format/stream: avoid unsoundness splitting Stream into StreamMut

src/format/stream/stream.rs

@@ -0,0 +1,116 @@
+use std::marker::PhantomData;
+
+use libc::c_int;
+use ffi::*;
+use ::format;
+use ::codec::{self, packet};
+use ::{Rational, Discard};
+use super::Disposition;
+
+#[derive(Eq, PartialEq)]
+pub struct Stream<'a> {
+	ptr: *mut AVStream,
+
+	_marker: PhantomData<&'a format::Context>,
+}
+
+impl<'a> Stream<'a> {
+	pub unsafe fn wrap(ptr: *mut AVStream) -> Self {
+		Stream { ptr: ptr, _marker: PhantomData }
+	}
+
+	pub unsafe fn as_ptr(&self) -> *const AVStream {
+		self.ptr as *const _
+	}
+}
+
+impl<'a> Stream<'a> {
+	pub fn codec(&self) -> codec::Context {
+		unsafe {
+			codec::Context::wrap((*self.as_ptr()).codec)
+		}
+	}
+
+	pub fn index(&self) -> usize {
+		unsafe {
+			(*self.as_ptr()).index as usize
+		}
+	}
+
+	pub fn time_base(&self) -> Rational {
+		unsafe {
+			Rational::from((*self.as_ptr()).time_base)
+		}
+	}
+
+	pub fn start_time(&self) -> i64 {
+		unsafe {
+			(*self.as_ptr()).start_time
+		}
+	}
+
+	pub fn duration(&self) -> i64 {
+		unsafe {
+			(*self.as_ptr()).duration
+		}
+	}
+
+	pub fn frames(&self) -> i64 {
+		unsafe {
+			(*self.as_ptr()).nb_frames
+		}
+	}
+
+	pub fn disposition(&self) -> Disposition {
+		unsafe {
+			Disposition::from_bits_truncate((*self.as_ptr()).disposition)
+		}
+	}
+
+	pub fn discard(&self) -> Discard {
+		unsafe {
+			Discard::from((*self.as_ptr()).discard)
+		}
+	}
+
+	pub fn side_data(&self) -> SideDataIter {
+		unsafe {
+			SideDataIter::new(self.as_ptr())
+		}
+	}
+
+	pub fn frame_rate(&self) -> Rational {
+		unsafe {
+			Rational::from(av_stream_get_r_frame_rate(self.as_ptr()))
+		}
+	}
+}
+
+pub struct SideDataIter<'a> {
+	ptr: *const AVStream,
+	cur: c_int,
+
+	_marker: PhantomData<&'a Stream<'a>>,
+}
+
+impl<'a> SideDataIter<'a> {
+	pub fn new(ptr: *const AVStream) -> Self {
+		SideDataIter { ptr: ptr, cur: 0, _marker: PhantomData }
+	}
+}
+
+impl<'a> Iterator for SideDataIter<'a> {
+	type Item = packet::SideData<'a>;
+
+	fn next(&mut self) -> Option<<Self as Iterator>::Item> {
+		unsafe {
+			if self.cur >= (*self.ptr).nb_side_data {
+				None
+			}
+			else {
+				self.cur += 1;
+				Some(packet::SideData::wrap((*self.ptr).side_data.offset((self.cur - 1) as isize)))
+			}
+		}
+	}
+}