Homebrew GDAL

[zakjan]

Currently GDAL installed from Homebrew doesn't support LERC.

Is it possible to publish LERC to Homebrew, and link it with libtiff there?

See Homebrew/homebrew-core#106450 for how ZSTD support was enabled.

[tmaurer3]

@zakjan AFAIK both WebP and Lerc were added to libtiff in 2021. Gdal at this time already supported Lerc and certain combinations of Lerc with other, additional lossless compressors. You can find more on this here: https://gdal.org/drivers/raster/gtiff.html . So this should be a matter of setting the right options in Homebrew. In case of problems, the Gdal experts are your best bet.

[jshrake]

You can add LERC support to the homebrew installed gdal by modifying the libtiff formula and rebuilding it from source.

1. Clone and build https://github.com/Esri/lerc.git

   cd /Users/justin/code
   git clone https://github.com/Esri/lerc.git
   cd lerc
   cmake -S. -Bbuild -DCMAKE_BUILD_TYPE=Release
   cmake --build build

2. Edit the homebrew libtiff formula with the following patch:

   diff --git a/Formula/libtiff.rb b/Formula/libtiff.rb
   index 4e20a84bb74..2ec59f64314 100644
   --- a/Formula/libtiff.rb
   +++ b/Formula/libtiff.rb
   @@ -33,7 +33,9 @@ class Libtiff < Formula
       args = %W[
       --prefix=#{prefix}
       --enable-zstd
   +   --enable-lerc
   +   --with-lerc-include-dir=/Users/justin/code/lerc/src/LercLib/include
   +   --with-lerc-lib-dir=/Users/justin/code/lerc/build
       --disable-lzma
       --disable-webp
       --with-jpeg-include-dir=#{Formula["jpeg-turbo"].opt_include}

   Replace the paths with-lerc-include-dir and with-lerc-lib-dir with the path you cloned above.
   Then, copy the patch and apply it:

   cd "$(brew --repository homebrew/core)"
   pbpaste | patch -p1
   brew reinstall --build-from-source libtiff
   git restore Formula/libtiff.rb

3. Your homebrew installed gdal should now have the LERC codec available:

   gdal_translate -of GTIFF -co COMPRESS=LERC -co MAX_Z_ERROR=1 input.tif output.tif

[jshrake]

I created a PR to add a formula for lerc to homebrew Homebrew/homebrew-core#121231. Once this is merged, I can make a followup PR to enable lerc in the libtiff formula, which also enables lerc in the homebrew installed GDAL.

[jshrake]

PR to enable lerc in libtiff Homebrew/homebrew-core#121300