ref: 3746b6e128324fff7468463aeac332279eb5d59c
dir: /src/getbits.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_GETBITS_H__
#define __DAV1D_SRC_GETBITS_H__
#include <stddef.h>
#include <stdint.h>
typedef struct GetBits {
int error, eof;
uint64_t state;
unsigned bits_left;
const uint8_t *ptr, *ptr_start, *ptr_end;
} GetBits;
void dav1d_init_get_bits(GetBits *c, const uint8_t *data, size_t sz);
unsigned dav1d_get_bits(GetBits *c, unsigned n);
int dav1d_get_sbits(GetBits *c, unsigned n);
// Output in range 0..max-1
unsigned dav1d_get_uniform(GetBits *c, unsigned max);
unsigned dav1d_get_vlc(GetBits *c);
int dav1d_get_bits_subexp(GetBits *c, int ref, unsigned n);
// Discard bits from the buffer until we're next byte-aligned.
void dav1d_bytealign_get_bits(GetBits *c);
// Return the current bit position relative to the start of the buffer.
static inline unsigned dav1d_get_bits_pos(const GetBits *c) {
return (c->ptr - c->ptr_start) * 8 - c->bits_left;
}
#endif /* __DAV1D_SRC_GETBITS_H__ */