frame_superres: Add members to AV1_COMMON

Adds the superres scale numerator, width, and height to the AV1_COMMON
struct for later use in encoding and decoding. This value will also be
added to the uncompressed frame header.

A #define statement is also added to represent the denominator - 16.

Change-Id: I4acec39ef3c67fa9f7118dac28daec3a2d734ed5

av1/common/enums.h

@@ -502,6 +502,9 @@ typedef enum {
   RESTORE_SWITCHABLE_TYPES = RESTORE_SWITCHABLE,
   RESTORE_TYPES,
 } RestorationType;
+#if CONFIG_FRAME_SUPERRES
+#define SUPERRES_SCALE_DENOMINATOR 16
+#endif  // CONFIG_FRAME_SUPERRES
 #endif  // CONFIG_LOOP_RESTORATION
 #ifdef __cplusplus
 }  // extern "C"

av1/common/onyxc_int.h

@@ -293,6 +293,11 @@ typedef struct AV1Common {
 #if CONFIG_LOOP_RESTORATION
   RestorationInfo rst_info[MAX_MB_PLANE];
   RestorationInternal rst_internal;
+#if CONFIG_FRAME_SUPERRES
+  // The numerator of the superres scale, the denominator is fixed
+  uint8_t superres_scale_numerator;
+  int superres_width, superres_height;
+#endif  // CONFIG_FRAME_SUPERRES
 #endif  // CONFIG_LOOP_RESTORATION
 
   // Flag signaling how frame contexts should be updated at the end of