codec/packet: add data access and constructor

src/codec/packet/mod.rs

@@ -6,6 +6,7 @@ pub use self::flag::Flags;
 
 use std::marker::PhantomData;
 use std::mem;
+use std::slice;
 
 use libc::c_int;
 use ffi::*;
@@ -47,6 +48,15 @@ impl Packet {
 		}
 	}
 
+	pub fn copy(data: &[u8]) -> Self {
+		use std::io::Write;
+
+		let mut packet = Packet::new(data.len());
+		packet.data_mut().unwrap().write(data).unwrap();
+
+		packet
+	}
+
 	pub fn shrink(&mut self, size: usize) {
 		unsafe {
 			av_shrink_packet(&mut self.0, size as c_int);
@@ -123,6 +133,28 @@ impl Packet {
 		SideDataIter::new(&self.0)
 	}
 
+	pub fn data(&self) -> Option<&[u8]> {
+		unsafe {
+			if self.0.data.is_null() {
+				None
+			}
+			else {
+				Some(slice::from_raw_parts(self.0.data, self.0.size as usize))
+			}
+		}
+	}
+
+	pub fn data_mut(&mut self) -> Option<&mut [u8]> {
+		unsafe {
+			if self.0.data.is_null() {
+				None
+			}
+			else {
+				Some(slice::from_raw_parts_mut(self.0.data, self.0.size as usize))
+			}
+		}
+	}
+
 	pub fn read(&mut self, format: &mut format::context::Input) -> Result<(), Error> {
 		unsafe {
 			match av_read_frame(format.as_mut_ptr(), self.as_mut_ptr()) {