Fix clippy::ptr_offset_with_cast

src/format/chapter/chapter.rs

@@ -16,9 +16,7 @@ impl<'a> Chapter<'a> {
     }
 
     pub unsafe fn as_ptr(&self) -> *const AVChapter {
-        *(*self.context.as_ptr())
+        *(*self.context.as_ptr()).chapters.add(self.index)
-            .chapters
-            .offset(self.index as isize)
     }
 }
 

src/format/chapter/chapter_mut.rs

@@ -26,9 +26,7 @@ impl<'a> ChapterMut<'a> {
     }
 
     pub unsafe fn as_mut_ptr(&mut self) -> *mut AVChapter {
-        *(*self.context.as_mut_ptr())
+        *(*self.context.as_mut_ptr()).chapters.add(self.index)
-            .chapters
-            .offset(self.index as isize)
     }
 }
 

src/format/stream/stream.rs

@@ -16,7 +16,7 @@ impl<'a> Stream<'a> {
     }
 
     pub unsafe fn as_ptr(&self) -> *const AVStream {
-        *(*self.context.as_ptr()).streams.offset(self.index as isize)
+        *(*self.context.as_ptr()).streams.add(self.index)
     }
 }
 

src/format/stream/stream_mut.rs

@@ -24,9 +24,7 @@ impl<'a> StreamMut<'a> {
     }
 
     pub unsafe fn as_mut_ptr(&mut self) -> *mut AVStream {
-        *(*self.context.as_mut_ptr())
+        *(*self.context.as_mut_ptr()).streams.add(self.index)
-            .streams
-            .offset(self.index as isize)
     }
 }
 

src/util/format/sample.rs

@@ -185,7 +185,7 @@ impl Index<usize> for Buffer {
             panic!("out of bounds");
         }
 
-        unsafe { slice::from_raw_parts(*self.buffer.offset(index as isize), self.size as usize) }
+        unsafe { slice::from_raw_parts(*self.buffer.add(index), self.size as usize) }
     }
 }