[resolved] OfflineMaps+ - Extract some caches from .dat file ..

[Ramadnio]

hi

i need to find a way to extract some caches from cache file of OfflineMaps that extention .dat file

ex.

i downloaded caches of england .. and the cache stored in this path..
OfflineMaps/cache/builtin-maps/OSMMPQ.DAT

how can i extract some caches area from this file "OSMMPQ.DAT" ?

please help
thx.

[Psyberia-Support]

Hi,
This .dat format is quite complex and no specs are available now.
Why not getting the data directly from where it comes, ie here, where it's simply available as images?

[mzicoll]

Well,
not so many answers here in the last years

However, as e.g. OTM does not allow to download too many files at once, the cache saves some time, when re-using the tiles somewhere else...
So, I worked on extracting the cached tiles (IDX and DAT) and hopefully it helps somebody out there.

The code is not checked very well, but for me (AQ v 2.2.5d) it perfectly extracts some PNG on UNIX (Don't worry, should run on other "OS's" as well).
So please accept that this utility and code comes with absolutely no warranty!

Attached is a zip file, containing to jars, one executable, the other just containing the source code.
Some typical calls could be:

Code: Select all

  java -jar /path-to-jar/AqCache.jar  (general help)
  
  java -jar /path-to-jar/AqCache.jar  AqDatDump (specific help)
  java -jar /path-to-jar/AqCache.jar  AqDatDump OSMOTM.DAT (just list)
  java -jar /path-to-jar/AqCache.jar  AqDatDump -e png OSMOTM.DAT (list and extract)
  
  java -jar /path-to-jar/AqCache.jar  AqIdxDump (specific help)
  java -jar /path-to-jar/AqCache.jar  AqIdxDump OSMOTM.IDX (just list)
  java -jar /path-to-jar/AqCache.jar  AqIdxDump -e png OSMOTM.IDX (list and extract)

Maybe the IDX stuff does not really help, but if you want to understand the structure and/or extract specific tiles (or on the fly by other applications), you should understand the IDX.

I did not understand all of the bits and bytes in the IDX or DAT file, so the tool might not work always ;/

Give it a try, comments welcome
Martin

[Psyberia-Support]

Thanks for the tool!