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  1. #1
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    Thanks, i like your method, in a way is similar to "add zeros" method, preserving absolute offsets of the data, but your method is even faster, i like it!!
    Obviously, for proper conversion, it is needed to do the whole "subtract" offsets thing and you get a proper non-nt img with a proper size.
    But with your method you get a quick way to obtain the the non-nt img and then the *.mp (polish format map). Even if the img is oversized, the .mp data is not, so is perfect for that.
    And that is ultimately what we want it for. The oversized img is not needed anyway as the original "nt whatever" is already available if we don't want the data.

    Quote Originally Posted by kunix View Post
    2.1.2) replace the GMP header with XXX header in YYYYYYYY.XXX
    To be clear, i would add that the XXX header need to be "overwritten" to whatever is at the beginning, and NOT inserted if you "insert" you move the data and loose the original absolute offset position, and it won't work.

    Definitely, "add zeros method" is deprecated in favor of yours.
    Quote Originally Posted by kunix View Post
    Well, I wasn't talking only about headers, I was talking about some data referring other data through specifying the offset. You can't fix that without deep IMG format knowledge.
    But your doc and the fact that you can convert CarteBlanche convince me that your way is just fine.
    There was NO differences in the "body" of the sufiles, comparing pseudo-nt to non-nt (not even a byte). The only differences where in the headers, so no need to correct anything in the data itself.

    Quote Originally Posted by kunix View Post
    And also all maps converted this way (I've tested NT and pseudo-NT) worked fine on Garmin devices.
    You say here NT (real NT?), what do you mean, you say you could open it on Garmin devices, but Could you open NT(real) converted maps in Gpsmapedit?

    Could you point me to a link to a real NT map?(better if it is a small size download!)
    Last edited by testlelelala; 12th August 2013 at 09:15 AM.

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  3. #2
    Navigation software Moderator kunix's Avatar
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    Quote Originally Posted by testlelelala View Post
    There was NO differences in the "body" of the sufiles, comparing pseudo-nt to non-nt (not even a byte). The only differences where in the headers.
    I remember that. But don't you think it's true only because your map is too small and you don't test all the available data formats? It would be nice to compare this way something like CNE, huh ?

    Quote Originally Posted by testlelelala View Post
    You say here NT (real NT?), what do you mean, you say you could open it on Garmin devices, but Could you open NT(real) converted maps in Gpsmapedit?
    Of course, I've tried it! I could open a real NT map after my "conversion". But, mapedit opened it waay too quickly and didn't draw anything at all, though, it did save something to .mp file. The produced .mp file mainly consists of "[POI]" sections. Nothing interesting...
    In the map statistics mapedit shows the following:
    Spoiler: pic
    [Only registered and activated users can see links. ]

    So you see it can't decode addresses, polylines, polygons, roads...

    Quote Originally Posted by testlelelala View Post
    Could you point me to a link to a real NT map?(better if it is a small size download!)
    I used some maps that I could find on my PC. I don't have any working links... Also I can't download/upload anything large right now, as I have a very bad internet connection right now.
    But I do believe that almost any map you can find here is NT. pseudo-NT and non-NT maps are quite rare. If want to to be absolutely sure, download City Navigator XXX NT
    Last edited by kunix; 12th August 2013 at 10:15 AM.

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    Navigation software Moderator kunix's Avatar
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    Quote Originally Posted by testlelelala View Post
    To be clear, i would add that the XXX header need to be "overwritten" to whatever is at the beginning, and NOT inserted if you "insert" you move the data and loose the original absolute offset position, and it won't work.
    Yes, of course. I was doing it by
    1) calculating the maximum header size that definitely doesn't overlap the subfile bodies (=max(offset_of_header[i] + header_size[i]))
    2) copying the calculated amount of bytes starting from header XXX to offset 0.
    Of course, we could do something more subtle like calculating the exact size of header XXX in each case. But it would require knowledge of IMG format much deeper than I have. I'm an absolute IMG-noob, as I said.

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    The header size is located in the first two bytes of each header.
    Example: When you found "GARMIN RGN" before that you see two bytes 7D 00 it means x7D which after conversion to decimal is 125 bytes.
    Analog with LBL (xEC-->236 bytes), NET(x64-->100 bytes) and NOD(x3F-->3 bytes)
    The only one "odd" is the TRE header that is larger that what you see in the first two bytes, because it could change with copyright info, nevertheless this extra info is not necessary, you could only grab the size that you get from the first two bytes.

 

 

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