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GUI Overview

The OSL Annotation Tool supports two distinct annotation modes: Classification and Localization (Action Spotting). The interface adapts based on the project type selected at startup.

1. Welcome Page (Startup Interface)

The Welcome Page is the entry point of the OSL Annotation Tool. It allows users to create or import projects and access additional resources.

Welcome Interface

Main Actions

  • Create New Project

  • Start a new annotation project.

  • You will be prompted to select the annotation mode (Classification, Localization, Description, or Dense Description).

  • Initializes an empty workspace.

  • Import Project JSON

  • Load an existing annotation project from a JSON file.

  • The interface automatically adapts to the project type.
  • If the JSON contains validation errors, a detailed error message will be displayed.

Additional Resources

  • Video Tutorial

  • Opens a guided tutorial explaining how to use the tool.

  • Recommended for first-time users.

  • GitHub Repo

  • Redirects to the official GitHub repository.

  • Includes documentation, updates, and issue tracking.

2. Classification Mode

Designed for assigning global labels (Single or Multi-label) to video clips.

Classification Interface

Left Panel: Clip Management

  • Scene/Clip List: Displays the list of imported video files.
  • Status Icons: A checkmark (✓) indicates the clip has been annotated.
  • Add Data: Import new video files into the current project.
  • Clear: Clears the current workspace.
  • Project Controls: New Project, Load Project, Add Data, Save JSON, Export JSON.

Center Panel: Video Player

  • Video Display: Main playback area for the selected clip.
  • Playback Controls:
  • Standard Play/Pause.
  • Frame stepping and seeking (1s, 5s).
  • Playback speed control (0.25x to 4.0x).

Right Panel: Labeling

  • Task Info: Displays the current task name.
  • Label Groups:
  • Single Label: Radio buttons for mutually exclusive categories (e.g., Weather).
  • Multi Label: Checkboxes for non-exclusive attributes (e.g., Objects present).
  • Dynamic Editing: Users can add new label options on the fly using the input field within each group.
  • Controls:
  • Confirm Annotation: Saves the current selection to the clip.
  • Undo/Redo: Controls to undo or redo annotation actions.
  • Clear Selection: Resets the current selection.
  • Save/Export: Options to save the project JSON.

3. Localization Mode (Action Spotting)

Designed for marking specific timestamps (spotting) with event labels.

Localization Interface

Left Panel: Sequence Management

  • Clip List: Hierarchical view of video sequences.
  • Project Controls: New Project, Load Project, Add Data, Save JSON, Export JSON.
  • Filter: Filter the list to show "All", "Labelled Only", or "Unlabelled Only".
  • Clear All: Resets the entire workspace.

Center Panel: Timeline & Player

  • Media Preview: Video player with precise seeking.
  • Timeline: Visual representation of the video duration.
  • Markers: Blue ticks indicate spotted events on the timeline.
  • Playback Controls: Includes standard transport controls and variable speed playback.

Right Panel: Annotation & Spotting

This panel is divided into a header, a spotting area, and an event list.

  • Undo/Redo: Dedicated buttons to undo or redo spotting actions and schema changes.

Top: Spotting Controls (Tabs)

  • Multi-Head Tabs: Organize labels by categories (Heads) such as "Action", "Card", "Goal".
  • Label Grid: Click any label button to instantly spot an event at the current playhead time.
  • Context Menu: Right-click a label button to Rename or Delete it.
  • Add New Label: - Click "+ Add new label at current time" to pause the video, define a new label name, and automatically spot it at the paused timestamp. The video resumes automatically after confirmation.

Bottom: Event List (Table)

  • Table Columns:
  • Time: The timestamp of the event.
  • Head: The category of the event.
  • Label: The specific label name.
  • Interaction:
  • Double-click: Jumps the video player to the event's timestamp.
  • Right-click: Opens a context menu to Edit Time, Change Head/Label, or Delete Event.

4. Description Mode (Clip-level Description / Captioning)

Designed for assigning structured textual descriptions to short video clips, including question–answer style annotations.

Description Interface

Left Panel: Action / Clip Management

  • Action List: Displays imported action clips (e.g., XFouls_test_action_*).

  • A checkmark (✓) indicates the clip has been annotated.

  • Project Controls: New Project, Load Project, Add Data, Save JSON, Export JSON.
  • Filter: Filter by annotation status.
  • Clear All: Clears the current workspace.

Center Panel: Video Player

  • Video Display: Main playback area for the selected action clip.
  • Timeline Slider: Shows clip progress.

  • Playback Controls:

  • Play / Pause

  • Navigate between actions or clips
  • Fine seeking
  • Time Indicator: Displays current time and total clip duration.

Right Panel: Description / Caption Annotation

This panel is dedicated to structured textual annotation.

Description / Caption Text Area

  • Large editable text field.
  • Supports multi-line structured annotations.

  • Typical format includes:

  • Question–Answer (Q/A)

  • Event reasoning explanations
  • Referee decision analysis

Example structure:

Q: "Is it a foul or not? Why?"
A: "..."

Controls

  • Confirm

  • Saves the description to the current clip.

  • Clear

  • Clears the text field without saving.

  • Undo / Redo

* Reverts recent text changes.

5. Dense Description Mode (Event-level Captioning)

Designed for fine-grained event-level captioning across full-length videos.

Dense Description Interface

This mode combines timestamped events with free-text descriptions.

Left Panel: Video Management

  • Video List: Displays imported video halves (e.g., GB1415_TE_001_H1, H2).

  • ✓ indicates that the video contains at least one annotated event.

  • Project Controls: New Project, Load Project, Add Data, Save JSON, Export JSON.
  • Filter: Filter videos by annotation state.
  • Clear All: Resets workspace.

Center Panel: Timeline & Player

  • Media Preview: Main video playback window.

  • Timeline:

  • Visual representation of the full video duration.

  • Markers:

    • Yellow ticks represent annotated events.
    • Red indicator represents the current playhead position.
    • Current Time Display: Shown above the description input.
    • Playback Controls:

  • Frame stepping

  • 1s / 5s seeking
  • Speed control (0.25x–4.0x)
  • Previous/Next event navigation

Right Panel: Dense Annotation

Divided into two functional areas.

Top: Create / Edit Description

  • Current Time Indicator

  • Displays the precise timestamp of the playhead.

  • Description Text Box

  • Enter detailed natural-language descriptions of events.

  • Designed for dense commentary-style annotation.

  • Confirm Description

  • Saves a new event at the current timestamp.

  • Adds a marker to the timeline.
  • Appends the event to the event table.

Bottom: Events List (Table)

Displays all annotated events in chronological order.

Columns:

  • Time – Timestamp of the event.
  • Lang – Language tag (e.g., "en").
  • Description – The textual annotation.

Interaction:

  • Single-click – Select event.
  • Double-click – Jump to event timestamp.
  • Editing – Modify description text and confirm to update.
  • Delete – Remove event from table and timeline.