media/libvpx/vp9/encoder/vp9_write_bit_buffer.h@ac0c01689b40
media/libvpx/vp9/encoder/vp9_write_bit_buffer.h
Thu, 15 Jan 2015 15:59:08 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 15 Jan 2015 15:59:08 +0100
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
- permissions
- -rw-r--r--
Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
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 */
11 #ifndef VP9_BIT_WRITE_BUFFER_H_
12 #define VP9_BIT_WRITE_BUFFER_H_
14 #include <limits.h>
16 #include "vpx/vpx_integer.h"
18 struct vp9_write_bit_buffer {
19 uint8_t *bit_buffer;
20 size_t bit_offset;
21 };
23 static size_t vp9_rb_bytes_written(struct vp9_write_bit_buffer *wb) {
24 return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0);
25 }
27 static void vp9_wb_write_bit(struct vp9_write_bit_buffer *wb, int bit) {
28 const int off = wb->bit_offset;
29 const int p = off / CHAR_BIT;
30 const int q = CHAR_BIT - 1 - off % CHAR_BIT;
31 if (q == CHAR_BIT -1) {
32 wb->bit_buffer[p] = bit << q;
33 } else {
34 wb->bit_buffer[p] &= ~(1 << q);
35 wb->bit_buffer[p] |= bit << q;
36 }
37 wb->bit_offset = off + 1;
38 }
40 static void vp9_wb_write_literal(struct vp9_write_bit_buffer *wb,
41 int data, int bits) {
42 int bit;
43 for (bit = bits - 1; bit >= 0; bit--)
44 vp9_wb_write_bit(wb, (data >> bit) & 1);
45 }
48 #endif // VP9_BIT_WRITE_BUFFER_H_
