[mkgmap-dev] LBL subfile details

Wed Sep 23 15:52:55 BST 2009

Hi,
Here are some findings that i can not manage to code in java... In mkgmap the text between the header and the first lbl section is hardcoded to the string 'mkgmap'. This section is defined at the end of the header:
LBLHDR at 0xB0 - 4 byte Text section begin
LBLHDR at 0xB4 - 4 byte Text section length (INFO_LEN in mkgmap)
These values are hardcoded in mkgmap and i do not know how to change that code. It should be converted to something as the other subsections. In all original files the text is 'American'. In the source it is commented as "// Sort descriptor ??? ...". I could speculate that this is kind of dictionary name(like 'American English'). Another finding is (when the texts are coded in 6bits) that the first byte of LBL1 is 0xFF(in Metro Guide) which is decoded as 0x3F == 'End Marker'. In mkgmap it is 0x00 that i think is not correct. All elements that have no name have lbl1 pointer to this end marker so it should be 0xFF. If there are points for the cities and LBL1,2,3,4 are filled in the overview map img, menu Find->Find Places has working City tab in MapSource. Maybe overview img participate in the indexing in some way? Best Regards,
Anton Todorov