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Diffstat (limited to 'apps/codecs/libatrac/bitstream.c')
-rw-r--r-- | apps/codecs/libatrac/bitstream.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/apps/codecs/libatrac/bitstream.c b/apps/codecs/libatrac/bitstream.c new file mode 100644 index 0000000000..1375134b21 --- /dev/null +++ b/apps/codecs/libatrac/bitstream.c | |||
@@ -0,0 +1,276 @@ | |||
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 | * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at> | ||
7 | * | ||
8 | * This file is part of FFmpeg. | ||
9 | * | ||
10 | * FFmpeg is free software; you can redistribute it and/or | ||
11 | * modify it under the terms of the GNU Lesser General Public | ||
12 | * License as published by the Free Software Foundation; either | ||
13 | * version 2.1 of the License, or (at your option) any later version. | ||
14 | * | ||
15 | * FFmpeg is distributed in the hope that it will be useful, | ||
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
18 | * Lesser General Public License for more details. | ||
19 | * | ||
20 | * You should have received a copy of the GNU Lesser General Public | ||
21 | * License along with FFmpeg; if not, write to the Free Software | ||
22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
23 | */ | ||
24 | |||
25 | #include "bitstream.h" | ||
26 | |||
27 | #ifdef ROCKBOX | ||
28 | #undef DEBUGF | ||
29 | #define DEBUGF(...) | ||
30 | #endif | ||
31 | |||
32 | const uint8_t ff_log2_run[32]={ | ||
33 | 0, 0, 0, 0, 1, 1, 1, 1, | ||
34 | 2, 2, 2, 2, 3, 3, 3, 3, | ||
35 | 4, 4, 5, 5, 6, 6, 7, 7, | ||
36 | 8, 9,10,11,12,13,14,15 | ||
37 | }; | ||
38 | |||
39 | /** | ||
40 | * Same as av_mallocz_static(), but does a realloc. | ||
41 | * | ||
42 | * @param[in] ptr The block of memory to reallocate. | ||
43 | * @param[in] size The requested size. | ||
44 | * @return Block of memory of requested size. | ||
45 | * @deprecated. Code which uses ff_realloc_static is broken/misdesigned | ||
46 | * and should correctly use static arrays | ||
47 | */ | ||
48 | |||
49 | |||
50 | void ff_put_string(PutBitContext * pbc, const char *s, int put_zero) | ||
51 | { | ||
52 | while(*s){ | ||
53 | put_bits(pbc, 8, *s); | ||
54 | s++; | ||
55 | } | ||
56 | if(put_zero) | ||
57 | put_bits(pbc, 8, 0); | ||
58 | } | ||
59 | |||
60 | /* VLC decoding */ | ||
61 | |||
62 | //#define DEBUG_VLC | ||
63 | |||
64 | #define GET_DATA(v, table, i, wrap, size) \ | ||
65 | {\ | ||
66 | const uint8_t *ptr = (const uint8_t *)table + i * wrap;\ | ||
67 | switch(size) {\ | ||
68 | case 1:\ | ||
69 | v = *(const uint8_t *)ptr;\ | ||
70 | break;\ | ||
71 | case 2:\ | ||
72 | v = *(const uint16_t *)ptr;\ | ||
73 | break;\ | ||
74 | default:\ | ||
75 | v = *(const uint32_t *)ptr;\ | ||
76 | break;\ | ||
77 | }\ | ||
78 | } | ||
79 | |||
80 | |||
81 | static int alloc_table(VLC *vlc, int size, int use_static) | ||
82 | { | ||
83 | int index; | ||
84 | index = vlc->table_size; | ||
85 | vlc->table_size += size; | ||
86 | if (vlc->table_size > vlc->table_allocated) { | ||
87 | if(use_static>1){ | ||
88 | DEBUGF("init_vlc() used with too little memory : table_size > allocated_memory\n"); | ||
89 | } | ||
90 | |||
91 | if (!vlc->table) | ||
92 | return -1; | ||
93 | } | ||
94 | return index; | ||
95 | } | ||
96 | |||
97 | static int build_table(VLC *vlc, int table_nb_bits, | ||
98 | int nb_codes, | ||
99 | const void *bits, int bits_wrap, int bits_size, | ||
100 | const void *codes, int codes_wrap, int codes_size, | ||
101 | const void *symbols, int symbols_wrap, int symbols_size, | ||
102 | uint32_t code_prefix, int n_prefix, int flags) | ||
103 | { | ||
104 | int i, j, k, n, table_size, table_index, nb, n1, index, code_prefix2, symbol; | ||
105 | uint32_t code; | ||
106 | VLC_TYPE (*table)[2]; | ||
107 | |||
108 | table_size = 1 << table_nb_bits; | ||
109 | table_index = alloc_table(vlc, table_size, flags & (INIT_VLC_USE_STATIC|INIT_VLC_USE_NEW_STATIC)); | ||
110 | #ifdef DEBUG_VLC | ||
111 | DEBUGF("new table index=%d size=%d code_prefix=%x n=%d\n", | ||
112 | table_index, table_size, code_prefix, n_prefix); | ||
113 | #endif | ||
114 | if (table_index < 0) | ||
115 | return -1; | ||
116 | table = &vlc->table[table_index]; | ||
117 | |||
118 | for(i=0;i<table_size;i++) { | ||
119 | table[i][1] = 0; //bits | ||
120 | table[i][0] = -1; //codes | ||
121 | } | ||
122 | |||
123 | /* first pass: map codes and compute auxillary table sizes */ | ||
124 | for(i=0;i<nb_codes;i++) { | ||
125 | GET_DATA(n, bits, i, bits_wrap, bits_size); | ||
126 | GET_DATA(code, codes, i, codes_wrap, codes_size); | ||
127 | /* we accept tables with holes */ | ||
128 | if (n <= 0) | ||
129 | continue; | ||
130 | if (!symbols) | ||
131 | symbol = i; | ||
132 | else | ||
133 | GET_DATA(symbol, symbols, i, symbols_wrap, symbols_size); | ||
134 | #if defined(DEBUG_VLC) && 0 | ||
135 | DEBUGF("i=%d n=%d code=0x%x\n", i, n, code); | ||
136 | #endif | ||
137 | /* if code matches the prefix, it is in the table */ | ||
138 | n -= n_prefix; | ||
139 | if(flags & INIT_VLC_LE) | ||
140 | code_prefix2= code & (n_prefix>=32 ? (int)0xffffffff : (1 << n_prefix)-1); | ||
141 | else | ||
142 | code_prefix2= code >> n; | ||
143 | if (n > 0 && code_prefix2 == (int)code_prefix) { | ||
144 | if (n <= table_nb_bits) { | ||
145 | /* no need to add another table */ | ||
146 | j = (code << (table_nb_bits - n)) & (table_size - 1); | ||
147 | nb = 1 << (table_nb_bits - n); | ||
148 | for(k=0;k<nb;k++) { | ||
149 | if(flags & INIT_VLC_LE) | ||
150 | j = (code >> n_prefix) + (k<<n); | ||
151 | #ifdef DEBUG_VLC | ||
152 | DEBUGF("%4x: code=%d n=%d\n", | ||
153 | j, i, n); | ||
154 | #endif | ||
155 | if (table[j][1] /*bits*/ != 0) { | ||
156 | DEBUGF("incorrect codes\n"); | ||
157 | return -1; | ||
158 | } | ||
159 | table[j][1] = n; //bits | ||
160 | table[j][0] = symbol; | ||
161 | j++; | ||
162 | } | ||
163 | } else { | ||
164 | n -= table_nb_bits; | ||
165 | j = (code >> ((flags & INIT_VLC_LE) ? n_prefix : n)) & ((1 << table_nb_bits) - 1); | ||
166 | #ifdef DEBUG_VLC | ||
167 | DEBUGF("%4x: n=%d (subtable)\n", | ||
168 | j, n); | ||
169 | #endif | ||
170 | /* compute table size */ | ||
171 | n1 = -table[j][1]; //bits | ||
172 | if (n > n1) | ||
173 | n1 = n; | ||
174 | table[j][1] = -n1; //bits | ||
175 | } | ||
176 | } | ||
177 | } | ||
178 | |||
179 | /* second pass : fill auxillary tables recursively */ | ||
180 | for(i=0;i<table_size;i++) { | ||
181 | n = table[i][1]; //bits | ||
182 | if (n < 0) { | ||
183 | n = -n; | ||
184 | if (n > table_nb_bits) { | ||
185 | n = table_nb_bits; | ||
186 | table[i][1] = -n; //bits | ||
187 | } | ||
188 | index = build_table(vlc, n, nb_codes, | ||
189 | bits, bits_wrap, bits_size, | ||
190 | codes, codes_wrap, codes_size, | ||
191 | symbols, symbols_wrap, symbols_size, | ||
192 | (flags & INIT_VLC_LE) ? (code_prefix | (i << n_prefix)) : ((code_prefix << table_nb_bits) | i), | ||
193 | n_prefix + table_nb_bits, flags); | ||
194 | if (index < 0) | ||
195 | return -1; | ||
196 | /* note: realloc has been done, so reload tables */ | ||
197 | table = &vlc->table[table_index]; | ||
198 | table[i][0] = index; //code | ||
199 | } | ||
200 | } | ||
201 | return table_index; | ||
202 | } | ||
203 | |||
204 | |||
205 | /* Build VLC decoding tables suitable for use with get_vlc(). | ||
206 | |||
207 | 'nb_bits' set thee decoding table size (2^nb_bits) entries. The | ||
208 | bigger it is, the faster is the decoding. But it should not be too | ||
209 | big to save memory and L1 cache. '9' is a good compromise. | ||
210 | |||
211 | 'nb_codes' : number of vlcs codes | ||
212 | |||
213 | 'bits' : table which gives the size (in bits) of each vlc code. | ||
214 | |||
215 | 'codes' : table which gives the bit pattern of of each vlc code. | ||
216 | |||
217 | 'symbols' : table which gives the values to be returned from get_vlc(). | ||
218 | |||
219 | 'xxx_wrap' : give the number of bytes between each entry of the | ||
220 | 'bits' or 'codes' tables. | ||
221 | |||
222 | 'xxx_size' : gives the number of bytes of each entry of the 'bits' | ||
223 | or 'codes' tables. | ||
224 | |||
225 | 'wrap' and 'size' allows to use any memory configuration and types | ||
226 | (byte/word/long) to store the 'bits', 'codes', and 'symbols' tables. | ||
227 | |||
228 | 'use_static' should be set to 1 for tables, which should be freed | ||
229 | with av_free_static(), 0 if free_vlc() will be used. | ||
230 | */ | ||
231 | int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes, | ||
232 | const void *bits, int bits_wrap, int bits_size, | ||
233 | const void *codes, int codes_wrap, int codes_size, | ||
234 | const void *symbols, int symbols_wrap, int symbols_size, | ||
235 | int flags) | ||
236 | { | ||
237 | vlc->bits = nb_bits; | ||
238 | if(flags & INIT_VLC_USE_NEW_STATIC){ | ||
239 | if(vlc->table_size && vlc->table_size == vlc->table_allocated){ | ||
240 | return 0; | ||
241 | }else if(vlc->table_size){ | ||
242 | return -1; // fatal error, we are called on a partially initialized table | ||
243 | } | ||
244 | }else if(!(flags & INIT_VLC_USE_STATIC)) { | ||
245 | vlc->table = NULL; | ||
246 | vlc->table_allocated = 0; | ||
247 | vlc->table_size = 0; | ||
248 | } else { | ||
249 | /* Static tables are initially always NULL, return | ||
250 | if vlc->table != NULL to avoid double allocation */ | ||
251 | if(vlc->table) | ||
252 | return 0; | ||
253 | } | ||
254 | |||
255 | #ifdef DEBUG_VLC | ||
256 | DEBUGF("build table nb_codes=%d\n", nb_codes); | ||
257 | #endif | ||
258 | |||
259 | if (build_table(vlc, nb_bits, nb_codes, | ||
260 | bits, bits_wrap, bits_size, | ||
261 | codes, codes_wrap, codes_size, | ||
262 | symbols, symbols_wrap, symbols_size, | ||
263 | 0, 0, flags) < 0) { | ||
264 | //free(&vlc->table); | ||
265 | return -1; | ||
266 | } | ||
267 | /* Changed the following condition to be true if table_size > table_allocated. * | ||
268 | * This would be more sensible for static tables since we want warnings for * | ||
269 | * memory shortages only. */ | ||
270 | #ifdef TEST | ||
271 | if((flags & INIT_VLC_USE_NEW_STATIC) && vlc->table_size > vlc->table_allocated) | ||
272 | DEBUGF("needed %d had %d\n", vlc->table_size, vlc->table_allocated); | ||
273 | #endif | ||
274 | return 0; | ||
275 | } | ||
276 | |||