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author | Sean Bartell <wingedtachikoma@gmail.com> | 2011-06-25 21:32:25 -0400 |
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committer | Nils Wallménius <nils@rockbox.org> | 2012-04-25 22:13:20 +0200 |
commit | f40bfc9267b13b54e6379dfe7539447662879d24 (patch) | |
tree | 9b20069d5e62809ff434061ad730096836f916f2 /lib/rbcodec/codecs/libmad/bit.c | |
parent | a0009907de7a0107d49040d8a180f140e2eff299 (diff) | |
download | rockbox-f40bfc9267b13b54e6379dfe7539447662879d24.tar.gz rockbox-f40bfc9267b13b54e6379dfe7539447662879d24.zip |
Add codecs to librbcodec.
Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97
Reviewed-on: http://gerrit.rockbox.org/137
Reviewed-by: Nils Wallménius <nils@rockbox.org>
Tested-by: Nils Wallménius <nils@rockbox.org>
Diffstat (limited to 'lib/rbcodec/codecs/libmad/bit.c')
-rw-r--r-- | lib/rbcodec/codecs/libmad/bit.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libmad/bit.c b/lib/rbcodec/codecs/libmad/bit.c new file mode 100644 index 0000000000..c08806d385 --- /dev/null +++ b/lib/rbcodec/codecs/libmad/bit.c | |||
@@ -0,0 +1,218 @@ | |||
1 | /* | ||
2 | * libmad - MPEG audio decoder library | ||
3 | * Copyright (C) 2000-2004 Underbit Technologies, Inc. | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or modify | ||
6 | * it under the terms of the GNU General Public License as published by | ||
7 | * the Free Software Foundation; either version 2 of the License, or | ||
8 | * (at your option) any later version. | ||
9 | * | ||
10 | * This program is distributed in the hope that it will be useful, | ||
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
13 | * GNU General Public License for more details. | ||
14 | * | ||
15 | * You should have received a copy of the GNU General Public License | ||
16 | * along with this program; if not, write to the Free Software | ||
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
18 | * | ||
19 | * $Id$ | ||
20 | */ | ||
21 | |||
22 | # ifdef HAVE_CONFIG_H | ||
23 | # include "config.h" | ||
24 | # endif | ||
25 | |||
26 | # include "global.h" | ||
27 | |||
28 | # ifdef HAVE_LIMITS_H | ||
29 | # include <limits.h> | ||
30 | # else | ||
31 | # undef CHAR_BIT | ||
32 | # define CHAR_BIT 8 | ||
33 | # endif | ||
34 | |||
35 | # include "bit.h" | ||
36 | |||
37 | /* | ||
38 | * This is the lookup table for computing the CRC-check word. | ||
39 | * As described in section 2.4.3.1 and depicted in Figure A.9 | ||
40 | * of ISO/IEC 11172-3, the generator polynomial is: | ||
41 | * | ||
42 | * G(X) = X^16 + X^15 + X^2 + 1 | ||
43 | */ | ||
44 | static | ||
45 | unsigned short const crc_table[256] = { | ||
46 | 0x0000, 0x8005, 0x800f, 0x000a, 0x801b, 0x001e, 0x0014, 0x8011, | ||
47 | 0x8033, 0x0036, 0x003c, 0x8039, 0x0028, 0x802d, 0x8027, 0x0022, | ||
48 | 0x8063, 0x0066, 0x006c, 0x8069, 0x0078, 0x807d, 0x8077, 0x0072, | ||
49 | 0x0050, 0x8055, 0x805f, 0x005a, 0x804b, 0x004e, 0x0044, 0x8041, | ||
50 | 0x80c3, 0x00c6, 0x00cc, 0x80c9, 0x00d8, 0x80dd, 0x80d7, 0x00d2, | ||
51 | 0x00f0, 0x80f5, 0x80ff, 0x00fa, 0x80eb, 0x00ee, 0x00e4, 0x80e1, | ||
52 | 0x00a0, 0x80a5, 0x80af, 0x00aa, 0x80bb, 0x00be, 0x00b4, 0x80b1, | ||
53 | 0x8093, 0x0096, 0x009c, 0x8099, 0x0088, 0x808d, 0x8087, 0x0082, | ||
54 | |||
55 | 0x8183, 0x0186, 0x018c, 0x8189, 0x0198, 0x819d, 0x8197, 0x0192, | ||
56 | 0x01b0, 0x81b5, 0x81bf, 0x01ba, 0x81ab, 0x01ae, 0x01a4, 0x81a1, | ||
57 | 0x01e0, 0x81e5, 0x81ef, 0x01ea, 0x81fb, 0x01fe, 0x01f4, 0x81f1, | ||
58 | 0x81d3, 0x01d6, 0x01dc, 0x81d9, 0x01c8, 0x81cd, 0x81c7, 0x01c2, | ||
59 | 0x0140, 0x8145, 0x814f, 0x014a, 0x815b, 0x015e, 0x0154, 0x8151, | ||
60 | 0x8173, 0x0176, 0x017c, 0x8179, 0x0168, 0x816d, 0x8167, 0x0162, | ||
61 | 0x8123, 0x0126, 0x012c, 0x8129, 0x0138, 0x813d, 0x8137, 0x0132, | ||
62 | 0x0110, 0x8115, 0x811f, 0x011a, 0x810b, 0x010e, 0x0104, 0x8101, | ||
63 | |||
64 | 0x8303, 0x0306, 0x030c, 0x8309, 0x0318, 0x831d, 0x8317, 0x0312, | ||
65 | 0x0330, 0x8335, 0x833f, 0x033a, 0x832b, 0x032e, 0x0324, 0x8321, | ||
66 | 0x0360, 0x8365, 0x836f, 0x036a, 0x837b, 0x037e, 0x0374, 0x8371, | ||
67 | 0x8353, 0x0356, 0x035c, 0x8359, 0x0348, 0x834d, 0x8347, 0x0342, | ||
68 | 0x03c0, 0x83c5, 0x83cf, 0x03ca, 0x83db, 0x03de, 0x03d4, 0x83d1, | ||
69 | 0x83f3, 0x03f6, 0x03fc, 0x83f9, 0x03e8, 0x83ed, 0x83e7, 0x03e2, | ||
70 | 0x83a3, 0x03a6, 0x03ac, 0x83a9, 0x03b8, 0x83bd, 0x83b7, 0x03b2, | ||
71 | 0x0390, 0x8395, 0x839f, 0x039a, 0x838b, 0x038e, 0x0384, 0x8381, | ||
72 | |||
73 | 0x0280, 0x8285, 0x828f, 0x028a, 0x829b, 0x029e, 0x0294, 0x8291, | ||
74 | 0x82b3, 0x02b6, 0x02bc, 0x82b9, 0x02a8, 0x82ad, 0x82a7, 0x02a2, | ||
75 | 0x82e3, 0x02e6, 0x02ec, 0x82e9, 0x02f8, 0x82fd, 0x82f7, 0x02f2, | ||
76 | 0x02d0, 0x82d5, 0x82df, 0x02da, 0x82cb, 0x02ce, 0x02c4, 0x82c1, | ||
77 | 0x8243, 0x0246, 0x024c, 0x8249, 0x0258, 0x825d, 0x8257, 0x0252, | ||
78 | 0x0270, 0x8275, 0x827f, 0x027a, 0x826b, 0x026e, 0x0264, 0x8261, | ||
79 | 0x0220, 0x8225, 0x822f, 0x022a, 0x823b, 0x023e, 0x0234, 0x8231, | ||
80 | 0x8213, 0x0216, 0x021c, 0x8219, 0x0208, 0x820d, 0x8207, 0x0202 | ||
81 | }; | ||
82 | |||
83 | # define CRC_POLY 0x8005 | ||
84 | |||
85 | #if INT_MAX != 0x7fffffff | ||
86 | #warning current libmad bit handling is optimized for architectures using 32 bit integers | ||
87 | #endif | ||
88 | |||
89 | /* | ||
90 | * NAME: bit->init() | ||
91 | * DESCRIPTION: initialize bit pointer struct | ||
92 | */ | ||
93 | void mad_bit_init(struct mad_bitptr *bitptr, unsigned char const *byte) | ||
94 | { | ||
95 | bitptr->ptr = (uint32_t*)((uintptr_t)byte & ~3); | ||
96 | bitptr->readbit = ((uintptr_t)byte & 3) << 3; | ||
97 | } | ||
98 | |||
99 | /* | ||
100 | * NAME: bit->length() | ||
101 | * DESCRIPTION: return number of bits between start and end points | ||
102 | */ | ||
103 | unsigned int mad_bit_length(struct mad_bitptr const *begin, | ||
104 | struct mad_bitptr const *end) | ||
105 | { | ||
106 | return end->readbit - begin->readbit; | ||
107 | } | ||
108 | |||
109 | /* rockbox: not used | ||
110 | unsigned char mad_bit_bitsleft(struct mad_bitptr const *bitptr) | ||
111 | { | ||
112 | return 8 - (bitptr->readbit & 7); | ||
113 | } | ||
114 | */ | ||
115 | |||
116 | /* | ||
117 | * NAME: bit->nextbyte() | ||
118 | * DESCRIPTION: return pointer to next unprocessed byte | ||
119 | */ | ||
120 | unsigned char const *mad_bit_nextbyte(struct mad_bitptr const *bitptr) | ||
121 | { | ||
122 | return (unsigned char const*)bitptr->ptr + ((bitptr->readbit + 7) >> 3); | ||
123 | } | ||
124 | |||
125 | /* | ||
126 | * NAME: bit->skip() | ||
127 | * DESCRIPTION: advance bit pointer | ||
128 | */ | ||
129 | void mad_bit_skip(struct mad_bitptr *bitptr, unsigned int len) | ||
130 | { | ||
131 | bitptr->readbit += len; | ||
132 | } | ||
133 | |||
134 | /* | ||
135 | * NAME: bit->read() | ||
136 | * DESCRIPTION: read an arbitrary number of bits and return their UIMSBF value | ||
137 | */ | ||
138 | |||
139 | uint32_t mad_bit_read(struct mad_bitptr *bitptr, unsigned int len) ICODE_ATTR; | ||
140 | uint32_t mad_bit_read(struct mad_bitptr *bitptr, unsigned int len) | ||
141 | { | ||
142 | uint32_t *curr = &bitptr->ptr[bitptr->readbit>>5]; | ||
143 | |||
144 | if(len) | ||
145 | { | ||
146 | uint32_t r = betoh32(curr[0]) << (bitptr->readbit & 31); | ||
147 | |||
148 | if((bitptr->readbit & 31) + len > 32) | ||
149 | r += betoh32(curr[1]) >> (-bitptr->readbit & 31); | ||
150 | |||
151 | bitptr->readbit += len; | ||
152 | return r >> (32 - len); | ||
153 | } | ||
154 | |||
155 | return 0; | ||
156 | } | ||
157 | |||
158 | # if 0 /* rockbox: not used */ | ||
159 | /* | ||
160 | * NAME: bit->write() | ||
161 | * DESCRIPTION: write an arbitrary number of bits | ||
162 | */ | ||
163 | void mad_bit_write(struct mad_bitptr *bitptr, unsigned int len, | ||
164 | uint32_t value) | ||
165 | { | ||
166 | unsigned char *ptr; | ||
167 | |||
168 | ptr = (unsigned char *) bitptr->byte; | ||
169 | |||
170 | /* ... */ | ||
171 | } | ||
172 | # endif | ||
173 | |||
174 | /* | ||
175 | * NAME: bit->crc() | ||
176 | * DESCRIPTION: compute CRC-check word | ||
177 | */ | ||
178 | unsigned short mad_bit_crc(struct mad_bitptr bitptr, unsigned int len, | ||
179 | unsigned short init) | ||
180 | { | ||
181 | register unsigned int crc; | ||
182 | |||
183 | for (crc = init; len >= 32; len -= 32) { | ||
184 | register uint32_t data; | ||
185 | |||
186 | data = mad_bit_read(&bitptr, 32); | ||
187 | |||
188 | crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 24)) & 0xff]; | ||
189 | crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 16)) & 0xff]; | ||
190 | crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 8)) & 0xff]; | ||
191 | crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 0)) & 0xff]; | ||
192 | } | ||
193 | |||
194 | switch (len / 8) { | ||
195 | case 3: crc = (crc << 8) ^ | ||
196 | crc_table[((crc >> 8) ^ mad_bit_read(&bitptr, 8)) & 0xff]; | ||
197 | case 2: crc = (crc << 8) ^ | ||
198 | crc_table[((crc >> 8) ^ mad_bit_read(&bitptr, 8)) & 0xff]; | ||
199 | case 1: crc = (crc << 8) ^ | ||
200 | crc_table[((crc >> 8) ^ mad_bit_read(&bitptr, 8)) & 0xff]; | ||
201 | |||
202 | len %= 8; | ||
203 | |||
204 | case 0: break; | ||
205 | } | ||
206 | |||
207 | while (len--) { | ||
208 | register unsigned int msb; | ||
209 | |||
210 | msb = mad_bit_read(&bitptr, 1) ^ (crc >> 15); | ||
211 | |||
212 | crc <<= 1; | ||
213 | if (msb & 1) | ||
214 | crc ^= CRC_POLY; | ||
215 | } | ||
216 | |||
217 | return crc & 0xffff; | ||
218 | } | ||