add files from m62051: sstr pprr from Nokia

data/file_features/under_consideration/heif_single_stream_property_sstr/HEVC_1440x960_derived_image_SSTR.json

@@ -0,0 +1,14 @@
+{
+  "contributor": "Nokia",
+  "description": "A file with SingleStreamProperty associated with overlay derived image item",
+  "mdms_number": "m62051",
+  "rel_filepath": "./HEVC_1440x960_derived_image_SSTR.heic",
+  "associated_files": [],
+  "version": 1,
+  "md5": "00ec4328b48e4d9033bbbcc795ed416d",
+  "published": false,
+  "features": [],
+  "conforms_to": [],
+  "notes": "",
+  "license": ""
+}

data/file_features/under_consideration/heif_single_stream_property_sstr/HEVC_1440x960_derived_image_SSTR_gpac.ext.json

@@ -0,0 +1,41 @@
+{
+  "mp4boxVersion": "MP4Box - GPAC version 2.3-DEV-rev526-gef57f603-master",
+  "rel_filepath": "./HEVC_1440x960_derived_image_SSTR.heic",
+  "extensions": [
+    {
+      "location": "file",
+      "box": {
+        "@Size": "24",
+        "@Type": "etyp",
+        "@Specification": "unknown",
+        "@Container": "file",
+        "UnknownBox": {
+          "@Size": "16",
+          "@Type": "tyco",
+          "@Specification": "unknown",
+          "@Container": "unknown",
+          "@data": "0x6D69663170726564"
+        }
+      }
+    },
+    {
+      "location": "file.meta.iprp.ipco",
+      "box": {
+        "@Size": "17",
+        "@Type": "rref",
+        "@Specification": "unknown",
+        "@Container": "ipco",
+        "@data": "0x000000000170726564"
+      }
+    },
+    {
+      "location": "file.meta.iprp.ipco",
+      "box": {
+        "@Size": "8",
+        "@Type": "sstr",
+        "@Specification": "unknown",
+        "@Container": "ipco"
+      }
+    }
+  ]
+}