Add serialize support for enums

src/codec/id.rs

@@ -3,10 +3,13 @@ use std::str::from_utf8_unchecked;
 
 use ffi::AVCodecID::*;
 use ffi::*;
+#[cfg(feature = "serialize")]
+use serde::{Deserialize, Serialize};
 use util::media;
 
 #[allow(non_camel_case_types)]
 #[derive(Eq, PartialEq, Clone, Copy, Debug)]
+#[cfg_attr(feature = "serialize", derive(Serialize, Deserialize))]
 pub enum Id {
     None,