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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/vp9/decoder/vp9_reader.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'media/libvpx/vp9/decoder/vp9_reader.h')
-rw-r--r--media/libvpx/vp9/decoder/vp9_reader.h120
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diff --git a/media/libvpx/vp9/decoder/vp9_reader.h b/media/libvpx/vp9/decoder/vp9_reader.h
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+/*
+ * 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_DECODER_VP9_READER_H_
+#define VP9_DECODER_VP9_READER_H_
+
+#include <stddef.h>
+#include <limits.h>
+
+#include "./vpx_config.h"
+#include "vpx_ports/mem.h"
+#include "vpx/vp8dx.h"
+#include "vpx/vpx_integer.h"
+
+#include "vp9/common/vp9_prob.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef size_t BD_VALUE;
+
+#define BD_VALUE_SIZE ((int)sizeof(BD_VALUE) * CHAR_BIT)
+
+typedef struct {
+ // Be careful when reordering this struct, it may impact the cache negatively.
+ BD_VALUE value;
+ unsigned int range;
+ int count;
+ const uint8_t *buffer_end;
+ const uint8_t *buffer;
+ vpx_decrypt_cb decrypt_cb;
+ void *decrypt_state;
+ uint8_t clear_buffer[sizeof(BD_VALUE) + 1];
+} vp9_reader;
+
+int vp9_reader_init(vp9_reader *r,
+ const uint8_t *buffer,
+ size_t size,
+ vpx_decrypt_cb decrypt_cb,
+ void *decrypt_state);
+
+void vp9_reader_fill(vp9_reader *r);
+
+int vp9_reader_has_error(vp9_reader *r);
+
+const uint8_t *vp9_reader_find_end(vp9_reader *r);
+
+static INLINE int vp9_read(vp9_reader *r, int prob) {
+ unsigned int bit = 0;
+ BD_VALUE value;
+ BD_VALUE bigsplit;
+ int count;
+ unsigned int range;
+ unsigned int split = (r->range * prob + (256 - prob)) >> CHAR_BIT;
+
+ if (r->count < 0)
+ vp9_reader_fill(r);
+
+ value = r->value;
+ count = r->count;
+
+ bigsplit = (BD_VALUE)split << (BD_VALUE_SIZE - CHAR_BIT);
+
+ range = split;
+
+ if (value >= bigsplit) {
+ range = r->range - split;
+ value = value - bigsplit;
+ bit = 1;
+ }
+
+ {
+ register unsigned int shift = vp9_norm[range];
+ range <<= shift;
+ value <<= shift;
+ count -= shift;
+ }
+ r->value = value;
+ r->count = count;
+ r->range = range;
+
+ return bit;
+}
+
+static INLINE int vp9_read_bit(vp9_reader *r) {
+ return vp9_read(r, 128); // vp9_prob_half
+}
+
+static INLINE int vp9_read_literal(vp9_reader *r, int bits) {
+ int literal = 0, bit;
+
+ for (bit = bits - 1; bit >= 0; bit--)
+ literal |= vp9_read_bit(r) << bit;
+
+ return literal;
+}
+
+static INLINE int vp9_read_tree(vp9_reader *r, const vp9_tree_index *tree,
+ const vp9_prob *probs) {
+ vp9_tree_index i = 0;
+
+ while ((i = tree[i + vp9_read(r, probs[i >> 1])]) > 0)
+ continue;
+
+ return -i;
+}
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // VP9_DECODER_VP9_READER_H_