codec/packet: refactoring to allow zero-copy packet creation

src/codec/packet/packet.rs

@@ -0,0 +1,290 @@
+use std::marker::PhantomData;
+use std::mem;
+use std::slice;
+
+use libc::c_int;
+use ffi::*;
+use ::{Error, Rational, format};
+use super::{flag, Flags, SideData, Ref, Mut, Borrow};
+
+pub struct Packet(AVPacket);
+
+unsafe impl Send for Packet { }
+unsafe impl Sync for Packet { }
+
+impl Packet {
+	#[inline(always)]
+	pub unsafe fn is_empty(&self) -> bool {
+		self.0.size == 0
+	}
+}
+
+impl Packet {
+	#[inline]
+	pub fn empty() -> Self {
+		unsafe {
+			let mut pkt: AVPacket = mem::zeroed();
+
+			av_init_packet(&mut pkt);
+
+			Packet(pkt)
+		}
+	}
+
+	#[inline]
+	pub fn new(size: usize) -> Self {
+		unsafe {
+			let mut pkt: AVPacket = mem::zeroed();
+
+			av_init_packet(&mut pkt);
+			av_new_packet(&mut pkt, size as c_int);
+
+			Packet(pkt)
+		}
+	}
+
+	#[inline]
+	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
+	}
+
+	#[inline]
+	pub fn borrow(data: &[u8]) -> Borrow {
+		Borrow::new(data)
+	}
+
+	#[inline]
+	pub fn shrink(&mut self, size: usize) {
+		unsafe {
+			av_shrink_packet(&mut self.0, size as c_int);
+		}
+	}
+
+	#[inline]
+	pub fn grow(&mut self, size: usize) {
+		unsafe {
+			av_grow_packet(&mut self.0, size as c_int);
+		}
+	}
+
+	#[inline]
+	pub fn rescale_ts<S, D>(&mut self, source: S, destination: D)
+		where S: Into<Rational>,
+		      D: Into<Rational>
+	{
+		unsafe {
+			av_packet_rescale_ts(self.as_mut_ptr(), source.into().into(), destination.into().into());
+		}
+	}
+
+	#[inline]
+	pub fn flags(&self) -> Flags {
+		Flags::from_bits_truncate(self.0.flags)
+	}
+
+	#[inline]
+	pub fn set_flags(&mut self, value: Flags) {
+		self.0.flags = value.bits();
+	}
+
+	#[inline]
+	pub fn is_key(&self) -> bool {
+		self.flags().contains(flag::KEY)
+	}
+
+	#[inline]
+	pub fn is_corrupt(&self) -> bool {
+		self.flags().contains(flag::CORRUPT)
+	}
+
+	#[inline]
+	pub fn stream(&self) -> usize {
+		self.0.stream_index as usize
+	}
+
+	#[inline]
+	pub fn set_stream(&mut self, index: usize) {
+		self.0.stream_index = index as c_int;
+	}
+
+	#[inline]
+	pub fn pts(&self) -> Option<i64> {
+		match self.0.pts {
+			AV_NOPTS_VALUE => None,
+			pts            => Some(pts as i64),
+		}
+	}
+
+	#[inline]
+	pub fn dts(&self) -> i64 {
+		self.0.dts as i64
+	}
+
+	#[inline]
+	pub fn size(&self) -> usize {
+		self.0.size as usize
+	}
+
+	#[inline]
+	pub fn duration(&self) -> usize {
+		self.0.duration as usize
+	}
+
+	#[inline]
+	pub fn position(&self) -> isize {
+		self.0.pos as isize
+	}
+
+	#[inline]
+	pub fn convergence(&self) -> isize {
+		self.0.convergence_duration as isize
+	}
+
+	#[inline]
+	pub fn side_data(&self) -> SideDataIter {
+		SideDataIter::new(&self.0)
+	}
+
+	#[inline]
+	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))
+			}
+		}
+	}
+
+	#[inline]
+	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))
+			}
+		}
+	}
+
+	#[inline]
+	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()) {
+				0 => Ok(()),
+				e => Err(Error::from(e))
+			}
+		}
+	}
+
+	#[inline]
+	pub fn write(&self, format: &mut format::context::Output) -> Result<bool, Error> {
+		unsafe {
+			if self.is_empty() {
+				return Err(Error::InvalidData);
+			}
+
+			match av_write_frame(format.as_mut_ptr(), self.as_ptr()) {
+				1 => Ok(true),
+				0 => Ok(false),
+				e => Err(Error::from(e))
+			}
+		}
+	}
+
+	#[inline]
+	pub fn write_interleaved(&self, format: &mut format::context::Output) -> Result<bool, Error> {
+		unsafe {
+			if self.is_empty() {
+				return Err(Error::InvalidData);
+			}
+
+			match av_interleaved_write_frame(format.as_mut_ptr(), self.as_ptr()) {
+				1 => Ok(true),
+				0 => Ok(false),
+				e => Err(Error::from(e))
+			}
+		}
+	}
+}
+
+impl Ref for Packet {
+	fn as_ptr(&self) -> *const AVPacket {
+		&self.0
+	}
+}
+
+impl Mut for Packet {
+	fn as_mut_ptr(&mut self) -> *mut AVPacket {
+		&mut self.0
+	}
+}
+
+impl Clone for Packet {
+	#[inline]
+	fn clone(&self) -> Self {
+		let mut pkt = Packet::empty();
+		pkt.clone_from(self);
+
+		pkt
+	}
+
+	#[inline]
+	fn clone_from(&mut self, source: &Self) {
+		unsafe {
+			av_copy_packet(&mut self.0, &source.0);
+		}
+	}
+}
+
+impl Drop for Packet {
+	fn drop(&mut self) {
+		unsafe {
+			av_free_packet(&mut self.0);
+		}
+	}
+}
+
+pub struct SideDataIter<'a> {
+	ptr: *const AVPacket,
+	cur: c_int,
+
+	_marker: PhantomData<&'a Packet>,
+}
+
+impl<'a> SideDataIter<'a> {
+	pub fn new(ptr: *const AVPacket) -> Self {
+		SideDataIter { ptr: ptr, cur: 0, _marker: PhantomData }
+	}
+}
+
+impl<'a> Iterator for SideDataIter<'a> {
+	type Item = SideData<'a>;
+
+	fn next(&mut self) -> Option<<Self as Iterator>::Item> {
+		unsafe {
+			if self.cur >= (*self.ptr).side_data_elems {
+				None
+			}
+			else {
+				self.cur += 1;
+				Some(SideData::wrap((*self.ptr).side_data.offset((self.cur - 1) as isize)))
+			}
+		}
+	}
+
+	fn size_hint(&self) -> (usize, Option<usize>) {
+		unsafe {
+			((*self.ptr).side_data_elems as usize, Some((*self.ptr).side_data_elems as usize))
+		}
+	}
+}
+
+impl<'a> ExactSizeIterator for SideDataIter<'a> { }