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1 /* | 1 /* |
2 * Copyright (c) 2013 The WebM project authors. All Rights Reserved. | 2 * Copyright (c) 2013 The WebM project authors. All Rights Reserved. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license | 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 | 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 | 6 * tree. An additional intellectual property rights grant can be found |
7 * in the file PATENTS. All contributing project authors may | 7 * in the file PATENTS. All contributing project authors may |
8 * be found in the AUTHORS file in the root of the source tree. | 8 * be found in the AUTHORS file in the root of the source tree. |
9 */ | 9 */ |
10 | 10 |
11 #ifndef VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_ | 11 #ifndef VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_ |
12 #define VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_ | 12 #define VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_ |
13 | 13 |
14 #include <limits.h> | 14 #include <limits.h> |
15 | 15 |
16 #include "vpx/vpx_integer.h" | 16 #include "vpx/vpx_integer.h" |
17 | 17 |
18 #ifdef __cplusplus | 18 #ifdef __cplusplus |
19 extern "C" { | 19 extern "C" { |
20 #endif | 20 #endif |
21 | 21 |
22 struct vp9_write_bit_buffer { | 22 struct vp9_write_bit_buffer { |
23 uint8_t *bit_buffer; | 23 uint8_t *bit_buffer; |
24 size_t bit_offset; | 24 size_t bit_offset; |
25 }; | 25 }; |
26 | 26 |
27 static size_t vp9_rb_bytes_written(struct vp9_write_bit_buffer *wb) { | 27 size_t vp9_rb_bytes_written(struct vp9_write_bit_buffer *wb); |
28 return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0); | |
29 } | |
30 | 28 |
31 static void vp9_wb_write_bit(struct vp9_write_bit_buffer *wb, int bit) { | 29 void vp9_wb_write_bit(struct vp9_write_bit_buffer *wb, int bit); |
32 const int off = (int)wb->bit_offset; | |
33 const int p = off / CHAR_BIT; | |
34 const int q = CHAR_BIT - 1 - off % CHAR_BIT; | |
35 if (q == CHAR_BIT -1) { | |
36 wb->bit_buffer[p] = bit << q; | |
37 } else { | |
38 wb->bit_buffer[p] &= ~(1 << q); | |
39 wb->bit_buffer[p] |= bit << q; | |
40 } | |
41 wb->bit_offset = off + 1; | |
42 } | |
43 | 30 |
44 static void vp9_wb_write_literal(struct vp9_write_bit_buffer *wb, | 31 void vp9_wb_write_literal(struct vp9_write_bit_buffer *wb, int data, int bits); |
45 int data, int bits) { | |
46 int bit; | |
47 for (bit = bits - 1; bit >= 0; bit--) | |
48 vp9_wb_write_bit(wb, (data >> bit) & 1); | |
49 } | |
50 | 32 |
51 | 33 |
52 #ifdef __cplusplus | 34 #ifdef __cplusplus |
53 } // extern "C" | 35 } // extern "C" |
54 #endif | 36 #endif |
55 | 37 |
56 #endif // VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_ | 38 #endif // VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_ |
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