util/frame/video: set alignment to 32 in av_frame_get_buffer()

In all places where the function `av_frame_get_buffer()` was used on a video
frame in the ffmpeg sources the value `32` was used as an alignment.

src/util/frame/video.rs

@@ -26,7 +26,7 @@ impl Video {
 		self.set_width(width);
 		self.set_height(height);
 
-		av_frame_get_buffer(self.as_mut_ptr(), 1);
+		av_frame_get_buffer(self.as_mut_ptr(), 32);
 	}
 }