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 "vp9/encoder/vp9_write_bit_buffer.h"
12 
vp9_rb_bytes_written(struct vp9_write_bit_buffer * wb)13 size_t vp9_rb_bytes_written(struct vp9_write_bit_buffer *wb) {
14   return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0);
15 }
16 
vp9_wb_write_bit(struct vp9_write_bit_buffer * wb,int bit)17 void vp9_wb_write_bit(struct vp9_write_bit_buffer *wb, int bit) {
18   const int off = (int)wb->bit_offset;
19   const int p = off / CHAR_BIT;
20   const int q = CHAR_BIT - 1 - off % CHAR_BIT;
21   if (q == CHAR_BIT -1) {
22     wb->bit_buffer[p] = bit << q;
23   } else {
24     wb->bit_buffer[p] &= ~(1 << q);
25     wb->bit_buffer[p] |= bit << q;
26   }
27   wb->bit_offset = off + 1;
28 }
29 
vp9_wb_write_literal(struct vp9_write_bit_buffer * wb,int data,int bits)30 void vp9_wb_write_literal(struct vp9_write_bit_buffer *wb, int data, int bits) {
31   int bit;
32   for (bit = bits - 1; bit >= 0; bit--)
33     vp9_wb_write_bit(wb, (data >> bit) & 1);
34 }
35