diff --git a/src/decode/mod.rs b/src/decode/mod.rs
index e69de29..094ac03 100644
--- a/src/decode/mod.rs
+++ b/src/decode/mod.rs
@@ -0,0 +1,18 @@
+use std::sync::mpsc;
+use std::error::Error;
+use crate::util;
+
+pub fn spawn(
+        v: mpsc::Receiver<util::NALUPacket>,
+        a: mpsc::Receiver<util::NALUPacket>,
+        metadata: &util::Metadata
+    ) -> Result<
+        (
+            mpsc::Receiver<util::RawMedia>,
+            mpsc::Receiver<util::RawMedia>,
+            mpsc::Receiver<Box<dyn Error>>
+        ),
+        Box<dyn Error>
+    > {
+    todo!();
+}
diff --git a/src/demux/mod.rs b/src/demux/mod.rs
index e69de29..5fbb4aa 100644
--- a/src/demux/mod.rs
+++ b/src/demux/mod.rs
@@ -0,0 +1,16 @@
+use std::sync::mpsc;
+use std::error::Error;
+
+use crate::util;
+
+pub fn spawn() -> Result<
+    (
+        mpsc::Receiver<util::NALUPacket>,
+        mpsc::Receiver<util::NALUPacket>,
+        util::Metadata,
+        mpsc::Receiver<Box<dyn Error>>
+    ),
+    Box<dyn Error>
+    > {
+    todo!();
+}
diff --git a/src/encode/mod.rs b/src/encode/mod.rs
index e69de29..9572052 100644
--- a/src/encode/mod.rs
+++ b/src/encode/mod.rs
@@ -0,0 +1,19 @@
+use std::sync::mpsc;
+use std::error::Error;
+
+use crate::util;
+
+pub fn spawn(
+        v: mpsc::Receiver<util::RawMedia>,
+        a: mpsc::Receiver<util::RawMedia>,
+        metadata: &util::Metadata
+    ) -> Result< 
+        (
+            mpsc::Receiver<util::NALUPacket>,
+            mpsc::Receiver<util::NALUPacket>,
+            mpsc::Receiver<Box<dyn Error>>
+        ),
+        Box<dyn Error>
+    > {
+    todo!();
+}
diff --git a/src/main.rs b/src/main.rs
index 10e51d8..18b9060 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,13 +4,29 @@ mod decode;
 mod encode;
 mod muxer;
 
-fn init() {
+use std::process::exit;
+use std::sync::mpsc;
+
+fn init() -> Result<[mpsc::Receiver<Box<dyn std::error::Error>>; 4], Box<dyn std::error::Error>>{
+    let (v_out, a_out, metadata, demux_err_recv) = demux::spawn()?;
+    let (raw_v_out, raw_a_out, decode_err_recv) = decode::spawn(v_out, a_out, &metadata)?;
+    let (enc_v_out, enc_a_out, encode_err_recv) = encode::spawn(raw_v_out, raw_a_out, &metadata)?;
+    let muxer_err_recv = muxer::spawn(enc_v_out, enc_a_out, &metadata)?;
+    return Ok([demux_err_recv, decode_err_recv, encode_err_recv, muxer_err_recv]);
 }
 
-fn process() {
+fn process(error_handles: [mpsc::Receiver<Box<dyn std::error::Error>>; 4]) -> Result<(), Box<dyn std::error::Error>> {
+    todo!();
 }
 
 fn main() {
-    init();
-    process();
+    let error_handles = match init() {
+        Ok(x) => x,
+        Err(x) => {dbg!(x); exit(1);}
+    };
+    match process(error_handles) {
+        Ok(_) => (),
+        Err(x) => {dbg!(x); exit(1)}
+    };
+    exit(0);
 }
diff --git a/src/muxer/mod.rs b/src/muxer/mod.rs
index e69de29..b5540f8 100644
--- a/src/muxer/mod.rs
+++ b/src/muxer/mod.rs
@@ -0,0 +1,15 @@
+use std::sync::mpsc;
+use std::error::Error;
+
+use crate::util;
+
+pub fn spawn(
+        v: mpsc::Receiver<util::NALUPacket>,
+        a: mpsc::Receiver<util::NALUPacket>,
+        metadata: &util::Metadata
+    ) -> Result< 
+        mpsc::Receiver<Box<dyn Error>>,
+        Box<dyn Error>
+    > {
+    todo!();
+}