Add accessor for owned Buffer to read-mapped AudioBuffer / MappedBuffer

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1374>

gstreamer-audio/src/audio_buffer.rs

@@ -2,7 +2,7 @@
 
 use std::{fmt, marker::PhantomData, mem, ops, ptr, slice};
 
-use glib::translate::{from_glib, Borrowed, ToGlibPtr};
+use glib::translate::*;
 
 use smallvec::SmallVec;
 
@@ -200,6 +200,11 @@ impl AudioBuffer<Readable> {
             }
         }
     }
+
+    #[inline]
+    pub fn buffer_owned(&self) -> gst::Buffer {
+        unsafe { from_glib_none(self.audio_buffer.buffer) }
+    }
 }
 
 impl AudioBuffer<Writable> {

gstreamer/src/buffer.rs

@@ -1368,6 +1368,14 @@ impl<T> MappedBuffer<T> {
     }
 }
 
+impl MappedBuffer<Readable> {
+    #[doc(alias = "get_buffer")]
+    #[inline]
+    pub fn buffer_owned(&self) -> Buffer {
+        self.buffer.clone()
+    }
+}
+
 impl MappedBuffer<Writable> {
     #[inline]
     pub fn as_mut_slice(&mut self) -> &mut [u8] {

gstreamer/src/buffer_cursor.rs

@@ -287,6 +287,10 @@ impl BufferCursor<Readable> {
             phantom: PhantomData,
         }
     }
+
+    pub fn buffer_owned(&self) -> Buffer {
+        self.buffer.as_ref().unwrap().clone()
+    }
 }
 
 impl BufferCursor<Writable> {