Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

1 files changed, 61 insertions, 0 deletions

diff --git a/third_party/aom/av1/encoder/variance_tree.c b/third_party/aom/av1/encoder/variance_tree.c
new file mode 100644
index 000000000..9384cd78e
--- /dev/null
+++ b/third_party/aom/av1/encoder/variance_tree.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "av1/encoder/variance_tree.h"
+#include "av1/encoder/encoder.h"
+
+void av1_setup_var_tree(struct AV1Common *cm, ThreadData *td) {
+  int i, j;
+#if CONFIG_EXT_PARTITION
+  const int leaf_nodes = 1024;
+  const int tree_nodes = 1024 + 256 + 64 + 16 + 4 + 1;
+#else
+  const int leaf_nodes = 256;
+  const int tree_nodes = 256 + 64 + 16 + 4 + 1;
+#endif  // CONFIG_EXT_PARTITION
+  int index = 0;
+  VAR_TREE *this_var;
+  int nodes;
+
+  aom_free(td->var_tree);
+  CHECK_MEM_ERROR(cm, td->var_tree,
+                  aom_calloc(tree_nodes, sizeof(*td->var_tree)));
+
+  this_var = &td->var_tree[0];
+
+  // Sets up all the leaf nodes in the tree.
+  for (index = 0; index < leaf_nodes; ++index) {
+    VAR_TREE *const leaf = &td->var_tree[index];
+    leaf->split[0] = NULL;
+  }
+
+  // Each node has 4 leaf nodes, fill in the child pointers
+  // from leafs to the root.
+  for (nodes = leaf_nodes >> 2; nodes > 0; nodes >>= 2) {
+    for (i = 0; i < nodes; ++i, ++index) {
+      VAR_TREE *const node = &td->var_tree[index];
+      for (j = 0; j < 4; j++) node->split[j] = this_var++;
+    }
+  }
+
+  // Set up the root node for the largest superblock size
+  i = MAX_MIB_SIZE_LOG2 - MIN_MIB_SIZE_LOG2;
+  td->var_root[i] = &td->var_tree[tree_nodes - 1];
+  // Set up the root nodes for the rest of the possible superblock sizes
+  while (--i >= 0) {
+    td->var_root[i] = td->var_root[i + 1]->split[0];
+  }
+}
+
+void av1_free_var_tree(ThreadData *td) {
+  aom_free(td->var_tree);
+  td->var_tree = NULL;
+}