Volleyball Action Annotator (VAA)

A desktop tool for annotating volleyball videos with:

• rally boundaries
• nested rally actions
• YOLO bounding boxes
• normal frame and 3-frame superframe viewing
• manual ball position markup

Interface

Features

• Load a video and save/load project state.
• Mark rally start and rally end.
• Derive nested actions inside a rally from box classes.
• Show a hierarchical panel on the right: Rally -> Start / Actions / End.
• Draw, move, delete, copy/paste, and resize bounding boxes.
• Export YOLO labels and project JSON.

Project Structure

core/
├── annotation_manager.py   # rallies, actions, yolo boxes, export
├── video_processor.py      # frame loading and superframe generation
└── yolo_tracker.py         # YOLO integration

ui/
├── image_canvas.py         # frame view, boxes, ball markup
├── main_window.py          # main window and shortcuts
└── widgets/
    ├── action_panel.py     # rally/action tree + playback step
    └── timeline.py         # timeline widgets

config/
└── config.py               # action types, colors, UI settings

Typical Workflow

1. Open a video or project.
2. Start a rally.
3. Draw boxes with the needed classes such as Serve, Receive, Set, Attack, and others.
4. Switch to superframe when needed.
5. End the rally.
6. Review the rally tree on the right.
7. Export the annotations.

Keyboard Shortcuts

Navigation and Playback

• Space - Play / Pause
• Left - Previous frame
• Right - Next frame
• A - Previous frame
• D - Next frame
• S - Jump backward by 15 frames
• W - Jump forward by 15 frames
• Q - Go to previous annotated frame
• E - Go to next annotated frame
• Home - Go to the first frame
• End - Go to the last frame

Rally Annotation

• Return - Start rally
• Shift+Return - End rally
• [ - Start rally
• ] - End rally
• | - Split the current rally at the current frame

Display

• F1 - Toggle superframe
• F2 - Toggle bounding boxes

Box Editing

• Delete - Delete selected box
• Ctrl+C - Copy boxes from the current frame
• Ctrl+V - Paste boxes into the current frame

UI Notes

• The selected box has resize handles in the top-left and bottom-right corners.
• The right panel includes a Step field (1..30) that controls playback frame stepping during Play.
• Clicking any item in the rally/action tree seeks to the corresponding frame.

Output Formats

• YOLO labels: one .txt file per frame
• Project JSON: rallies, nested actions, yolo_boxes, and saved app state