aboutsummaryrefslogtreecommitdiffhomepage
path: root/libfaad2/bits.h
blob: f66d5a6d360cfcd1342dba7cc63dbabd39762f04 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
**
** Initially modified for use with MPlayer by Arpad Gereöffy on 2003/08/30
** $Id$
** detailed changelog at http://svn.mplayerhq.hu/mplayer/trunk/
** local_changes.diff contains the exact changes to this file.
**/

#ifndef __BITS_H__
#define __BITS_H__

#ifdef __cplusplus
extern "C" {
#endif

#include "analysis.h"
#ifdef ANALYSIS
#include <stdio.h>
#endif

#define BYTE_NUMBIT 8
#define bit2byte(a) ((a+7)/BYTE_NUMBIT)

typedef struct _bitfile
{
    /* bit input */
    uint32_t bufa;
    uint32_t bufb;
    uint32_t bits_left;
    uint32_t buffer_size; /* size of the buffer in bytes */
    uint32_t bytes_used;
    uint8_t no_more_reading;
    uint8_t error;
    uint32_t *tail;
    uint32_t *start;
    void *buffer;
} bitfile;


#if defined (_WIN32) && !defined(_WIN32_WCE) && !defined(__MINGW32__)
#define BSWAP(a) __asm mov eax,a __asm bswap eax __asm mov a, eax
#elif defined(LINUX) || defined(DJGPP)
#define BSWAP(a) __asm__ ( "bswapl %0\n" : "=r" (a) : "0" (a) )
#else
#define BSWAP(a) \
    ((a) = ( ((a)&0xff)<<24) | (((a)&0xff00)<<8) | (((a)>>8)&0xff00) | (((a)>>24)&0xff))
#endif

static uint32_t bitmask[] = {
    0x0, 0x1, 0x3, 0x7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, 0x1FF,
    0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF,
    0x1FFFF, 0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF,
    0x7FFFFF, 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF, 0x7FFFFFF,
    0xFFFFFFF, 0x1FFFFFFF, 0x3FFFFFFF, 0x7FFFFFFF
    /* added bitmask 32, correct?!?!?! */
    , 0xFFFFFFFF
};

void faad_initbits(bitfile *ld, const void *buffer, const uint32_t buffer_size);
void faad_endbits(bitfile *ld);
void faad_initbits_rev(bitfile *ld, void *buffer,
                       uint32_t bits_in_buffer);
uint8_t faad_byte_align(bitfile *ld);
uint32_t faad_get_processed_bits(bitfile *ld);
void faad_flushbits_ex(bitfile *ld, uint32_t bits);
void faad_rewindbits(bitfile *ld);
uint8_t *faad_getbitbuffer(bitfile *ld, uint32_t bits
                       DEBUGDEC);
#ifdef DRM
void *faad_origbitbuffer(bitfile *ld);
uint32_t faad_origbitbuffer_size(bitfile *ld);
#endif

/* circumvent memory alignment errors on ARM */
static INLINE uint32_t getdword(void *mem)
{
#ifdef ARM
    uint32_t tmp;
#ifndef ARCH_IS_BIG_ENDIAN
    ((uint8_t*)&tmp)[0] = ((uint8_t*)mem)[3];
    ((uint8_t*)&tmp)[1] = ((uint8_t*)mem)[2];
    ((uint8_t*)&tmp)[2] = ((uint8_t*)mem)[1];
    ((uint8_t*)&tmp)[3] = ((uint8_t*)mem)[0];
#else
    ((uint8_t*)&tmp)[0] = ((uint8_t*)mem)[0];
    ((uint8_t*)&tmp)[1] = ((uint8_t*)mem)[1];
    ((uint8_t*)&tmp)[2] = ((uint8_t*)mem)[2];
    ((uint8_t*)&tmp)[3] = ((uint8_t*)mem)[3];
#endif

    return tmp;
#else
    uint32_t tmp;
    tmp = *(uint32_t*)mem;
#ifndef ARCH_IS_BIG_ENDIAN
    BSWAP(tmp);
#endif
    return tmp;
#endif
}

static INLINE uint32_t faad_showbits(bitfile *ld, uint32_t bits)
{
    if (bits <= ld->bits_left)
    {
        return (ld->bufa >> (ld->bits_left - bits)) & bitmask[bits];
    }

    bits -= ld->bits_left;
    return ((ld->bufa & bitmask[ld->bits_left]) << bits) | (ld->bufb >> (32 - bits));
}

static INLINE void faad_flushbits(bitfile *ld, uint32_t bits)
{
    /* do nothing if error */
    if (ld->error != 0)
        return;

    if (bits < ld->bits_left)
    {
        ld->bits_left -= bits;
    } else {
        faad_flushbits_ex(ld, bits);
    }
}

/* return next n bits (right adjusted) */
static INLINE uint32_t faad_getbits(bitfile *ld, uint32_t n DEBUGDEC)
{
    uint32_t ret;

    if (ld->no_more_reading || n == 0)
        return 0;

    ret = faad_showbits(ld, n);
    faad_flushbits(ld, n);

#ifdef ANALYSIS
    if (print)
        fprintf(stdout, "%4d %2d bits, val: %4d, variable: %d %s\n", dbg_count++, n, ret, var, dbg);
#endif

    return ret;
}

static INLINE uint8_t faad_get1bit(bitfile *ld DEBUGDEC)
{
    uint8_t r;

    if (ld->bits_left > 0)
    {
        ld->bits_left--;
        r = (uint8_t)((ld->bufa >> ld->bits_left) & 1);
        return r;
    }

    /* bits_left == 0 */
#if 0
    r = (uint8_t)(ld->bufb >> 31);
    faad_flushbits_ex(ld, 1);
#else
    r = (uint8_t)faad_getbits(ld, 1);
#endif
    return r;
}

/* reversed bitreading routines */
static INLINE uint32_t faad_showbits_rev(bitfile *ld, uint32_t bits)
{
    uint8_t i;
    uint32_t B = 0;

    if (bits <= ld->bits_left)
    {
        for (i = 0; i < bits; i++)
        {
            if (ld->bufa & (1 << (i + (32 - ld->bits_left))))
                B |= (1 << (bits - i - 1));
        }
        return B;
    } else {
        for (i = 0; i < ld->bits_left; i++)
        {
            if (ld->bufa & (1 << (i + (32 - ld->bits_left))))
                B |= (1 << (bits - i - 1));
        }
        for (i = 0; i < bits - ld->bits_left; i++)
        {
            if (ld->bufb & (1 << (i + (32-ld->bits_left))))
                B |= (1 << (bits - ld->bits_left - i - 1));
        }
        return B;
    }
}

static INLINE void faad_flushbits_rev(bitfile *ld, uint32_t bits)
{
    /* do nothing if error */
    if (ld->error != 0)
        return;

    if (bits < ld->bits_left)
    {
        ld->bits_left -= bits;
    } else {
        uint32_t tmp;

        ld->bufa = ld->bufb;
        tmp = getdword(ld->start);
        ld->bufb = tmp;
        ld->start--;
        ld->bits_left += (32 - bits);

        ld->bytes_used += 4;
        if (ld->bytes_used == ld->buffer_size)
            ld->no_more_reading = 1;
        if (ld->bytes_used > ld->buffer_size)
            ld->error = 1;
    }
}

static INLINE uint32_t faad_getbits_rev(bitfile *ld, uint32_t n
                                        DEBUGDEC)
{
    uint32_t ret;

    if (ld->no_more_reading)
        return 0;

    if (n == 0)
        return 0;

    ret = faad_showbits_rev(ld, n);
    faad_flushbits_rev(ld, n);

#ifdef ANALYSIS
    if (print)
        fprintf(stdout, "%4d %2d bits, val: %4d, variable: %d %s\n", dbg_count++, n, ret, var, dbg);
#endif

    return ret;
}

#ifdef DRM
static uint8_t faad_check_CRC(bitfile *ld, uint16_t len)
{
    uint8_t CRC;
    uint16_t r=255;  /* Initialize to all ones */

    /* CRC polynome used x^8 + x^4 + x^3 + x^2 +1 */
#define GPOLY 0435

    faad_rewindbits(ld);

    CRC = (uint8_t) ~faad_getbits(ld, 8
        DEBUGVAR(1,999,"faad_check_CRC(): CRC"));          /* CRC is stored inverted */

    for (; len>0; len--)
    {
        r = ( (r << 1) ^ (( ( faad_get1bit(ld
            DEBUGVAR(1,998,""))  & 1) ^ ((r >> 7) & 1)) * GPOLY )) & 0xFF;
    }

    if (r != CRC)
    {
        return 8;
    } else {
        return 0;
    }
}

static uint8_t tabFlipbits[256] = {
    0,128,64,192,32,160,96,224,16,144,80,208,48,176,112,240,
    8,136,72,200,40,168,104,232,24,152,88,216,56,184,120,248,
    4,132,68,196,36,164,100,228,20,148,84,212,52,180,116,244,
    12,140,76,204,44,172,108,236,28,156,92,220,60,188,124,252,
    2,130,66,194,34,162,98,226,18,146,82,210,50,178,114,242,
    10,138,74,202,42,170,106,234,26,154,90,218,58,186,122,250,
    6,134,70,198,38,166,102,230,22,150,86,214,54,182,118,246,
    14,142,78,206,46,174,110,238,30,158,94,222,62,190,126,254,
    1,129,65,193,33,161,97,225,17,145,81,209,49,177,113,241,
    9,137,73,201,41,169,105,233,25,153,89,217,57,185,121,249,
    5,133,69,197,37,165,101,229,21,149,85,213,53,181,117,245,
    13,141,77,205,45,173,109,237,29,157,93,221,61,189,125,253,
    3,131,67,195,35,163,99,227,19,147,83,211,51,179,115,243,
    11,139,75,203,43,171,107,235,27,155,91,219,59,187,123,251,
    7,135,71,199,39,167,103,231,23,151,87,215,55,183,119,247,
    15,143,79,207,47,175,111,239,31,159,95,223,63,191,127,255
};
#endif

#ifdef ERROR_RESILIENCE

/* Modified bit reading functions for HCR */

typedef struct
{
    /* bit input */
    uint32_t bufa;
    uint32_t bufb;
    int8_t len;
} bits_t;


static INLINE uint32_t showbits_hcr(bits_t *ld, uint8_t bits)
{
    if (bits == 0) return 0;
    if (ld->len <= 32)
    {
        /* huffman_spectral_data_2 needs to read more than may be available, bits maybe
           > ld->len, deliver 0 than */
        if (ld->len >= bits)
            return ((ld->bufa >> (ld->len - bits)) & (0xFFFFFFFF >> (32 - bits)));
        else
            return ((ld->bufa << (bits - ld->len)) & (0xFFFFFFFF >> (32 - bits)));
    } else {
        if ((ld->len - bits) < 32)
        {
            return ( (ld->bufb & (0xFFFFFFFF >> (64 - ld->len))) << (bits - ld->len + 32)) |
                (ld->bufa >> (ld->len - bits));
        } else {
            return ((ld->bufb >> (ld->len - bits - 32)) & (0xFFFFFFFF >> (32 - bits)));
        }
    }
}

/* return 1 if position is outside of buffer, 0 otherwise */
static INLINE int8_t flushbits_hcr( bits_t *ld, uint8_t bits)
{
    ld->len -= bits;

    if (ld->len <0)
    {
        ld->len = 0;
        return 1;
    } else {
        return 0;
    }
}

static INLINE int8_t getbits_hcr(bits_t *ld, uint8_t n, uint32_t *result)
{
    *result = showbits_hcr(ld, n);
    return flushbits_hcr(ld, n);
}

static INLINE int8_t get1bit_hcr(bits_t *ld, uint8_t *result)
{
    uint32_t res;
    int8_t ret;

    ret = getbits_hcr(ld, 1, &res);
    *result = (int8_t)(res & 1);
    return ret;
}

#endif


#ifdef __cplusplus
}
#endif
#endif