codec: refactor API

src/codec/encoder.rs

@@ -1,15 +1,119 @@
 use std::ffi::CString;
 use std::ptr;
+use std::ops::Deref;
 
+use libc::c_int;
 use ffi::*;
-use ::codec::Id;
-use ::{Codec, Packet, Subtitle, Error};
+use super::Id;
+use super::context::Opened;
+use ::{Codec, Packet, Error};
 use ::frame;
+use ::media;
 
-pub trait Encode {
-	fn video(&self, frame: &frame::Video, out: &mut Packet) -> Result<bool, Error>;
-	fn audio(&self, frame: &frame::Audio, out: &mut Packet) -> Result<bool, Error>;
-	fn subtitle(&self, subtitle: &Subtitle, out: &mut [u8]) -> Result<bool, Error>;
+pub struct Encoder(pub Opened);
+
+impl Encoder {
+	pub fn video(self) -> Result<Video, Error> {
+		if self.medium() == media::Type::Video {
+			Ok(Video(self))
+		}
+		else {
+			Err(Error::from(AVERROR_INVALIDDATA))
+		}
+	}
+
+	pub fn audio(self) -> Result<Audio, Error> {
+		if self.medium() == media::Type::Audio {
+			Ok(Audio(self))
+		}
+		else {
+			Err(Error::from(AVERROR_INVALIDDATA))
+		}
+	}
+
+	pub fn subtitle(self) -> Result<Subtitle, Error> {
+		if self.medium() == media::Type::Subtitle {
+			Ok(Subtitle(self))
+		}
+		else {
+			Err(Error::from(AVERROR_INVALIDDATA))
+		}
+	}
+}
+
+impl Deref for Encoder {
+	type Target = Opened;
+
+	fn deref(&self) -> &<Self as Deref>::Target {
+		&self.0
+	}
+}
+
+pub struct Video(pub Encoder);
+
+impl Video {
+	pub fn encode(&self, frame: &frame::Video, out: &mut Packet) -> Result<bool, Error> {
+		unsafe {
+			let mut got: c_int = 0;
+
+			match avcodec_encode_video2(self.ptr, &mut out.val, frame.ptr, &mut got) {
+				e if e < 0 => Err(Error::new(e)),
+				_          => Ok(got != 0)
+			}
+		}
+	}
+}
+
+impl Deref for Video {
+	type Target = Encoder;
+
+	fn deref(&self) -> &<Self as Deref>::Target {
+		&self.0
+	}
+}
+
+pub struct Audio(pub Encoder);
+
+impl Audio {
+	pub fn encode(&self, frame: &frame::Audio, out: &mut Packet) -> Result<bool, Error> {
+		unsafe {
+			let mut got: c_int = 0;
+
+			match avcodec_encode_audio2(self.ptr, &mut out.val, frame.ptr, &mut got) {
+				e if e < 0 => Err(Error::new(e)),
+				_          => Ok(got != 0)
+			}
+		}
+	}
+}
+
+impl Deref for Audio {
+	type Target = Encoder;
+
+	fn deref(&self) -> &<Self as Deref>::Target {
+		&self.0
+	}
+}
+
+pub struct Subtitle(pub Encoder);
+
+impl Subtitle {
+	pub fn encode(&self, subtitle: &::Subtitle, out: &mut [u8]) -> Result<bool, Error> {
+		unsafe {
+			match avcodec_encode_subtitle(self.ptr, out.as_mut_ptr(), out.len() as c_int, &subtitle.val) {
+				e if e < 0 => Err(Error::new(e)),
+				_          => Ok(true)
+			}
+		}
+	}
+}
+
+impl Deref for Subtitle {
+	type Target = Encoder;
+
+	fn deref(&self) -> &<Self as Deref>::Target {
+		&self.0
+	}
 }
 
 pub fn find(id: Id) -> Option<Codec<'static>> {