diff --git a/src/codec/encoder/mod.rs b/src/codec/encoder/mod.rs
index 91d4632..e964f63 100644
--- a/src/codec/encoder/mod.rs
+++ b/src/codec/encoder/mod.rs
@@ -88,10 +88,10 @@ impl Encoder {
 		}
 	}
 
-	pub fn set_frame_rate(&mut self, value: Option<Rational>) {
+	pub fn set_frame_rate<R: Into<Rational>>(&mut self, value: Option<R>) {
 		unsafe {
 			if let Some(value) = value {
-				(*self.as_mut_ptr()).framerate = value.into();
+				(*self.as_mut_ptr()).framerate = value.into().into();
 			}
 			else {
 				(*self.as_mut_ptr()).framerate.num = 0;
@@ -100,9 +100,9 @@ impl Encoder {
 		}
 	}
 
-	pub fn set_time_base(&mut self, value: Rational) {
+	pub fn set_time_base<R: Into<Rational>>(&mut self, value: R) {
 		unsafe {
-			(*self.as_mut_ptr()).time_base = value.into();
+			(*self.as_mut_ptr()).time_base = value.into().into();
 		}
 	}
 }
diff --git a/src/codec/encoder/video.rs b/src/codec/encoder/video.rs
index 4d3c304..35204fb 100644
--- a/src/codec/encoder/video.rs
+++ b/src/codec/encoder/video.rs
@@ -118,9 +118,9 @@ impl Video {
 		}
 	}
 
-	pub fn set_aspect_ratio(&mut self, value: Rational) {
+	pub fn set_aspect_ratio<R: Into<Rational>>(&mut self, value: R) {
 		unsafe {
-			(*self.as_mut_ptr()).sample_aspect_ratio = value.into();
+			(*self.as_mut_ptr()).sample_aspect_ratio = value.into().into();
 		}
 	}
 
diff --git a/src/format/stream/stream_mut.rs b/src/format/stream/stream_mut.rs
index 63fd3bb..dd27044 100644
--- a/src/format/stream/stream_mut.rs
+++ b/src/format/stream/stream_mut.rs
@@ -25,9 +25,9 @@ impl<'a> StreamMut<'a> {
 }
 
 impl<'a> StreamMut<'a> {
-	pub fn set_frame_rate(&mut self, value: Rational) {
+	pub fn set_frame_rate<R: Into<Rational>>(&mut self, value: R) {
 		unsafe {
-			av_stream_set_r_frame_rate(self.as_mut_ptr(), value.into());
+			av_stream_set_r_frame_rate(self.as_mut_ptr(), value.into().into());
 		}
 	}
 }