Rename Raw-rs to Rawkit (#2088)

* Rename within files

* Rename in CI

* Rename the folder and file names

* Rename raw_rs to rawkit

* Add example to README

* Add initial documentation

* Small API changes and extra documentation

* Bump versions and stuff

* Readme improvements

* Merge proc-macro crates into one

* Add README to rawkit-proc-macros

* Remove keywords and categories

* Add licenses to rawkit-proc-macros

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

libraries/rawkit/src/decoder/arw1.rs

@@ -0,0 +1,109 @@
+use crate::tiff::file::TiffRead;
+use crate::tiff::tags::SonyDataOffset;
+use crate::tiff::Ifd;
+use crate::{RawImage, SubtractBlack, Transform};
+
+use bitstream_io::{BitRead, BitReader, Endianness, BE};
+use std::io::{Read, Seek};
+
+pub fn decode_a100<R: Read + Seek>(ifd: Ifd, file: &mut TiffRead<R>) -> RawImage {
+	let data_offset = ifd.get_value::<SonyDataOffset, _>(file).unwrap();
+
+	let image_width = 3881;
+	let image_height = 2608;
+
+	file.seek_from_start(data_offset).unwrap();
+	let mut image = sony_arw_load_raw(image_width, image_height, &mut BitReader::<_, BE>::new(file)).unwrap();
+
+	let len = image.len();
+	image[len - image_width..].fill(0);
+
+	RawImage {
+		data: image,
+		width: image_width,
+		height: image_height,
+		cfa_pattern: todo!(),
+		#[allow(unreachable_code)]
+		maximum: (1 << 12) - 1,
+		black: SubtractBlack::None,
+		transform: Transform::Horizontal,
+		camera_model: None,
+		camera_white_balance: None,
+		white_balance: None,
+		camera_to_rgb: None,
+	}
+}
+
+fn read_and_huffman_decode_file<R: Read + Seek, E: Endianness>(huff: &[u16], file: &mut BitReader<R, E>) -> u32 {
+	let number_of_bits = huff[0].into();
+	let huffman_table = &huff[1..];
+
+	// `number_of_bits` will be no more than 32, so the result is put into a u32
+	let bits: u32 = file.read(number_of_bits).unwrap();
+	let bits = bits as usize;
+
+	let bits_to_seek_from = huffman_table[bits].to_le_bytes()[1] as i64 - number_of_bits as i64;
+	file.seek_bits(std::io::SeekFrom::Current(bits_to_seek_from)).unwrap();
+
+	huffman_table[bits].to_le_bytes()[0].into()
+}
+
+fn read_n_bits_from_file<R: Read + Seek, E: Endianness>(number_of_bits: u32, file: &mut BitReader<R, E>) -> u32 {
+	// `number_of_bits` will be no more than 32, so the result is put into a u32
+	file.read(number_of_bits).unwrap()
+}
+
+/// ljpeg is a lossless variant of JPEG which gets used for decoding the embedded (thumbnail) preview images in raw files
+fn ljpeg_diff<R: Read + Seek, E: Endianness>(huff: &[u16], file: &mut BitReader<R, E>, dng_version: Option<u32>) -> i32 {
+	let length = read_and_huffman_decode_file(huff, file);
+
+	if length == 16 && dng_version.map(|x| x >= 0x1010000).unwrap_or(true) {
+		return -32768;
+	}
+
+	let diff = read_n_bits_from_file(length, file) as i32;
+
+	if length == 0 || (diff & (1 << (length - 1))) == 0 {
+		diff - (1 << length) - 1
+	} else {
+		diff
+	}
+}
+
+fn sony_arw_load_raw<R: Read + Seek>(width: usize, height: usize, file: &mut BitReader<R, BE>) -> Option<Vec<u16>> {
+	const TABLE: [u16; 18] = [
+		0x0f11, 0x0f10, 0x0e0f, 0x0d0e, 0x0c0d, 0x0b0c, 0x0a0b, 0x090a, 0x0809, 0x0708, 0x0607, 0x0506, 0x0405, 0x0304, 0x0303, 0x0300, 0x0202, 0x0201,
+	];
+
+	let mut huffman_table = [0_u16; 32770];
+	// The first element is the number of bits to read
+	huffman_table[0] = 15;
+
+	let mut n = 0;
+	for x in TABLE {
+		let first_byte = x >> 8;
+		let repeats = 0x8000 >> first_byte;
+		for _ in 0_u16..repeats {
+			n += 1;
+			huffman_table[n] = x;
+		}
+	}
+
+	let mut sum = 0;
+	let mut image = vec![0_u16; width * height];
+	for column in (0..width).rev() {
+		for row in (0..height).step_by(2).chain((1..height).step_by(2)) {
+			sum += ljpeg_diff(&huffman_table, file, None);
+
+			if (sum >> 12) != 0 {
+				return None;
+			}
+
+			if row < height {
+				image[row * width + column] = sum as u16;
+			}
+		}
+	}
+
+	Some(image)
+}