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diff --git a/third_party/aom/aom_dsp/ansreader.h b/third_party/aom/aom_dsp/ansreader.h
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-/*
- * Copyright (c) 2016, Alliance for Open Media. All rights reserved
- *
- * This source code is subject to the terms of the BSD 2 Clause License and
- * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
- * was not distributed with this source code in the LICENSE file, you can
- * obtain it at www.aomedia.org/license/software. If the Alliance for Open
- * Media Patent License 1.0 was not distributed with this source code in the
- * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
- */
-
-#ifndef AOM_DSP_ANSREADER_H_
-#define AOM_DSP_ANSREADER_H_
-// An implementation of Asymmetric Numeral Systems
-// http://arxiv.org/abs/1311.2540v2
-// Implements decoding of:
-// * rABS (range Asymmetric Binary Systems), a boolean coder
-// * rANS (range Asymmetric Numeral Systems), a multi-symbol coder
-
-#include <assert.h>
-#include "./aom_config.h"
-#include "aom/aom_integer.h"
-#include "aom_dsp/prob.h"
-#include "aom_dsp/ans.h"
-#include "aom_ports/mem_ops.h"
-#if CONFIG_ACCOUNTING
-#include "av1/decoder/accounting.h"
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif // __cplusplus
-
-struct AnsDecoder {
- const uint8_t *buf;
- int buf_offset;
- uint32_t state;
-#if ANS_MAX_SYMBOLS
- int symbols_left;
- int window_size;
-#endif
-#if CONFIG_ACCOUNTING
- Accounting *accounting;
-#endif
-};
-
-static INLINE int ans_read_reinit(struct AnsDecoder *const ans);
-
-static INLINE unsigned refill_state(struct AnsDecoder *const ans,
- unsigned state) {
-#if ANS_REVERSE
- while (state < L_BASE && ans->buf_offset < 0) {
- state = state * IO_BASE + ans->buf[ans->buf_offset++];
- }
-#else
- while (state < L_BASE && ans->buf_offset > 0) {
- state = state * IO_BASE + ans->buf[--ans->buf_offset];
- }
-#endif
- return state;
-}
-
-// Decode one rABS encoded boolean where the probability of the value being zero
-// is p0.
-static INLINE int rabs_read(struct AnsDecoder *ans, AnsP8 p0) {
-#if ANS_MAX_SYMBOLS
- if (ans->symbols_left-- == 0) {
- ans_read_reinit(ans);
- ans->symbols_left--;
- }
-#endif
- unsigned state = refill_state(ans, ans->state);
- const unsigned quotient = state / ANS_P8_PRECISION;
- const unsigned remainder = state % ANS_P8_PRECISION;
- const int value = remainder >= p0;
- const unsigned qp0 = quotient * p0;
- if (value)
- state = state - qp0 - p0;
- else
- state = qp0 + remainder;
- ans->state = state;
- return value;
-}
-
-// Decode one rABS encoded boolean where the probability of the value being zero
-// is one half.
-static INLINE int rabs_read_bit(struct AnsDecoder *ans) {
-#if ANS_MAX_SYMBOLS
- if (ans->symbols_left-- == 0) {
- ans_read_reinit(ans);
- ans->symbols_left--;
- }
-#endif
- unsigned state = refill_state(ans, ans->state);
- const int value = !!(state & 0x80);
- ans->state = ((state >> 1) & ~0x7F) | (state & 0x7F);
- return value;
-}
-
-struct rans_dec_sym {
- uint8_t val;
- aom_cdf_prob prob;
- aom_cdf_prob cum_prob; // not-inclusive
-};
-
-static INLINE void fetch_sym(struct rans_dec_sym *out, const aom_cdf_prob *cdf,
- aom_cdf_prob rem) {
- int i;
- aom_cdf_prob cum_prob = 0, top_prob;
- // TODO(skal): if critical, could be a binary search.
- // Or, better, an O(1) alias-table.
- for (i = 0; rem >= (top_prob = cdf[i]); ++i) {
- cum_prob = top_prob;
- }
- out->val = i;
- out->prob = top_prob - cum_prob;
- out->cum_prob = cum_prob;
-}
-
-static INLINE int rans_read(struct AnsDecoder *ans, const aom_cdf_prob *tab) {
- unsigned rem;
- unsigned quo;
- struct rans_dec_sym sym;
-#if ANS_MAX_SYMBOLS
- if (ans->symbols_left-- == 0) {
- ans_read_reinit(ans);
- ans->symbols_left--;
- }
-#endif
- ans->state = refill_state(ans, ans->state);
- quo = ans->state / RANS_PRECISION;
- rem = ans->state % RANS_PRECISION;
- fetch_sym(&sym, tab, rem);
- ans->state = quo * sym.prob + rem - sym.cum_prob;
- return sym.val;
-}
-
-static INLINE int ans_read_init(struct AnsDecoder *const ans,
- const uint8_t *const buf, int offset) {
- unsigned x;
- if (offset < 1) return 1;
-#if ANS_REVERSE
- ans->buf = buf + offset;
- ans->buf_offset = -offset;
- x = buf[0];
- if ((x & 0x80) == 0) { // Marker is 0xxx xxxx
- if (offset < 2) return 1;
- ans->buf_offset += 2;
- ans->state = mem_get_be16(buf) & 0x7FFF;
-#if L_BASE * IO_BASE > (1 << 23)
- } else if ((x & 0xC0) == 0x80) { // Marker is 10xx xxxx
- if (offset < 3) return 1;
- ans->buf_offset += 3;
- ans->state = mem_get_be24(buf) & 0x3FFFFF;
- } else { // Marker is 11xx xxxx
- if (offset < 4) return 1;
- ans->buf_offset += 4;
- ans->state = mem_get_be32(buf) & 0x3FFFFFFF;
-#else
- } else { // Marker is 1xxx xxxx
- if (offset < 3) return 1;
- ans->buf_offset += 3;
- ans->state = mem_get_be24(buf) & 0x7FFFFF;
-#endif
- }
-#else
- ans->buf = buf;
- x = buf[offset - 1];
- if ((x & 0x80) == 0) { // Marker is 0xxx xxxx
- if (offset < 2) return 1;
- ans->buf_offset = offset - 2;
- ans->state = mem_get_le16(buf + offset - 2) & 0x7FFF;
- } else if ((x & 0xC0) == 0x80) { // Marker is 10xx xxxx
- if (offset < 3) return 1;
- ans->buf_offset = offset - 3;
- ans->state = mem_get_le24(buf + offset - 3) & 0x3FFFFF;
- } else if ((x & 0xE0) == 0xE0) { // Marker is 111x xxxx
- if (offset < 4) return 1;
- ans->buf_offset = offset - 4;
- ans->state = mem_get_le32(buf + offset - 4) & 0x1FFFFFFF;
- } else {
- // Marker 110x xxxx implies this byte is a superframe marker
- return 1;
- }
-#endif // ANS_REVERSE
-#if CONFIG_ACCOUNTING
- ans->accounting = NULL;
-#endif
- ans->state += L_BASE;
- if (ans->state >= L_BASE * IO_BASE) return 1;
-#if ANS_MAX_SYMBOLS
- assert(ans->window_size > 1);
- ans->symbols_left = ans->window_size;
-#endif
- return 0;
-}
-
-#if ANS_REVERSE
-static INLINE int ans_read_reinit(struct AnsDecoder *const ans) {
- return ans_read_init(ans, ans->buf + ans->buf_offset, -ans->buf_offset);
-}
-#endif
-
-static INLINE int ans_read_end(const struct AnsDecoder *const ans) {
- return ans->buf_offset == 0 && ans->state < L_BASE;
-}
-
-static INLINE int ans_reader_has_error(const struct AnsDecoder *const ans) {
- return ans->state < L_BASE / RANS_PRECISION;
-}
-#ifdef __cplusplus
-} // extern "C"
-#endif // __cplusplus
-#endif // AOM_DSP_ANSREADER_H_
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