codec: add various Codec related stuff

src/codec/encoder.rs

@@ -0,0 +1,39 @@
+use std::ffi::CString;
+use std::ptr;
+
+use ffi::*;
+use ::codec::Id;
+use ::{Codec, Packet, Subtitle, Error};
+use ::frame;
+
+pub trait Encode {
+	fn video(&self, frame: &frame::Video, out: &mut Packet) -> Result<bool, Error>;
+	fn audio(&self, frame: &frame::Audio, out: &mut Packet) -> Result<bool, Error>;
+	fn subtitle(&self, subtitle: &Subtitle, out: &mut [u8]) -> Result<bool, Error>;
+}
+
+pub fn find(id: Id) -> Option<Codec<'static>> {
+	unsafe {
+		let ptr = avcodec_find_encoder(id.into());
+
+		if ptr == ptr::null_mut() {
+			None
+		}
+		else {
+			Some(Codec::wrap(ptr))
+		}
+	}
+}
+
+pub fn find_by_name(name: &str) -> Option<Codec<'static>> {
+	unsafe {
+		let ptr = avcodec_find_encoder_by_name(CString::new(name).unwrap().as_ptr());
+
+		if ptr == ptr::null_mut() {
+			None
+		}
+		else {
+			Some(Codec::wrap(ptr))
+		}
+	}
+}