[gdal-dev] Tickets 2385 and 2683 (ECW and MrSID plugins)

[Francesco P. Lovergine]

On Sun, May 03, 2009 at 10:41:55PM -0400, Frank Warmerdam wrote:
> Francesco Paolo Lovergine wrote:
>> On Sat, May 02, 2009 at 11:18:34AM -0400, Frank Warmerdam wrote:
>>> I'm going to close these tickets as WONTFIX, though folks are welcome to use
>>> the patches for their own use.
>>>
>>> I think it is more appropriate to improve the "in tree" plugin configuration
>>> and makefile logic rather than pushing drivers out as their own packages.
>>>
>>
>> The reason for those patches is having an independent compilation unit. This is
>> the only purpose for a plugin hack for ecw/mrsid, i.e. to solve a
>> licensing problem. But for that, I agree that a more general approach to
>> support a plugin mechanism (possibly with a versioning support) would 
>> be nice. Are you thinking to something like an apache-like mechanism to 
>> support DSO modules?
>> It would be useful defining the constraints for that you are thinking.
>
> Frankie,
>
> I'm afraid I don't understand what you mean by "independent compilation
> unit" or why exactly the licensing issues of ecw and mrsid make them special
> with regard to how the plugin gets compiled.
>

The reason for having a separated source is allow adding both supports
to a pre-compiled gdal that does not enable them. An independent compilation
unit is stuff that can be compiled a part and added to the base after.

Both ecw and mrsid
SDK require accepting a specific EULA beforei building/using
and do not distribute sources and/or patches for the sources 
(both .deb and .rpm stuff can require them) in the case of ecw,
so it is an problem for binary distributions distribute a gdal+ecw and/or
gdal+mrsid.

> I don't know how apache handles DSO modules, so I can't comment on whether
> things would evolve in that direction.
>
> I am imagining adding configure options to specify particular drivers should
> be build and installed as plugins.
>
> So in addition to --with-ecw=<path to ecw sdk> there might also be
> --with-ecw-as-plugin which would cause the ECW driver to be built and
> installed as a plugin.
>
> Best regards,

That's absolutely reasonable and can co-exists with the previous goal.

-- 
Francesco P. Lovergine