implement best effort decoding for type 1,2,3 when there are extra bi…

…ts present

ais_tools/ais.py

@@ -1,5 +1,6 @@
 from ais_tools.transcode import DecodeError
 from ais_tools.transcode import ASCII8toAIS6
+from ais_tools import ais_1_2_3
 from ais_tools import ais5
 from ais_tools import ais8
 from ais_tools import ais9
@@ -19,6 +20,9 @@
 }
 
 decode_fn = {
+    1: ais_1_2_3.ais_1_2_3_decode,
+    2: ais_1_2_3.ais_1_2_3_decode,
+    3: ais_1_2_3.ais_1_2_3_decode,
     5: ais5.ais5_decode,
     8: ais8.ais8_decode,
     9: ais9.ais9_decode,

ais_tools/ais_1_2_3.py

@@ -0,0 +1,10 @@
+import ais as libais
+from ais import DecodeError
+
+
+def ais_1_2_3_decode(body, pad):
+    try:
+        return libais.decode(body[:28], 0)
+    except DecodeError as e:
+        raise DecodeError(f'TYPE 1-2-3 LIBAIS ERR: {str(e)}')
+

sample/type1-bad-bitcount.nmea

@@ -0,0 +1,13 @@
+\s:rMT4097,t:ais-listener,c:1697012399*7E\!AIVDM,1,1,,A,13UuUj0P00QgDCLEiGAcOOwl2<0Igw;,0*28
+\s:rMT1200,t:ais-listener,c:1697012048*78\!AIVDM,1,1,,A,33lP4T5P00QJoU6Fd1<v4?v>2D`Jal<,0*7F
+\s:rMT1200,t:ais-listener,c:1697011998*7F\!AIVDM,1,1,,A,13R3iq00001LhHDFVNd@RC@R0<0FPF=,0*6C
+\s:rMT6030,t:ais-listener,c:1697011876*78\!AIVDM,1,1,,B,15Ca7j002HQer4PClUD<1qbH089PRn4,0*07
+\s:rMT6168,t:ais-listener,c:1697014351*7F\!AIVDM,1,1,,B,16eg3D1P00RT5kHCfSje>Ovr:`AhPc=,0*57
+\s:rMT6030,t:ais-listener,c:1697014102*77\!AIVDM,1,1,,A,13R3=u3P00QfIwhCt;09V?v`0530Li7,0*61
+\s:rMT1200,t:ais-listener,c:1697011340*70\!AIVDM,1,1,,B,13VOUT002W1KM1hFbSbcrITb0<1Muw>,0*03
+\s:rMT6030,t:ais-listener,c:1717190215*76\!AIVDM,1,1,,A,144d5;0uiHQjSVjC6w:iL1Ab26a05d4,0*72
+\s:rMT6030,t:ais-listener,c:1717190199*71\!AIVDM,1,1,,A,13lHkf001C1o?`HC3=Oc@8w408Cos:<,0*3D
+\s:rMT6030,t:ais-listener,c:1717190200*72\!AIVDM,1,1,,B,19@9=p0P1<1mUP`C7ttkBOw800RqWe=,0*3C
+\s:rMT1200,t:ais-listener,c:1717190111*77\!AIVDM,1,1,,B,34i:=V50001K=nbFbsWeH42D2000j0<,0*5F
+\s:rMT1200,t:ais-listener,c:1717189944*77\!AIVDM,1,1,,B,33TVdn1P01QK>R`Fc78v4?vh2DlbI03,0*20
+

tests/test_aivdm.py

@@ -19,7 +19,9 @@
     ('\\s:66,c:1663246931*35\\!AIVDM,1,1,,,9001?BP=h:qJ9vb;:f7EN1h240Rb,0*3F',
         {'alt_sensor': 0, 'assigned_mode': False}),
     ('\\c:1712130370,s:dynamic,t:spire*55\\!AIVDM,1,1,,A,403wboivQ1WfE`4gnt5MJT?024rp,0*24',
-     {'year': 2024, 'month': 4, 'day': 3, 'hour': 7, 'minute': 46, 'second': 21})
+     {'year': 2024, 'month': 4, 'day': 3, 'hour': 7, 'minute': 46, 'second': 21}),
+    ('\\s:rMT4097,t:ais-listener,c:1697012399*7E\\!AIVDM,1,1,,A,13UuUj0P00QgDCLEiGAcOOwl2<0Igw;,0*28',
+     {'id': 1, 'mmsi': 241133000}),
 ])
 def test_decode(nmea, expected):
     decoder = AIVDM()