1 files changed, 82 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vp8/common/treecoder.h b/media/libvpx/libvpx/vp8/common/treecoder.h
new file mode 100644
index 0000000000..d7d8d0ead0
--- /dev/null
+++ b/media/libvpx/libvpx/vp8/common/treecoder.h
@@ -0,0 +1,82 @@
+/*
+ *  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_COMMON_TREECODER_H_
+#define VPX_VP8_COMMON_TREECODER_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef unsigned char vp8bc_index_t; /* probability index */
+
+typedef unsigned char vp8_prob;
+
+#define vp8_prob_half ((vp8_prob)128)
+
+typedef signed char vp8_tree_index;
+struct bool_coder_spec;
+
+typedef struct bool_coder_spec bool_coder_spec;
+typedef struct bool_writer bool_writer;
+typedef struct bool_reader bool_reader;
+
+typedef const bool_coder_spec c_bool_coder_spec;
+typedef const bool_writer c_bool_writer;
+typedef const bool_reader c_bool_reader;
+
+#define vp8_complement(x) (255 - (x))
+
+/* We build coding trees compactly in arrays.
+   Each node of the tree is a pair of vp8_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 vp8_tree_index vp8_tree[], *vp8_tree_p;
+
+typedef const struct vp8_token_struct {
+  int value;
+  int Len;
+} vp8_token;
+
+/* Construct encoding array from tree. */
+
+void vp8_tokens_from_tree(struct vp8_token_struct *, vp8_tree);
+void vp8_tokens_from_tree_offset(struct vp8_token_struct *, vp8_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 vp8_tree_probs_from_distribution(int n, /* n = size of alphabet */
+                                      vp8_token tok[/* n */], vp8_tree tree,
+                                      vp8_prob probs[/* n-1 */],
+                                      unsigned int branch_ct[/* n-1 */][2],
+                                      const unsigned int num_events[/* n */],
+                                      unsigned int Pfactor, int Round);
+
+/* Variant of above using coder spec rather than hardwired 8-bit probs. */
+
+void vp8bc_tree_probs_from_distribution(int n, /* n = size of alphabet */
+                                        vp8_token tok[/* n */], vp8_tree tree,
+                                        vp8_prob probs[/* n-1 */],
+                                        unsigned int branch_ct[/* n-1 */][2],
+                                        const unsigned int num_events[/* n */],
+                                        c_bool_coder_spec *s);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VPX_VP8_COMMON_TREECODER_H_