more boilerplate for encoder spawning

src/demux/nalu_flv.rs

@@ -3,14 +3,14 @@ use crate::util;
 pub fn prepend_v(data: Vec<u8>, metadata: &util::Metadata) -> Vec<u8> {
     match metadata.video.codec {
         Some(util::VideoCodec::H264) => preprocess_h264(data),
-        None => panic!("not possible for codec to be None by this point")
+        _ => panic!("not possible for codec to be anything else by this point")
     }
 }
 
 pub fn prepend_a(data: Vec<u8>, metadata: &util::Metadata) -> Vec<u8> {
     match metadata.audio.codec {
         Some(util::AudioCodec::AAC) => preprocess_aac(data, metadata),
-        None => panic!("not possible for codec to be None by this point")
+        _ => panic!("not possible for codec to be anything else by this point")
     }
 }
 

src/encode/cmds.rs

@@ -3,11 +3,20 @@ use std::sync::{Arc, mpsc};
 
 use crate::util;
 use crate::encode::codecs::Encoder;
+use crate::encode::codecs;
 
-pub fn spawn(v_target: util::VideoCodec, a_target: util::AudioCodec) -> Result<(impl Encoder, impl Encoder), Box<dyn Error>> {
-    todo!();
+pub fn spawn(metadata: Arc<util::Metadata>, v_target: util::VideoCodec, a_target: util::AudioCodec) -> Result<(impl Encoder, impl Encoder), Box<dyn Error>> {
+    let v = match v_target {
+        util::VideoCodec::VP9 => codecs::video::new_vp9(metadata.clone())?,
+        _ => return Err(Box::new(util::EncoderError::CodecNotSupported))
+    };
+    let a = match a_target {
+        util::AudioCodec::OPUS => codecs::audio::new_opus(metadata)?,
+        _ => return Err(Box::new(util::EncoderError::CodecNotSupported))
+    };
+    Ok((v, a))
 }
 
-pub fn handle_encoder(encoder: impl Encoder, c_in: mpsc::Receiver<util::RawMedia>, c_out: mpsc::Sender<util::NALUPacket>, metadata: Arc<util::Metadata>, c_err: mpsc::Sender<Box<dyn Error + Send + Sync>>) {
+pub fn handle_encoder(encoder: impl Encoder, c_in: mpsc::Receiver<util::RawMedia>, c_out: mpsc::Sender<util::NALUPacket>, c_err: mpsc::Sender<Box<dyn Error + Send + Sync>>) {
     todo!();
 }

src/encode/codecs/audio.rs

@@ -0,0 +1,17 @@
+use std::error::Error;
+use std::process::{Child, Command, Stdio, ChildStdin, ChildStdout};
+use std::sync::Arc;
+
+use crate::util;
+use crate::encode::codecs::Encoder;
+
+pub struct OpusEncoder {
+    cmd: Child,
+}
+
+impl Encoder for OpusEncoder {}
+
+pub fn new_opus(metadata: Arc<util::Metadata>) -> Result<OpusEncoder, Box<dyn Error>> {
+    todo!();
+}
+

src/encode/codecs/mod.rs

@@ -1,2 +1,5 @@
+pub mod video;
+pub mod audio;
+
 pub trait Encoder {
 }

src/encode/codecs/video.rs

@@ -0,0 +1,16 @@
+use std::error::Error;
+use std::process::{Child, Command, Stdio, ChildStdin, ChildStdout};
+use std::sync::Arc;
+
+use crate::util;
+use crate::encode::codecs::Encoder;
+
+pub struct VP9Encoder {
+    cmd: Child,
+}
+
+impl Encoder for VP9Encoder {}
+
+pub fn new_vp9(metadata: Arc<util::Metadata>) -> Result<VP9Encoder, Box<dyn Error>> {
+    todo!();
+}

src/encode/mod.rs

@@ -25,13 +25,12 @@ pub fn spawn(
     let (a_in, a_out) = mpsc::channel();
     let (err_in_v, err_out) = mpsc::channel();
     let err_in_a = err_in_v.clone();
-    let (v_encoder, a_encoder) = cmds::spawn(v_target, a_target)?;
-    let metadata_cp = metadata.clone();
+    let (v_encoder, a_encoder) = cmds::spawn(metadata, v_target, a_target)?;
     thread::spawn(move || {
-        cmds::handle_encoder(v_encoder, v, v_in, metadata_cp, err_in_v);
+        cmds::handle_encoder(v_encoder, v, v_in, err_in_v);
     });
     thread::spawn(move || {
-        cmds::handle_encoder(a_encoder, a, a_in, metadata, err_in_a);
+        cmds::handle_encoder(a_encoder, a, a_in, err_in_a);
     });
     return Ok((v_out, a_out, err_out));
 }

src/util/mod.rs

@@ -159,6 +159,33 @@ impl fmt::Display for DecoderError {
     }
 }
 
+pub enum EncoderError {
+    CodecNotSupported,
+    BrokenInPipe,
+    BrokenOutPipe,
+    EOF,
+}
+
+impl Error for EncoderError {}
+
+#[allow(unreachable_patterns)]
+impl fmt::Debug for EncoderError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            EncoderError::CodecNotSupported => write!(f, "Codec not recognized or not allowed for encoding"),
+            EncoderError::BrokenInPipe => write!(f, "Encoder has invalid piping, stdin closed"),
+            EncoderError::BrokenInPipe => write!(f, "Encoder has invalid piping, stdout closed"),
+            EncoderError::EOF => write!(f, "Encoder output closed, expected EOF"),
+            _ => write!(f, "Error not described yet")
+        }
+    }
+}
+
+impl fmt::Display for EncoderError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(self, f)
+    }
+}
 // funcs
 
 pub fn thread_freeze(err_sender: mpsc::Sender<Box<dyn Error + Send + Sync>>, err: Box<dyn Error + Send + Sync>) {