Handle Garmin GPX Conversion

User reports: “ERROR: mapillary_tools process not possible when parameter = --geotag_source gpx”.

User finds the issue is that the specific Garmin device's GPX seems to not match the format that mapillary_tools expects:

• --geotag_source gpx is processing a gpx file.

• But mapillary_tools is expecting a Unix, UTF8 file.

• If the gpx file is created by Garmin GPS and processed on a Windows OS, the file is not expected format.

• mapillary_tools is not validating the input file and not returning an Error Message I understand.

To convert the GPX file:

• Replace CrLf (Windows) by Lf (Unix)

• Remove 3x BOM header characters (Windows)

• And - perhaps - convert to UTF8.

Now the GPX input file will be processed correctly

^^ following this, we should consider either a handler with the GPX process fails to then run this conversion, or a handler before attempting to process the GPX to run this conversion or see if the headers exist and should be removed, and if not in UTF8 to then convert it.

@ptpt could you take a look at this in a next update?