Some dive computers store the depth as an absolute pressure value (in
bar). To convert to a depth value (in meters), the atmospheric pressure
and water density are required. For dive computers that do not have
those values available, libdivecomputer uses a default value. With the
new public api functions, applications can adjust those default values.
Some dive computers already provided a backend specific calibration
function. Those functions are now deprecated. They are kept around to
maintain backwards compatibility for now, but they will be removed in
the next version.
The gauge and freedives have a slightly different data format compared
to scuba dives. The main difference is the size of the header and two
new sample types.
The logbook header has 5 bytes extra, which are not present in the dive
header. Those 5 extra bytes contain the dive mode, which is required for
parsing the dive data. Therefore, insert all 5 bytes again and update
the parser.
The remaining 4 bytes appear to be some 32 bit address. They are not
used for anything right now, but are preserved as well in case they are
needed in the future.
The depth value is encoded with only 11 bits instead of 12 bits. The
extra bit contains the gas mix index. This resulted in wrong depths,
with values larger than 204.8m.
