diff --git a/aom/aom_image.h b/aom/aom_image.h
index bb6973f..03bc73e 100644
--- a/aom/aom_image.h
+++ b/aom/aom_image.h
@@ -360,6 +360,9 @@
  * \param[in]    data         Metadata contents
  * \param[in]    sz           Metadata contents size
  * \param[in]    insert_flag  Metadata insert flag
+ *
+ * \return Returns 0 on success. If img or data is NULL, sz is 0, or memory
+ * allocation fails, it returns -1.
  */
 int aom_img_add_metadata(aom_image_t *img, uint32_t type, const uint8_t *data,
                          size_t sz, aom_metadata_insert_flags_t insert_flag);
@@ -410,6 +413,9 @@
  * \param[in]    data         Metadata data pointer
  * \param[in]    sz           Metadata size
  * \param[in]    insert_flag  Metadata insert flag
+ *
+ * \return Returns the newly allocated aom_metadata struct. If data is NULL,
+ * sz is 0, or memory allocation fails, it returns NULL.
  */
 aom_metadata_t *aom_img_metadata_alloc(uint32_t type, const uint8_t *data,
                                        size_t sz,
diff --git a/aom/internal/aom_image_internal.h b/aom/internal/aom_image_internal.h
index 7f2fd18..1b04c9e 100644
--- a/aom/internal/aom_image_internal.h
+++ b/aom/internal/aom_image_internal.h
@@ -32,8 +32,8 @@
 /*!\brief Alloc memory for aom_metadata_array struct.
  *
  * Allocate memory for aom_metadata_array struct.
- * If sz is 0 the aom_metadata_array structs internal buffer list will be NULL,
- * but the aom_metadata_array struct itself will still be allocated.
+ * If sz is 0 the aom_metadata_array struct's internal buffer list will be
+ * NULL, but the aom_metadata_array struct itself will still be allocated.
  * Returns a pointer to the allocated struct or NULL on failure.
  *
  * \param[in]    sz       Size of internal metadata list buffer
diff --git a/aom/src/aom_image.c b/aom/src/aom_image.c
index cd0b5ed..dfdee87 100644
--- a/aom/src/aom_image.c
+++ b/aom/src/aom_image.c
@@ -350,26 +350,18 @@
   }
   aom_metadata_t *metadata =
       aom_img_metadata_alloc(type, data, sz, insert_flag);
-  if (!metadata) goto fail;
-  if (!img->metadata->metadata_array) {
-    img->metadata->metadata_array =
-        (aom_metadata_t **)calloc(1, sizeof(metadata));
-    if (!img->metadata->metadata_array || img->metadata->sz != 0) {
-      aom_img_metadata_free(metadata);
-      goto fail;
-    }
-  } else {
-    img->metadata->metadata_array =
-        (aom_metadata_t **)realloc(img->metadata->metadata_array,
-                                   (img->metadata->sz + 1) * sizeof(metadata));
+  if (!metadata) return -1;
+  aom_metadata_t **metadata_array =
+      (aom_metadata_t **)realloc(img->metadata->metadata_array,
+                                 (img->metadata->sz + 1) * sizeof(metadata));
+  if (!metadata_array) {
+    aom_img_metadata_free(metadata);
+    return -1;
   }
+  img->metadata->metadata_array = metadata_array;
   img->metadata->metadata_array[img->metadata->sz] = metadata;
   img->metadata->sz++;
   return 0;
-fail:
-  aom_img_metadata_array_free(img->metadata);
-  img->metadata = NULL;
-  return -1;
 }
 
 void aom_img_remove_metadata(aom_image_t *img) {
diff --git a/av1/decoder/obu.c b/av1/decoder/obu.c
index a172e88..2fd06ce 100644
--- a/av1/decoder/obu.c
+++ b/av1/decoder/obu.c
@@ -576,30 +576,30 @@
                                 const uint8_t *data, size_t sz,
                                 aom_metadata_insert_flags_t insert_flag) {
   AV1_COMMON *const cm = &pbi->common;
+  if (!pbi->metadata) {
+    pbi->metadata = aom_img_metadata_array_alloc(0);
+    if (!pbi->metadata) {
+      aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
+                         "Failed to allocate metadata array");
+    }
+  }
   aom_metadata_t *metadata =
       aom_img_metadata_alloc(metadata_type, data, sz, insert_flag);
   if (!metadata) {
     aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
                        "Error allocating metadata");
   }
-  if (!pbi->metadata) {
-    pbi->metadata = aom_img_metadata_array_alloc(1);
-    if (!pbi->metadata) {
-      aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
-                         "Failed to allocate metadata array");
-    }
-  } else {
-    aom_metadata_t **metadata_array =
-        (aom_metadata_t **)realloc(pbi->metadata->metadata_array,
-                                   (pbi->metadata->sz + 1) * sizeof(metadata));
-    if (!metadata_array) {
-      aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
-                         "Error allocating metadata");
-    }
-    pbi->metadata->metadata_array = metadata_array;
-    pbi->metadata->sz++;
+  aom_metadata_t **metadata_array =
+      (aom_metadata_t **)realloc(pbi->metadata->metadata_array,
+                                 (pbi->metadata->sz + 1) * sizeof(metadata));
+  if (!metadata_array) {
+    aom_img_metadata_free(metadata);
+    aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
+                       "Error growing metadata array");
   }
-  pbi->metadata->metadata_array[pbi->metadata->sz - 1] = metadata;
+  pbi->metadata->metadata_array = metadata_array;
+  pbi->metadata->metadata_array[pbi->metadata->sz] = metadata;
+  pbi->metadata->sz++;
 }
 
 // On failure, calls aom_internal_error() and does not return.