style(util/frame): only mark functions as unsafe if their invocation can directly cause memory unsafety

src/software/scaling/context.rs

@@ -134,10 +134,8 @@ impl Context {
 			return Err(Error::InputChanged);
 		}
 
-		unsafe {
-			if output.is_empty() {
-				output.alloc(self.output.format, self.output.width, self.output.height);
-			}
+		if output.is_empty() {
+			output.alloc(self.output.format, self.output.width, self.output.height);
 		}
 
 		if output.format() != self.output.format

src/util/frame/audio.rs

@@ -19,29 +19,29 @@ impl Audio {
 	}
 
 	#[inline]
-	pub unsafe fn alloc(&mut self, format: format::Sample, samples: usize, layout: ChannelLayout) {
-		self.set_format(format);
-		self.set_samples(samples);
-		self.set_channel_layout(layout);
+	pub fn alloc(&mut self, format: format::Sample, samples: usize, layout: ChannelLayout) {
+		unsafe {
+			self.set_format(format);
+			self.set_samples(samples);
+			self.set_channel_layout(layout);
 
-		av_frame_get_buffer(self.as_mut_ptr(), 0);
+			av_frame_get_buffer(self.as_mut_ptr(), 0);
+		}
 	}
 }
 
 impl Audio {
 	#[inline(always)]
 	pub fn empty() -> Self {
-		unsafe { Audio(Frame::empty()) }
+		Audio(Frame::empty())
 	}
 
 	#[inline]
 	pub fn new(format: format::Sample, samples: usize, layout: ChannelLayout) -> Self {
-		unsafe {
-			let mut frame = Audio::empty();
-			frame.alloc(format, samples, layout);
+		let mut frame = Audio::empty();
+		frame.alloc(format, samples, layout);
 
-			frame
-		}
+		frame
 	}
 
 	#[inline]

src/util/frame/mod.rs

@@ -40,26 +40,28 @@ impl Frame {
 	}
 
 	#[inline(always)]
-	pub unsafe fn empty() -> Self {
-		Frame {
-			ptr: av_frame_alloc(),
-			_own: true,
+	pub fn empty() -> Self {
+		unsafe {
+			Frame {
+				ptr: av_frame_alloc(),
+				_own: true,
+			}
 		}
 	}
 
 	#[inline(always)]
-	pub unsafe fn as_ptr(&self) -> *const AVFrame {
+	pub fn as_ptr(&self) -> *const AVFrame {
 		self.ptr as *const _
 	}
 
 	#[inline(always)]
-	pub unsafe fn as_mut_ptr(&mut self) -> *mut AVFrame {
+	pub fn as_mut_ptr(&mut self) -> *mut AVFrame {
 		self.ptr
 	}
 
 	#[inline(always)]
-	pub unsafe fn is_empty(&self) -> bool {
-		(*self.as_ptr()).data[0].is_null()
+	pub fn is_empty(&self) -> bool {
+		unsafe { (*self.as_ptr()).data[0].is_null() }
 	}
 }
 

src/util/frame/video.rs

@@ -25,29 +25,29 @@ impl Video {
 	}
 
 	#[inline]
-	pub unsafe fn alloc(&mut self, format: format::Pixel, width: u32, height: u32) {
-		self.set_format(format);
-		self.set_width(width);
-		self.set_height(height);
+	pub fn alloc(&mut self, format: format::Pixel, width: u32, height: u32) {
+		unsafe {
+			self.set_format(format);
+			self.set_width(width);
+			self.set_height(height);
 
-		av_frame_get_buffer(self.as_mut_ptr(), 32);
+			av_frame_get_buffer(self.as_mut_ptr(), 32);
+		}
 	}
 }
 
 impl Video {
 	#[inline(always)]
 	pub fn empty() -> Self {
-		unsafe { Video(Frame::empty()) }
+		Video(Frame::empty())
 	}
 
 	#[inline]
 	pub fn new(format: format::Pixel, width: u32, height: u32) -> Self {
-		unsafe {
-			let mut frame = Video::empty();
-			frame.alloc(format, width, height);
+		let mut frame = Video::empty();
+		frame.alloc(format, width, height);
 
-			frame
-		}
+		frame
 	}
 
 	#[inline]