[mkgmap-dev] Binary OSM file support?

Mon Sep 13 21:36:17 BST 2010

On 13/09/10 17:55, Scott Crosby wrote:

> Not yet. There are too many 'osm binary formats'. I asked for
> suggestions on osm-dev yesterday and got 'protobuf binary format'. Do
> you have any ideas?
>

Not really, I'm calling it osmprotobuf at the moment...

> I have not thought about how one might detect the format. How
> important is this?

Its needed because mkgmap takes all kinds of input files and I don't
want the user to have to say what the file format is, I just want
mkgmap to work out the file format and use the correct reader.

I do this by extension or by reading the beginning of the file and
looking for something distinctive.  It doesn't have to be fool proof
just good enough to tell genuine files apart.

Hence why I was asking if OSMHeader and or OSMData would always
be present near the beginning of the file, I could look for
them.

>> 4. Does the osmosis conversion from XML to binary keep the order of
>>     the elements the same as they were in the XML file?
>
> Yes. Absolutely.

Great, should be easy to test it is working by comparing the resulting
files.

Thanks
..Steve