ETSI Layer2 implementation; stage1: link control analysis

dmrtools/dmrproto/etsi_l2.py

@@ -0,0 +1,50 @@
+from __future__ import annotations
+
+import enum
+
+from abc import ABC, abstractmethod
+from bitarray import bitarray
+from dmr_utils3.bptc import decode_full_lc
+
+from .exceptions import DMRPL2BadDataException
+
+
+class DMRPL2Base(ABC):
+    DataTypes = enum.StrEnum('DataTypes', [
+        'UNKNOWN', 'FULL_LC', 'VOICE_BURST'
+    ])
+
+    def __init__(self, data: bytes) -> None:
+        self.set_data(data)
+
+    def set_data(self, data: bytes) -> None:
+        if len(data) != 33:
+            DMRPL2BadDataException("Data must be 33 bytes long")
+
+        self.bitdata: bitarray = bitarray(data, endian='big')
+
+    def get_data(self) -> bytes:
+        return self.bitdata.tobytes()
+
+    @abstractmethod
+    def get_data_type(self) -> DMRPL2Base.DataTypes:
+        pass
+
+
+class DMRPL2FullLC(DMRPL2Base):
+    def get_data_type(self) -> DMRPL2Base.DataTypes:
+        return DMRPL2Base.DataTypes.FULL_LC
+
+    def get_full_lc(self) -> bytes:
+        return decode_full_lc(self.bitdata[:98] + self.bitdata[-98:]).tobytes()
+
+
+class DMRPL2VoiceBurst(DMRPL2Base):
+    def get_data_type(self) -> DMRPL2Base.DataTypes:
+        return DMRPL2Base.DataTypes.VOICE_BURST
+
+    def get_voice_bits(self) -> tuple[bitarray, bitarray]:
+        return (self.bitdata[:108], self.bitdata[-108:])
+
+    def get_emb_lc(self) -> bytes:
+        return self.bitdata[116:148].tobytes()