[PROPOSAL] Add instructions on how to compile with HARDSUBX (on macOS) to docs/HARDSUBX.txt

[cottuli]

Adding some instructions on how to compile with HARDSUBX, on macOS, to either COMPILATION.md or docs/HARDSUBX.txt, would be much appreciated.

When I installed I first tried brew install ccextractor, and cd ccextractor/mac; ./build.command OCR, as suggested in COMPILATION.md, but both of these methods don't provide hardsubx suport.

I then tried using cmake (cd ccextractor/; mkdir build; cd build; cmake -DWITH_OCR=on -DWITH_HARDSUBX=on ../src/; make) but this gave undefined symbol errors like

Undefined symbols for architecture x86_64: "_TessBaseAPICreate", referenced from: __init_hardsubx in ccextractor-hardsubx.o _init_ocr in ccextractor-ocr.o

which seem to be similar to the errors vr8hub mentioned in one of his comments.

I then read through the relevant bug reports (see #1173 and #1111) and was finally able to get hardsubx working by quoting the relevant portion of line 6763 as suggested by vr8hub in #1173 (comment).

So I think all new users trying to get the hardsub extractor working on mac would appreciate some instructions on how to do so in the docs.

It's also worth noting that the parameter that needs to be passed to ccextractor is -hardsubx, whereas most long-time unix users would expect it to be --hardsubx (see #1173 (comment)).

[cfsmp3]

We'll need a Mac user to send us a PR. I think none of the core team developers actually uses a Mac, so the reason it works is just portability, not that an actual effort was made here.

[canihavesomecoffee]

IIRC @MatejMecka is one of the persons who has a Mac. Maybe he can look at it (if he has time)

[MatejMecka]

Hey there! I'll happily take to solve the issue 🐱

[cfsmp3]

@MatejMecka ? Where's that PR?

[MatejMecka]

Hey there! I'm getting some issues compiling Leptonica using the build script, working on fixing that :)