diff options
Diffstat (limited to 'driver_ais.c')
| -rw-r--r-- | driver_ais.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/driver_ais.c b/driver_ais.c index 38edc843..4c753520 100644 --- a/driver_ais.c +++ b/driver_ais.c @@ -784,7 +784,7 @@ bool ais_binary_decode(struct ais_t *ais, } ais->type21.aid_type = UBITS(38, 5); from_sixbit((unsigned char *)bits, - 43, 20, ais->type21.name); + 43, 21, ais->type21.name); if (strlen(ais->type21.name) == 20 && bitlen > 272) from_sixbit((unsigned char *)bits, 272, (bitlen - 272)/6, @@ -883,7 +883,20 @@ bool ais_binary_decode(struct ais_t *ais, return false; } ais->type24.shiptype = UBITS(40, 8); + /* + * In ITU-R 1371-4, there are new model and serial fields + * carved out of the right-hand end of vendorid, which is + * reduced from 7 chars to 3. It is not clear in which + * minor revision this change took place. To cope with + * older AIS implementations, unpack the trailing bits + * *both* ways; truly revision-4-conformant implementations + * will have up to four characters of trailing garbage on + * the vendorid, and older implementations will have + * garbafe in the model and serial fields. + */ UCHARS(48, ais->type24.vendorid); + ais->type24.model = UBITS(66, 4); + ais->type24.serial = UBITS(70, 20); UCHARS(90, ais->type24.callsign); if (AIS_AUXILIARY_MMSI(ais->mmsi)) { ais->type24.mothership_mmsi = UBITS(132, 30); |