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