From b08ac436beed955053b672d65715811535a46096 Mon Sep 17 00:00:00 2001
From: gennyble <gen@nyble.dev>
Date: Fri, 9 Jun 2023 01:38:51 -0500
Subject: unpacker

---
 unpacker/Cargo.lock  |  7 +++++++
 unpacker/Cargo.toml  |  8 ++++++++
 unpacker/src/lib.rs  | 44 ++++++++++++++++++++++++++++++++++++++++++++
 unpacker/src/main.rs | 24 ++++++++++++++++++++++++
 4 files changed, 83 insertions(+)
 create mode 100644 unpacker/Cargo.lock
 create mode 100644 unpacker/Cargo.toml
 create mode 100644 unpacker/src/lib.rs
 create mode 100644 unpacker/src/main.rs

(limited to 'unpacker')

diff --git a/unpacker/Cargo.lock b/unpacker/Cargo.lock
new file mode 100644
index 0000000..44d0a0f
--- /dev/null
+++ b/unpacker/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "unpacker"
+version = "0.1.0"
diff --git a/unpacker/Cargo.toml b/unpacker/Cargo.toml
new file mode 100644
index 0000000..147529a
--- /dev/null
+++ b/unpacker/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "unpacker"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/unpacker/src/lib.rs b/unpacker/src/lib.rs
new file mode 100644
index 0000000..f649581
--- /dev/null
+++ b/unpacker/src/lib.rs
@@ -0,0 +1,44 @@
+#[derive(Debug)]
+pub struct Unpacker {
+	pub out: Vec<u8>,
+	pub work: u16,
+	pub work_idx: usize,
+}
+
+impl Unpacker {
+	pub fn new() -> Self {
+		Self {
+			out: vec![],
+			work: 0,
+			work_idx: 0,
+		}
+	}
+
+	pub fn push(&mut self, byte: u8) {
+		self.work = self.work << 8;
+		self.work |= byte as u16;
+		self.work_idx += 8;
+
+		//println!("[{work_idx}]");
+
+		if self.work_idx >= 10 {
+			let to_front = self.work_idx - 10;
+			let fronted = self.work >> to_front;
+			let masked = fronted & 0b000_000_111_11_111_11;
+
+			let fixwork = fronted << to_front;
+
+			self.out.extend(masked.to_le_bytes());
+			self.work_idx -= 10;
+			self.work ^= fixwork;
+		}
+	}
+
+	pub fn finish(&mut self) {
+		if self.work_idx > 0 {
+			let remain = 10 - self.work_idx;
+			let out = self.work << remain;
+			self.out.extend(out.to_le_bytes())
+		}
+	}
+}
diff --git a/unpacker/src/main.rs b/unpacker/src/main.rs
new file mode 100644
index 0000000..047b4c5
--- /dev/null
+++ b/unpacker/src/main.rs
@@ -0,0 +1,24 @@
+use unpacker::Unpacker;
+
+fn main() {
+	// Four bits padding at the end.
+	let testdata = vec![
+		0b10000000, 0b00010000, 0b00000010, 0b00000000, 0b01000000, 0b00001000, 0b00000001,
+		0b00000000, 0b00100000, 0b00000100, 0b00000000, 0b10000000, 0b00010000,
+	];
+
+	let mut up = Unpacker {
+		out: vec![],
+		work: 0,
+		work_idx: 0,
+	};
+
+	for byte in testdata {
+		up.push(byte);
+	}
+	up.finish();
+
+	for chnk in up.out.chunks(2) {
+		println!("{:08b} {:08b}", chnk[0], chnk[1]);
+	}
+}
-- 
cgit 1.4.1-3-g733a5