Convert garmin .img pseudo-NT to non-NT? I know it's possible, but how?(SOLVED!!!)

**testlelelala** · 6th August 2013, 09:32 AM

Perhaps it has a bug when left or right are undefined (none).
I'll check.
But the roads numbers i checked, all are okay, but they have both sides defined left and right numbering.
example: Numbers1=1,E,100,200,O,101,199

Kanopus · 6th August 2013, 11:51 AM

Try: Numbers1=2,E,100,200,O,101,199

I really hope that old cgpsmapper is not good enough to kick out of business 3-rd party map publishers like CarteBlanche.

**testlelelala** · 6th August 2013, 08:26 PM

I also hope that no one get kicked out of business.
But i do hope that old cgpsmapper do things right (as it seems to be for the moment.)

Kanopus · 6th August 2013, 10:02 PM

Internal structure of Garmin NT format is not known. This thread is not about revers engineering Garmin NT maps but about disassembling maps from independent publishers, who use cgpsmapper.

**kunix** · 6th August 2013, 10:33 PM

I don't really believe that people who reverse engineered non-NT IMG files can't do the same with NT IMG files

There should be some other reasons... Like all of them being involved in some economic relations which make decompiling NT maps by others not desirable

**Giomen** · 7th August 2013, 02:03 AM

Originally Posted by Kanopus

Internal structure of Garmin NT format is not known.

What about it?

Spoiler: CLICK

It is really work!

**kunix** · 7th August 2013, 10:16 AM

gimgtools is a very nice set of utilities. But they still don't help us convert NT maps to polish map format, while we can do this for non-NT maps using some utilities (gpsmapedit, for example). Also I don't see how to convert NT map to non-NT one using gimgtools.
In conclusion, gimgtools still doesn't help us decompile NT maps, even partially.

**Giomen** · 8th August 2013, 12:35 AM

Originally Posted by kunix

gimgtools still doesn't help us decompile NT maps, even partially.

I do not write what it is saucer with blue border! But source code is very useful things sometime. We had big provocative discussion about non-NT and NT format on russian forum. Do the bible by John Mechalas have another analogue?

**catymag** · 8th August 2013, 02:08 AM

It could be nice to hear
[Only registered and activated users can see links. ]
opinion about this matter

syzygy · 9th August 2013, 12:13 AM

Originally Posted by testlelelala

I think i got it!!!
It seems to be that what is changed are the offsets of each internal section of each sub-file.
Which are changed simply because the header is displaced from the rest of the sub-file.
working...

PS: Now i need to learn how to interpret and change the offsets, which is probably very basic, but i don't have a clue

As you have found out, the difference between two, say TRE, headers are the contained offset values pointing to data sections in the TRE data area. In a NT or pseudo-NT GMP subfile the offset is always relative to the start of GMP header. But in a non-NT TRE/RGN/LBL subfile, the offset is relative to the start of TRE/RGN/LBL header respectively. So, for example, after you join a TRE header with its TRE data area (both from a pseudo-NT file), you need to update those offsets in TRE header to be relative to the start of the TRE header.

The location of an offset within a non-NT subfile header can be found in the document below.
[Only registered and activated users can see links. ]

Thread: Convert garmin .img pseudo-NT to non-NT? I know it's possible, but how?(SOLVED!!!)

Thread Tools

Display

Advertissements

Bookmarks

Bookmarks

Posting Permissions