1 files changed, 106 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vp8/encoder/treewriter.h b/media/libvpx/libvpx/vp8/encoder/treewriter.h
new file mode 100644
index 0000000000..4e9ed6af17
--- /dev/null
+++ b/media/libvpx/libvpx/vp8/encoder/treewriter.h
@@ -0,0 +1,106 @@
+/*
+ *  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.
+ */
+
+#ifndef VPX_VP8_ENCODER_TREEWRITER_H_
+#define VPX_VP8_ENCODER_TREEWRITER_H_
+
+/* Trees map alphabets into huffman-like codes suitable for an arithmetic
+   bit coder.  Timothy S Murphy  11 October 2004 */
+
+#include <stdint.h>
+
+#include "./vpx_config.h"
+#include "vp8/common/treecoder.h"
+
+#include "boolhuff.h" /* for now */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef BOOL_CODER vp8_writer;
+
+#define vp8_write vp8_encode_bool
+#define vp8_write_literal vp8_encode_value
+#define vp8_write_bit(W, V) vp8_write(W, V, vp8_prob_half)
+
+#define vp8bc_write vp8bc_write_bool
+#define vp8bc_write_literal vp8bc_write_bits
+#define vp8bc_write_bit(W, V) vp8bc_write_bits(W, V, 1)
+
+/* Approximate length of an encoded bool in 256ths of a bit at given prob */
+
+#define vp8_cost_zero(x) (vp8_prob_cost[x])
+#define vp8_cost_one(x) vp8_cost_zero(vp8_complement(x))
+
+#define vp8_cost_bit(x, b) vp8_cost_zero((b) ? vp8_complement(x) : (x))
+
+/* VP8BC version is scaled by 2^20 rather than 2^8; see bool_coder.h */
+
+/* Both of these return bits, not scaled bits. */
+
+static INLINE unsigned int vp8_cost_branch(const unsigned int ct[2],
+                                           vp8_prob p) {
+  /* Imitate existing calculation */
+
+  return (unsigned int)(((((uint64_t)ct[0]) * vp8_cost_zero(p)) +
+                         (((uint64_t)ct[1]) * vp8_cost_one(p))) >>
+                        8);
+}
+
+/* Small functions to write explicit values and tokens, as well as
+   estimate their lengths. */
+
+static void vp8_treed_write(vp8_writer *const w, vp8_tree t,
+                            const vp8_prob *const p, int v,
+                            int n) { /* number of bits in v, assumed nonzero */
+  vp8_tree_index i = 0;
+
+  do {
+    const int b = (v >> --n) & 1;
+    vp8_write(w, b, p[i >> 1]);
+    i = t[i + b];
+  } while (n);
+}
+static INLINE void vp8_write_token(vp8_writer *const w, vp8_tree t,
+                                   const vp8_prob *const p,
+                                   vp8_token *const x) {
+  vp8_treed_write(w, t, p, x->value, x->Len);
+}
+
+static int vp8_treed_cost(vp8_tree t, const vp8_prob *const p, int v,
+                          int n) { /* number of bits in v, assumed nonzero */
+  int c = 0;
+  vp8_tree_index i = 0;
+
+  do {
+    const int b = (v >> --n) & 1;
+    c += vp8_cost_bit(p[i >> 1], b);
+    i = t[i + b];
+  } while (n);
+
+  return c;
+}
+static INLINE int vp8_cost_token(vp8_tree t, const vp8_prob *const p,
+                                 vp8_token *const x) {
+  return vp8_treed_cost(t, p, x->value, x->Len);
+}
+
+/* Fill array of costs for all possible token values. */
+
+void vp8_cost_tokens(int *c, const vp8_prob *, vp8_tree);
+
+void vp8_cost_tokens2(int *c, const vp8_prob *, vp8_tree, int);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VPX_VP8_ENCODER_TREEWRITER_H_