wav` audio extracted alongside)
+- **Portrait crop** — crop to 9:16, 4:5, or 1:1 before export; adjustable horizontal crop position
+- **Resize** — scale short side to a fixed pixel size (e.g. 256)
+- **Export history** — timeline markers show previously exported clips; fuzzy filename matching detects resolution variants of the same file (e.g. `_2160p` vs `_1080p`)
+- **Mask generation** — generate binary foreground masks per-frame using SAM2 (segmentation) or Depth Anything V2 (depth-based), via a bundled venv
+- **Playlist** — drag-and-drop multiple files; duplicates are ignored
+
+## Requirements
+
+- Python 3.11+
+- `ffmpeg` in `PATH`
+- PyQt6
+- python-mpv (requires libmpv)
+
+```
+pip install -r requirements.txt
+```
+
+For mask generation tools, additional dependencies (PyTorch, transformers, segment-anything-2, opencv) are installed into `~/.8cut/venv/` via the Settings dialog.
+
+## Usage
+
+```
+python main.py
+```
+
+Drop a video onto the playlist or use the file picker. Scrub to your cut point, set the output folder and clip name, then press **Export** (or `E`).
+
+### Export formats
+
+| Format | Output |
+|--------|--------|
+| MP4 | `<folder>/<name>_NNN.mp4` — H.264 video + AAC audio |
+| WebP sequence | `<folder>/<name>_NNN/frame_%04d.webp` — lossless WebP frames + `<name>_NNN.wav` PCM audio |
+
+### Keyboard shortcuts
+
+| Key | Action |
+|-----|--------|
+| `←` / `J` | Step back 1 frame |
+| `→` / `L` | Step forward 1 frame |
+| `Shift+←` / `Shift+J` | Step back 1 second |
+| `Shift+→` / `Shift+L` | Step forward 1 second |
+| `Space` / `P` | Toggle play/pause |
+| `K` | Pause and snap video to cursor |
+| `E` | Export clip |
+| `M` | Jump to next export marker (wraps) |
+
+Arrow keys and J/K/L are ignored when a text field has focus.
+
+### Mask generation tools
+
+Two standalone scripts live in `tools/`. They are run by the app via a managed venv but can also be called directly:
+
+```
+python tools/sam_masks.py  --input clip.mp4 --output masks_dir/
+python tools/depth_masks.py --input clip.mp4 --output masks_dir/
+```
+
+Both output one binary PNG per frame (`frame_0000.png`, …) where white = foreground.
+
+- **SAM2** (`sam_masks.py`) — uses `facebook/sam2-hiera-large`; center-point prompt propagated across all frames
+- **Depth Anything V2** (`depth_masks.py`) — uses `depth-anything/Depth-Anything-V2-Large-hf`; Otsu threshold on the depth map
+
+## Database
+
+Export history is stored in `~/.8cut.db` (SQLite). The database records filename, start time, and output path for every clip. When you open a file, 8-cut checks whether a similar filename has been processed before (stripping resolution tags like `_2160p`, `_1080p`, codec tags, etc.) and pre-populates the timeline with existing markers.
+
+## Testing
+
+```
+pytest tests/ -v
+```
+
+38 unit tests covering path builders, ffmpeg command generation, time formatting, and the processed-clips database.