Move *_static to bitstream.c which is the only file left which needs
[libav.git] / libavcodec / bitstream.c
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 /**
26 * @file bitstream.c
27 * bitstream api.
28 */
29
30 #include "avcodec.h"
31 #include "bitstream.h"
32
33 /**
34 * Same as av_mallocz_static(), but does a realloc.
35 *
36 * @param[in] ptr The block of memory to reallocate.
37 * @param[in] size The requested size.
38 * @return Block of memory of requested size.
39 * @deprecated. Code which uses ff_realloc_static is broken/misdesigned
40 * and should correctly use static arrays
41 */
42 attribute_deprecated av_alloc_size(2)
43 static void *ff_realloc_static(void *ptr, unsigned int size);
44
45 static unsigned int last_static = 0;
46 static unsigned int allocated_static = 0;
47 static void** array_static = NULL;
48
49 static void *av_mallocz_static(unsigned int size)
50 {
51 void *ptr = av_mallocz(size);
52
53 if(ptr){
54 array_static =av_fast_realloc(array_static, &allocated_static, sizeof(void*)*(last_static+1));
55 if(!array_static)
56 return NULL;
57 array_static[last_static++] = ptr;
58 }
59
60 return ptr;
61 }
62
63 static void *ff_realloc_static(void *ptr, unsigned int size)
64 {
65 int i;
66 if(!ptr)
67 return av_mallocz_static(size);
68 /* Look for the old ptr */
69 for(i = 0; i < last_static; i++) {
70 if(array_static[i] == ptr) {
71 array_static[i] = av_realloc(array_static[i], size);
72 return array_static[i];
73 }
74 }
75 return NULL;
76
77 }
78
79 static void av_free_static(void)
80 {
81 while(last_static){
82 av_freep(&array_static[--last_static]);
83 }
84 av_freep(&array_static);
85 }
86
87 /**
88 * Call av_free_static automatically before it's too late
89 */
90
91 static void do_free(void) __attribute__ ((destructor));
92
93 static void do_free(void)
94 {
95 av_free_static();
96 }
97
98
99 void align_put_bits(PutBitContext *s)
100 {
101 #ifdef ALT_BITSTREAM_WRITER
102 put_bits(s,( - s->index) & 7,0);
103 #else
104 put_bits(s,s->bit_left & 7,0);
105 #endif
106 }
107
108 void ff_put_string(PutBitContext * pbc, const char *s, int put_zero)
109 {
110 while(*s){
111 put_bits(pbc, 8, *s);
112 s++;
113 }
114 if(put_zero)
115 put_bits(pbc, 8, 0);
116 }
117
118 void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
119 {
120 const uint16_t *srcw= (const uint16_t*)src;
121 int words= length>>4;
122 int bits= length&15;
123 int i;
124
125 if(length==0) return;
126
127 if(ENABLE_SMALL || words < 16 || put_bits_count(pb)&7){
128 for(i=0; i<words; i++) put_bits(pb, 16, be2me_16(srcw[i]));
129 }else{
130 for(i=0; put_bits_count(pb)&31; i++)
131 put_bits(pb, 8, src[i]);
132 flush_put_bits(pb);
133 memcpy(pbBufPtr(pb), src+i, 2*words-i);
134 skip_put_bytes(pb, 2*words-i);
135 }
136
137 put_bits(pb, bits, be2me_16(srcw[words])>>(16-bits));
138 }
139
140 /* VLC decoding */
141
142 //#define DEBUG_VLC
143
144 #define GET_DATA(v, table, i, wrap, size) \
145 {\
146 const uint8_t *ptr = (const uint8_t *)table + i * wrap;\
147 switch(size) {\
148 case 1:\
149 v = *(const uint8_t *)ptr;\
150 break;\
151 case 2:\
152 v = *(const uint16_t *)ptr;\
153 break;\
154 default:\
155 v = *(const uint32_t *)ptr;\
156 break;\
157 }\
158 }
159
160
161 static int alloc_table(VLC *vlc, int size, int use_static)
162 {
163 int index;
164 index = vlc->table_size;
165 vlc->table_size += size;
166 if (vlc->table_size > vlc->table_allocated) {
167 if(use_static>1)
168 abort(); //cant do anything, init_vlc() is used with too little memory
169 vlc->table_allocated += (1 << vlc->bits);
170 if(use_static)
171 vlc->table = ff_realloc_static(vlc->table,
172 sizeof(VLC_TYPE) * 2 * vlc->table_allocated);
173 else
174 vlc->table = av_realloc(vlc->table,
175 sizeof(VLC_TYPE) * 2 * vlc->table_allocated);
176 if (!vlc->table)
177 return -1;
178 }
179 return index;
180 }
181
182 static int build_table(VLC *vlc, int table_nb_bits,
183 int nb_codes,
184 const void *bits, int bits_wrap, int bits_size,
185 const void *codes, int codes_wrap, int codes_size,
186 const void *symbols, int symbols_wrap, int symbols_size,
187 uint32_t code_prefix, int n_prefix, int flags)
188 {
189 int i, j, k, n, table_size, table_index, nb, n1, index, code_prefix2, symbol;
190 uint32_t code;
191 VLC_TYPE (*table)[2];
192
193 table_size = 1 << table_nb_bits;
194 table_index = alloc_table(vlc, table_size, flags & (INIT_VLC_USE_STATIC|INIT_VLC_USE_NEW_STATIC));
195 #ifdef DEBUG_VLC
196 av_log(NULL,AV_LOG_DEBUG,"new table index=%d size=%d code_prefix=%x n=%d\n",
197 table_index, table_size, code_prefix, n_prefix);
198 #endif
199 if (table_index < 0)
200 return -1;
201 table = &vlc->table[table_index];
202
203 for(i=0;i<table_size;i++) {
204 table[i][1] = 0; //bits
205 table[i][0] = -1; //codes
206 }
207
208 /* first pass: map codes and compute auxillary table sizes */
209 for(i=0;i<nb_codes;i++) {
210 GET_DATA(n, bits, i, bits_wrap, bits_size);
211 GET_DATA(code, codes, i, codes_wrap, codes_size);
212 /* we accept tables with holes */
213 if (n <= 0)
214 continue;
215 if (!symbols)
216 symbol = i;
217 else
218 GET_DATA(symbol, symbols, i, symbols_wrap, symbols_size);
219 #if defined(DEBUG_VLC) && 0
220 av_log(NULL,AV_LOG_DEBUG,"i=%d n=%d code=0x%x\n", i, n, code);
221 #endif
222 /* if code matches the prefix, it is in the table */
223 n -= n_prefix;
224 if(flags & INIT_VLC_LE)
225 code_prefix2= code & (n_prefix>=32 ? 0xffffffff : (1 << n_prefix)-1);
226 else
227 code_prefix2= code >> n;
228 if (n > 0 && code_prefix2 == code_prefix) {
229 if (n <= table_nb_bits) {
230 /* no need to add another table */
231 j = (code << (table_nb_bits - n)) & (table_size - 1);
232 nb = 1 << (table_nb_bits - n);
233 for(k=0;k<nb;k++) {
234 if(flags & INIT_VLC_LE)
235 j = (code >> n_prefix) + (k<<n);
236 #ifdef DEBUG_VLC
237 av_log(NULL, AV_LOG_DEBUG, "%4x: code=%d n=%d\n",
238 j, i, n);
239 #endif
240 if (table[j][1] /*bits*/ != 0) {
241 av_log(NULL, AV_LOG_ERROR, "incorrect codes\n");
242 return -1;
243 }
244 table[j][1] = n; //bits
245 table[j][0] = symbol;
246 j++;
247 }
248 } else {
249 n -= table_nb_bits;
250 j = (code >> ((flags & INIT_VLC_LE) ? n_prefix : n)) & ((1 << table_nb_bits) - 1);
251 #ifdef DEBUG_VLC
252 av_log(NULL,AV_LOG_DEBUG,"%4x: n=%d (subtable)\n",
253 j, n);
254 #endif
255 /* compute table size */
256 n1 = -table[j][1]; //bits
257 if (n > n1)
258 n1 = n;
259 table[j][1] = -n1; //bits
260 }
261 }
262 }
263
264 /* second pass : fill auxillary tables recursively */
265 for(i=0;i<table_size;i++) {
266 n = table[i][1]; //bits
267 if (n < 0) {
268 n = -n;
269 if (n > table_nb_bits) {
270 n = table_nb_bits;
271 table[i][1] = -n; //bits
272 }
273 index = build_table(vlc, n, nb_codes,
274 bits, bits_wrap, bits_size,
275 codes, codes_wrap, codes_size,
276 symbols, symbols_wrap, symbols_size,
277 (flags & INIT_VLC_LE) ? (code_prefix | (i << n_prefix)) : ((code_prefix << table_nb_bits) | i),
278 n_prefix + table_nb_bits, flags);
279 if (index < 0)
280 return -1;
281 /* note: realloc has been done, so reload tables */
282 table = &vlc->table[table_index];
283 table[i][0] = index; //code
284 }
285 }
286 return table_index;
287 }
288
289
290 /* Build VLC decoding tables suitable for use with get_vlc().
291
292 'nb_bits' set thee decoding table size (2^nb_bits) entries. The
293 bigger it is, the faster is the decoding. But it should not be too
294 big to save memory and L1 cache. '9' is a good compromise.
295
296 'nb_codes' : number of vlcs codes
297
298 'bits' : table which gives the size (in bits) of each vlc code.
299
300 'codes' : table which gives the bit pattern of of each vlc code.
301
302 'symbols' : table which gives the values to be returned from get_vlc().
303
304 'xxx_wrap' : give the number of bytes between each entry of the
305 'bits' or 'codes' tables.
306
307 'xxx_size' : gives the number of bytes of each entry of the 'bits'
308 or 'codes' tables.
309
310 'wrap' and 'size' allows to use any memory configuration and types
311 (byte/word/long) to store the 'bits', 'codes', and 'symbols' tables.
312
313 'use_static' should be set to 1 for tables, which should be freed
314 with av_free_static(), 0 if free_vlc() will be used.
315 */
316 int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
317 const void *bits, int bits_wrap, int bits_size,
318 const void *codes, int codes_wrap, int codes_size,
319 const void *symbols, int symbols_wrap, int symbols_size,
320 int flags)
321 {
322 vlc->bits = nb_bits;
323 if(flags & INIT_VLC_USE_NEW_STATIC){
324 if(vlc->table_size && vlc->table_size == vlc->table_allocated){
325 return 0;
326 }else if(vlc->table_size){
327 abort(); // fatal error, we are called on a partially initialized table
328 }
329 }else if(!(flags & INIT_VLC_USE_STATIC)) {
330 vlc->table = NULL;
331 vlc->table_allocated = 0;
332 vlc->table_size = 0;
333 } else {
334 /* Static tables are initially always NULL, return
335 if vlc->table != NULL to avoid double allocation */
336 if(vlc->table)
337 return 0;
338 }
339
340 #ifdef DEBUG_VLC
341 av_log(NULL,AV_LOG_DEBUG,"build table nb_codes=%d\n", nb_codes);
342 #endif
343
344 if (build_table(vlc, nb_bits, nb_codes,
345 bits, bits_wrap, bits_size,
346 codes, codes_wrap, codes_size,
347 symbols, symbols_wrap, symbols_size,
348 0, 0, flags) < 0) {
349 av_freep(&vlc->table);
350 return -1;
351 }
352 if((flags & INIT_VLC_USE_NEW_STATIC) && vlc->table_size != vlc->table_allocated)
353 av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", vlc->table_size, vlc->table_allocated);
354 return 0;
355 }
356
357
358 void free_vlc(VLC *vlc)
359 {
360 av_freep(&vlc->table);
361 }
362