[Qgis-user] QGIS and ECW and MrSid formats

[Martin Dobias]

On Fri, Oct 31, 2008 at 11:20 AM, Micha Silver <micha at arava.co.il> wrote:
> Hi Agus:
>
>
> Agustin Lobo wrote:
>
>> Hi!
>>
>> Could we clarify the situation for ecw and Mrsid
>> formats in QGIS? (and perhaps put a note
>> somewhere in the qgis web pages).
>>
> The situation is, unfortunately, clear: The QGIS project can't allow itself
> to distribute software with support for formats which they themselves can
> not be further distributed.  And that seems to be the case with ecw.

I think that things are not really that bad. Today I've took a brief
look at the licenses for ECW and MrSid and it seems that it's okay to
build and distribute qgis with their pieces of software if we
distribute only the binaries (i.e. not their SDKs). They additionaly
request to add their copyright text to about box / readme. MrSid SDK
allows only decoding, ECW also encoding, but only up to 500mb. And I
think they also require that user accepts their EULA before using
those formats.


>> If there is a compiled version of gdal including
>> support for these formats, why QGIS cannot? In any
>> case, is there any workaround so that users can get
>> to have ecw/Mrsid support out of their compiled version?
>> Perhaps through a plugin?
>>
> While I'm not a developer, the with my (very) little understanding of how
> QGIS and gdal interact, I don't think this is possible with a plugin.

For all work with raster data (except WMS) we use GDAL.
So, support for ecw/mrsid must be compiled against gdal.


>> I really think that the final QGIS1.0 should be able to read in
>> those formats, somehow. This is probably seen as a minor concern for
>> developers, but a significant problem for users.
>>
> I totally agree. My guess is that this will eventually be resolved if some
> kind soul will produce a QGIS+gdal pair of binaries with the ecw and/or
> mrSid libraries compiled in.
> Last time we exchanged our frustration with this situation, I even gave a
> name to the new gdal binaries: we need a "gdal-good" "gdal-bad" and
> "gdal-ugly" in the same fashion that licence encumbered audio codecs are
> released as binaries outside of the standard distro repositories.

>From what I've written above, I think everything is just a matter of
packaging (and some more annoyances with license statements and
copyright notices).
- for windows we create the whole toolchain by ourselves so including
these formats in GDAL is a matter of compiling GDAL with appropriate
SDKs
- for linux the situation is more complicated. users usually use gdal
packages from their distribution, so we would need to produce
alternative packages for several distributions which would be
compatible with original ones. Or create "qgis-with-gdal-ugly"
packages with GDAL inside (but that would be nasty solution)
- for mac I have no idea


Martin