Write feedback as a DDS rather than a NPY file

This is more consistent with the other outputs and also allows feeding
the file back as an input for another frame.

Change-Id: Ib41454ee02f1f403dab52b6e456ee6b22e6cc286

scenario/scenario.json

@@ -100,7 +100,7 @@
                     {
                         "set": 0,
                         "id": 1,
-                        "resource_ref": "out_feedback"
+                        "resource_ref": "out_feedback_aliaser"
                     },
                     {
                         "set": 0,
@@ -493,17 +493,40 @@
             }
         },
         {
-            "tensor": {
+            "image": {
                 "uid": "out_feedback",
+                "dims": [
+                    1,
+                    960,
+                    544,
+                    1
+                ],
+                "dst": "./out_feedback.dds",
+                "format": "VK_FORMAT_R8G8B8A8_SNORM",
+                "shader_access": "writeonly",
+                "mips": 1,
+                "min_filter": "LINEAR",
+                "mag_filter": "LINEAR",
+                "mip_filter": "NEAREST",
+                "border_address_mode": "CLAMP_BORDER",
+                "border_color": "FLOAT_TRANSPARENT_BLACK",
+                "tiling": "LINEAR"
+            }
+        },
+        {
+            "tensor": {
+                "uid": "out_feedback_aliaser",
                 "dims": [
                     1,
                     544,
                     960,
                     4
                 ],
-                "dst": "./out_feedback.npy",
                 "format": "VK_FORMAT_R8_SINT",
-                "shader_access": "writeonly",
+                "shader_access": "readwrite",
+                "alias_target": {
+                    "resource_ref": "out_feedback"
+                },
                 "tiling": "LINEAR"
             }
         },