Coverage Report

Created: 2025-07-16 07:53

/src/aom/aom_dsp/binary_codes_reader.c
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/*
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 * Copyright (c) 2017, Alliance for Open Media. All rights reserved.
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 *
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 * This source code is subject to the terms of the BSD 2 Clause License and
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 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
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 * was not distributed with this source code in the LICENSE file, you can
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 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
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 * Media Patent License 1.0 was not distributed with this source code in the
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 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
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 */
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#include "aom_dsp/binary_codes_reader.h"
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#include "aom_dsp/recenter.h"
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#define read_primitive_quniform(r, n, ACCT_STR_NAME) \
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  read_primitive_quniform_(r, n ACCT_STR_ARG(ACCT_STR_NAME))
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#define read_primitive_subexpfin(r, n, k, ACCT_STR_NAME) \
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  read_primitive_subexpfin_(r, n, k ACCT_STR_ARG(ACCT_STR_NAME))
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static uint16_t read_primitive_quniform_(aom_reader *r,
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                                         uint16_t n ACCT_STR_PARAM) {
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  if (n <= 1) return 0;
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  const int l = get_msb(n) + 1;
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  const int m = (1 << l) - n;
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  const int v = aom_read_literal(r, l - 1, ACCT_STR_NAME);
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  return v < m ? v : (v << 1) - m + aom_read_bit(r, ACCT_STR_NAME);
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}
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// Decode finite subexponential code that for a symbol v in [0, n-1] with
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// parameter k
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static uint16_t read_primitive_subexpfin_(aom_reader *r, uint16_t n,
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                                          uint16_t k ACCT_STR_PARAM) {
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  int i = 0;
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  int mk = 0;
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  while (1) {
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    int b = (i ? k + i - 1 : k);
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    int a = (1 << b);
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    if (n <= mk + 3 * a) {
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      return read_primitive_quniform(r, n - mk, ACCT_STR_NAME) + mk;
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    }
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    if (!aom_read_bit(r, ACCT_STR_NAME)) {
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      return aom_read_literal(r, b, ACCT_STR_NAME) + mk;
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    }
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    i = i + 1;
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    mk += a;
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  }
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  assert(0);
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  return 0;
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}
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uint16_t aom_read_primitive_refsubexpfin_(aom_reader *r, uint16_t n, uint16_t k,
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                                          uint16_t ref ACCT_STR_PARAM) {
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  return inv_recenter_finite_nonneg(
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      n, ref, read_primitive_subexpfin(r, n, k, ACCT_STR_NAME));
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}