63 lines
2.0 KiB
Python
63 lines
2.0 KiB
Python
"""跨摄像头关联 — 基于「同类别 + 时间窗口 + 空间邻近摄像头」的轻量启发式匹配"""
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import logging
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import threading
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import time
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logger = logging.getLogger("services.cross_camera")
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# 最近结束的目标：list of dict(stream_id, track_id, label, global_track_id, ended_at)
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_recent_ended = []
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_lock = threading.Lock()
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_WINDOW_SEC = 60.0
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def register_ended(stream_id, track_id, label, global_track_id):
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with _lock:
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_recent_ended.append({
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"stream_id": stream_id,
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"track_id": track_id,
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"label": label,
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"global_track_id": global_track_id,
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"ended_at": time.time(),
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})
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cutoff = time.time() - _WINDOW_SEC * 2
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while _recent_ended and _recent_ended[0]["ended_at"] < cutoff:
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_recent_ended.pop(0)
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def try_link(stream_id, track_id, label):
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"""新目标出现时尝试关联到其他摄像头刚消失的同类别目标。
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返回 (global_track_id, linked_from) ；linked_from 为 dict 或 None。
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"""
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now = time.time()
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best = None
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with _lock:
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for item in reversed(_recent_ended):
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if item["stream_id"] == stream_id:
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continue
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if item["label"] != label:
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continue
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if now - item["ended_at"] > _WINDOW_SEC:
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continue
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best = item
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break
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if not best:
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return "cam%d-%d" % (stream_id, track_id), None
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return best["global_track_id"], best
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def make_cross_camera_event(from_info, to_stream_id, to_track_id, label):
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return {
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"type": "cross_camera",
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"stream_id": to_stream_id,
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"track_id": to_track_id,
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"label": label,
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"from_stream_id": from_info.get("stream_id"),
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"from_track_id": from_info.get("track_id"),
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"global_track_id": from_info.get("global_track_id"),
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"timestamp": time.time(),
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"description": "cross camera: %s -> stream#%s" % (
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from_info.get("stream_id"), to_stream_id),
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}
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