From 03740c31c092cafde46aa2ee62d6272e1c3f9761 Mon Sep 17 00:00:00 2001
From: lummax <luogpg@googlemail.com>
Date: Sun, 25 Oct 2015 13:31:51 +0100
Subject: [PATCH] util/mathematics: add rounding and rescaling

---
 src/lib.rs                       |  1 +
 src/util/mathematics/mod.rs      |  5 ++++
 src/util/mathematics/rescale.rs  | 34 ++++++++++++++++++++++++++
 src/util/mathematics/rounding.rs | 41 ++++++++++++++++++++++++++++++++
 src/util/mod.rs                  |  1 +
 src/util/rounding.rs             |  0
 src/util/timebase.rs             | 34 ++++++++++++++++++++++++++
 7 files changed, 116 insertions(+)
 create mode 100644 src/util/mathematics/mod.rs
 create mode 100644 src/util/mathematics/rescale.rs
 create mode 100644 src/util/mathematics/rounding.rs
 create mode 100644 src/util/rounding.rs
 create mode 100644 src/util/timebase.rs

diff --git a/src/lib.rs b/src/lib.rs
index f2ab5d7..2233e8f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,6 +22,7 @@ pub use util::time;
 pub use util::frame::{self, Frame};
 pub use util::channel_layout::{self, ChannelLayout};
 pub use util::option;
+pub use util::mathematics::{self, Rounding, Rescale, rescale};
 
 #[cfg(feature = "format")]
 pub mod format;
diff --git a/src/util/mathematics/mod.rs b/src/util/mathematics/mod.rs
new file mode 100644
index 0000000..dfef2e6
--- /dev/null
+++ b/src/util/mathematics/mod.rs
@@ -0,0 +1,5 @@
+pub mod rounding;
+pub use self::rounding::Rounding;
+
+pub mod rescale;
+pub use self::rescale::Rescale;
diff --git a/src/util/mathematics/rescale.rs b/src/util/mathematics/rescale.rs
new file mode 100644
index 0000000..96dd107
--- /dev/null
+++ b/src/util/mathematics/rescale.rs
@@ -0,0 +1,34 @@
+use ffi::*;
+use ::{Rational, Rounding};
+
+pub const TIME_BASE: Rational = Rational(AV_TIME_BASE_Q.num, AV_TIME_BASE_Q.den);
+
+pub trait Rescale {
+	fn rescale<S, D>(&self, source: S, destination: D) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>;
+
+	fn rescale_with<S, D>(&self, source: S, destination: D, rounding: Rounding) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>;
+}
+
+impl<T: Into<i64> + Clone> Rescale for T {
+	fn rescale<S, D>(&self, source: S, destination: D) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>
+	{
+		unsafe {
+			av_rescale_q(self.clone().into(), source.into().into(), destination.into().into()).into()
+		}
+	}
+
+	fn rescale_with<S, D>(&self, source: S, destination: D, rounding: Rounding) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>
+	{
+		unsafe {
+			av_rescale_q_rnd(self.clone().into(), source.into().into(), destination.into().into(), rounding.into()).into()
+		}
+	}
+}
diff --git a/src/util/mathematics/rounding.rs b/src/util/mathematics/rounding.rs
new file mode 100644
index 0000000..9e13a60
--- /dev/null
+++ b/src/util/mathematics/rounding.rs
@@ -0,0 +1,41 @@
+use ffi::*;
+
+#[derive(Eq, PartialEq, Clone, Copy, Debug)]
+pub enum Rounding {
+	Zero,
+	Infinity,
+	Down,
+	Up,
+	NearInfinity,
+	PassMinMax,
+}
+
+impl From<AVRounding> for Rounding {
+	#[inline(always)]
+	fn from(value: AVRounding) -> Self {
+		match value {
+			AV_ROUND_ZERO        => Rounding::Zero,
+			AV_ROUND_INF         => Rounding::Infinity,
+			AV_ROUND_DOWN        => Rounding::Down,
+			AV_ROUND_UP          => Rounding::Up,
+			AV_ROUND_NEAR_INF    => Rounding::NearInfinity,
+			AV_ROUND_PASS_MINMAX => Rounding::PassMinMax,
+		}
+	}
+}
+
+impl Into<AVRounding> for Rounding {
+	#[inline(always)]
+	fn into(self) -> AVRounding {
+		match self {
+			Rounding::Zero         => AV_ROUND_ZERO,
+			Rounding::Infinity     => AV_ROUND_INF,
+			Rounding::Down         => AV_ROUND_DOWN,
+			Rounding::Up           => AV_ROUND_UP,
+			Rounding::NearInfinity => AV_ROUND_NEAR_INF,
+			Rounding::PassMinMax   => AV_ROUND_PASS_MINMAX,
+		}
+	}
+}
+
+
diff --git a/src/util/mod.rs b/src/util/mod.rs
index a9d0beb..db3b92c 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -11,6 +11,7 @@ pub mod time;
 pub mod channel_layout;
 pub mod option;
 pub mod range;
+pub mod mathematics;
 
 use std::ffi::CStr;
 use std::str::from_utf8_unchecked;
diff --git a/src/util/rounding.rs b/src/util/rounding.rs
new file mode 100644
index 0000000..e69de29
diff --git a/src/util/timebase.rs b/src/util/timebase.rs
new file mode 100644
index 0000000..a55fb8e
--- /dev/null
+++ b/src/util/timebase.rs
@@ -0,0 +1,34 @@
+use ffi::*;
+use ::{Rational, Rounding};
+
+pub const DEFAULT: Rational = Rational(AV_TIME_BASE_Q.num, AV_TIME_BASE_Q.den);
+
+pub trait Rescaling {
+	fn rescale<S, D>(&self, source: S, destination: D) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>;
+
+	fn rescale_with<S, D>(&self, source: S, destination: D, rounding: Rounding) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>;
+}
+
+impl<T: Into<i64> + From<i64>> Rescaling for T {
+	fn rescale<S, D>(&self, source: S, destination: D) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>
+	{
+		unsafe {
+			av_rescale_q(self.into(), source.into().into(), destination.into().into()).into()
+		}
+	}
+
+	fn rescale_with<S, D>(&self, source: S, destination: D, rounding: Rounding) -> i64
+		where S: Into<Rational>,
+		      D: Into<Rational>
+	{
+		unsafe {
+			av_rescale_q(self.into(), source.into().into(), destination.into().into()).into()
+		}
+	}
+}