ref: 80812829c2d45d9f5597e619b8759e9562d6f1c0
dir: /vp9/decoder/vp9_read_bit_buffer.h/
/*
* Copyright (c) 2013 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef VP9_READ_BIT_BUFFER_
#define VP9_READ_BIT_BUFFER_
struct vp9_read_bit_buffer {
const uint8_t *const bit_buffer;
size_t bit_offset;
};
static int vp9_rb_read_bit(struct vp9_read_bit_buffer *rb) {
const int off = rb->bit_offset;
const int p = off / CHAR_BIT;
const int q = /*CHAR_BIT - 1 -*/ off % CHAR_BIT;
const int bit = (rb->bit_buffer[p] & (1 << q)) >> q;
rb->bit_offset = off + 1;
return bit;
}
static int vp9_rb_read_literal(struct vp9_read_bit_buffer *rb, int bits) {
int value = 0, bit;
for (bit = bits - 1; bit >= 0; bit--)
value |= vp9_rb_read_bit(rb) << bit;
return value;
}
#endif // VP9_READ_BIT_BUFFER_