Fix clippy lints (#68)

* Specify type params in transmute calls

* Replace legacy numeric methods with constants

src/format/context/input.rs

@@ -122,9 +122,9 @@ impl Input {
             match avformat_seek_file(
                 self.as_mut_ptr(),
                 -1,
-                range.start().cloned().unwrap_or(i64::min_value()),
+                range.start().cloned().unwrap_or(i64::MIN),
                 ts,
-                range.end().cloned().unwrap_or(i64::max_value()),
+                range.end().cloned().unwrap_or(i64::MAX),
                 0,
             ) {
                 s if s >= 0 => Ok(()),

src/util/frame/audio.rs

@@ -63,7 +63,9 @@ impl Audio {
             if (*self.as_ptr()).format == -1 {
                 format::Sample::None
             } else {
-                format::Sample::from(mem::transmute::<_, AVSampleFormat>((*self.as_ptr()).format))
+                format::Sample::from(mem::transmute::<c_int, AVSampleFormat>(
+                    (*self.as_ptr()).format,
+                ))
             }
         }
     }

src/util/frame/video.rs

@@ -52,7 +52,9 @@ impl Video {
             if (*self.as_ptr()).format == -1 {
                 format::Pixel::None
             } else {
-                format::Pixel::from(mem::transmute::<_, AVPixelFormat>((*self.as_ptr()).format))
+                format::Pixel::from(mem::transmute::<c_int, AVPixelFormat>(
+                    (*self.as_ptr()).format,
+                ))
             }
         }
     }

src/util/rational.rs

@@ -26,7 +26,7 @@ impl Rational {
 
     #[inline]
     pub fn reduce(&self) -> Rational {
-        match self.reduce_with_limit(i32::max_value()) {
+        match self.reduce_with_limit(i32::MAX) {
             Ok(r) => r,
             Err(r) => r,
         }
@@ -80,7 +80,7 @@ impl From<Rational> for AVRational {
 impl From<f64> for Rational {
     #[inline]
     fn from(value: f64) -> Rational {
-        unsafe { Rational::from(av_d2q(value, c_int::max_value())) }
+        unsafe { Rational::from(av_d2q(value, c_int::MAX)) }
     }
 }