Add initial atem testing

Cargo.lock

@@ -789,6 +789,7 @@ dependencies = [
  "actix 0.7.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "actix-net 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "actix-web 0.7.18 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-channel 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "ctrlc 3.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -16,3 +16,4 @@ edition = "2018"
     ctrlc = "3.1.1"
     serde = { version = "1.0", features = ["derive"]}
     serde_json = "1.0"
+    byteorder = "1.3.1"

src/bin/atem.rs

@@ -0,0 +1,57 @@
+use byteorder::{BigEndian, WriteBytesExt};
+use std::net::UdpSocket;
+
+enum Command {
+    NoCommand = 0x0,
+    AckRequest = 0x1,
+    HelloPacket = 0x2,
+    Resend = 0x4,
+    Undefined = 0x8,
+    Ack = 0x10,
+}
+
+// much thanks to https://github.com/petersimonsson/libqatemcontrol/blob/master/qatemconnection.cpp
+struct ATEMPacket {
+    raw: Vec<u8>,
+}
+
+impl ATEMPacket {
+    const HEADER_SIZE: u16 = 12;
+    fn new(cmd: Command, uid: u16, ack_id: u16, payload: Vec<u16>) -> ATEMPacket {
+        let mut a = ATEMPacket { raw: vec![] };
+        for word in vec![
+            ((cmd as u16) << 11) | ((payload.len() as u16 * 2) + ATEMPacket::HEADER_SIZE),
+            uid,
+            ack_id,
+            0,
+            0,
+            0, // TODO: packageid
+        ]
+        .into_iter()
+        .chain(payload.into_iter())
+        {
+            a.raw.write_u16::<BigEndian>(word).unwrap();
+        }
+        a
+    }
+}
+
+fn main() {
+    let mut sock = UdpSocket::bind("0.0.0.0:0").expect("Couldn't bind");
+    let a = ATEMPacket::new(
+        Command::HelloPacket,
+        0x1337,
+        0x0,
+        vec![0x100, 0x0, 0x0, 0x0],
+    );
+    sock.send_to(&a.raw[..], "192.168.0.240:9910")
+        .expect("Couldn't send data");
+}
+
+#[test]
+fn test_newpacket() {
+    assert_eq!(
+        ATEMPacket::new(Command::Undefined, 0x1234, 0x5678, vec![0x1337, 0x0420]).raw,
+        vec![0x10, 0x40, 0x34, 0x12, 0x78, 0x56, 0x0, 0x0, 0x0, 0x0, 0x37, 0x13, 0x20, 0x04]
+    );
+}