libfaad2/bits.h

   1 /*
   2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
   3 ** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
   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 ** Any non-GPL usage of this software or parts of this software is strictly
  20 ** forbidden.
  21 **
  22 ** Commercial non-GPL licensing of this software is possible.
  23 ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
  24 **
  25 ** Initially modified for use with MPlayer by Arpad Gereöffy on 2003/08/30
  26 ** $Id$
  27 ** detailed CVS changelog at http://www.mplayerhq.hu/cgi-bin/cvsweb.cgi/main/
  28 **/
  29
  30 #ifndef __BITS_H__
  31 #define __BITS_H__
  32
  33 #ifdef __cplusplus
  34 extern "C" {
  35 #endif
  36
  37 #include "analysis.h"
  38 #ifdef ANALYSIS
  39 #include <stdio.h>
  40 #endif
  41
  42 #define BYTE_NUMBIT 8
  43 #define bit2byte(a) ((a+7)/BYTE_NUMBIT)
  44
  45 typedef struct _bitfile
  46 {
  47     /* bit input */
  48     uint32_t bufa;
  49     uint32_t bufb;
  50     uint32_t bits_left;
  51     uint32_t buffer_size; /* size of the buffer in bytes */
  52     uint32_t bytes_used;
  53     uint8_t no_more_reading;
  54     uint8_t error;
  55     uint32_t *tail;
  56     uint32_t *start;
  57     void *buffer;
  58 } bitfile;
  59
  60
  61 #if defined (_WIN32) && !defined(_WIN32_WCE) && !defined(__MINGW32__)
  62 #define BSWAP(a) __asm mov eax,a __asm bswap eax __asm mov a, eax
  63 #elif defined(LINUX) || defined(DJGPP)
  64 #define BSWAP(a) __asm__ ( "bswapl %0\n" : "=r" (a) : "0" (a) )
  65 #else
  66 #define BSWAP(a) \
  67     ((a) = ( ((a)&0xff)<<24) | (((a)&0xff00)<<8) | (((a)>>8)&0xff00) | (((a)>>24)&0xff))
  68 #endif
  69
  70 static uint32_t bitmask[] = {
  71     0x0, 0x1, 0x3, 0x7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, 0x1FF,
  72     0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF,
  73     0x1FFFF, 0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF,
  74     0x7FFFFF, 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF, 0x7FFFFFF,
  75     0xFFFFFFF, 0x1FFFFFFF, 0x3FFFFFFF, 0x7FFFFFFF
  76     /* added bitmask 32, correct?!?!?! */
  77     , 0xFFFFFFFF
  78 };
  79
  80 void faad_initbits(bitfile *ld, const void *buffer, const uint32_t buffer_size);
  81 void faad_endbits(bitfile *ld);
  82 void faad_initbits_rev(bitfile *ld, void *buffer,
  83                        uint32_t bits_in_buffer);
  84 uint8_t faad_byte_align(bitfile *ld);
  85 uint32_t faad_get_processed_bits(bitfile *ld);
  86 void faad_flushbits_ex(bitfile *ld, uint32_t bits);
  87 void faad_rewindbits(bitfile *ld);
  88 uint8_t *faad_getbitbuffer(bitfile *ld, uint32_t bits
  89                        DEBUGDEC);
  90 #ifdef DRM
  91 void *faad_origbitbuffer(bitfile *ld);
  92 uint32_t faad_origbitbuffer_size(bitfile *ld);
  93 #endif
  94
  95 /* circumvent memory alignment errors on ARM */
  96 static INLINE uint32_t getdword(void *mem)
  97 {
  98 #ifdef ARM
  99     uint32_t tmp;
 100 #ifndef ARCH_IS_BIG_ENDIAN
 101     ((uint8_t*)&tmp)[0] = ((uint8_t*)mem)[3];
 102     ((uint8_t*)&tmp)[1] = ((uint8_t*)mem)[2];
 103     ((uint8_t*)&tmp)[2] = ((uint8_t*)mem)[1];
 104     ((uint8_t*)&tmp)[3] = ((uint8_t*)mem)[0];
 105 #else
 106     ((uint8_t*)&tmp)[0] = ((uint8_t*)mem)[0];
 107     ((uint8_t*)&tmp)[1] = ((uint8_t*)mem)[1];
 108     ((uint8_t*)&tmp)[2] = ((uint8_t*)mem)[2];
 109     ((uint8_t*)&tmp)[3] = ((uint8_t*)mem)[3];
 110 #endif
 111
 112     return tmp;
 113 #else
 114     uint32_t tmp;
 115     tmp = *(uint32_t*)mem;
 116 #ifndef ARCH_IS_BIG_ENDIAN
 117     BSWAP(tmp);
 118 #endif
 119     return tmp;
 120 #endif
 121 }
 122
 123 static INLINE uint32_t faad_showbits(bitfile *ld, uint32_t bits)
 124 {
 125     if (bits <= ld->bits_left)
 126     {
 127         return (ld->bufa >> (ld->bits_left - bits)) & bitmask[bits];
 128     }
 129
 130     bits -= ld->bits_left;
 131     return ((ld->bufa & bitmask[ld->bits_left]) << bits) | (ld->bufb >> (32 - bits));
 132 }
 133
 134 static INLINE void faad_flushbits(bitfile *ld, uint32_t bits)
 135 {
 136     /* do nothing if error */
 137     if (ld->error != 0)
 138         return;
 139
 140     if (bits < ld->bits_left)
 141     {
 142         ld->bits_left -= bits;
 143     } else {
 144         faad_flushbits_ex(ld, bits);
 145     }
 146 }
 147
 148 /* return next n bits (right adjusted) */
 149 static INLINE uint32_t faad_getbits(bitfile *ld, uint32_t n DEBUGDEC)
 150 {
 151     uint32_t ret;
 152
 153     if (ld->no_more_reading || n == 0)
 154         return 0;
 155
 156     ret = faad_showbits(ld, n);
 157     faad_flushbits(ld, n);
 158
 159 #ifdef ANALYSIS
 160     if (print)
 161         fprintf(stdout, "%4d %2d bits, val: %4d, variable: %d %s\n", dbg_count++, n, ret, var, dbg);
 162 #endif
 163
 164     return ret;
 165 }
 166
 167 static INLINE uint8_t faad_get1bit(bitfile *ld DEBUGDEC)
 168 {
 169     uint8_t r;
 170
 171     if (ld->bits_left > 0)
 172     {
 173         ld->bits_left--;
 174         r = (uint8_t)((ld->bufa >> ld->bits_left) & 1);
 175         return r;
 176     }
 177
 178     /* bits_left == 0 */
 179 #if 0
 180     r = (uint8_t)(ld->bufb >> 31);
 181     faad_flushbits_ex(ld, 1);
 182 #else
 183     r = (uint8_t)faad_getbits(ld, 1);
 184 #endif
 185     return r;
 186 }
 187
 188 /* reversed bitreading routines */
 189 static INLINE uint32_t faad_showbits_rev(bitfile *ld, uint32_t bits)
 190 {
 191     uint8_t i;
 192     uint32_t B = 0;
 193
 194     if (bits <= ld->bits_left)
 195     {
 196         for (i = 0; i < bits; i++)
 197         {
 198             if (ld->bufa & (1 << (i + (32 - ld->bits_left))))
 199                 B |= (1 << (bits - i - 1));
 200         }
 201         return B;
 202     } else {
 203         for (i = 0; i < ld->bits_left; i++)
 204         {
 205             if (ld->bufa & (1 << (i + (32 - ld->bits_left))))
 206                 B |= (1 << (bits - i - 1));
 207         }
 208         for (i = 0; i < bits - ld->bits_left; i++)
 209         {
 210             if (ld->bufb & (1 << (i + (32-ld->bits_left))))
 211                 B |= (1 << (bits - ld->bits_left - i - 1));
 212         }
 213         return B;
 214     }
 215 }
 216
 217 static INLINE void faad_flushbits_rev(bitfile *ld, uint32_t bits)
 218 {
 219     /* do nothing if error */
 220     if (ld->error != 0)
 221         return;
 222
 223     if (bits < ld->bits_left)
 224     {
 225         ld->bits_left -= bits;
 226     } else {
 227         uint32_t tmp;
 228
 229         ld->bufa = ld->bufb;
 230         tmp = getdword(ld->start);
 231         ld->bufb = tmp;
 232         ld->start--;
 233         ld->bits_left += (32 - bits);
 234
 235         ld->bytes_used += 4;
 236         if (ld->bytes_used == ld->buffer_size)
 237             ld->no_more_reading = 1;
 238         if (ld->bytes_used > ld->buffer_size)
 239             ld->error = 1;
 240     }
 241 }
 242
 243 static INLINE uint32_t faad_getbits_rev(bitfile *ld, uint32_t n
 244                                         DEBUGDEC)
 245 {
 246     uint32_t ret;
 247
 248     if (ld->no_more_reading)
 249         return 0;
 250
 251     if (n == 0)
 252         return 0;
 253
 254     ret = faad_showbits_rev(ld, n);
 255     faad_flushbits_rev(ld, n);
 256
 257 #ifdef ANALYSIS
 258     if (print)
 259         fprintf(stdout, "%4d %2d bits, val: %4d, variable: %d %s\n", dbg_count++, n, ret, var, dbg);
 260 #endif
 261
 262     return ret;
 263 }
 264
 265 #ifdef DRM
 266 static uint8_t faad_check_CRC(bitfile *ld, uint16_t len)
 267 {
 268     uint8_t CRC;
 269     uint16_t r=255;  /* Initialize to all ones */
 270
 271     /* CRC polynome used x^8 + x^4 + x^3 + x^2 +1 */
 272 #define GPOLY 0435
 273
 274     faad_rewindbits(ld);
 275
 276     CRC = (uint8_t) ~faad_getbits(ld, 8
 277         DEBUGVAR(1,999,"faad_check_CRC(): CRC"));          /* CRC is stored inverted */
 278
 279     for (; len>0; len--)
 280     {
 281         r = ( (r << 1) ^ (( ( faad_get1bit(ld
 282             DEBUGVAR(1,998,""))  & 1) ^ ((r >> 7) & 1)) * GPOLY )) & 0xFF;
 283     }
 284
 285     if (r != CRC)
 286     {
 287         return 8;
 288     } else {
 289         return 0;
 290     }
 291 }
 292
 293 static uint8_t tabFlipbits[256] = {
 294     0,128,64,192,32,160,96,224,16,144,80,208,48,176,112,240,
 295     8,136,72,200,40,168,104,232,24,152,88,216,56,184,120,248,
 296     4,132,68,196,36,164,100,228,20,148,84,212,52,180,116,244,
 297     12,140,76,204,44,172,108,236,28,156,92,220,60,188,124,252,
 298     2,130,66,194,34,162,98,226,18,146,82,210,50,178,114,242,
 299     10,138,74,202,42,170,106,234,26,154,90,218,58,186,122,250,
 300     6,134,70,198,38,166,102,230,22,150,86,214,54,182,118,246,
 301     14,142,78,206,46,174,110,238,30,158,94,222,62,190,126,254,
 302     1,129,65,193,33,161,97,225,17,145,81,209,49,177,113,241,
 303     9,137,73,201,41,169,105,233,25,153,89,217,57,185,121,249,
 304     5,133,69,197,37,165,101,229,21,149,85,213,53,181,117,245,
 305     13,141,77,205,45,173,109,237,29,157,93,221,61,189,125,253,
 306     3,131,67,195,35,163,99,227,19,147,83,211,51,179,115,243,
 307     11,139,75,203,43,171,107,235,27,155,91,219,59,187,123,251,
 308     7,135,71,199,39,167,103,231,23,151,87,215,55,183,119,247,
 309     15,143,79,207,47,175,111,239,31,159,95,223,63,191,127,255
 310 };
 311 #endif
 312
 313 #ifdef ERROR_RESILIENCE
 314
 315 /* Modified bit reading functions for HCR */
 316
 317 typedef struct
 318 {
 319     /* bit input */
 320     uint32_t bufa;
 321     uint32_t bufb;
 322     int8_t len;
 323 } bits_t;
 324
 325
 326 static INLINE uint32_t showbits_hcr(bits_t *ld, uint8_t bits)
 327 {
 328     if (bits == 0) return 0;
 329     if (ld->len <= 32)
 330     {
 331         /* huffman_spectral_data_2 needs to read more than may be available, bits maybe
 332            > ld->len, deliver 0 than */
 333         if (ld->len >= bits)
 334             return ((ld->bufa >> (ld->len - bits)) & (0xFFFFFFFF >> (32 - bits)));
 335         else
 336             return ((ld->bufa << (bits - ld->len)) & (0xFFFFFFFF >> (32 - bits)));
 337     } else {
 338         if ((ld->len - bits) < 32)
 339         {
 340             return ( (ld->bufb & (0xFFFFFFFF >> (64 - ld->len))) << (bits - ld->len + 32)) |
 341                 (ld->bufa >> (ld->len - bits));
 342         } else {
 343             return ((ld->bufb >> (ld->len - bits - 32)) & (0xFFFFFFFF >> (32 - bits)));
 344         }
 345     }
 346 }
 347
 348 /* return 1 if position is outside of buffer, 0 otherwise */
 349 static INLINE int8_t flushbits_hcr( bits_t *ld, uint8_t bits)
 350 {
 351     ld->len -= bits;
 352
 353     if (ld->len <0)
 354     {
 355         ld->len = 0;
 356         return 1;
 357     } else {
 358         return 0;
 359     }
 360 }
 361
 362 static INLINE int8_t getbits_hcr(bits_t *ld, uint8_t n, uint32_t *result)
 363 {
 364     *result = showbits_hcr(ld, n);
 365     return flushbits_hcr(ld, n);
 366 }
 367
 368 static INLINE int8_t get1bit_hcr(bits_t *ld, uint8_t *result)
 369 {
 370     uint32_t res;
 371     int8_t ret;
 372
 373     ret = getbits_hcr(ld, 1, &res);
 374     *result = (int8_t)(res & 1);
 375     return ret;
 376 }
 377
 378 #endif
 379
 380
 381 #ifdef __cplusplus
 382 }
 383 #endif
 384 #endif