feat(avutil): add unsafe constructors for AVChannelLayout and AVChannelLayoutRef

Author: ldm0

src/avutil/channel_layout.rs

@@ -47,6 +47,12 @@ impl Clone for AVChannelLayout {
 }
 
 impl AVChannelLayout {
+    /// Create a new channel layout from raw, user need to be sure that channel
+    /// layout is correctly constructed.
+    pub unsafe fn new(ch_layout: ffi::AVChannelLayout) -> Self {
+        unsafe { Self::from_raw(NonNull::new(Box::into_raw(Box::new(ch_layout))).unwrap()) }
+    }
+
     /// Convert self into [`ffi::AVChannelLayout`]`.
     ///
     /// Be careful when using it. Since this fucntion leaks the raw type,
@@ -203,6 +209,14 @@ impl AVChannelLayout {
     }
 }
 
+impl AVChannelLayoutRef<'_> {
+    /// Create a new channel layout reference from raw, user need to be sure
+    /// that channel layout is correctly constructed.
+    pub unsafe fn new(ch_layout: &ffi::AVChannelLayout) -> Self {
+        unsafe { Self::from_raw(NonNull::new(ch_layout as *const _ as *mut _).unwrap()) }
+    }
+}
+
 /// Iterate over all standard channel layouts.
 pub struct AVChannelLayoutIter {
     opaque: *mut c_void,