ref: f8e1a621f9b68ac60115773874b0ce646e79c02d
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__ */