diff --git a/src/format/context/input.rs b/src/format/context/input.rs
index a8bd7b4..f87a69e 100644
--- a/src/format/context/input.rs
+++ b/src/format/context/input.rs
@@ -3,7 +3,7 @@ use std::ptr;
 use std::ffi::CString;
 
 use ffi::*;
-use ::{Error, Codec, Stream, Packet};
+use ::{Error, Codec, Stream, Packet, format};
 use super::common::Context;
 
 pub struct Input {
@@ -28,6 +28,12 @@ impl Input {
 }
 
 impl Input {
+	pub fn format(&self) -> format::Input {
+		unsafe {
+			format::Input::wrap((*self.as_ptr()).iformat)
+		}
+	}
+
 	pub fn video_codec(&self) -> Option<Codec> {
 		unsafe {
 			let ptr = av_format_get_video_codec(self.as_ptr());
diff --git a/src/format/context/output.rs b/src/format/context/output.rs
index 080c057..b1f90ec 100644
--- a/src/format/context/output.rs
+++ b/src/format/context/output.rs
@@ -3,7 +3,7 @@ use std::ptr;
 use std::ffi::CString;
 
 use ffi::*;
-use ::{Error, Codec, StreamMut, Dictionary};
+use ::{Error, Codec, StreamMut, Dictionary, format};
 use super::common::Context;
 
 pub struct Output {
@@ -28,6 +28,12 @@ impl Output {
 }
 
 impl Output {
+	pub fn format(&self) -> format::Output {
+		unsafe {
+			format::Output::wrap((*self.as_ptr()).oformat)
+		}
+	}
+
 	pub fn write_header(&mut self) -> Result<(), Error> {
 		unsafe {
 			match avformat_write_header(self.as_mut_ptr(), ptr::null_mut()) {
@@ -74,7 +80,7 @@ impl Output {
 
 	pub fn set_metadata(&mut self, dictionary: Dictionary) {
 		unsafe {
-			(*self.as_mut_ptr()).metadata = dictionary.take();
+			(*self.as_mut_ptr()).metadata = dictionary.disown();
 		}
 	}
 }
diff --git a/src/format/format.rs b/src/format/format.rs
deleted file mode 100644
index ceca921..0000000
--- a/src/format/format.rs
+++ /dev/null
@@ -1,221 +0,0 @@
-use std::ptr;
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
-use ffi::*;
-
-pub enum Format {
-	Input(Input),
-	Output(Output),
-}
-
-impl Format {
-	pub fn name(&self) -> &str {
-		match self {
-			&Format::Input(ref f)  => f.name(),
-			&Format::Output(ref f) => f.name()
-		}
-	}
-
-	pub fn description(&self) -> &str {
-		match self {
-			&Format::Input(ref f)  => f.description(),
-			&Format::Output(ref f) => f.description()
-		}
-	}
-
-	pub fn extensions(&self) -> Vec<&str> {
-		match self {
-			&Format::Input(ref f)  => f.extensions(),
-			&Format::Output(ref f) => f.extensions()
-		}
-	}
-
-	pub fn mime_types(&self) -> Vec<&str> {
-		match self {
-			&Format::Input(ref f)  => f.mime_types(),
-			&Format::Output(ref f) => f.mime_types()
-		}
-	}
-}
-
-pub struct Input {
-	ptr: *mut AVInputFormat,
-}
-
-impl Input {
-	pub unsafe fn wrap(ptr: *mut AVInputFormat) -> Self {
-		Input { ptr: ptr }
-	}
-
-	pub unsafe fn as_ptr(&self) -> *const AVInputFormat {
-		self.ptr as *const _
-	}
-
-	pub unsafe fn as_mut_ptr(&mut self) -> *mut AVInputFormat {
-		self.ptr
-	}
-}
-
-impl Input {
-	pub fn name(&self) -> &str {
-		unsafe {
-			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
-		}
-	}
-
-	pub fn description(&self) -> &str {
-		unsafe {
-			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
-		}
-	}
-
-	pub fn extensions(&self) -> Vec<&str> {
-		unsafe {
-			let ptr = (*self.as_ptr()).extensions;
-
-			if ptr.is_null() {
-				Vec::new()
-			}
-			else {
-				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
-			}
-		}
-	}
-
-	pub fn mime_types(&self) -> Vec<&str> {
-		unsafe {
-			let ptr = (*self.as_ptr()).mime_type;
-
-			if ptr.is_null() {
-				Vec::new()
-			}
-			else {
-				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
-			}
-		}
-	}
-}
-
-pub struct Output {
-	ptr: *mut AVOutputFormat,
-}
-
-impl Output {
-	pub unsafe fn wrap(ptr: *mut AVOutputFormat) -> Self {
-		Output { ptr: ptr }
-	}
-
-	pub unsafe fn as_ptr(&self) -> *const AVOutputFormat {
-		self.ptr as *const _
-	}
-
-	pub unsafe fn as_mut_ptr(&mut self) -> *mut AVOutputFormat {
-		self.ptr
-	}
-}
-
-impl Output {
-	pub fn name(&self) -> &str {
-		unsafe {
-			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
-		}
-	}
-
-	pub fn description(&self) -> &str {
-		unsafe {
-			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
-		}
-	}
-
-	pub fn extensions(&self) -> Vec<&str> {
-		unsafe {
-			let ptr = (*self.as_ptr()).extensions;
-
-			if ptr.is_null() {
-				Vec::new()
-			}
-			else {
-				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
-			}
-		}
-	}
-
-	pub fn mime_types(&self) -> Vec<&str> {
-		unsafe {
-			let ptr = (*self.as_ptr()).mime_type;
-
-			if ptr.is_null() {
-				Vec::new()
-			}
-			else {
-				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
-			}
-		}
-	}
-}
-
-pub fn list() -> FormatIter {
-	FormatIter::new()
-}
-
-pub struct FormatIter {
-	input:  *mut AVInputFormat,
-	output: *mut AVOutputFormat,
-	step:   Step,
-}
-
-enum Step {
-	Input,
-	Output,
-	Done,
-}
-
-impl FormatIter {
-	pub fn new() -> Self {
-		FormatIter { input: ptr::null_mut(), output: ptr::null_mut(), step: Step::Input }
-	}
-}
-
-impl Iterator for FormatIter {
-	type Item = Format;
-
-	fn next(&mut self) -> Option<<Self as Iterator>::Item> {
-		unsafe {
-			match self.step {
-				Step::Input => {
-					let ptr = av_iformat_next(self.input);
-
-					if ptr.is_null() && !self.input.is_null() {
-						self.step = Step::Output;
-
-						self.next()
-					}
-					else {
-						self.input = ptr;
-
-						Some(Format::Input(Input::wrap(ptr)))
-					}
-				}
-
-				Step::Output => {
-					let ptr = av_oformat_next(self.output);
-
-					if ptr.is_null() && !self.output.is_null() {
-						self.step = Step::Done;
-
-						self.next()
-					}
-					else {
-						self.output = ptr;
-
-						Some(Format::Output(Output::wrap(ptr)))
-					}
-				}
-
-				Step::Done =>
-					None
-			}
-		}
-	}
-}
diff --git a/src/format/format/input.rs b/src/format/format/input.rs
new file mode 100644
index 0000000..e7e760b
--- /dev/null
+++ b/src/format/format/input.rs
@@ -0,0 +1,62 @@
+use std::ffi::CStr;
+use std::str::from_utf8_unchecked;
+
+use ffi::*;
+
+pub struct Input {
+	ptr: *mut AVInputFormat,
+}
+
+impl Input {
+	pub unsafe fn wrap(ptr: *mut AVInputFormat) -> Self {
+		Input { ptr: ptr }
+	}
+
+	pub unsafe fn as_ptr(&self) -> *const AVInputFormat {
+		self.ptr as *const _
+	}
+
+	pub unsafe fn as_mut_ptr(&mut self) -> *mut AVInputFormat {
+		self.ptr
+	}
+}
+
+impl Input {
+	pub fn name(&self) -> &str {
+		unsafe {
+			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
+		}
+	}
+
+	pub fn description(&self) -> &str {
+		unsafe {
+			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
+		}
+	}
+
+	pub fn extensions(&self) -> Vec<&str> {
+		unsafe {
+			let ptr = (*self.as_ptr()).extensions;
+
+			if ptr.is_null() {
+				Vec::new()
+			}
+			else {
+				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
+			}
+		}
+	}
+
+	pub fn mime_types(&self) -> Vec<&str> {
+		unsafe {
+			let ptr = (*self.as_ptr()).mime_type;
+
+			if ptr.is_null() {
+				Vec::new()
+			}
+			else {
+				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
+			}
+		}
+	}
+}
diff --git a/src/format/format/iter.rs b/src/format/format/iter.rs
new file mode 100644
index 0000000..a0c3afc
--- /dev/null
+++ b/src/format/format/iter.rs
@@ -0,0 +1,65 @@
+use std::ptr;
+
+use ffi::*;
+use super::{Format, Input, Output};
+
+pub struct Iter {
+	input:  *mut AVInputFormat,
+	output: *mut AVOutputFormat,
+	step:   Step,
+}
+
+enum Step {
+	Input,
+	Output,
+	Done,
+}
+
+impl Iter {
+	pub fn new() -> Self {
+		Iter { input: ptr::null_mut(), output: ptr::null_mut(), step: Step::Input }
+	}
+}
+
+impl Iterator for Iter {
+	type Item = Format;
+
+	fn next(&mut self) -> Option<<Self as Iterator>::Item> {
+		unsafe {
+			match self.step {
+				Step::Input => {
+					let ptr = av_iformat_next(self.input);
+
+					if ptr.is_null() && !self.input.is_null() {
+						self.step = Step::Output;
+
+						self.next()
+					}
+					else {
+						self.input = ptr;
+
+						Some(Format::Input(Input::wrap(ptr)))
+					}
+				}
+
+				Step::Output => {
+					let ptr = av_oformat_next(self.output);
+
+					if ptr.is_null() && !self.output.is_null() {
+						self.step = Step::Done;
+
+						self.next()
+					}
+					else {
+						self.output = ptr;
+
+						Some(Format::Output(Output::wrap(ptr)))
+					}
+				}
+
+				Step::Done =>
+					None
+			}
+		}
+	}
+}
diff --git a/src/format/format/mod.rs b/src/format/format/mod.rs
new file mode 100644
index 0000000..9cb12a6
--- /dev/null
+++ b/src/format/format/mod.rs
@@ -0,0 +1,47 @@
+mod input;
+pub use self::input::Input;
+
+mod output;
+pub use self::output::Output;
+
+mod iter;
+pub use self::iter::Iter;
+
+pub enum Format {
+	Input(Input),
+	Output(Output),
+}
+
+impl Format {
+	pub fn name(&self) -> &str {
+		match self {
+			&Format::Input(ref f)  => f.name(),
+			&Format::Output(ref f) => f.name()
+		}
+	}
+
+	pub fn description(&self) -> &str {
+		match self {
+			&Format::Input(ref f)  => f.description(),
+			&Format::Output(ref f) => f.description()
+		}
+	}
+
+	pub fn extensions(&self) -> Vec<&str> {
+		match self {
+			&Format::Input(ref f)  => f.extensions(),
+			&Format::Output(ref f) => f.extensions()
+		}
+	}
+
+	pub fn mime_types(&self) -> Vec<&str> {
+		match self {
+			&Format::Input(ref f)  => f.mime_types(),
+			&Format::Output(ref f) => f.mime_types()
+		}
+	}
+}
+
+pub fn list() -> Iter {
+	Iter::new()
+}
diff --git a/src/format/format/output.rs b/src/format/format/output.rs
new file mode 100644
index 0000000..a3012e9
--- /dev/null
+++ b/src/format/format/output.rs
@@ -0,0 +1,75 @@
+use std::path::Path;
+
+use std::ptr;
+use std::ffi::{CStr, CString};
+use std::str::from_utf8_unchecked;
+
+use ffi::*;
+use {codec, media};
+
+pub struct Output {
+	ptr: *mut AVOutputFormat,
+}
+
+impl Output {
+	pub unsafe fn wrap(ptr: *mut AVOutputFormat) -> Self {
+		Output { ptr: ptr }
+	}
+
+	pub unsafe fn as_ptr(&self) -> *const AVOutputFormat {
+		self.ptr as *const _
+	}
+
+	pub unsafe fn as_mut_ptr(&mut self) -> *mut AVOutputFormat {
+		self.ptr
+	}
+}
+
+impl Output {
+	pub fn name(&self) -> &str {
+		unsafe {
+			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
+		}
+	}
+
+	pub fn description(&self) -> &str {
+		unsafe {
+			from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes())
+		}
+	}
+
+	pub fn extensions(&self) -> Vec<&str> {
+		unsafe {
+			let ptr = (*self.as_ptr()).extensions;
+
+			if ptr.is_null() {
+				Vec::new()
+			}
+			else {
+				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
+			}
+		}
+	}
+
+	pub fn mime_types(&self) -> Vec<&str> {
+		unsafe {
+			let ptr = (*self.as_ptr()).mime_type;
+
+			if ptr.is_null() {
+				Vec::new()
+			}
+			else {
+				from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()).split(',').collect()
+			}
+		}
+	}
+
+	pub fn codec<P: AsRef<Path>>(&self, path: &P, kind: media::Type) -> codec::Id {
+		// XXX: use to_cstring when stable
+		let path = CString::new(path.as_ref().as_os_str().to_str().unwrap()).unwrap();
+
+		unsafe {
+			codec::Id::from(av_guess_codec(self.as_ptr(), ptr::null(), path.as_ptr(), ptr::null(), kind.into()))
+		}
+	}
+}