format/context/input: add seek() method

src/format/context/input.rs

@@ -7,6 +7,7 @@ use ffi::*;
 use ::{Error, Codec, Stream, Packet, format};
 use super::common::Context;
 use super::destructor;
+use util::range::Range;
 
 pub struct Input {
 	ptr: *mut AVFormatContext,
@@ -115,6 +116,18 @@ impl Input {
 			}
 		}
 	}
+
+	pub fn seek<R: Range<i64>>(&mut self, ts: i64, range: R) -> Result<(), Error> {
+		unsafe {
+			match avformat_seek_file(self.as_mut_ptr(), -1,
+			                         range.start().map(|v| *v).unwrap_or(i64::min_value()), ts,
+			                         range.end().map(|v| *v).unwrap_or(i64::max_value()), 0)
+			{
+				s if s >= 0 => Ok(()),
+				e => Err(Error::from(e)),
+			}
+		}
+	}
 }
 
 impl Deref for Input {

src/util/mod.rs

@@ -10,6 +10,7 @@ pub mod chroma;
 pub mod time;
 pub mod channel_layout;
 pub mod option;
+pub mod range;
 
 use std::ffi::CStr;
 use std::str::from_utf8_unchecked;

src/util/range.rs

@@ -0,0 +1,35 @@
+use std::ops;
+
+pub trait Range<T> {
+	fn start(&self) -> Option<&T> {
+		None
+	}
+
+	fn end(&self) -> Option<&T> {
+		None
+	}
+}
+
+impl<T> Range<T> for ops::Range<T> {
+	fn start(&self) -> Option<&T> {
+		Some(&self.start)
+	}
+
+	fn end(&self) -> Option<&T> {
+		Some(&self.end)
+	}
+}
+
+impl<T> Range<T> for ops::RangeTo<T> {
+	fn end(&self) -> Option<&T> {
+		Some(&self.end)
+	}
+}
+
+impl<T> Range<T> for ops::RangeFrom<T> {
+	fn start(&self) -> Option<&T> {
+		Some(&self.start)
+	}
+}
+
+impl<T> Range<T> for ops::RangeFull { }