| Index: third_party/libvpx/source/libvpx/vp8/common/treecoder.c
|
| diff --git a/third_party/libvpx/source/libvpx/vp8/common/treecoder.c b/third_party/libvpx/source/libvpx/vp8/common/treecoder.c
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..d80c64bdfa1b079bbbc14efbee3c33024e864d2b
|
| --- /dev/null
|
| +++ b/third_party/libvpx/source/libvpx/vp8/common/treecoder.c
|
| @@ -0,0 +1,143 @@
|
| +/*
|
| + * 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.
|
| + */
|
| +
|
| +
|
| +#if CONFIG_DEBUG
|
| +#include <assert.h>
|
| +#endif
|
| +#include <stdio.h>
|
| +
|
| +#include "treecoder.h"
|
| +
|
| +static void tree2tok(
|
| + struct vp8_token_struct *const p,
|
| + vp8_tree t,
|
| + int i,
|
| + int v,
|
| + int L
|
| +)
|
| +{
|
| + v += v;
|
| + ++L;
|
| +
|
| + do
|
| + {
|
| + const vp8_tree_index j = t[i++];
|
| +
|
| + if (j <= 0)
|
| + {
|
| + p[-j].value = v;
|
| + p[-j].Len = L;
|
| + }
|
| + else
|
| + tree2tok(p, t, j, v, L);
|
| + }
|
| + while (++v & 1);
|
| +}
|
| +
|
| +void vp8_tokens_from_tree(struct vp8_token_struct *p, vp8_tree t)
|
| +{
|
| + tree2tok(p, t, 0, 0, 0);
|
| +}
|
| +
|
| +void vp8_tokens_from_tree_offset(struct vp8_token_struct *p, vp8_tree t,
|
| + int offset)
|
| +{
|
| + tree2tok(p - offset, t, 0, 0, 0);
|
| +}
|
| +
|
| +static void branch_counts(
|
| + int n, /* n = size of alphabet */
|
| + vp8_token tok [ /* n */ ],
|
| + vp8_tree tree,
|
| + unsigned int branch_ct [ /* n-1 */ ] [2],
|
| + const unsigned int num_events[ /* n */ ]
|
| +)
|
| +{
|
| + const int tree_len = n - 1;
|
| + int t = 0;
|
| +
|
| +#if CONFIG_DEBUG
|
| + assert(tree_len);
|
| +#endif
|
| +
|
| + do
|
| + {
|
| + branch_ct[t][0] = branch_ct[t][1] = 0;
|
| + }
|
| + while (++t < tree_len);
|
| +
|
| + t = 0;
|
| +
|
| + do
|
| + {
|
| + int L = tok[t].Len;
|
| + const int enc = tok[t].value;
|
| + const unsigned int ct = num_events[t];
|
| +
|
| + vp8_tree_index i = 0;
|
| +
|
| + do
|
| + {
|
| + const int b = (enc >> --L) & 1;
|
| + const int j = i >> 1;
|
| +#if CONFIG_DEBUG
|
| + assert(j < tree_len && 0 <= L);
|
| +#endif
|
| +
|
| + branch_ct [j] [b] += ct;
|
| + i = tree[ i + b];
|
| + }
|
| + while (i > 0);
|
| +
|
| +#if CONFIG_DEBUG
|
| + assert(!L);
|
| +#endif
|
| + }
|
| + while (++t < n);
|
| +
|
| +}
|
| +
|
| +
|
| +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 Pfac,
|
| + int rd
|
| +)
|
| +{
|
| + const int tree_len = n - 1;
|
| + int t = 0;
|
| +
|
| + branch_counts(n, tok, tree, branch_ct, num_events);
|
| +
|
| + do
|
| + {
|
| + const unsigned int *const c = branch_ct[t];
|
| + const unsigned int tot = c[0] + c[1];
|
| +
|
| +#if CONFIG_DEBUG
|
| + assert(tot < (1 << 24)); /* no overflow below */
|
| +#endif
|
| +
|
| + if (tot)
|
| + {
|
| + const unsigned int p = ((c[0] * Pfac) + (rd ? tot >> 1 : 0)) / tot;
|
| + probs[t] = p < 256 ? (p ? p : 1) : 255; /* agree w/old version for now */
|
| + }
|
| + else
|
| + probs[t] = vp8_prob_half;
|
| + }
|
| + while (++t < tree_len);
|
| +}
|
|
|