[OSM-dev] Delta-encoding in PBF

[David Paleino]

On Sat, 18 Dec 2010 13:28:09 +0100, Stefan de Konink wrote:

> Op 18-12-10 11:53, David Paleino schreef:
> > Hello people,
> > I'm writing a parser in C# for PBF dumps. However, I'm having issues with
> > the Delta-{en|de}coding.
> 
> http://git.openstreetmap.nl/index.cgi/pbf2osm.git/tree/src/main.c#n588
> 
> Maybe that helps?

Aha, yes! :)

From that code, it seems like you're using what I thought before, i.e. given x,
x1 and x2, the delta-coded list would contain x, x1-x, x2-x1. And then you're
reconstructing them just by summing up.

So I found my bug. I was summing up deltas between them, instead of
previous result + current delta.

Thank you!,
David

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