Intial commit

lib.py

@@ -0,0 +1,42 @@
+import struct
+
+class RTLFWriter:
+    HEADER_FIXED_FORMAT = "<4sIII"
+    RECORD_FORMAT = "<dddddddddd"
+
+    MAGIC_NUMBER = b"RTLF"
+    VERSION = 1
+
+    def __init__(self, filename, car_id, track_name):
+        self.filename = filename
+        self.car_id = car_id
+        self.track_name = track_name.encode('utf-8')
+        self.file = open(filename, "wb")
+        self._write_header()
+
+    def _write_header(self):
+        track_len = len(self.track_name)
+        header_bytes = struct.pack(
+            self.HEADER_FIXED_FORMAT,
+            self.MAGIC_NUMBER,
+            self.VERSION,
+            self.car_id,
+            track_len
+        )
+        self.file.write(header_bytes)
+        self.file.write(self.track_name)
+
+    def write_record(self, timestamp, long, lat, fx, fy, fz, ax, ay, az, speed):
+        record_bytes = struct.pack(
+            self.RECORD_FORMAT,
+            timestamp, long, lat, fx, fy, fz, ax, ay, az, speed
+        )
+        self.file.write(record_bytes)
+
+    def close(self):
+        if self.file:
+            self.file.close()
+            self.file = None
+
+    def __enter__(self): return self
+    def __exit__(self, exc_type, exc_val, exc_tb): self.close()