On 2014-04-07 14:32, Rainer Mohr wrote:
Am 07.04.14 13:06, schrieb Jef Driesen:
For the Oceanics the situation is a bit different. It's a real event
based mechanism, without a base sample rate (like the 4s used by the
Uwatecs), at least not that I know about. To make things worse, is
that the resolution of the recorded timestamp is only 1 minute. The
result is that you can end up with zero or more values per minute.
Currently libdivecomputer tries to spread those evenly within that
minute. Far from perfect, but it does result in something reasonable.
Multiple values with the same timestamps is probably even more
confusing for applications. But the consequence is that the sample
interval is variable.
Ugh, that sucks...
I do have an Oceanic Import for the Oceanlog Software, its an Access
file and it actually does look like I get multiple values for the same
bottom time in some occasions... Oh dear...
One example file I have gives me a depth value every 15 secs with some
having multiple values. Another example file gives me continuous 1
second steps apparently with no multiple values.
I don't remember all the details from memory, but I believe all Oceanic
devices from the vtpro family record timestamps in each sample,
regardless of the time or depth based sampling. That timestamp has only
a resolution of one minute. For a time based sampling, that's not a
major problem because you can use the sample interval to figure out the
exact timestamp. But for the depth based sampling, there is no sample
rate, and you can't do this.
To make things even worse, Oceanic started encrypting their mdb Access
files starting with version 2.2.8 of the Oceanlog Software. You
somethimes wonder what goes on in peoples heads... Guess they really
needed to hide my own data from myself.
I never noticed. But I usually don't need to look into the database
files.
I can provide some data if you want to have a look.
I have two example Oceanlog files, but if you have anything else, that
would be helpful, thanks.
I have two memory dumps containing dives with a depth based sample rate.
Do I send you the raw memory dumps, or do you prefer to have the data
downloaded into oceanlog instead?
Jef
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