libvpx: Pull from upstream

source/libvpx/vp9/common/vp9_treecoder.h

 /*
  *  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 VP9_COMMON_VP9_TREECODER_H_
 #define VP9_COMMON_VP9_TREECODER_H_
 
-typedef unsigned char vp9_prob;
+#include "vpx/vpx_integer.h"
 
-#define vp9_prob_half ( (vp9_prob) 128)
+typedef uint8_t vp9_prob;
 
-typedef signed char vp9_tree_index;
-struct bool_coder_spec;
+#define vp9_prob_half ((vp9_prob) 128)
 
-typedef struct bool_coder_spec bool_coder_spec;
-typedef struct bool_writer bool_writer;
-typedef struct bool_reader bool_reader;
+typedef int8_t vp9_tree_index;
 
-typedef const bool_coder_spec c_bool_coder_spec;
-typedef const bool_writer c_bool_writer;
-typedef const bool_reader c_bool_reader;
-
-
-
-# define vp9_complement( x) (255 - x)
-
+#define vp9_complement(x) (255 - x)
 
 /* We build coding trees compactly in arrays.
    Each node of the tree is a pair of vp9_tree_indices.
    Array index often references a corresponding probability table.
    Index <= 0 means done encoding/decoding and value = -Index,
    Index > 0 means need another bit, specification at index.
    Nonnegative indices are always even;  processing begins at node 0. */
 
 typedef const vp9_tree_index vp9_tree[], *vp9_tree_p;
 
-
 typedef const struct vp9_token_struct {
   int value;
   int Len;
 } vp9_token;
 
 /* Construct encoding array from tree. */
 
 void vp9_tokens_from_tree(struct vp9_token_struct *, vp9_tree);
 void vp9_tokens_from_tree_offset(struct vp9_token_struct *, vp9_tree,
                                  int offset);
 
-
 /* Convert array of token occurrence counts into a table of probabilities
    for the associated binary encoding tree.  Also writes count of branches
    taken for each node on the tree; this facilitiates decisions as to
    probability updates. */
 
-void vp9_tree_probs_from_distribution(
-  int n,                      /* n = size of alphabet */
-  vp9_token tok               [ /* n */ ],
-  vp9_tree tree,
-  vp9_prob probs          [ /* n-1 */ ],
-  unsigned int branch_ct       [ /* n-1 */ ] [2],
-  const unsigned int num_events[ /* n */ ],
-  unsigned int Pfactor,
-  int Round
-);
+void vp9_tree_probs_from_distribution(int n,  /* n = size of alphabet */
+                                      vp9_token tok[ /* n */ ],
+                                      vp9_tree tree,
+                                      vp9_prob probs[ /* n - 1 */ ],
+                                      unsigned int branch_ct[ /* n - 1 */ ][2],
+                                      const unsigned int num_events[ /* n */ ]);
 
-static __inline int clip_prob(int p) {
-  if (p > 255)
-    return 255;
-  else if (p < 1)
-    return 1;
-  return p;
+static __inline vp9_prob clip_prob(int p) {
+  return (p > 255) ? 255u : (p < 1) ? 1u : p;
 }
 
-vp9_prob vp9_bin_prob_from_distribution(const unsigned int counts[2]);
+static __inline vp9_prob get_prob(int num, int den) {
+  return (den == 0) ? 128u : clip_prob((num * 256 + (den >> 1)) / den);
+}
 
-#endif
+static __inline vp9_prob get_binary_prob(int n0, int n1) {
+  return get_prob(n0, n0 + n1);
+}
+
+/* this function assumes prob1 and prob2 are already within [1,255] range */
+static __inline vp9_prob weighted_prob(int prob1, int prob2, int factor) {
+  return (prob1 * (256 - factor) + prob2 * factor + 128) >> 8;
+}
+
+#endif  // VP9_COMMON_VP9_TREECODER_H_