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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /media/libvpx/vp8/common/treecoder.c
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'media/libvpx/vp8/common/treecoder.c')
-rw-r--r--media/libvpx/vp8/common/treecoder.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/media/libvpx/vp8/common/treecoder.c b/media/libvpx/vp8/common/treecoder.c
new file mode 100644
index 000000000..d80c64bdf
--- /dev/null
+++ b/media/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);
+}