frigate/frigate/track/tracked_object.py

"""Object attribute."""

import logging
import math
import os
from collections import defaultdict
from statistics import median
from typing import Any, Optional, cast

import cv2
import numpy as np

from frigate.config import (
    CameraConfig,
    FilterConfig,
    UIConfig,
)
from frigate.const import CLIPS_DIR, REPLAY_CAMERA_PREFIX, THUMB_DIR
from frigate.detectors.detector_config import ModelConfig
from frigate.review.types import SeverityEnum
from frigate.util.builtin import sanitize_float
from frigate.util.image import (
    area,
    get_snapshot_bytes,
    is_better_thumbnail,
)
from frigate.util.object import box_inside
from frigate.util.velocity import calculate_real_world_speed

logger = logging.getLogger(__name__)


# In most cases objects that loiter in a loitering zone should alert,
# but can still be expected to stay stationary for extended periods of time
# (ex: car loitering on the street vs when a known person parks on the street)
# person is the main object that should keep alerts going as long as they loiter
# even if they are stationary.
EXTENDED_LOITERING_OBJECTS = ["person"]


class TrackedObject:
    def __init__(
        self,
        model_config: ModelConfig,
        camera_config: CameraConfig,
        ui_config: UIConfig,
        frame_cache: dict[float, dict[str, Any]],
        obj_data: dict[str, Any],
    ) -> None:
        # set the score history then remove as it is not part of object state
        self.score_history: list[float] = obj_data["score_history"]
        del obj_data["score_history"]

        self.obj_data = obj_data
        self.colormap = model_config.colormap
        self.logos = model_config.all_attribute_logos
        self.camera_config = camera_config
        self.ui_config = ui_config
        self.frame_cache = frame_cache
        self.zone_presence: dict[str, int] = {}
        self.zone_loitering: dict[str, int] = {}
        self.current_zones: list[str] = []
        self.entered_zones: list[str] = []
        self.new_zone_entered: bool = False
        self.attributes: dict[str, float] = defaultdict(float)
        self.false_positive = True
        self.has_clip = False
        self.has_snapshot = False
        self.top_score = self.computed_score = 0.0
        self.thumbnail_data: dict[str, Any] | None = None
        self.last_updated: float = 0
        self.last_published: float = 0
        self.frame = None
        self.active = True
        self.pending_loitering = False
        self.speed_history: list[float] = []
        self.current_estimated_speed: float = 0
        self.average_estimated_speed: float = 0
        self.velocity_angle = 0
        self.path_data: list[tuple[Any, float]] = []
        self.previous = self.to_dict()

    @property
    def max_severity(self) -> Optional[str]:
        review_config = self.camera_config.review

        if (
            self.camera_config.review.alerts.enabled
            and self.obj_data["label"] in review_config.alerts.labels
            and (
                not review_config.alerts.required_zones
                or set(self.entered_zones) & set(review_config.alerts.required_zones)
            )
        ):
            return SeverityEnum.alert

        if (
            self.camera_config.review.detections.enabled
            and (
                not review_config.detections.labels
                or self.obj_data["label"] in review_config.detections.labels
            )
            and (
                not review_config.detections.required_zones
                or set(self.entered_zones)
                & set(review_config.detections.required_zones)
            )
        ):
            return SeverityEnum.detection

        return None

    def _is_false_positive(self) -> bool:
        # once a true positive, always a true positive
        if not self.false_positive:
            return False

        threshold = self.camera_config.objects.filters[self.obj_data["label"]].threshold
        return self.computed_score < threshold

    def compute_score(self) -> float:
        """get median of scores for object."""
        return median(self.score_history)

    def update(
        self, current_frame_time: float, obj_data: dict[str, Any], has_valid_frame: bool
    ) -> tuple[bool, bool, bool, bool]:
        thumb_update = False
        significant_change = False
        path_update = False
        autotracker_update = False
        # if the object is not in the current frame, add a 0.0 to the score history
        if obj_data["frame_time"] != current_frame_time:
            self.score_history.append(0.0)
        else:
            self.score_history.append(obj_data["score"])

        # only keep the last 10 scores
        if len(self.score_history) > 10:
            self.score_history = self.score_history[-10:]

        # calculate if this is a false positive
        self.computed_score = self.compute_score()
        if self.computed_score > self.top_score:
            self.top_score = self.computed_score
        self.false_positive = self._is_false_positive()
        self.active = self.is_active()

        if not self.false_positive and has_valid_frame:
            # determine if this frame is a better thumbnail
            if self.thumbnail_data is None or is_better_thumbnail(
                self.obj_data["label"],
                self.thumbnail_data,
                obj_data,
                self.camera_config.frame_shape,
            ):
                if obj_data["frame_time"] == current_frame_time:
                    self.thumbnail_data = {
                        "frame_time": obj_data["frame_time"],
                        "box": obj_data["box"],
                        "area": obj_data["area"],
                        "region": obj_data["region"],
                        "score": obj_data["score"],
                        "attributes": obj_data["attributes"],
                        "current_estimated_speed": self.current_estimated_speed,
                        "velocity_angle": self.velocity_angle,
                        "path_data": self.path_data.copy(),
                        "recognized_license_plate": obj_data.get(
                            "recognized_license_plate"
                        ),
                        "recognized_license_plate_score": obj_data.get(
                            "recognized_license_plate_score"
                        ),
                    }
                    thumb_update = True
                else:
                    logger.debug(
                        f"{self.camera_config.name}: Object frame time {obj_data['frame_time']} is not equal to the current frame time {current_frame_time}, not updating thumbnail"
                    )

        # check zones
        current_zones = []
        bottom_center = (obj_data["centroid"][0], obj_data["box"][3])
        in_loitering_zone = False
        in_speed_zone = False

        # check each zone
        for name, zone in self.camera_config.zones.items():
            # skip disabled zones
            if not zone.enabled:
                continue

            # if the zone is not for this object type, skip
            if len(zone.objects) > 0 and obj_data["label"] not in zone.objects:
                continue
            contour = zone.contour
            zone_score = self.zone_presence.get(name, 0) + 1

            # check if the object is in the zone
            if cv2.pointPolygonTest(contour, bottom_center, False) >= 0:
                # if the object passed the filters once, dont apply again
                if name in self.current_zones or not zone_filtered(self, zone.filters):
                    # Calculate speed first if this is a speed zone
                    if (
                        zone.distances
                        and obj_data["frame_time"] == current_frame_time
                        and self.active
                    ):
                        speed_magnitude, self.velocity_angle = (
                            calculate_real_world_speed(
                                zone.contour,
                                zone.distances,
                                self.obj_data["estimate_velocity"],
                                bottom_center,
                                self.camera_config.detect.fps,
                            )
                        )

                        # users can configure speed zones incorrectly, so sanitize speed_magnitude
                        # and velocity_angle in case the values come back as inf or NaN
                        speed_magnitude = sanitize_float(speed_magnitude)
                        self.velocity_angle = sanitize_float(self.velocity_angle)

                        if self.ui_config.unit_system == "metric":
                            self.current_estimated_speed = (
                                speed_magnitude * 3.6
                            )  # m/s to km/h
                        else:
                            self.current_estimated_speed = (
                                speed_magnitude * 0.681818
                            )  # ft/s to mph

                        self.speed_history.append(self.current_estimated_speed)
                        if len(self.speed_history) > 10:
                            self.speed_history = self.speed_history[-10:]

                        self.average_estimated_speed = sum(self.speed_history) / len(
                            self.speed_history
                        )

                        # we've exceeded the speed threshold on the zone
                        # or we don't have a speed threshold set
                        if (
                            zone.speed_threshold is None
                            or self.average_estimated_speed > zone.speed_threshold
                        ):
                            in_speed_zone = True

                        logger.debug(
                            f"Camera: {self.camera_config.name}, tracked object ID: {self.obj_data['id']}, "
                            f"zone: {name}, pixel velocity: {str(tuple(np.round(self.obj_data['estimate_velocity']).flatten().astype(int)))}, "
                            f"speed magnitude: {speed_magnitude}, velocity angle: {self.velocity_angle}, "
                            f"estimated speed: {self.current_estimated_speed:.1f}, "
                            f"average speed: {self.average_estimated_speed:.1f}, "
                            f"length: {len(self.speed_history)}"
                        )

                    # Check zone entry conditions - for speed zones, require both inertia and speed
                    if zone_score >= zone.inertia:
                        if zone.distances and not in_speed_zone:
                            continue  # Skip zone entry for speed zones until speed threshold met

                        # if the zone has loitering time, and the object is an extended loiter object
                        # always mark it as loitering actively
                        if (
                            self.obj_data["label"] in EXTENDED_LOITERING_OBJECTS
                            and zone.loitering_time > 0
                        ):
                            in_loitering_zone = True

                        loitering_score = self.zone_loitering.get(name, 0) + 1

                        # loitering time is configured as seconds, convert to count of frames
                        if loitering_score >= (
                            self.camera_config.zones[name].loitering_time
                            * self.camera_config.detect.fps
                        ):
                            current_zones.append(name)

                            if name not in self.entered_zones:
                                self.entered_zones.append(name)
                                self.new_zone_entered = True
                        else:
                            self.zone_loitering[name] = loitering_score

                            # this object is pending loitering but has not entered the zone yet
                            if zone.loitering_time > 0:
                                in_loitering_zone = True
                    else:
                        self.zone_presence[name] = zone_score
            else:
                # once an object has a zone inertia of 3+ it is not checked anymore
                if 0 < zone_score < zone.inertia:
                    self.zone_presence[name] = zone_score - 1

            # Reset speed if not in speed zone
            if zone.distances and name not in current_zones:
                self.current_estimated_speed = 0

        # update loitering status
        self.pending_loitering = in_loitering_zone

        # maintain attributes
        for attr in obj_data["attributes"]:
            if self.attributes[attr["label"]] < attr["score"]:
                self.attributes[attr["label"]] = attr["score"]

        # populate the sub_label for object with highest scoring logo
        if self.obj_data["label"] in ["car", "motorcycle", "package", "person"]:
            recognized_logos = {
                k: self.attributes[k] for k in self.logos if k in self.attributes
            }
            if len(recognized_logos) > 0:
                max_logo = max(recognized_logos, key=recognized_logos.get)  # type: ignore[arg-type]

                # don't overwrite sub label if it is already set
                if (
                    self.obj_data.get("sub_label") is None
                    or self.obj_data["sub_label"][0] == max_logo
                ):
                    self.obj_data["sub_label"] = (max_logo, recognized_logos[max_logo])

        # check for significant change
        if not self.false_positive:
            # if the zones changed, signal an update
            if set(self.current_zones) != set(current_zones):
                significant_change = True

            # if the position changed, signal an update
            if self.obj_data["position_changes"] != obj_data["position_changes"]:
                significant_change = True

            # disappearance of a per-frame attribute can be caused by detection
            # skipping the object on a frame (stationary objects on non-interval
            # frames), so only flag when a new attribute label appears
            prev_labels = {a["label"] for a in self.obj_data["attributes"]}
            curr_labels = {a["label"] for a in obj_data["attributes"]}
            if curr_labels - prev_labels:
                significant_change = True

            # if the state changed between stationary and active
            if self.previous["active"] != self.active:
                significant_change = True

            # update at least once per minute
            if self.obj_data["frame_time"] - self.previous["frame_time"] > 60:
                significant_change = True

            # update autotrack at most 3 objects per second
            if self.obj_data["frame_time"] - self.previous["frame_time"] >= (1 / 3):
                autotracker_update = True

            # update path
            width = self.camera_config.detect.width
            height = self.camera_config.detect.height

            if width is not None and height is not None:
                bottom_center = (
                    round(obj_data["centroid"][0] / width, 4),
                    round(obj_data["box"][3] / height, 4),
                )

                # calculate a reasonable movement threshold (e.g., 5% of the frame diagonal)
                threshold = 0.05 * math.sqrt(width**2 + height**2) / max(width, height)

                if not self.path_data:
                    self.path_data.append((bottom_center, obj_data["frame_time"]))
                    path_update = True
                elif (
                    math.dist(self.path_data[-1][0], bottom_center) >= threshold
                    or len(self.path_data) == 1
                ):
                    # check Euclidean distance before appending
                    self.path_data.append((bottom_center, obj_data["frame_time"]))
                    path_update = True
                    logger.debug(
                        f"Point tracking: {obj_data['id']}, {bottom_center}, {obj_data['frame_time']}"
                    )

        self.obj_data.update(obj_data)
        self.current_zones = current_zones
        logger.debug(
            f"{self.camera_config.name}: Updating {obj_data['id']}: thumb update? {thumb_update}, significant change? {significant_change}, path update? {path_update}, autotracker update? {autotracker_update} "
        )
        return (thumb_update, significant_change, path_update, autotracker_update)

    def to_dict(self) -> dict[str, Any]:
        # Tracking internals excluded from output (centroid, estimate, estimate_velocity)
        _EXCLUDED_OBJ_DATA_KEYS = {
            "centroid",
            "estimate",
            "estimate_velocity",
        }

        event: dict[str, Any] = {
            "id": self.obj_data["id"],
            "camera": self.camera_config.name,
            "frame_time": self.obj_data["frame_time"],
            "snapshot": self.thumbnail_data,
            "snapshot_clean": True,
            "label": self.obj_data["label"],
            "sub_label": self.obj_data.get("sub_label"),
            "top_score": self.top_score,
            "false_positive": self.false_positive,
            "start_time": self.obj_data["start_time"],
            "end_time": self.obj_data.get("end_time", None),
            "score": self.obj_data["score"],
            "computed_score": self.computed_score,
            "box": self.obj_data["box"],
            "area": self.obj_data["area"],
            "ratio": self.obj_data["ratio"],
            "region": self.obj_data["region"],
            "active": self.active,
            "stationary": not self.active,
            "motionless_count": self.obj_data["motionless_count"],
            "position_changes": self.obj_data["position_changes"],
            "current_zones": self.current_zones.copy(),
            "entered_zones": self.entered_zones.copy(),
            "has_clip": self.has_clip,
            "has_snapshot": self.has_snapshot,
            "attributes": self.attributes,
            "current_attributes": self.obj_data["attributes"],
            "pending_loitering": self.pending_loitering,
            "max_severity": self.max_severity,
            "current_estimated_speed": self.current_estimated_speed,
            "average_estimated_speed": self.average_estimated_speed,
            "velocity_angle": self.velocity_angle,
            "path_data": self.path_data.copy(),
            "recognized_license_plate": self.obj_data.get("recognized_license_plate"),
        }

        # Add any other obj_data keys (e.g. custom attribute fields) not yet included
        for key, value in self.obj_data.items():
            if key not in _EXCLUDED_OBJ_DATA_KEYS and key not in event:
                event[key] = value

        return event

    def is_active(self) -> bool:
        return not self.is_stationary()

    def is_stationary(self) -> bool:
        count = cast(int | float, self.obj_data["motionless_count"])
        return count > (self.camera_config.detect.stationary.threshold or 50)

    def get_thumbnail(self, ext: str) -> bytes | None:
        img_bytes, _ = self.get_img_bytes(
            ext, timestamp=False, bounding_box=False, crop=True, height=175
        )

        if img_bytes:
            return img_bytes
        else:
            _, img = cv2.imencode(f".{ext}", np.zeros((175, 175, 3), np.uint8))
            return img.tobytes()

    def get_clean_webp(self) -> bytes | None:
        webp_bytes, _ = self.get_img_bytes(
            ext="webp",
            timestamp=False,
            bounding_box=False,
            crop=False,
            height=None,
            quality=self.camera_config.snapshots.quality,
        )
        return webp_bytes

    def get_img_bytes(
        self,
        ext: str,
        timestamp: bool = False,
        bounding_box: bool = False,
        crop: bool = False,
        height: int | None = None,
        quality: int | None = None,
    ) -> tuple[bytes | None, float | None]:
        if self.thumbnail_data is None:
            return None, None

        try:
            frame_time = self.thumbnail_data["frame_time"]
            best_frame = cv2.cvtColor(
                self.frame_cache[frame_time]["frame"],
                cv2.COLOR_YUV2BGR_I420,
            )
        except KeyError:
            logger.warning(
                f"Unable to create snapshot because frame {frame_time} is not in the cache"
            )
            return None, None

        return get_snapshot_bytes(
            best_frame,
            frame_time,
            ext=ext,
            timestamp=timestamp,
            bounding_box=bounding_box,
            crop=crop,
            height=height,
            quality=quality,
            label=self.obj_data["label"],
            box=self.thumbnail_data["box"],
            score=self.thumbnail_data["score"],
            area=self.thumbnail_data["area"],
            attributes=self.thumbnail_data["attributes"],
            color=self.colormap.get(self.obj_data["label"], (255, 255, 255)),
            timestamp_style=self.camera_config.timestamp_style,
            estimated_speed=self.thumbnail_data["current_estimated_speed"],
        )

    def write_snapshot_to_disk(self) -> None:
        webp_bytes = self.get_clean_webp()
        if webp_bytes is None:
            logger.warning(f"Unable to save snapshot for {self.obj_data['id']}.")
        else:
            with open(
                os.path.join(
                    CLIPS_DIR,
                    f"{self.camera_config.name}-{self.obj_data['id']}-clean.webp",
                ),
                "wb",
            ) as p:
                p.write(webp_bytes)

    def write_thumbnail_to_disk(self) -> None:
        if not self.camera_config.name:
            return

        if self.camera_config.name.startswith(REPLAY_CAMERA_PREFIX):
            return

        directory = os.path.join(THUMB_DIR, self.camera_config.name)

        os.makedirs(directory, exist_ok=True)

        thumb_bytes = self.get_thumbnail("webp")

        if thumb_bytes:
            with open(
                os.path.join(directory, f"{self.obj_data['id']}.webp"), "wb"
            ) as f:
                f.write(thumb_bytes)


def zone_filtered(obj: TrackedObject, object_config: dict[str, FilterConfig]) -> bool:
    object_name = obj.obj_data["label"]

    if object_name in object_config:
        obj_settings = object_config[object_name]

        # if the min area is larger than the
        # detected object, don't add it to detected objects
        if obj_settings.min_area > obj.obj_data["area"]:
            return True

        # if the detected object is larger than the
        # max area, don't add it to detected objects
        if obj_settings.max_area < obj.obj_data["area"]:
            return True

        # if the score is lower than the threshold, skip
        if obj_settings.threshold > obj.computed_score:
            return True

        # if the object is not proportionally wide enough
        if obj_settings.min_ratio > obj.obj_data["ratio"]:
            return True

        # if the object is proportionally too wide
        if obj_settings.max_ratio < obj.obj_data["ratio"]:
            return True

    return False


class TrackedObjectAttribute:
    def __init__(self, raw_data: tuple) -> None:
        self.label = raw_data[0]
        self.score = raw_data[1]
        self.box = raw_data[2]
        self.area = raw_data[3]
        self.ratio = raw_data[4]
        self.region = raw_data[5]

    def get_tracking_data(self) -> dict[str, Any]:
        """Return data saved to the object."""
        return {
            "label": self.label,
            "score": self.score,
            "box": self.box,
        }

    def find_best_object(self, objects: list[dict[str, Any]]) -> Optional[str]:
        """Find the best attribute for each object and return its ID."""
        best_object_area: float | None = None
        best_object_id: str | None = None
        best_object_label: str | None = None

        for obj in objects:
            if not box_inside(obj["box"], self.box):
                continue

            object_area = area(obj["box"])

            # if multiple objects have the same attribute then they
            # are overlapping, it is most likely that the smaller object
            # is the one with the attribute
            if best_object_area is None:
                best_object_area = object_area
                best_object_id = obj["id"]
                best_object_label = obj["label"]
            else:
                if best_object_label == obj["label"]:
                    # if multiple objects of the same type are overlapping
                    # then the attribute will not be assigned
                    return None
                elif object_area < best_object_area:
                    # if a car and person are overlapping then assign the label to the smaller object (which should be the person)
                    best_object_area = object_area
                    best_object_id = obj["id"]
                    best_object_label = obj["label"]

        return best_object_id