conversion of mrSID on-the-fly

[Ben Thompson]

>
>Hello mappers,
>
>Rather than dealing with 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?
>
>Thanks,
>Ben Thompson