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Geo-FIT-1.11
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/ Geo::FIT

NAME

Geo::FIT - Decode Garmin FIT files

SYNOPSIS

    use Geo::FIT;

Create an instance, assign a FIT file to it, open it:

    my $fit = Geo::FIT->new();
    $fit->file( $fname );
    $fit->open or die $fit->error;

Register a callback to get some info on where we've been and when:

    my $record_callback = sub {
        my ($self, $descriptor, $values) = @_;

        my $time= $self->field_value( 'timestamp',     $descriptor, $values );
        my $lat = $self->field_value( 'position_lat',  $descriptor, $values );
        my $lon = $self->field_value( 'position_long', $descriptor, $values );

        print "Time was: ", join("\t", $time, $lat, $lon), "\n"
        };

    $fit->data_message_callback_by_name('record', $record_callback ) or die $fit->error;

    my @header_things = $fit->fetch_header;

    1 while ( $fit->fetch );

    $fit->close;

DESCRIPTION

Geo::FIT is a Perl class to provide interfaces to decode Garmin FIT files (*.fit).

The module also provides a script to read and print the contents of FIT files (fitdump.pl), a script to convert FIT files to TCX files (fit2tcx.pl), and a script to convert a locations file to GPX format (locations2gpx.pl).

Constructor Methods

new()

creates a new object and returns it.

clone()

Returns a copy of a Geo::FIT instance.

clone() is experimental and support for it may be removed at any time. Use with caution particularly if there are open filehandles, it which case it is recommended to close() before cloning.

It also does not return a full deep copy if any callbacks are registered, it creates a reference to them. There is no known way to make deep copies of anonymous subroutines in Perl (if you know of one, please make a pull request).

The main use for c<clone()> is immediately after new(), and file(), to create a copy for later use.

Class methods

profile_version_string()

returns a string representing the .FIT profile version on which this class based.

Object methods

file( $filename )

returns the name of a .FIT file. Sets the name to $filename if called with an argument (raises an exception if the file does not exist).

open()

opens the .FIT file.

fetch_header()

reads .FIT file header, and returns an array of the file size (excluding the trailing CRC-16), the protocol version, the profile version, extra octets in the header other than documented 4 values, the header CRC-16 recorded in the header, and the calculated header CRC-16.

fetch()

reads a message in the .FIT file, and returns 1 on success, or undef on failure or EOF. fetch_header() must have been called before the first attempt to fetch() after opening the file.

If a data message callback is registered, fetch() will return the value returned by the callback. It is therefore important to define explicit return statements and values in any callback (this includes returning true if that is the desired outcome after fetch()).

error()

returns an error message recorded by a method.

crc()

CRC-16 calculated from the contents of a .FIT file.

crc_expected()

CRC-16 attached to the end of a .FIT file. Only available after all contents of the file has been read.

trailing_garbages()

number of octets after CRC-16, 0 usually.

data_message_callback_by_num(message number, callback function[, callback data, ...])

register a function callback function which is called when a data message with the messag number message number is fetched.

data_message_callback_by_name(message name, callback function[, callback data, ...])

register a function callback function which is called when a data message with the name message name is fetched.

switched(data message descriptor, array of values, data type table)

returns real data type attributes for a C's union like field.

fields_list( $descriptor [, keep_unknown => $boole )

Given a data message descriptor ($descriptor), returns the list of fields described in it. If keep_unknown is set to true, unknown field names will also be listed.

fields_defined( $descriptor, $values )

Given a data message descriptor ($descriptor) and a corresponding data array reference of values ($values), returns the list of fields whose value is defined. Unknow field names are never listed.

field_value( $field, $descriptor, $values )

Returns the value of the field named $field (a string).

The other arguments consist of the data message descriptor ($descriptor, a hash reference) and the values fetched from a data message ($values, an array reference). These are simply the references passed to data message callbacks by fetch(), if any are registered, and are simply to be passed on to this method (please do not modifiy them).

For example, we can define and register a callback for file_id data messages and get the name of the manufacturer of the device that recorded the FIT file:

    my $file_id_callback = sub {
        my ($self, $descriptor, $values) = @_;
        my $value = $self->field_value( 'manufacturer', $descriptor, $values );

        print "The manufacturer is: ", $value, "\n"
        };

    $fit->data_message_callback_by_name('file_id', $file_id_callback ) or die $fit->error;

    1 while ( $fit->fetch );
field_value_as_read( $field, $descriptor, $value [, $type_name_or_aref ] )

Converts the value parsed and returned by field_value() back to what it was when read from the FIT file and returns it.

This method is mostly for developers or if there is a particular need to inspect the data more closely, it should seldomly be used. Arguments are similar to field_value() except that a single value $value is passed instead of an array reference. That value corresponds to the value the former method has or would have returned.

As an example, we can obtain the actual value recorded in the FIT file for the manufacturer by adding these lines to the callback defined above:

        my $as_read = $self->field_value_as_read( 'manufacturer', $descriptor, $value );
        print "The manufacturer's value as recorded in the FIT file is: ", $as_read, "\n"

The method will raise an exception if $value would have been obtained by field_value() via an internal call to switched(). In that case, the type name or the original array reference of values that was passed to the callback must be provided as the last argument. Otherwise, there is no way to guess what the value read from the file may have been.

value_cooked(type name, field attributes table, invalid, value)

This method is now deprecated and is no longer supported. Please use field_value() instead.

converts value to a (hopefully) human readable form.

value_uncooked(type name, field attributes table, invalid, value representation)

This method is now deprecated and is no longer supported. Please use field_value_as_read() instead.

converts a human readable representation of a datum to an original form.

use_gmtime(boolean)

sets the flag which of GMT or local timezone is used for date_time type value conversion. Defaults to true.

unit_table(unit => unit conversion table)

sets unit conversion table for unit.

semicircles_to_degree(boolean)
mps_to_kph(boolean)

wrapper methods of unit_table() method. semicircle_to_deg() defaults to true.

close()

closes opened file handles.

profile_version_string()

Returns a string representation of the profile version used by the device or application that created the FIT file opened in the instance.

fetch_header() must have been called at least once for this method to be able to return a value, will raise an exception otherwise.

Functions

The following functions are provided. None are exported, they may be called as Geo::FIT::message_name(20), Geo::FIT::field_name('device_info', 4) Geo::FIT::field_number('device_info', 'product'), etc.

message_name(message spec)

returns the message name for message spec or undef.

message_number(message spec)

returns the message number for message spec or undef.

field_name(message spec, field spec)

returns the field name for field spec in message spec or undef.

field_number(message spec, field spec)

returns the field index for field spec in message spec or undef.

Constants

Following constants are exported: FIT_ENUM, FIT_SINT8, FIT_UINT8, FIT_SINT16, FIT_UINT16, FIT_SINT32, FIT_UINT32, FIT_SINT64, FIT_UINT64, FIT_STRING, FIT_FLOAT16, FIT_FLOAT32, FIT_UINT8Z, FIT_UINT16Z, FIT_UINT32Z, FIT_UINT64Z.

Also exported are:

FIT_BYTE

numbers representing base types of field values in data messages.

FIT_BASE_TYPE_MAX

the maximal number representing base types of field values in data messages.

FIT_HEADER_LENGTH

length of a .FIT file header.

Data message descriptor

When fetch method meets a definition message, it creates a hash which includes various information about the corresponding data message. We call the hash a data message descriptor. It includes the following key value pairs.

field index => field name

in a global .FIT profile.

local_message_type => local message type

necessarily.

message_number => message number

necessarily.

message_name => message name

only if the message is documented.

callback => reference to an array

of a callback function and callback data, only if a callback is registered.

endian => endian

of multi-octets data in this message, where 0 for littel-endian and 1 for big-endian.

template => template for unpack

used to convert the binary data to an array of Perl representations.

i_field name => offset in data array

of the value(s) of the field named field name.

o_field_name => offset in binary data

of the value(s) of the field named field name.

c_field_name => the number of values

of the field named field name.

s_field_name => size in octets

of whole the field named field name in binary data.

a_field name => reference to a hash

of attributes of the field named field name.

t_field name => type name

only if the type of the value of the field named field name has a name.

T_field name => a number

representing base type of the value of the field named field name.

N_field name => a number

representing index of the filed named field name in the global .FIT profile.

I_field name => a number

representing the invalid value of the field named field name, that is, if the value of the field in a binary datum equals to this number, the field must be treated as though it does not exist in the datum.

endian_converter => reference to an array

used for endian conversion.

message_length => length of binary data

in octets.

array_length => length of data array

of Perl representations.

Callback function

When fetch method meets a data message, it calls a callback function registered with data_message_callback_by_name or data_message_callback_by_num, in the form

callback function->(object, data message descriptor, array of field values, callback data, ...).

The return value of the function becomes the return value of fetch. It is expected to be 1 on success, or undef on failure status.

Developer data

Fields in devloper data are given names of the form developer data index_field definition number_converted field name, and related informations are included data message descriptors in the same way as the fields defined in the global .FIT profile.

Each converted field name is made from the value of field_name field in the corresponding field description message, after the following conversion rules:

(1) Each sequence of space characters is converted to single _.
(2) Each of remaining non-word-constituend characters is converted to _ + 2 column hex representation of ord() of the character + _.

64bit data

If your perl lacks 64bit integer support, you need the module Math::BigInt.

DEPENDENCIES

Nothing in particular so far.

SEE ALSO

fit2tcx.pl, fitdump.pl, locations2gpx.pl, Geo::TCX, Geo::Gpx.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests to bug-geo-gpx@rt.cpan.org, or through the web interface at http://rt.cpan.org.

AUTHOR

Originally written by Kiyokazu Suto suto@ks-and-ks.ne.jp with contributions by Matjaz Rihtar.

This version is maintained by Patrick Joly <patjol@cpan.org>.

Please visit the project page at: https://github.com/patjoly/geo-fit.

VERSION

1.11

LICENSE AND COPYRIGHT

Copyright 2022, Patrick Joly patjol@cpan.org. All rights reserved.

Copyright 2016-2022, Kiyokazu Suto suto@ks-and-ks.ne.jp. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENSE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.