In theory, 32bit HD Radio station ID + subchannel index (parts of
HD_STATION_ID_EXT) is a globally unique identifier. It allows broadcast
radio framework to determine which programs are the same and allow the
application to match entries from favourite list and the program list
provided by the tuner.
However, some broadcasters don't perform equipment setup correctly and
don't set station ID. As a result, there are some stations with
conflicting IDs.
As a workaround to treat these stations separately in a given location,
FM frequency was added as a part of HD_STATION_ID_EXT. This still doesn't
solve the global uniqueness problem: user might save KCQW 105.5 (sid=0) in
California, travel to Nevada and find KNAB 105.5 (sid=0). It turns out
there is no reliable identifier that might identify the station globally.
As a workaround, shortened station name is added for double-checking.
This is a best-effort fix, so it's not required for such misbehaving
stations to get correctly identified in every corner case.
Bug: 69958777
Test: VTS
Change-Id: Id11243096f1cde7fdda5cb70a7248d1831985cdd
