{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://infactory.ai/schemas/camera-detection/annotation/v1",
  "title": "Camera Detection Frame Annotation",
  "description": "Schema for per-frame annotations in the Infactory Camera Detection Dataset. Each record describes the camera characteristics of a single video frame across three orthogonal dimensions: shot scale, camera angle, and camera movement.",
  "type": "object",
  "required": [
    "frame_id",
    "source_video",
    "frame_number",
    "timestamp_sec",
    "shot_scale",
    "shot_scale_code",
    "camera_angle",
    "camera_movement",
    "annotator",
    "annotation_version"
  ],
  "properties": {
    "frame_id": {
      "type": "string",
      "format": "uuid",
      "description": "Unique identifier for this annotated frame (UUID v4)."
    },
    "source_video": {
      "type": "string",
      "description": "Filename of the source video from which this frame was extracted.",
      "pattern": "^.+\\.(mp4|avi|mov|mkv|webm)$"
    },
    "source_video_id": {
      "type": "string",
      "description": "Unique identifier for the source video, if available (e.g., UUID or dataset-specific ID)."
    },
    "frame_number": {
      "type": "integer",
      "minimum": 0,
      "description": "Zero-indexed frame number within the source video."
    },
    "timestamp_sec": {
      "type": "number",
      "minimum": 0,
      "description": "Timestamp of the frame in seconds from the start of the source video."
    },

    "shot_scale": {
      "type": "string",
      "enum": ["ECU", "CU", "MCU", "MS", "MLS", "LS", "ELS", "FS", "IS"],
      "description": "Primary shot scale classification. See DEFINITIONS.md Section 1 for full definitions."
    },
    "shot_scale_code": {
      "type": "integer",
      "enum": [0, 1, 2, 3, 4, 5, 6, 7, 8],
      "description": "Numeric code for shot scale. Codes 1-7 are ordinal (closest to farthest). 0=FS, 8=IS are non-ordinal."
    },
    "shot_scale_underlying": {
      "type": ["string", "null"],
      "enum": ["ECU", "CU", "MCU", "MS", "MLS", "LS", "ELS", null],
      "description": "When shot_scale is 'FS' (Foreground Shot), this field captures the underlying shot scale of the primary subject behind the foreground element. Null for all other shot_scale values."
    },

    "camera_angle": {
      "type": "string",
      "enum": ["OVH", "HIGH", "NEU", "LOW", "DUTCH"],
      "description": "Camera angle classification. See DEFINITIONS.md Section 2 for full definitions."
    },
    "camera_angle_vertical_tendency": {
      "type": ["string", "null"],
      "enum": ["OVH", "HIGH", "NEU", "LOW", null],
      "description": "When camera_angle is 'DUTCH', this optional field captures the underlying vertical tendency. Null when camera_angle is not DUTCH."
    },

    "camera_movement": {
      "type": "string",
      "enum": ["STATIC", "PAN", "TILT", "TRACK", "ZOOM_IN", "ZOOM_OUT", "HANDHELD", "CRANE", "AERIAL"],
      "description": "Camera movement classification based on temporal context around this frame. See DEFINITIONS.md Section 3 for full definitions."
    },

    "subject_type": {
      "type": "string",
      "enum": ["person", "group", "field_of_play", "object", "graphic", "crowd", "venue", "mixed"],
      "description": "What the primary subject of the frame is. See DEFINITIONS.md Section 4.2."
    },
    "subject_count": {
      "type": ["integer", "null"],
      "minimum": 0,
      "description": "Number of distinct subjects visible when subject_type is 'person' or 'group'. Null when not applicable."
    },

    "camera_position": {
      "type": ["string", "null"],
      "enum": [
        "main_center", "main_left", "main_right",
        "behind_goal", "goal_line_tech", "spider_cam",
        "sideline", "corner", "inside_goal",
        "aerial", "tunnel", "studio", "other", null
      ],
      "description": "Physical camera position in the venue. Primarily for sports broadcast content. Null when unknown or not applicable. See DEFINITIONS.md Section 4.1."
    },

    "transition_context": {
      "type": "string",
      "enum": ["none", "hard_cut", "dissolve", "wipe", "fade_black", "logo_transition"],
      "default": "none",
      "description": "How this frame relates to surrounding editorial transitions. See DEFINITIONS.md Section 4.3."
    },

    "safe_area": {
      "type": ["object", "null"],
      "description": "SMPTE ST 2046-1 safe area compliance. Null when not evaluated.",
      "properties": {
        "action_safe": {
          "type": "boolean",
          "description": "Subject's key features fall within the Action-Safe zone (inner 93% of frame per SMPTE ST 2046-1)."
        },
        "title_safe": {
          "type": "boolean",
          "description": "Subject's key features fall within the Title-Safe zone (inner 90% of frame per SMPTE ST 2046-1)."
        }
      },
      "required": ["action_safe", "title_safe"]
    },

    "technical": {
      "type": "object",
      "description": "Technical metadata about the source frame.",
      "properties": {
        "resolution_width": {
          "type": "integer",
          "minimum": 1,
          "description": "Frame width in pixels."
        },
        "resolution_height": {
          "type": "integer",
          "minimum": 1,
          "description": "Frame height in pixels."
        },
        "frame_rate": {
          "type": "number",
          "minimum": 0,
          "description": "Source video frame rate in frames per second."
        },
        "aspect_ratio": {
          "type": "string",
          "description": "Display aspect ratio (e.g., '16:9', '4:3', '21:9')."
        },
        "codec": {
          "type": ["string", "null"],
          "description": "Video codec (e.g., 'H.264', 'H.265', 'VP9')."
        },
        "color_space": {
          "type": ["string", "null"],
          "description": "Color sampling format (e.g., '4:2:0', '4:2:2', '4:4:4')."
        },
        "bit_depth": {
          "type": ["integer", "null"],
          "description": "Bit depth per channel (e.g., 8, 10, 12)."
        }
      },
      "required": ["resolution_width", "resolution_height", "frame_rate"]
    },

    "annotator": {
      "type": "string",
      "description": "Identifier of the annotator or model that produced this annotation (e.g., 'human_annotator_01', 'model_v1.0', 'gemini_2.0_flash')."
    },
    "annotation_version": {
      "type": "string",
      "description": "Version of the annotation schema used (e.g., '1.0.0').",
      "pattern": "^\\d+\\.\\d+\\.\\d+$"
    },
    "confidence": {
      "type": ["number", "null"],
      "minimum": 0.0,
      "maximum": 1.0,
      "description": "Model confidence score for the annotation. Null for human annotations. Range [0.0, 1.0]."
    },
    "human_verified": {
      "type": "boolean",
      "default": false,
      "description": "Whether this annotation has been verified by a human reviewer."
    },
    "verification_annotator": {
      "type": ["string", "null"],
      "description": "Identifier of the human who verified this annotation. Null if not yet verified."
    },

    "notes": {
      "type": ["string", "null"],
      "description": "Free-text annotator notes for edge cases or ambiguous frames."
    },

    "domain": {
      "type": "string",
      "enum": ["sports_broadcast", "news_broadcast", "cinema", "documentary", "user_generated", "other"],
      "description": "Content domain of the source material."
    },
    "sport_type": {
      "type": ["string", "null"],
      "description": "Specific sport, when domain is 'sports_broadcast' (e.g., 'soccer', 'basketball', 'tennis'). Null otherwise."
    }
  },
  "additionalProperties": false,

  "if": {
    "properties": { "shot_scale": { "const": "FS" } }
  },
  "then": {
    "required": ["shot_scale_underlying"]
  },

  "examples": [
    {
      "frame_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
      "source_video": "GA_ITS_MSA_20241201_JUV_NAP_SIS2.mp4",
      "source_video_id": "b0558318-3605-4d54-9930-41c77fd4b20a",
      "frame_number": 1234,
      "timestamp_sec": 41.13,
      "shot_scale": "MCU",
      "shot_scale_code": 3,
      "shot_scale_underlying": null,
      "camera_angle": "NEU",
      "camera_angle_vertical_tendency": null,
      "camera_movement": "STATIC",
      "subject_type": "person",
      "subject_count": 1,
      "camera_position": "sideline",
      "transition_context": "none",
      "safe_area": {
        "action_safe": true,
        "title_safe": true
      },
      "technical": {
        "resolution_width": 1920,
        "resolution_height": 1080,
        "frame_rate": 25.0,
        "aspect_ratio": "16:9",
        "codec": "H.264",
        "color_space": "4:2:0",
        "bit_depth": 8
      },
      "annotator": "model_v1.0",
      "annotation_version": "1.0.0",
      "confidence": 0.94,
      "human_verified": false,
      "verification_annotator": null,
      "notes": null,
      "domain": "sports_broadcast",
      "sport_type": "soccer"
    },
    {
      "frame_id": "f9e8d7c6-b5a4-3210-fedc-ba9876543210",
      "source_video": "GA_ITS_MSA_20241201_JUV_NAP_SIS2.mp4",
      "source_video_id": "b0558318-3605-4d54-9930-41c77fd4b20a",
      "frame_number": 5678,
      "timestamp_sec": 189.27,
      "shot_scale": "ELS",
      "shot_scale_code": 7,
      "shot_scale_underlying": null,
      "camera_angle": "HIGH",
      "camera_angle_vertical_tendency": null,
      "camera_movement": "PAN",
      "subject_type": "field_of_play",
      "subject_count": null,
      "camera_position": "main_center",
      "transition_context": "hard_cut",
      "safe_area": null,
      "technical": {
        "resolution_width": 1920,
        "resolution_height": 1080,
        "frame_rate": 25.0,
        "aspect_ratio": "16:9",
        "codec": "H.264",
        "color_space": "4:2:0",
        "bit_depth": 8
      },
      "annotator": "model_v1.0",
      "annotation_version": "1.0.0",
      "confidence": 0.87,
      "human_verified": true,
      "verification_annotator": "human_annotator_01",
      "notes": "Main broadcast camera following open play left to right.",
      "domain": "sports_broadcast",
      "sport_type": "soccer"
    }
  ]
}