aux/util: Add u_frame_clone

src/xrt/auxiliary/util/u_frame.c

@@ -42,3 +42,39 @@ u_frame_create_one_off(enum xrt_format f, uint32_t width, uint32_t height, struc
 
 	xrt_frame_reference(out_frame, xf);
 }
+
+static void
+free_clone(struct xrt_frame *xf)
+{
+	assert(xf->reference.count == 0);
+	free(xf->data);
+	free(xf);
+}
+
+void
+u_frame_clone(struct xrt_frame *to_copy, struct xrt_frame **out_frame)
+{
+	struct xrt_frame *xf = U_TYPED_CALLOC(struct xrt_frame);
+
+	// Paranoia: Explicitly only copy the fields we want
+	xf->width = to_copy->width;
+	xf->height = to_copy->height;
+	xf->stride = to_copy->stride;
+	xf->size = to_copy->size;
+
+	xf->format = to_copy->format;
+	xf->stereo_format = to_copy->stereo_format;
+
+	xf->timestamp = to_copy->timestamp;
+	xf->source_timestamp = to_copy->source_timestamp;
+	xf->source_sequence = to_copy->source_sequence;
+	xf->source_id = to_copy->source_id;
+
+	xf->destroy = free_clone;
+
+	xf->data = malloc(xf->size);
+
+	memcpy(xf->data, to_copy->data, xf->size);
+
+	xrt_frame_reference(out_frame, xf);
+}

src/xrt/auxiliary/util/u_frame.h

@@ -23,6 +23,12 @@ extern "C" {
 void
 u_frame_create_one_off(enum xrt_format f, uint32_t width, uint32_t height, struct xrt_frame **out_frame);
 
+/*!
+ * Clones a frame. The cloned frame is not freed when the original frame is freed; instead the cloned frame is freed
+ * when its reference reaches zero.
+ */
+void
+u_frame_clone(struct xrt_frame *to_copy, struct xrt_frame **out_frame);
 
 #ifdef __cplusplus
 }