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-rw-r--r--media/libvpx/vp9/encoder/vp9_treewriter.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/media/libvpx/vp9/encoder/vp9_treewriter.c b/media/libvpx/vp9/encoder/vp9_treewriter.c
new file mode 100644
index 000000000..bb04b4025
--- /dev/null
+++ b/media/libvpx/vp9/encoder/vp9_treewriter.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "vp9/encoder/vp9_treewriter.h"
+
+static void tree2tok(struct vp9_token *tokens, const vp9_tree_index *tree,
+ int i, int v, int l) {
+ v += v;
+ ++l;
+
+ do {
+ const vp9_tree_index j = tree[i++];
+ if (j <= 0) {
+ tokens[-j].value = v;
+ tokens[-j].len = l;
+ } else {
+ tree2tok(tokens, tree, j, v, l);
+ }
+ } while (++v & 1);
+}
+
+void vp9_tokens_from_tree(struct vp9_token *tokens,
+ const vp9_tree_index *tree) {
+ tree2tok(tokens, tree, 0, 0, 0);
+}
+
+static unsigned int convert_distribution(unsigned int i, vp9_tree tree,
+ unsigned int branch_ct[][2],
+ const unsigned int num_events[]) {
+ unsigned int left, right;
+
+ if (tree[i] <= 0)
+ left = num_events[-tree[i]];
+ else
+ left = convert_distribution(tree[i], tree, branch_ct, num_events);
+
+ if (tree[i + 1] <= 0)
+ right = num_events[-tree[i + 1]];
+ else
+ right = convert_distribution(tree[i + 1], tree, branch_ct, num_events);
+
+ branch_ct[i >> 1][0] = left;
+ branch_ct[i >> 1][1] = right;
+ return left + right;
+}
+
+void vp9_tree_probs_from_distribution(vp9_tree tree,
+ unsigned int branch_ct[/* n-1 */][2],
+ const unsigned int num_events[/* n */]) {
+ convert_distribution(0, tree, branch_ct, num_events);
+}