[gdal-dev] OpenJPEG Testers Needed

[Even Rouault]

> So, are you saying there are actual pixel differences between encoded file
> and original?

Yes

> > oh, so how does one make a forward struct declaration to make gcc 4.4
> happy ?

Apparently it doesn't like to see "typedef struct foo { ... } bar" 
(openjpeg.h) and "typedef struct foo bar" (region_mgr.h).
If openjpeg.h was "struct foo { ... }", that would work (but we cannot touch 
that one). Why not just including openjpeg.h in region_mgr.h to avoid the 
typedef redefinitions ?

> 
> > Testing with 2048x2048 tiled images, with OpenMP enabled, I can see perf
> > improvements.
> > For example ~2s  (4 vCPU) vs ~3s (openjpeg 2.1) to decode a tile.
> > 
> > Great. So, this is good. What are your system specs, may I ask ?

Was on a i5 CPU 750 @ 2.67GHz, 4 GB RAM, 64bit build

> > 
> > 
> > 
> > 
> > With a single tiled 11310x17310 image with which GDAL uses the
> > opj_set_decode_area() area,
> > I couldn't really see the difference as the memory consumption grows to
> > above 2 GB,
> > which cause disk trashing on the system on which I test.
> 
> Yes, that makes sense, there is still work to be done, I guess. The wavelet
> transform
> needs to be modified to be more memory efficient.  What size of decode area
> would you
> typically want to set on an image of that size ?

One use case could be for displaying in a desktop GIS application (QGIS for 
example), so the size of the display area. Let's say 2000x1000 max.

> 
> 
> Thanks again,
> Aaron
> 
> 
> Even
> 
> > --
> > Spatialys - Geospatial professional services
> > http://www.spatialys.com

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com