Hi everyone, I started looking at/using OSM a few weeks ago with the aim of getting the UK map (~7M nodes, 900K ways) on my new iPAQ which I've almost finished porting linux to.
Firstly, I'd like to say the whole OSM project is pure genius and am very thankful for the work every last developer/contributor has done. I'd certainly like to give something back by helping out. I spent most of the time looking at a few PDA apps that are already out there and trying to convert the UK planet extract to the required format for each app. I wrote up what I found out as an e-mail but it was a bit long so I've put it on my user page ( http://wiki.openstreetmap.org/wiki/User:Oliford ) as a sort of (subjective) review for anyone who's interested in PDA OSM use or interested in what working with the OSM data is like for a newbie. The short(er) story... Getting anything to handle the whole UK data without running out of memory, seg-faulting or falling over on invalid UTF-8 is hard work. In the end I used roadmap which converts from the OSM Mobile Binary (OSMMB) format and I've written my own C program which converts the whole UK XML extract to OSMMB in about a minute. I'm considering writing my own PDA app (open source of course) which would work directly from the OSMMB tiled vector data, give a slippy/scrollable and zoomable interface like Roadmap's but also provide the place/street name lookup and routing on all loaded tile data. The newer proposal on the OSM wiki for the OSMMB seems to be well suited to this. Currently the whole of the UK ends up in a 100MB OSSMB file which is really quick to parse. I can slice it into tiles, linearly search it for street names etc in a few seconds on a machine it takes several minutes to do the same on the XML. I have some thoughts about things like merging multiple tiles' data and routing across different tiles but there are still some things I don't quite understand about the format (the wiki pages are a bit confusing on what is actually decided and what are just ideas). Is anyone actively working on the OSMMB format now that I could direct my questions at? Thanks, Oliver Ford PS: Just as I'm signing this off I've stumbled over the 'OSMbin(file_format)' wiki page. Is that format related to the OSM Mobile binary somehow? Is one more developed/used than the other, has one been abandoned? _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
