mrSID conversion on-the-fly

Andreas Albarello andreas.albarello at TERRITORIUMONLINE.COM
Wed Oct 10 15:25:48 EDT 2007

Ben Thompson wrote:
> Rather than recompiling gdal and mapserver with LizardTech's mrsid dsdk,
> I thought it would be simpler to somehow invoke gdal_translate or 
> mrsiddecode
> on-the-fly somewhere during the map drawing process, converting to tiff 
> or png.
> Anyone know where/how to insert a process into the system like that?

I fail to see how any of that might be easier than compiling gdal 
against the MrSID sdk. Besides, wouldn't it be easier to use TIFF in the 
first place, at that point? That sort of on-the-fly processing would 
sure cost you some disk space anyhow.

Nevertheless, you could be able to do this by using MapScript and 
performing the necessary decoding/translating steps yourself before you 
start the drawing process. No way though it is easier than recompiling 
gdal if you want to add those steps somewhere *during* (as opposed to 
right before) the drawing process or if you don't use any of the 
MapScript flavors and rely on CGI for your maps which would require 
fiddling with the C-code. Trust me.

Best regards,

Andreas Albarello
Analysis & SW Development

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

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