mrSID conversion on-the-fly

Andreas Albarello andreas.albarello at TERRITORIUMONLINE.COM
Fri Oct 12 06:32:28 EDT 2007

Ben Thompson wrote:
> Thanking you in advance for your help: Thanks!
> I have downloaded the mrsid dsdk called "GeoExpress SDK", with a huge 
> bunch of irrelevant it the right one?

Yes, there's only that for Windows so it has to be the right one. Make 
sure you've got the right version for your compiler.

> And have managed to build gdal14.dll.
> But have not managed to find any sort of coherent write-up on the 
> specifics for building it with whatever part of the DSDK to make a 
> sid-friendly gdal. All I see is snippets like "set the MRSID_HOME 
> variable in the GDAL nmake.opt"..there's GOT to be more to it than that.

Not necessarily. In fact, for the heck of it, I just tried this myself 
right now and it built fine. I hadn't ever built gdal with mrsid before 
but now I know that it works fine. You just need to comment out the 
MRSID_DIR, MRSID_INCLUDE (all 4 lines) and MRSID_LIB vars in nmake.opt 
and point MRSID_DIR to the directory which you extracted the SDK to.

Once compiled, gdal will require the lti_dsdk_dll.dll included in the 
SDK which has to be placed somewhere so gdal14.dll can find it. Also, 
your mapserver might still be linking to gdal13.dll, so either you 
recompile mapserver as well or you try to rename gdal14.dll to 
gdal13.dll, which will work only if the function exports are the same. 
Check with DependencyWalker.

> Oh, and regarding MS4W: the mapserver people warn  agains using it for a 
> "production" server, which is the case here. Are they just saying that? 
> You know any real reason not to?

First time I hear that. Where did you read this? But yes, maybe it's not 
advisable to use the whole bloated package in production, as - my guess 
- it's not been tested in it's entirety. But I don't think there is 
anything wrong with using the MS4W mapserver + gdal, which is a 
thoroughly tested product, in production.

This has gotten a somewhat off-topic discussion and might have been 
better carried out over at the gdal mailing list, but in the end, I 
don't think it matters. Still, when you reply, you might want to hit the 
reply to all button so that the list gets your email too and someone 
else can read this if he's interested.

Best regards,
Andreas Albarello
Analysis & SW Development

Territorium Online srl/GmbH
Via Buozzi/Buozzistraße 12 - I 39100 Bolzano/Bozen
email: andreas.albarello at

More information about the mapserver-dev mailing list