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Diffstat (limited to 'apps/codecs/libwma/common.c')
-rw-r--r-- | apps/codecs/libwma/common.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/apps/codecs/libwma/common.c b/apps/codecs/libwma/common.c new file mode 100644 index 0000000000..4d165ed0a8 --- /dev/null +++ b/apps/codecs/libwma/common.c | |||
@@ -0,0 +1,107 @@ | |||
1 | /* | ||
2 | * Common bit i/o utils | ||
3 | * Copyright (c) 2000, 2001 Fabrice Bellard. | ||
4 | * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> | ||
5 | * | ||
6 | * This library is free software; you can redistribute it and/or | ||
7 | * modify it under the terms of the GNU Lesser General Public | ||
8 | * License as published by the Free Software Foundation; either | ||
9 | * version 2 of the License, or (at your option) any later version. | ||
10 | * | ||
11 | * This library is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
14 | * Lesser General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU Lesser General Public | ||
17 | * License along with this library; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
19 | * | ||
20 | * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at> | ||
21 | */ | ||
22 | |||
23 | /** | ||
24 | * @file common.c | ||
25 | * common internal api. | ||
26 | */ | ||
27 | |||
28 | #include "avcodec.h" | ||
29 | |||
30 | const uint8_t ff_sqrt_tab[128]={ | ||
31 | 0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, | ||
32 | 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | ||
33 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | ||
34 | 9, 9, 9, 9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11 | ||
35 | }; | ||
36 | |||
37 | const uint8_t ff_log2_tab[256]={ | ||
38 | 0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, | ||
39 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, | ||
40 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, | ||
41 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, | ||
42 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, | ||
43 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, | ||
44 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, | ||
45 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 | ||
46 | }; | ||
47 | |||
48 | /** | ||
49 | * init GetBitContext. | ||
50 | * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits | ||
51 | * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end | ||
52 | * @param bit_size the size of the buffer in bits | ||
53 | */ | ||
54 | void init_get_bits(GetBitContext *s, | ||
55 | const uint8_t *buffer, int bit_size) | ||
56 | { | ||
57 | const int buffer_size= (bit_size+7)>>3; | ||
58 | |||
59 | s->buffer= buffer; | ||
60 | s->size_in_bits= bit_size; | ||
61 | s->buffer_end= buffer + buffer_size; | ||
62 | s->index=0; | ||
63 | { | ||
64 | OPEN_READER(re, s) | ||
65 | UPDATE_CACHE(re, s) | ||
66 | UPDATE_CACHE(re, s) | ||
67 | CLOSE_READER(re, s) | ||
68 | } | ||
69 | } | ||
70 | |||
71 | /** | ||
72 | * reads 0-32 bits. | ||
73 | */ | ||
74 | unsigned int get_bits_long(GetBitContext *s, int n){ | ||
75 | if(n<=17) return get_bits(s, n); | ||
76 | else{ | ||
77 | int ret= get_bits(s, 16) << (n-16); | ||
78 | return ret | get_bits(s, n-16); | ||
79 | } | ||
80 | } | ||
81 | |||
82 | /** | ||
83 | * shows 0-32 bits. | ||
84 | */ | ||
85 | unsigned int show_bits_long(GetBitContext *s, int n){ | ||
86 | if(n<=17) return show_bits(s, n); | ||
87 | else{ | ||
88 | GetBitContext gb= *s; | ||
89 | int ret= get_bits_long(s, n); | ||
90 | *s= gb; | ||
91 | return ret; | ||
92 | } | ||
93 | } | ||
94 | |||
95 | void align_get_bits(GetBitContext *s) | ||
96 | { | ||
97 | int n= (-get_bits_count(s)) & 7; | ||
98 | if(n) skip_bits(s, n); | ||
99 | } | ||
100 | |||
101 | int check_marker(GetBitContext *s, const char *msg) | ||
102 | { | ||
103 | (void)msg; | ||
104 | int bit= get_bits1(s); | ||
105 | return bit; | ||
106 | } | ||
107 | |||