[mkgmap-dev] Feedback: Searchable Addresses (using r991)

Wed Apr 8 23:42:52 BST 2009

On Wed, Apr 08, 2009 at 07:36:09PM +0200, Bernhard Heibler wrote:
> Is there anybody who wants to join me in understanding the MDR file ?  I  
> did already some research on the MDR file. Most of the sections I have  
> not decoded until now. The MDR file has about 20 mysterious sections.  
> What I found out so far is that we need at least 7 sections to enable  
> the Nuvi address search. I found this out by removing section by section  
> out of the header of a working MDR file. I have added some code to  
> libgarmin to display some sections of the MDR. I'm able to decode some  
> parts of the city, street and region index.

Have you looked at the MdrDisplay program in the display svn:
http://svn.mkgmap.org.uk/display/trunk/src/test/display/MdrDisplay.java
This contains everything I know about the format.  Hopefully
you can add to that knowledge.

One difficulty is that there are different versions of the sections with
different sizes.  Also when downloaded to a GPSr device some of the
sections are not sent and the sections that are can have a reduced size.

MDR5 contains pointers the the string table in MDR 15 and also to the
LBL section.  I guess that the MDR 15 pointers are used by mapsource and
the LBL pointers by the device.  Neither the MDR15 section nor the pointers
to it are in the device version.

..Steve