It was actually step 2 on how to add the files.

Anyway, I've it figured out so it is now compiled correctly. There was an error in the 01. patch, it should remove 'final' from CameraMetaData, and not adding to it.

There is also another error in CMakeLists.txt in RawSpeed-v3/src/librawspeed/common:

target_sources(rawspeed_get_number_of_processor_cores should be set to PUBLIC not PRIVATE. Or else it libraw would not link (can't find rawspeed_get_number_of_processor_cores).

There is one addition error in converting the cameras.xml file to cameras.cpp file. A null character was added in the last line of the cpp file. It won't compile unless it is removed. The null char was preceding the last line "";

I also need to add -fsanitize=address compile option to Makefile.dist, as RawSpeed3 source code automatically detect and enable -fsanitize=address compile flag, and it'll not link unless the same is specified in libraw and my code.

Now that I got it to compile and link, how do I specify RawSpeed3 during runtime?

I set imgdata.rawparams.use_rawspeed = 1 and for all the RAW files I tried, it doesn't decode them with RawSpeed3, including Sony ARW files or Nikon Z camera RAW files.

The doc mentioned about:

RawSpeed-v3 support is controlled via libraw_decoder_info.t->flags (LIBRAW_DECODER_TRYRAWSPEED3 bit).

First of all, there is no libraw_decoder_info.t->flags, but there is libraw_decoder_info_t->decoder_flags.

I assume you're referring to this decoder_flags?

I can assign decoder_flags = LIBRAW_DECODER_TRYRAWSPEED3, but how do I pass the libraw_decoder_info_t data structure to the raw processor so that it knows I want it to try RawSpeed3?

There is a get_decoder_info() function, but not a set_decoder_info().