1/*
2 *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include <limits.h>
12#include "vp9/encoder/vp9_write_bit_buffer.h"
13
14size_t vp9_wb_bytes_written(const struct vp9_write_bit_buffer *wb) {
15  return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0);
16}
17
18void vp9_wb_write_bit(struct vp9_write_bit_buffer *wb, int bit) {
19  const int off = (int)wb->bit_offset;
20  const int p = off / CHAR_BIT;
21  const int q = CHAR_BIT - 1 - off % CHAR_BIT;
22  if (q == CHAR_BIT -1) {
23    wb->bit_buffer[p] = bit << q;
24  } else {
25    wb->bit_buffer[p] &= ~(1 << q);
26    wb->bit_buffer[p] |= bit << q;
27  }
28  wb->bit_offset = off + 1;
29}
30
31void vp9_wb_write_literal(struct vp9_write_bit_buffer *wb, int data, int bits) {
32  int bit;
33  for (bit = bits - 1; bit >= 0; bit--)
34    vp9_wb_write_bit(wb, (data >> bit) & 1);
35}
36