notes.txt

General LibRaw Process
	1. open_file()		libraw_cxx.cpp
	2. unpack()		libraw_cxx.cpp
	3. unpack_thumb()	libraw_cxx.cpp

Open file has the most intersting stuff though

FNC LibRaw::open_file(const char *fname, INT64 max_buf_size)
1. LibRaw_file_datastream(fname)
	I think all this really does is to open the file
	data stream. Nothing really curcial/important
2. int ret = open_datastream(stream)
	This is where the magic happens. I'm pretty sure
	of it
FNC LibRaw::open_datastream(LibRaw_abstract_datastream *stream)
1. This function gets passed the result of the 
   LibRaw_file_datastream(fname)
2. identify();
	This happens in dcraw/dcraw.c
	There's a lot that's happening in there. What I think
	happens is it gets basic data about the raw file:
	
	raw_height
	raw_width
	load_raw	This appears to be a function pointer
	write_thumb

	load_raw is set depending on the type of camera
	For example:
	if (!memcmp(head, "NOKIARAW", 8)) {
		.....blah blah....
		load_raw = &CLASS eight_bit_load_raw break;
	}

	inside of each of these "specialized" raw loaders is
	where most of the raw loading (obviously) happens
	Inside of:
	
	FNC void CLASS eight_bit_load_raw()
	1. Declares a pixel pointer which is a line of pixels
		pixel = (uchar *)calloc(raw_width, sizeof *pixel)
	2. For every row and column, it first does
		fread(pixel, 1, raw_width, ifp)
		Which I think just loads the next line into the pixel
		pointer
	3. Then for every pixel, it does
		RAW(row,col) = curve[pixel[col]];
		RAW is under a define:
		#define RAW(row,col) \
			raw_image[(row)*raw_width+(col)]
3. First checks if load_raw (set from identify) is equal
   to LibRaw::x3f_load_raw() which is a custom load raw?

ALTERNATIVE PATH TO FOLLOW


Just follow the path in dcraw.cc easy peasy