支持 HI13/H32 主机 UTC 桥接对齐、多会话联合标定与 CAD 平移先验。

Co-authored-by: Cursor <cursoragent@cursor.com>

tools/h32_dlog/timeutil.py

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+"""Wall-clock helpers for Medulla tick filtering.
+
+Two tick conventions appear in this dataset:
+
+- LiDAR DObject ``tic`` / recovered ``indices.log``: ``DateTime.Now.Ticks`` (local)
+- IMU / MSOP payload host receive fields: UTC ``DateTime.UtcNow.Ticks``
+"""
+
+from __future__ import annotations
+
+from datetime import datetime, timedelta, timezone
+
+TICKS_PER_SECOND = 10_000_000
+DOTNET_UNIX_EPOCH_TICKS = 621355968000000000
+
+
+def _parse_local_wall(text: str) -> datetime:
+    normalized = text.strip().replace(" ", "T")
+    if normalized.endswith("Z"):
+        raise ValueError("expected local wall time without Z; got UTC marker")
+    if "+" in normalized[10:]:
+        idx = normalized.find("+", 10)
+        normalized = normalized[:idx]
+    elif normalized.count("-") > 2:
+        # timezone like -08:00 after the date
+        idx = normalized.find("-", 10)
+        if idx > 0 and ":" in normalized[idx + 1 :]:
+            normalized = normalized[:idx]
+    return datetime.fromisoformat(normalized).replace(tzinfo=None)
+
+
+def local_wall_to_dotnet_ticks(text: str) -> int:
+    """Local wall time → ``DateTime.Now.Ticks`` (LiDAR DObject tic)."""
+
+    dt = _parse_local_wall(text)
+    delta = dt - datetime(1, 1, 1)
+    return int(delta.total_seconds() * TICKS_PER_SECOND)
+
+
+def local_wall_to_utc_dotnet_ticks(text: str, *, tz_hours: float = 8.0) -> int:
+    """Local wall time in ``tz_hours`` → UTC ``DateTime.UtcNow.Ticks`` (IMU host)."""
+
+    dt = _parse_local_wall(text).replace(tzinfo=timezone(timedelta(hours=tz_hours)))
+    unix = dt.timestamp()
+    return int(round(unix * TICKS_PER_SECOND)) + DOTNET_UNIX_EPOCH_TICKS
+
+
+def dotnet_ticks_to_local_iso(ticks: int) -> str:
+    dt = datetime(1, 1, 1) + timedelta(microseconds=ticks / 10.0)
+    return dt.isoformat(timespec="milliseconds")
+
+
+def utc_dotnet_ticks_to_unix_s(ticks: int) -> float:
+    """UTC ``DateTime.UtcNow.Ticks`` → Unix seconds."""
+
+    return (float(ticks) - float(DOTNET_UNIX_EPOCH_TICKS)) / float(TICKS_PER_SECOND)