Hi Even, just before reading your reply I opened an issue on the libtiff issue tracker [1]. If you thing that the request makes sense I can also try to implement it and open a merge request.
Of course I suppose that updating libtiff is a by far slower process than the solution you suggest in your reply. > On 17 Sep 2020, at 21:08, Even Rouault <[email protected]> wrote: > > On jeudi 17 septembre 2020 20:26:59 CEST Sebastiaan Couwenberg wrote: > > On 9/17/20 7:56 PM, Antonio Valentino wrote: > > > today I tried to made some tests to generate Cloud Optimized Geotiff > > > (COG) files with LERC compression. > > > > > > I realized that this is not possible in debian because, if I understand > > > correctly, we build GDAL using system libtiff while the LERC compressor, > > > according to [1], need the internal libtiff. > > > > Yes, and that's somewhat broken by design. > > > > libtiff should expose the features required by GDAL for this. IIRC GDAL > > uses a private header currently. > > One potential one way forward would be that Debian provides a > libtiff-private-dev package (similarly to libpoppler-private-dev) with the > "tiffiop.h" header, and then GDAL build logic could be modified to use it. At > least that's the theory. I haven't tried (TM) > > > > The strange thing, to me, is that the same limitation also applies to > > > the the ZSTD compressor [1], but in this case I'm perfectly able to > > > generate COG files with ZSTD compression in debian. > > That isn't the same situation. The ZSTD codec is in official libtiff, so I > assume Debian libtiff is built with ZSTD support, hence you get in GDAL. Yes, now I realised it, but the documentation [2] is a little bit misleading: > "ZSTD is available when using internal libtiff and if GDAL built against > libzstd >=1.0, or if built against external libtiff with zstd support.” The option to linking against an external libtiff >= 4.0.10 is not currently mentioned that’s why I was a little bit surprised. [1] https://gitlab.com/libtiff/libtiff/-/issues/213 <https://gitlab.com/libtiff/libtiff/-/issues/213> [2] https://gdal.org/drivers/raster/cog.html#raster-cog <https://gdal.org/drivers/raster/cog.html#raster-cog> Kind regards -- Antonio Valentino
