ref: 72af9329c0c003f68639301be33d4632147245b6
dir: /src/msac.h/
/*
* Copyright © 2018, VideoLAN and dav1d authors
* Copyright © 2018, Two Orioles, LLC
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __DAV1D_SRC_MSAC_H__
#define __DAV1D_SRC_MSAC_H__
#include <stdint.h>
#include <stdlib.h>
/* Using uint32_t should be faster on 32 bit systems, in theory, maybe */
typedef uint64_t ec_win;
typedef struct MsacContext {
const uint8_t *buf_pos;
const uint8_t *buf_end;
ec_win dif;
uint16_t rng;
int cnt;
int allow_update_cdf;
} MsacContext;
#define EC_PROB_SHIFT 6
#define EC_BOOL_EPROB 256
void msac_init(MsacContext *c, const uint8_t *data, size_t sz, int disable_cdf_update_flag);
unsigned msac_decode_symbol(MsacContext *s, const uint16_t *cdf,
const unsigned n_symbols);
unsigned msac_decode_symbol_adapt(MsacContext *s, uint16_t *cdf,
const unsigned n_symbols);
unsigned msac_decode_bool(MsacContext *s, unsigned f);
unsigned msac_decode_bool_adapt(MsacContext *s, uint16_t *cdf);
unsigned msac_decode_bools(MsacContext *c, unsigned l);
int msac_decode_subexp(MsacContext *c, int ref, int n, unsigned k);
int msac_decode_uniform(MsacContext *c, unsigned n);
#endif /* __DAV1D_SRC_MSAC_H__ */