diff --git a/src/decode/cmds.rs b/src/decode/cmds.rs
new file mode 100644
index 0000000..082013e
--- /dev/null
+++ b/src/decode/cmds.rs
@@ -0,0 +1,9 @@
+use std::sync::Arc;
+use std::error::Error;
+
+use crate::util;
+use crate::decode::codecs::Decoder;
+
+pub fn spawn(metadata: Arc<util::Metadata>) -> Result<(impl Decoder, impl Decoder), Box<dyn Error>> {
+    todo!();
+}
diff --git a/src/decode/codecs/mod.rs b/src/decode/codecs/mod.rs
new file mode 100644
index 0000000..31f3302
--- /dev/null
+++ b/src/decode/codecs/mod.rs
@@ -0,0 +1,33 @@
+use std::sync::mpsc;
+use std::error::Error;
+
+use crate::util;
+
+pub trait Decoder {
+    fn write_nalu(&mut self, nalu: util::NALUPacket) -> Result<(), Box<dyn Error + Send + Sync>>;
+    fn write_loop(&mut self, chan_in: mpsc::Receiver<util::NALUPacket>, err_in: mpsc::Sender<Box<dyn Error + Send + Sync>>) {
+        loop {
+            let nalu = match chan_in.recv() {
+                Ok(x) => x,
+                Err(err) => {util::thread_freeze(err_in, Box::new(err)); return}
+            };
+            match self.write_nalu(nalu) {
+                Ok(_) => (),
+                Err(err) => {util::thread_freeze(err_in, err); return}
+            }
+        }
+    }
+    fn read_raw(&mut self) -> Result<util::RawMedia, Box<dyn Error + Send + Sync>>;
+    fn read_loop(&mut self, chan_out: mpsc::Sender<util::RawMedia>, err_in: mpsc::Sender<Box<dyn Error + Send + Sync>>) {
+        loop {
+            let raw_sample = match self.read_raw() {
+                Ok(x) => x,
+                Err(err) => {util::thread_freeze(err_in, err); return}
+            };
+            match chan_out.send(raw_sample) {
+                Ok(_) => (),
+                Err(err) => {util::thread_freeze(err_in, Box::new(err)); return}
+            }
+        }
+    }
+}
diff --git a/src/decode/mod.rs b/src/decode/mod.rs
index 8963386..acc0d44 100644
--- a/src/decode/mod.rs
+++ b/src/decode/mod.rs
@@ -1,8 +1,12 @@
+mod cmds;
+mod codecs;
+
 use std::sync::{mpsc, Arc};
 use std::error::Error;
 use std::thread;
 
 use crate::util;
+use crate::decode::codecs::Decoder;
 
 pub fn spawn(
         v: mpsc::Receiver<util::NALUPacket>,
@@ -19,15 +23,27 @@ pub fn spawn(
     let (raw_v_in, raw_v_out) = mpsc::channel();
     let (raw_a_in, raw_a_out) = mpsc::channel();
     let (err_in, err_out) = mpsc::channel();
-    let metadata_handle = metadata.clone();
+    let (v_decoder, a_decoder) = cmds::spawn(metadata.clone())?;
+    spawn_threads(v, raw_v_in, v_decoder, a, raw_a_in, a_decoder, err_in);
     thread::spawn(move || {
         &raw_v_in;
         &raw_a_in;
         &err_in;
-        &metadata_handle;
         &v;
         &a;
         thread::park();
     });
     return Ok((raw_v_out, raw_a_out, err_out));
 }
+
+fn spawn_threads(
+    v: mpsc::Receiver<util::NALUPacket>,
+    raw_v_in: mpsc::Sender<util::RawMedia>,
+    v_decoder: impl Decoder,
+    a: mpsc::Receiver<util::NALUPacket>,
+    raw_a_in: mpsc::Sender<util::RawMedia>,
+    a_decoder: impl Decoder,
+    err_in: mpsc::Sender<Box<dyn Error + Send + Sync>>
+) {
+    todo!();
+}