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[/] [or1k_old/] [trunk/] [mp3/] [sw/] [mad-xess/] [libmad/] [layer3.c] - Blame information for rev 1782

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Line No. Rev Author Line
1 291 simons 
/*
2 
 * mad - MPEG audio decoder
3 
 * Copyright (C) 2000-2001 Robert Leslie
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 
 * $Id: layer3.c,v 1.3 2001-11-06 17:01:28 simons Exp $
20 
 */
21 
 
22 
# ifdef HAVE_CONFIG_H
23 
#  include "config.h"
24 
# endif
25 
 
26 
# include "global.h"
27 
 
28 
# ifndef EMBED
29 
#  include <string.h>
30 
#  include <assert.h>
31 
#  include <stdio.h>
32 
#  ifdef HAVE_LIMITS_H
33 
#   include <limits.h>
34 
#  else
35 
#   define CHAR_BIT  8
36 
#  endif
37 
#else
38 
 
39 
# define assert(x)
40 
# define CHAR_BIT  8
41 
#endif
42 
 
43 
# include "fixed.h"
44 
# include "bit.h"
45 
# include "stream.h"
46 
# include "frame.h"
47 
# include "huffman.h"
48 
# include "layer3.h"
49 
 
50 
/* --- Layer III ----------------------------------------------------------- */
51 
 
52 
enum {
53 
  count1table_select = 0x01,
54 
  scalefac_scale     = 0x02,
55 
  preflag            = 0x04,
56 
  mixed_block_flag   = 0x08
57 
};
58 
 
59 
struct sideinfo {
60 
  unsigned int main_data_begin;
61 
  unsigned int private_bits;
62 
 
63 
  unsigned char scfsi[2];
64 
 
65 
  struct granule {
66 
    struct channel {
67 
      /* from side info */
68 
      unsigned short part2_3_length;
69 
      unsigned short big_values;
70 
      unsigned short global_gain;
71 
      unsigned short scalefac_compress;
72 
 
73 
      unsigned char flags;
74 
      unsigned char block_type;
75 
      unsigned char table_select[3];
76 
      unsigned char subblock_gain[3];
77 
      unsigned char region0_count;
78 
      unsigned char region1_count;
79 
 
80 
      /* from main_data */
81 
      unsigned char scalefac[39];       /* scalefac_l and/or scalefac_s */
82 
    } ch[2];
83 
  } gr[2];
84 
};
85 
 
86 
/*
87 
 * scalefactor bit lengths
88 
 * derived from section 2.4.2.7 of ISO/IEC 11172-3
89 
 */
90 
static
91 
struct {
92 
  unsigned char slen1;
93 
  unsigned char slen2;
94 
} const sflen_table[16] = {
95 
  { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 },
96 
  { 3, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 },
97 
  { 2, 1 }, { 2, 2 }, { 2, 3 }, { 3, 1 },
98 
  { 3, 2 }, { 3, 3 }, { 4, 2 }, { 4, 3 }
99 
};
100 
 
101 
/*
102 
 * number of LSF scalefactor band values
103 
 * derived from section 2.4.3.2 of ISO/IEC 13818-3
104 
 */
105 
static
106 
unsigned char const nsfb_table[6][3][4] = {
107 
  { {  6,  5,  5, 5 },
108 
    {  9,  9,  9, 9 },
109 
    {  6,  9,  9, 9 } },
110 
 
111 
  { {  6,  5,  7, 3 },
112 
    {  9,  9, 12, 6 },
113 
    {  6,  9, 12, 6 } },
114 
 
115 
  { { 11, 10,  0, 0 },
116 
    { 18, 18,  0, 0 },
117 
    { 15, 18,  0, 0 } },
118 
 
119 
  { {  7,  7,  7, 0 },
120 
    { 12, 12, 12, 0 },
121 
    {  6, 15, 12, 0 } },
122 
 
123 
  { {  6,  6,  6, 3 },
124 
    { 12,  9,  9, 6 },
125 
    {  6, 12,  9, 6 } },
126 
 
127 
  { {  8,  8,  5, 0 },
128 
    { 15, 12,  9, 0 },
129 
    {  6, 18,  9, 0 } }
130 
};
131 
 
132 
/*
133 
 * MPEG-1 scalefactor band widths
134 
 * derived from Table B.8 of ISO/IEC 11172-3
135 
 */
136 
static
137 
unsigned char const sfb_48000_long[] = {
138 
   4,  4,  4,  4,  4,  4,  6,  6,  6,   8,  10,
139 
  12, 16, 18, 22, 28, 34, 40, 46, 54,  54, 192
140 
};
141 
 
142 
static
143 
unsigned char const sfb_44100_long[] = {
144 
   4,  4,  4,  4,  4,  4,  6,  6,  8,   8,  10,
145 
  12, 16, 20, 24, 28, 34, 42, 50, 54,  76, 158
146 
};
147 
 
148 
static
149 
unsigned char const sfb_32000_long[] = {
150 
   4,  4,  4,  4,  4,  4,  6,  6,  8,  10,  12,
151 
  16, 20, 24, 30, 38, 46, 56, 68, 84, 102,  26
152 
};
153 
 
154 
static
155 
unsigned char const sfb_48000_short[] = {
156 
   4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  6,
157 
   6,  6,  6,  6,  6, 10, 10, 10, 12, 12, 12, 14, 14,
158 
  14, 16, 16, 16, 20, 20, 20, 26, 26, 26, 66, 66, 66
159 
};
160 
 
161 
static
162 
unsigned char const sfb_44100_short[] = {
163 
   4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  6,
164 
   6,  6,  8,  8,  8, 10, 10, 10, 12, 12, 12, 14, 14,
165 
  14, 18, 18, 18, 22, 22, 22, 30, 30, 30, 56, 56, 56
166 
};
167 
 
168 
static
169 
unsigned char const sfb_32000_short[] = {
170 
   4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  6,
171 
   6,  6,  8,  8,  8, 12, 12, 12, 16, 16, 16, 20, 20,
172 
  20, 26, 26, 26, 34, 34, 34, 42, 42, 42, 12, 12, 12
173 
};
174 
 
175 
static
176 
unsigned char const sfb_48000_mixed[] = {
177 
  /* long */   4,  4,  4,  4,  4,  4,  6,  6,
178 
  /* short */  4,  4,  4,  6,  6,  6,  6,  6,  6, 10,
179 
              10, 10, 12, 12, 12, 14, 14, 14, 16, 16,
180 
              16, 20, 20, 20, 26, 26, 26, 66, 66, 66
181 
};
182 
 
183 
static
184 
unsigned char const sfb_44100_mixed[] = {
185 
  /* long */   4,  4,  4,  4,  4,  4,  6,  6,
186 
  /* short */  4,  4,  4,  6,  6,  6,  8,  8,  8, 10,
187 
              10, 10, 12, 12, 12, 14, 14, 14, 18, 18,
188 
              18, 22, 22, 22, 30, 30, 30, 56, 56, 56
189 
};
190 
 
191 
static
192 
unsigned char const sfb_32000_mixed[] = {
193 
  /* long */   4,  4,  4,  4,  4,  4,  6,  6,
194 
  /* short */  4,  4,  4,  6,  6,  6,  8,  8,  8, 12,
195 
              12, 12, 16, 16, 16, 20, 20, 20, 26, 26,
196 
              26, 34, 34, 34, 42, 42, 42, 12, 12, 12
197 
};
198 
 
199 
/*
200 
 * MPEG-2 scalefactor band widths
201 
 * derived from Table B.2 of ISO/IEC 13818-3
202 
 */
203 
static
204 
unsigned char const sfb_24000_long[] = {
205 
   6,  6,  6,  6,  6,  6,  8, 10, 12,  14,  16,
206 
  18, 22, 26, 32, 38, 46, 54, 62, 70,  76,  36
207 
};
208 
 
209 
static
210 
unsigned char const sfb_22050_long[] = {
211 
   6,  6,  6,  6,  6,  6,  8, 10, 12,  14,  16,
212 
  20, 24, 28, 32, 38, 46, 52, 60, 68,  58,  54
213 
};
214 
 
215 
# define sfb_16000_long  sfb_22050_long
216 
 
217 
static
218 
unsigned char const sfb_24000_short[] = {
219 
   4,  4,  4,  4,  4,  4,  4,  4,  4,  6,  6,  6,  8,
220 
   8,  8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18,
221 
  18, 24, 24, 24, 32, 32, 32, 44, 44, 44, 12, 12, 12
222 
};
223 
 
224 
static
225 
unsigned char const sfb_22050_short[] = {
226 
   4,  4,  4,  4,  4,  4,  4,  4,  4,  6,  6,  6,  6,
227 
   6,  6,  8,  8,  8, 10, 10, 10, 14, 14, 14, 18, 18,
228 
  18, 26, 26, 26, 32, 32, 32, 42, 42, 42, 18, 18, 18
229 
};
230 
 
231 
static
232 
unsigned char const sfb_16000_short[] = {
233 
   4,  4,  4,  4,  4,  4,  4,  4,  4,  6,  6,  6,  8,
234 
   8,  8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18,
235 
  18, 24, 24, 24, 30, 30, 30, 40, 40, 40, 18, 18, 18
236 
};
237 
 
238 
static
239 
unsigned char const sfb_24000_mixed[] = {
240 
  /* long */   6,  6,  6,  6,  6,  6,
241 
  /* short */  6,  6,  6,  8,  8,  8, 10, 10, 10, 12,
242 
              12, 12, 14, 14, 14, 18, 18, 18, 24, 24,
243 
              24, 32, 32, 32, 44, 44, 44, 12, 12, 12
244 
};
245 
 
246 
static
247 
unsigned char const sfb_22050_mixed[] = {
248 
  /* long */   6,  6,  6,  6,  6,  6,
249 
  /* short */  6,  6,  6,  6,  6,  6,  8,  8,  8, 10,
250 
              10, 10, 14, 14, 14, 18, 18, 18, 26, 26,
251 
              26, 32, 32, 32, 42, 42, 42, 18, 18, 18
252 
};
253 
 
254 
static
255 
unsigned char const sfb_16000_mixed[] = {
256 
  /* long */   6,  6,  6,  6,  6,  6,
257 
  /* short */  6,  6,  6,  8,  8,  8, 10, 10, 10, 12,
258 
              12, 12, 14, 14, 14, 18, 18, 18, 24, 24,
259 
              24, 30, 30, 30, 40, 40, 40, 18, 18, 18
260 
};
261 
 
262 
/*
263 
 * MPEG 2.5 scalefactor band widths
264 
 * derived from public sources
265 
 */
266 
# define sfb_12000_long  sfb_16000_long
267 
# define sfb_11025_long  sfb_12000_long
268 
 
269 
static
270 
unsigned char const sfb_8000_long[] = {
271 
  12, 12, 12, 12, 12, 12, 16, 20, 24,  28,  32,
272 
  40, 48, 56, 64, 76, 90,  2,  2,  2,   2,   2
273 
};
274 
 
275 
# define sfb_12000_short  sfb_16000_short
276 
# define sfb_11025_short  sfb_12000_short
277 
 
278 
static
279 
unsigned char const sfb_8000_short[] = {
280 
   8,  8,  8,  8,  8,  8,  8,  8,  8, 12, 12, 12, 16,
281 
  16, 16, 20, 20, 20, 24, 24, 24, 28, 28, 28, 36, 36,
282 
  36,  2,  2,  2,  2,  2,  2,  2,  2,  2, 26, 26, 26
283 
};
284 
 
285 
# define sfb_12000_mixed  sfb_16000_mixed
286 
# define sfb_11025_mixed  sfb_12000_mixed
287 
 
288 
/* the 8000 Hz short block scalefactor bands do not break after the first 36
289 
   frequency lines, so this is probably wrong */
290 
static
291 
unsigned char const sfb_8000_mixed[] = {
292 
  /* long */  12, 12, 12,
293 
  /* short */  4,  4,  4,  8,  8,  8, 12, 12, 12, 16, 16, 16,
294 
              20, 20, 20, 24, 24, 24, 28, 28, 28, 36, 36, 36,
295 
               2,  2,  2,  2,  2,  2,  2,  2,  2, 26, 26, 26
296 
};
297 
 
298 
static
299 
struct {
300 
  unsigned char const *l;
301 
  unsigned char const *s;
302 
  unsigned char const *m;
303 
} const sfbwidth_table[9] = {
304 
  { sfb_48000_long, sfb_48000_short, sfb_48000_mixed },
305 
  { sfb_44100_long, sfb_44100_short, sfb_44100_mixed },
306 
  { sfb_32000_long, sfb_32000_short, sfb_32000_mixed },
307 
  { sfb_24000_long, sfb_24000_short, sfb_24000_mixed },
308 
  { sfb_22050_long, sfb_22050_short, sfb_22050_mixed },
309 
  { sfb_16000_long, sfb_16000_short, sfb_16000_mixed },
310 
  { sfb_12000_long, sfb_12000_short, sfb_12000_mixed },
311 
  { sfb_11025_long, sfb_11025_short, sfb_11025_mixed },
312 
  {  sfb_8000_long,  sfb_8000_short,  sfb_8000_mixed }
313 
};
314 
 
315 
/*
316 
 * scalefactor band preemphasis (used only when preflag is set)
317 
 * derived from Table B.6 of ISO/IEC 11172-3
318 
 */
319 
static
320 
unsigned char const pretab[22] = {
321 
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 3, 2, 0
322 
};
323 
 
324 
/*
325 
 * table for requantization
326 
 *
327 
 * rq_table[x].mantissa * 2^(rq_table[x].exponent) = x^(4/3)
328 
 * MM: shortened table
329 
 */
330 
#define RQ_START_BITS 7
331 
static
332 
struct fixedfloat {
333 
  unsigned long mantissa  : 27;
334 
  unsigned short exponent :  5;
335 
} const rq_table[512] = {
336 
# include "rq_short.dat"
337 
};
338 
 
339 
/*
340 
 * fractional powers of two
341 
 * used for requantization and joint stereo decoding
342 
 *
343 
 * root_table[3 + x] = 2^(x/4)
344 
 */
345 
static
346 
mad_fixed_t const root_table[7] = {
347 
  MAD_F(0x09837f05) /* 2^(-3/4) == 0.59460355750136 */,
348 
  MAD_F(0x0b504f33) /* 2^(-2/4) == 0.70710678118655 */,
349 
  MAD_F(0x0d744fcd) /* 2^(-1/4) == 0.84089641525371 */,
350 
  MAD_F(0x10000000) /* 2^( 0/4) == 1.00000000000000 */,
351 
  MAD_F(0x1306fe0a) /* 2^(+1/4) == 1.18920711500272 */,
352 
  MAD_F(0x16a09e66) /* 2^(+2/4) == 1.41421356237310 */,
353 
  MAD_F(0x1ae89f99) /* 2^(+3/4) == 1.68179283050743 */
354 
};
355 
 
356 
/*
357 
 * coefficients for aliasing reduction
358 
 * derived from Table B.9 of ISO/IEC 11172-3
359 
 *
360 
 *  c[]  = { -0.6, -0.535, -0.33, -0.185, -0.095, -0.041, -0.0142, -0.0037 }
361 
 * cs[i] =    1 / sqrt(1 + c[i]^2)
362 
 * ca[i] = c[i] / sqrt(1 + c[i]^2)
363 
 */
364 
static
365 
mad_fixed_t const cs[8] = {
366 
  +MAD_F(0x0db84a81) /* +0.857492926 */, +MAD_F(0x0e1b9d7f) /* +0.881741997 */,
367 
  +MAD_F(0x0f31adcf) /* +0.949628649 */, +MAD_F(0x0fbba815) /* +0.983314592 */,
368 
  +MAD_F(0x0feda417) /* +0.995517816 */, +MAD_F(0x0ffc8fc8) /* +0.999160558 */,
369 
  +MAD_F(0x0fff964c) /* +0.999899195 */, +MAD_F(0x0ffff8d3) /* +0.999993155 */
370 
};
371 
 
372 
static
373 
mad_fixed_t const ca[8] = {
374 
  -MAD_F(0x083b5fe7) /* -0.514495755 */, -MAD_F(0x078c36d2) /* -0.471731969 */,
375 
  -MAD_F(0x05039814) /* -0.313377454 */, -MAD_F(0x02e91dd1) /* -0.181913200 */,
376 
  -MAD_F(0x0183603a) /* -0.094574193 */, -MAD_F(0x00a7cb87) /* -0.040965583 */,
377 
  -MAD_F(0x003a2847) /* -0.014198569 */, -MAD_F(0x000f27b4) /* -0.003699975 */
378 
};
379 
 
380 
/*
381 
 * IMDCT coefficients for short blocks
382 
 * derived from section 2.4.3.4.10.2 of ISO/IEC 11172-3
383 
 *
384 
 * imdct_s[i/even][k] = cos((PI / 24) * (2 * (i / 2) + 7) * (2 * k + 1))
385 
 * imdct_s[i /odd][k] = cos((PI / 24) * (2 * (6 + (i-1)/2) + 7) * (2 * k + 1))
386 
 */
387 
static
388 
mad_fixed_t const imdct_s[6][6] = {
389 
# include "imdct_s.dat"
390 
};
391 
 
392 
# if !defined(ASO_IMDCT)
393 
/*
394 
 * windowing coefficients for long blocks
395 
 * derived from section 2.4.3.4.10.3 of ISO/IEC 11172-3
396 
 *
397 
 * window_l[i] = sin((PI / 36) * (i + 1/2))
398 
 */
399 
static
400 
mad_fixed_t const window_l[36] = {
401 
  MAD_F(0x00b2aa3e) /* 0.043619387 */, MAD_F(0x0216a2a2) /* 0.130526192 */,
402 
  MAD_F(0x03768962) /* 0.216439614 */, MAD_F(0x04cfb0e2) /* 0.300705800 */,
403 
  MAD_F(0x061f78aa) /* 0.382683432 */, MAD_F(0x07635284) /* 0.461748613 */,
404 
  MAD_F(0x0898c779) /* 0.537299608 */, MAD_F(0x09bd7ca0) /* 0.608761429 */,
405 
  MAD_F(0x0acf37ad) /* 0.675590208 */, MAD_F(0x0bcbe352) /* 0.737277337 */,
406 
  MAD_F(0x0cb19346) /* 0.793353340 */, MAD_F(0x0d7e8807) /* 0.843391446 */,
407 
 
408 
  MAD_F(0x0e313245) /* 0.887010833 */, MAD_F(0x0ec835e8) /* 0.923879533 */,
409 
  MAD_F(0x0f426cb5) /* 0.953716951 */, MAD_F(0x0f9ee890) /* 0.976296007 */,
410 
  MAD_F(0x0fdcf549) /* 0.991444861 */, MAD_F(0x0ffc19fd) /* 0.999048222 */,
411 
  MAD_F(0x0ffc19fd) /* 0.999048222 */, MAD_F(0x0fdcf549) /* 0.991444861 */,
412 
  MAD_F(0x0f9ee890) /* 0.976296007 */, MAD_F(0x0f426cb5) /* 0.953716951 */,
413 
  MAD_F(0x0ec835e8) /* 0.923879533 */, MAD_F(0x0e313245) /* 0.887010833 */,
414 
 
415 
  MAD_F(0x0d7e8807) /* 0.843391446 */, MAD_F(0x0cb19346) /* 0.793353340 */,
416 
  MAD_F(0x0bcbe352) /* 0.737277337 */, MAD_F(0x0acf37ad) /* 0.675590208 */,
417 
  MAD_F(0x09bd7ca0) /* 0.608761429 */, MAD_F(0x0898c779) /* 0.537299608 */,
418 
  MAD_F(0x07635284) /* 0.461748613 */, MAD_F(0x061f78aa) /* 0.382683432 */,
419 
  MAD_F(0x04cfb0e2) /* 0.300705800 */, MAD_F(0x03768962) /* 0.216439614 */,
420 
  MAD_F(0x0216a2a2) /* 0.130526192 */, MAD_F(0x00b2aa3e) /* 0.043619387 */,
421 
};
422 
# endif  /* ASO_IMDCT */
423 
 
424 
/*
425 
 * windowing coefficients for short blocks
426 
 * derived from section 2.4.3.4.10.3 of ISO/IEC 11172-3
427 
 *
428 
 * window_s[i] = sin((PI / 12) * (i + 1/2))
429 
 */
430 
static
431 
mad_fixed_t const window_s[12] = {
432 
  MAD_F(0x0216a2a2) /* 0.130526192 */, MAD_F(0x061f78aa) /* 0.382683432 */,
433 
  MAD_F(0x09bd7ca0) /* 0.608761429 */, MAD_F(0x0cb19346) /* 0.793353340 */,
434 
  MAD_F(0x0ec835e8) /* 0.923879533 */, MAD_F(0x0fdcf549) /* 0.991444861 */,
435 
  MAD_F(0x0fdcf549) /* 0.991444861 */, MAD_F(0x0ec835e8) /* 0.923879533 */,
436 
  MAD_F(0x0cb19346) /* 0.793353340 */, MAD_F(0x09bd7ca0) /* 0.608761429 */,
437 
  MAD_F(0x061f78aa) /* 0.382683432 */, MAD_F(0x0216a2a2) /* 0.130526192 */,
438 
};
439 
 
440 
/*
441 
 * coefficients for intensity stereo processing
442 
 * derived from section 2.4.3.4.9.3 of ISO/IEC 11172-3
443 
 *
444 
 * is_ratio[i] = tan(i * (PI / 12))
445 
 * is_table[i] = is_ratio[i] / (1 + is_ratio[i])
446 
 */
447 
static
448 
mad_fixed_t const is_table[7] = {
449 
  MAD_F(0x00000000) /* 0.000000000 */,
450 
  MAD_F(0x0361962f) /* 0.211324865 */,
451 
  MAD_F(0x05db3d74) /* 0.366025404 */,
452 
  MAD_F(0x08000000) /* 0.500000000 */,
453 
  MAD_F(0x0a24c28c) /* 0.633974596 */,
454 
  MAD_F(0x0c9e69d1) /* 0.788675135 */,
455 
  MAD_F(0x10000000) /* 1.000000000 */
456 
};
457 
 
458 
/*
459 
 * coefficients for LSF intensity stereo processing
460 
 * derived from section 2.4.3.2 of ISO/IEC 13818-3
461 
 *
462 
 * is_lsf_table[0][i] = (1 / sqrt(sqrt(2)))^(i + 1)
463 
 * is_lsf_table[1][i] = (1 / sqrt(2))^(i + 1)
464 
 */
465 
static
466 
mad_fixed_t const is_lsf_table[2][15] = {
467 
  {
468 
    MAD_F(0x0d744fcd) /* 0.840896415 */,
469 
    MAD_F(0x0b504f33) /* 0.707106781 */,
470 
    MAD_F(0x09837f05) /* 0.594603558 */,
471 
    MAD_F(0x08000000) /* 0.500000000 */,
472 
    MAD_F(0x06ba27e6) /* 0.420448208 */,
473 
    MAD_F(0x05a8279a) /* 0.353553391 */,
474 
    MAD_F(0x04c1bf83) /* 0.297301779 */,
475 
    MAD_F(0x04000000) /* 0.250000000 */,
476 
    MAD_F(0x035d13f3) /* 0.210224104 */,
477 
    MAD_F(0x02d413cd) /* 0.176776695 */,
478 
    MAD_F(0x0260dfc1) /* 0.148650889 */,
479 
    MAD_F(0x02000000) /* 0.125000000 */,
480 
    MAD_F(0x01ae89fa) /* 0.105112052 */,
481 
    MAD_F(0x016a09e6) /* 0.088388348 */,
482 
    MAD_F(0x01306fe1) /* 0.074325445 */
483 
  }, {
484 
    MAD_F(0x0b504f33) /* 0.707106781 */,
485 
    MAD_F(0x08000000) /* 0.500000000 */,
486 
    MAD_F(0x05a8279a) /* 0.353553391 */,
487 
    MAD_F(0x04000000) /* 0.250000000 */,
488 
    MAD_F(0x02d413cd) /* 0.176776695 */,
489 
    MAD_F(0x02000000) /* 0.125000000 */,
490 
    MAD_F(0x016a09e6) /* 0.088388348 */,
491 
    MAD_F(0x01000000) /* 0.062500000 */,
492 
    MAD_F(0x00b504f3) /* 0.044194174 */,
493 
    MAD_F(0x00800000) /* 0.031250000 */,
494 
    MAD_F(0x005a827a) /* 0.022097087 */,
495 
    MAD_F(0x00400000) /* 0.015625000 */,
496 
    MAD_F(0x002d413d) /* 0.011048543 */,
497 
    MAD_F(0x00200000) /* 0.007812500 */,
498 
    MAD_F(0x0016a09e) /* 0.005524272 */
499 
  }
500 
};
501 
 
502 
/*
503 
 * NAME:        III_sideinfo()
504 
 * DESCRIPTION: decode frame side information from a bitstream
505 
 */
506 
static
507 
enum mad_error III_sideinfo(struct mad_bitptr *ptr, unsigned int nch,
508 
                            int lsf, struct sideinfo *si,
509 
                            unsigned int *data_bitlen,
510 
                            unsigned int *priv_bitlen)
511 
{
512 
  unsigned int ngr, gr, ch, i;
513 
  enum mad_error result = 0;
514 
 
515 
  *data_bitlen = 0;
516 
  *priv_bitlen = lsf ? ((nch == 1) ? 1 : 2) : ((nch == 1) ? 5 : 3);
517 
 
518 
  si->main_data_begin = mad_bit_read(ptr, lsf ? 8 : 9);
519 
  si->private_bits    = mad_bit_read(ptr, *priv_bitlen);
520 
 
521 
  ngr = 1;
522 
  if (!lsf) {
523 
    ngr = 2;
524 
 
525 
    for (ch = 0; ch < nch; ++ch)
526 
      si->scfsi[ch] = mad_bit_read(ptr, 4);
527 
  }
528 
 
529 
  for (gr = 0; gr < ngr; ++gr) {
530 
    struct granule *granule = &si->gr[gr];
531 
 
532 
    for (ch = 0; ch < nch; ++ch) {
533 
      struct channel *channel = &granule->ch[ch];
534 
 
535 
      channel->part2_3_length    = mad_bit_read(ptr, 12);
536 
      channel->big_values        = mad_bit_read(ptr, 9);
537 
      channel->global_gain       = mad_bit_read(ptr, 8);
538 
      channel->scalefac_compress = mad_bit_read(ptr, lsf ? 9 : 4);
539 
 
540 
      *data_bitlen += channel->part2_3_length;
541 
 
542 
      if (channel->big_values > 288 && result == 0)
543 
        result = MAD_ERROR_BADBIGVALUES;
544 
 
545 
      channel->flags = 0;
546 
 
547 
      /* window_switching_flag */
548 
      if (mad_bit_read(ptr, 1)) {
549 
        channel->block_type = mad_bit_read(ptr, 2);
550 
 
551 
        if (channel->block_type == 0 && result == 0)
552 
          result = MAD_ERROR_BADBLOCKTYPE;
553 
 
554 
        if (!lsf && channel->block_type == 2 && si->scfsi[ch] && result == 0)
555 
          result = MAD_ERROR_BADSCFSI;
556 
 
557 
        channel->region0_count = 7;
558 
        channel->region1_count = 36;
559 
 
560 
        if (mad_bit_read(ptr, 1))
561 
          channel->flags |= mixed_block_flag;
562 
        else if (channel->block_type == 2)
563 
          channel->region0_count = 8;
564 
 
565 
        for (i = 0; i < 2; ++i)
566 
          channel->table_select[i] = mad_bit_read(ptr, 5);
567 
 
568 
# if defined(DEBUG)
569 
        channel->table_select[2] = 4;  /* not used */
570 
# endif
571 
 
572 
        for (i = 0; i < 3; ++i)
573 
          channel->subblock_gain[i] = mad_bit_read(ptr, 3);
574 
      }
575 
      else {
576 
        channel->block_type = 0;
577 
 
578 
        for (i = 0; i < 3; ++i)
579 
          channel->table_select[i] = mad_bit_read(ptr, 5);
580 
 
581 
        channel->region0_count = mad_bit_read(ptr, 4);
582 
        channel->region1_count = mad_bit_read(ptr, 3);
583 
      }
584 
 
585 
      /* [preflag,] scalefac_scale, count1table_select */
586 
      channel->flags |= mad_bit_read(ptr, lsf ? 2 : 3);
587 
    }
588 
  }
589 
 
590 
  return result;
591 
}
592 
 
593 
/*
594 
 * NAME:        III_scalefactors_lsf()
595 
 * DESCRIPTION: decode channel scalefactors for LSF from a bitstream
596 
 */
597 
static
598 
unsigned int III_scalefactors_lsf(struct mad_bitptr *ptr,
599 
                                  struct channel *channel,
600 
                                  struct channel *gr1ch, int mode_extension)
601 
{
602 
  struct mad_bitptr start;
603 
  unsigned int scalefac_compress, index, slen[4], part, n, i;
604 
  unsigned char const *nsfb;
605 
 
606 
  start = *ptr;
607 
 
608 
  scalefac_compress = channel->scalefac_compress;
609 
  index = (channel->block_type == 2) ?
610 
    ((channel->flags & mixed_block_flag) ? 2 : 1) : 0;
611 
 
612 
  if (!((mode_extension & 0x1) && gr1ch)) {
613 
    if (scalefac_compress < 400) {
614 
      slen[0] = (scalefac_compress >> 4) / 5;
615 
      slen[1] = (scalefac_compress >> 4) % 5;
616 
      slen[2] = (scalefac_compress % 16) >> 2;
617 
      slen[3] =  scalefac_compress %  4;
618 
 
619 
      nsfb = nsfb_table[0][index];
620 
    }
621 
    else if (scalefac_compress < 500) {
622 
      scalefac_compress -= 400;
623 
 
624 
      slen[0] = (scalefac_compress >> 2) / 5;
625 
      slen[1] = (scalefac_compress >> 2) % 5;
626 
      slen[2] =  scalefac_compress %  4;
627 
      slen[3] = 0;
628 
 
629 
      nsfb = nsfb_table[1][index];
630 
    }
631 
    else {
632 
      scalefac_compress -= 500;
633 
 
634 
      slen[0] = scalefac_compress / 3;
635 
      slen[1] = scalefac_compress % 3;
636 
      slen[2] = 0;
637 
      slen[3] = 0;
638 
 
639 
      channel->flags |= preflag;
640 
 
641 
      nsfb = nsfb_table[2][index];
642 
    }
643 
 
644 
    n = 0;
645 
    for (part = 0; part < 4; ++part) {
646 
      for (i = 0; i < nsfb[part]; ++i)
647 
        channel->scalefac[n++] = mad_bit_read(ptr, slen[part]);
648 
    }
649 
 
650 
    while (n < 39)
651 
      channel->scalefac[n++] = 0;
652 
  }
653 
  else {  /* (mode_extension & 0x1) && gr1ch (i.e. ch == 1) */
654 
    scalefac_compress >>= 1;
655 
 
656 
    if (scalefac_compress < 180) {
657 
      slen[0] =  scalefac_compress / 36;
658 
      slen[1] = (scalefac_compress % 36) / 6;
659 
      slen[2] = (scalefac_compress % 36) % 6;
660 
      slen[3] = 0;
661 
 
662 
      nsfb = nsfb_table[3][index];
663 
    }
664 
    else if (scalefac_compress < 244) {
665 
      scalefac_compress -= 180;
666 
 
667 
      slen[0] = (scalefac_compress % 64) >> 4;
668 
      slen[1] = (scalefac_compress % 16) >> 2;
669 
      slen[2] =  scalefac_compress %  4;
670 
      slen[3] = 0;
671 
 
672 
      nsfb = nsfb_table[4][index];
673 
    }
674 
    else {
675 
      scalefac_compress -= 244;
676 
 
677 
      slen[0] = scalefac_compress / 3;
678 
      slen[1] = scalefac_compress % 3;
679 
      slen[2] = 0;
680 
      slen[3] = 0;
681 
 
682 
      nsfb = nsfb_table[5][index];
683 
    }
684 
 
685 
    n = 0;
686 
    for (part = 0; part < 4; ++part) {
687 
      unsigned int max, is_pos;
688 
 
689 
      max = (1 << slen[part]) - 1;
690 
 
691 
      for (i = 0; i < nsfb[part]; ++i) {
692 
        is_pos = mad_bit_read(ptr, slen[part]);
693 
 
694 
        channel->scalefac[n] = is_pos;
695 
        gr1ch->scalefac[n++] = (is_pos == max);
696 
      }
697 
    }
698 
 
699 
    while (n < 39) {
700 
      channel->scalefac[n] = 0;
701 
      gr1ch->scalefac[n++] = 0;  /* apparently not illegal */
702 
    }
703 
  }
704 
 
705 
  return mad_bit_length(&start, ptr);
706 
}
707 
 
708 
/*
709 
 * NAME:        III_scalefactors()
710 
 * DESCRIPTION: decode channel scalefactors of one granule from a bitstream
711 
 */
712 
static
713 
unsigned int III_scalefactors(struct mad_bitptr *ptr, struct channel *channel,
714 
                              struct channel const *gr0ch, unsigned int scfsi)
715 
{
716 
  struct mad_bitptr start;
717 
  unsigned int slen1, slen2, sfbi;
718 
 
719 
  start = *ptr;
720 
 
721 
  slen1 = sflen_table[channel->scalefac_compress].slen1;
722 
  slen2 = sflen_table[channel->scalefac_compress].slen2;
723 
 
724 
  if (channel->block_type == 2) {
725 
    unsigned int nsfb;
726 
 
727 
    sfbi = 0;
728 
 
729 
    nsfb = (channel->flags & mixed_block_flag) ? 8 + 3 * 3 : 6 * 3;
730 
    while (nsfb--)
731 
      channel->scalefac[sfbi++] = mad_bit_read(ptr, slen1);
732 
 
733 
    nsfb = 6 * 3;
734 
    while (nsfb--)
735 
      channel->scalefac[sfbi++] = mad_bit_read(ptr, slen2);
736 
 
737 
    nsfb = 1 * 3;
738 
    while (nsfb--)
739 
      channel->scalefac[sfbi++] = 0;
740 
  }
741 
  else {  /* channel->block_type != 2 */
742 
    if (scfsi & 0x8) {
743 
      for (sfbi = 0; sfbi < 6; ++sfbi)
744 
        channel->scalefac[sfbi] = gr0ch->scalefac[sfbi];
745 
    }
746 
    else {
747 
      for (sfbi = 0; sfbi < 6; ++sfbi)
748 
        channel->scalefac[sfbi] = mad_bit_read(ptr, slen1);
749 
    }
750 
 
751 
    if (scfsi & 0x4) {
752 
      for (sfbi = 6; sfbi < 11; ++sfbi)
753 
        channel->scalefac[sfbi] = gr0ch->scalefac[sfbi];
754 
    }
755 
    else {
756 
      for (sfbi = 6; sfbi < 11; ++sfbi)
757 
        channel->scalefac[sfbi] = mad_bit_read(ptr, slen1);
758 
    }
759 
 
760 
    if (scfsi & 0x2) {
761 
      for (sfbi = 11; sfbi < 16; ++sfbi)
762 
        channel->scalefac[sfbi] = gr0ch->scalefac[sfbi];
763 
    }
764 
    else {
765 
      for (sfbi = 11; sfbi < 16; ++sfbi)
766 
        channel->scalefac[sfbi] = mad_bit_read(ptr, slen2);
767 
    }
768 
 
769 
    if (scfsi & 0x1) {
770 
      for (sfbi = 16; sfbi < 21; ++sfbi)
771 
        channel->scalefac[sfbi] = gr0ch->scalefac[sfbi];
772 
    }
773 
    else {
774 
      for (sfbi = 16; sfbi < 21; ++sfbi)
775 
        channel->scalefac[sfbi] = mad_bit_read(ptr, slen2);
776 
    }
777 
 
778 
    channel->scalefac[21] = 0;
779 
  }
780 
 
781 
  return mad_bit_length(&start, ptr);
782 
}
783 
 
784 
/*
785 
 * NAME:        III_exponents()
786 
 * DESCRIPTION: calculate scalefactor exponents
787 
 */
788 
static
789 
void III_exponents(struct channel const *channel,
790 
                   unsigned char const *sfbwidth, signed int exponents[39])
791 
{
792 
  signed int gain;
793 
  unsigned int scalefac_multiplier, sfbi;
794 
 
795 
  gain = (signed int) channel->global_gain - 210;
796 
  scalefac_multiplier = (channel->flags & scalefac_scale) ? 2 : 1;
797 
 
798 
  if (channel->block_type == 2) {
799 
    unsigned int l;
800 
    signed int gain0, gain1, gain2;
801 
 
802 
    sfbi = l = 0;
803 
 
804 
    if (channel->flags & mixed_block_flag) {
805 
      unsigned int premask;
806 
 
807 
      premask = (channel->flags & preflag) ? ~0 : 0;
808 
 
809 
      /* long block subbands 0-1 */
810 
 
811 
      while (l < 36) {
812 
        exponents[sfbi] = gain -
813 
          (signed int) ((channel->scalefac[sfbi] + (pretab[sfbi] & premask)) <<
814 
                        scalefac_multiplier);
815 
 
816 
        l += sfbwidth[sfbi++];
817 
      }
818 
    }
819 
 
820 
    /* this is probably wrong for 8000 Hz short/mixed blocks */
821 
 
822 
    gain0 = gain - 8 * (signed int) channel->subblock_gain[0];
823 
    gain1 = gain - 8 * (signed int) channel->subblock_gain[1];
824 
    gain2 = gain - 8 * (signed int) channel->subblock_gain[2];
825 
 
826 
    while (l < 576) {
827 
      exponents[sfbi + 0] = gain0 -
828 
        (signed int) (channel->scalefac[sfbi + 0] << scalefac_multiplier);
829 
      exponents[sfbi + 1] = gain1 -
830 
        (signed int) (channel->scalefac[sfbi + 1] << scalefac_multiplier);
831 
      exponents[sfbi + 2] = gain2 -
832 
        (signed int) (channel->scalefac[sfbi + 2] << scalefac_multiplier);
833 
 
834 
      l    += 3 * sfbwidth[sfbi];
835 
      sfbi += 3;
836 
    }
837 
  }
838 
  else {  /* channel->block_type != 2 */
839 
    if (channel->flags & preflag) {
840 
      for (sfbi = 0; sfbi < 22; ++sfbi) {
841 
        exponents[sfbi] = gain -
842 
          (signed int) ((channel->scalefac[sfbi] + pretab[sfbi]) <<
843 
                        scalefac_multiplier);
844 
      }
845 
    }
846 
    else {
847 
      for (sfbi = 0; sfbi < 22; ++sfbi) {
848 
        exponents[sfbi] = gain -
849 
          (signed int) (channel->scalefac[sfbi] << scalefac_multiplier);
850 
      }
851 
    }
852 
  }
853 
}
854 
 
855 
/*
856 
 * NAME:        III_requantize()
857 
 * DESCRIPTION: requantize one (positive) value
858 
 */
859 
static
860 
mad_fixed_t III_requantize(unsigned int value, signed int exp)
861 
{
862 
  mad_fixed_t requantized;
863 
  signed int frac;
864 
  struct fixedfloat const *power;
865 
 
866 
  /*
867 
   * long blocks:
868 
   * xr[i] = sign(is[i]) * abs(is[i])^(4/3) *
869 
   *         2^((1/4) * (global_gain - 210)) *
870 
   *         2^-(scalefac_multiplier *
871 
   *             (scalefac_l[sfb] + preflag * pretab[sfb]))
872 
   *
873 
   * short blocks:
874 
   * xr[i] = sign(is[i]) * abs(is[i])^(4/3) *
875 
   *         2^((1/4) * (global_gain - 210 - 8 * subblock_gain[w])) *
876 
   *         2^-(scalefac_multiplier * scalefac_s[sfb][w])
877 
   *
878 
   * where:
879 
   * scalefac_multiplier = (scalefac_scale + 1) / 2
880 
   */
881 
 
882 
  frac = exp % 4;
883 
  exp /= 4;
884 
 
885 
  /* MM: recalculation for short table */
886 
  if (value < (1 << RQ_START_BITS))
887 
    power = &rq_table[value];
888 
  else {
889 
    int bits = 0, tmp = value;
890 
    while (tmp != 0) {
891 
      tmp <<= 1;
892 
      bits++;
893 
    }
894 
    bits -= RQ_START_BITS;
895 
    value &= ~((1 << bits) - 1);
896 
    power = &rq_table[value];
897 
  }
898 
 
899 
  requantized = power->mantissa;
900 
  exp += power->exponent;
901 
 
902 
  if (exp < 0) {
903 
    if (-exp >= sizeof(mad_fixed_t) * CHAR_BIT) {
904 
      /* underflow */
905 
      requantized = 0;
906 
    }
907 
    else
908 
      requantized >>= -exp;
909 
  }
910 
  else {
911 
    if (exp >= 5) {
912 
      /* overflow */
913 
# if defined(DEBUG)
914 
      fprintf(stderr, "requantize overflow (%f * 2^%d)\n",
915 
              mad_f_todouble(requantized), exp);
916 
# endif
917 
      requantized = MAD_F_MAX;
918 
    }
919 
    else
920 
      requantized <<= exp;
921 
  }
922 
 
923 
  return frac ? mad_f_mul(requantized, root_table[3 + frac]) : requantized;
924 
}
925 
 
926 
/* we must take care that sz >= bits and sz < sizeof(long) lest bits == 0 */
927 
# define MASK(cache, sz, bits)  \
928 
    (((cache) >> ((sz) - (bits))) & ((1 << (bits)) - 1))
929 
# define MASK1BIT(cache, sz)  \
930 
    ((cache) & (1 << ((sz) - 1)))
931 
 
932 
/*
933 
 * NAME:        III_huffdecode()
934 
 * DESCRIPTION: decode Huffman code words of one channel of one granule
935 
 */
936 
static
937 
enum mad_error III_huffdecode(struct mad_bitptr *ptr, mad_fixed_t xr[576],
938 
                              struct channel *channel,
939 
                              unsigned char const *sfbwidth,
940 
                              unsigned int part2_length)
941 
{
942 
  signed int exponents[39], exp;
943 
  signed int const *expptr;
944 
  struct mad_bitptr peek;
945 
  signed int bits_left, cachesz;
946 
  register mad_fixed_t *xrptr;
947 
  mad_fixed_t const *sfbound;
948 
  register unsigned long bitcache;
949 
 
950 
  bits_left = (signed) channel->part2_3_length - (signed) part2_length;
951 
  if (bits_left < 0)
952 
    return MAD_ERROR_BADPART3LEN;
953 
 
954 
  III_exponents(channel, sfbwidth, exponents);
955 
 
956 
  peek = *ptr;
957 
  mad_bit_skip(ptr, bits_left);
958 
 
959 
  /* align bit reads to byte boundaries */
960 
  cachesz  = mad_bit_bitsleft(&peek);
961 
  cachesz += ((32 - 1 - 24) + (24 - cachesz)) & ~7;
962 
 
963 
  bitcache   = mad_bit_read(&peek, cachesz);
964 
  bits_left -= cachesz;
965 
 
966 
  xrptr = &xr[0];
967 
 
968 
  /* big_values */
969 
  {
970 
    unsigned int region, rcount;
971 
    struct hufftable const *entry;
972 
    union huffpair const *table;
973 
    unsigned int linbits, startbits, big_values, reqhits;
974 
    mad_fixed_t reqcache[16];
975 
 
976 
    sfbound = xrptr + *sfbwidth++;
977 
    rcount  = channel->region0_count + 1;
978 
 
979 
    entry     = &mad_huff_pair_table[channel->table_select[region = 0]];
980 
    table     = entry->table;
981 
    linbits   = entry->linbits;
982 
    startbits = entry->startbits;
983 
 
984 
    if (table == 0)
985 
      return MAD_ERROR_BADHUFFTABLE;
986 
 
987 
    expptr  = &exponents[0];
988 
    exp     = *expptr++;
989 
    reqhits = 0;
990 
 
991 
    big_values = channel->big_values;
992 
 
993 
    while (big_values-- && cachesz + bits_left > 0) {
994 
      union huffpair const *pair;
995 
      unsigned int clumpsz, value;
996 
      register mad_fixed_t requantized;
997 
 
998 
      if (xrptr == sfbound) {
999 
        sfbound += *sfbwidth++;
1000 
 
1001 
        /* change table if region boundary */
1002 
 
1003 
        if (--rcount == 0) {
1004 
          if (region == 0)
1005 
            rcount = channel->region1_count + 1;
1006 
          else
1007 
            rcount = 0;  /* all remaining */
1008 
 
1009 
          entry     = &mad_huff_pair_table[channel->table_select[++region]];
1010 
          table     = entry->table;
1011 
          linbits   = entry->linbits;
1012 
          startbits = entry->startbits;
1013 
 
1014 
          if (table == 0)
1015 
            return MAD_ERROR_BADHUFFTABLE;
1016 
        }
1017 
 
1018 
        if (exp != *expptr) {
1019 
          exp = *expptr;
1020 
          reqhits = 0;
1021 
        }
1022 
 
1023 
        ++expptr;
1024 
      }
1025 
 
1026 
      if (cachesz < 21) {
1027 
        unsigned int bits;
1028 
 
1029 
        bits       = ((32 - 1 - 21) + (21 - cachesz)) & ~7;
1030 
        bitcache   = (bitcache << bits) | mad_bit_read(&peek, bits);
1031 
        cachesz   += bits;
1032 
        bits_left -= bits;
1033 
      }
1034 
 
1035 
      /* hcod (0..19) */
1036 
 
1037 
      clumpsz = startbits;
1038 
      pair    = &table[MASK(bitcache, cachesz, clumpsz)];
1039 
 
1040 
      while (!pair->final) {
1041 
        cachesz -= clumpsz;
1042 
 
1043 
        clumpsz = pair->ptr.bits;
1044 
        pair    = &table[pair->ptr.offset + MASK(bitcache, cachesz, clumpsz)];
1045 
      }
1046 
 
1047 
      cachesz -= pair->value.hlen;
1048 
 
1049 
      {
1050 
        int xy_sel;
1051 
 
1052 
        /* MM: joint x and y */
1053 
        value = pair->value.x;
1054 
 
1055 
        /* x (0..14) and y (0..14) and x (0..1) and y (0..1) */
1056 
        for (xy_sel = 0; xy_sel < 2; xy_sel++) {
1057 
          if (value == 0)
1058 
            xrptr[xy_sel] = 0;
1059 
          else {
1060 
            if (value == 15 && linbits) {
1061 
              if (cachesz < linbits + 2 - xy_sel) {
1062 
                bitcache   = (bitcache << 16) | mad_bit_read(&peek, 16);
1063 
                cachesz   += 16;
1064 
                bits_left -= 16;
1065 
              }
1066 
 
1067 
              value += MASK(bitcache, cachesz, linbits);
1068 
              cachesz -= linbits;
1069 
 
1070 
              requantized = III_requantize(value, exp);
1071 
            }
1072 
            else {
1073 
              if (reqhits & (1 << value))
1074 
                requantized = reqcache[value];
1075 
              else {
1076 
                reqhits |= (1 << value);
1077 
                requantized = reqcache[value] = III_requantize(value, exp);
1078 
              }
1079 
            }
1080 
            xrptr[xy_sel] = MASK1BIT(bitcache, cachesz--) ?
1081 
              -requantized : requantized;
1082 
          }
1083 
          value = pair->value.y;
1084 
        }
1085 
      }
1086 
 
1087 
      xrptr += 2;
1088 
    }
1089 
  }
1090 
 
1091 
  if (cachesz + bits_left < 0)
1092 
    return MAD_ERROR_BADHUFFDATA;  /* big_values overrun */
1093 
 
1094 
  /* count1 */
1095 
  {
1096 
    union huffquad const *table;
1097 
    register mad_fixed_t requantized;
1098 
 
1099 
    table = mad_huff_quad_table[channel->flags & count1table_select];
1100 
 
1101 
    requantized = III_requantize(1, exp);
1102 
 
1103 
    while (cachesz + bits_left > 0 && xrptr <= &xr[572]) {
1104 
      union huffquad const *quad;
1105 
 
1106 
      /* hcod (1..6) */
1107 
 
1108 
      if (cachesz < 10) {
1109 
        bitcache   = (bitcache << 16) | mad_bit_read(&peek, 16);
1110 
        cachesz   += 16;
1111 
        bits_left -= 16;
1112 
      }
1113 
 
1114 
      quad = &table[MASK(bitcache, cachesz, 4)];
1115 
 
1116 
      /* quad tables guaranteed to have at most one extra lookup */
1117 
      if (!quad->final) {
1118 
        cachesz -= 4;
1119 
 
1120 
        quad = &table[quad->ptr.offset +
1121 
                      MASK(bitcache, cachesz, quad->ptr.bits)];
1122 
      }
1123 
 
1124 
      cachesz -= quad->value.hlen;
1125 
 
1126 
      /* MM: code joined */
1127 
      {
1128 
        int sel_12;
1129 
        int vw_xy_sel = *((int *) &quad->value);
1130 
        for (sel_12 = 0; sel_12 < 2; sel_12++) {
1131 
          if (xrptr == sfbound) {
1132 
            sfbound += *sfbwidth++;
1133 
 
1134 
            if (exp != *expptr) {
1135 
              exp = *expptr;
1136 
              requantized = III_requantize(1, exp);
1137 
            }
1138 
 
1139 
            ++expptr;
1140 
          }
1141 
          {
1142 
            int tmp = MASK1BIT(bitcache, cachesz--) ? -requantized : requantized;
1143 
 
1144 
            /* v (0..1) or x (0..1) */
1145 
            xrptr[0] = vw_xy_sel&4 ? tmp : 0;
1146 
 
1147 
            /* w (0..1) or y (0..1) */
1148 
            xrptr[1] = vw_xy_sel&8 ? tmp : 0;
1149 
          }
1150 
          xrptr += 2;
1151 
          vw_xy_sel >>= 2;
1152 
        }
1153 
      }
1154 
    }
1155 
 
1156 
    if (cachesz + bits_left < 0) {
1157 
# if 0 && defined(DEBUG)
1158 
      fprintf(stderr, "huffman count1 overrun (%d bits)\n",
1159 
              -(cachesz + bits_left));
1160 
# endif
1161 
 
1162 
      /* technically the bitstream is misformatted, but apparently
1163 
         some encoders are just a bit sloppy with stuffing bits */
1164 
 
1165 
      xrptr -= 4;
1166 
    }
1167 
  }
1168 
 
1169 
  assert(-bits_left <= MAD_BUFFER_GUARD * CHAR_BIT);
1170 
 
1171 
# if 0 && defined(DEBUG)
1172 
  if (bits_left < 0)
1173 
    fprintf(stderr, "read %d bits too many\n", -bits_left);
1174 
  else if (cachesz + bits_left > 0)
1175 
    fprintf(stderr, "%d stuffing bits\n", cachesz + bits_left);
1176 
# endif
1177 
 
1178 
  /* rzero */
1179 
  while (xrptr < &xr[576]) {
1180 
    xrptr[0] = 0;
1181 
    xrptr[1] = 0;
1182 
 
1183 
    xrptr += 2;
1184 
  }
1185 
 
1186 
  return 0;
1187 
}
1188 
 
1189 
# undef MASK
1190 
# undef MASK1BIT
1191 
 
1192 
/*
1193 
 * NAME:        III_reorder()
1194 
 * DESCRIPTION: reorder frequency lines of a short block into subband order
1195 
 */
1196 
static
1197 
void III_reorder(mad_fixed_t xr[576], struct channel const *channel,
1198 
                 unsigned char const sfbwidth[39])
1199 
{
1200 
  mad_fixed_t tmp[32][3][6];
1201 
  unsigned int sb, l, sfbi, f, w, sbw[3], sw[3];
1202 
 
1203 
  /* this is probably wrong for 8000 Hz mixed blocks */
1204 
 
1205 
  if (channel->flags & mixed_block_flag)
1206 
    sb = 2, sfbi = 3 * 3;
1207 
  else
1208 
    sb = 0, sfbi = 0;
1209 
 
1210 
  for (w = 0; w < 3; ++w) {
1211 
    sbw[w] = sb;
1212 
    sw[w]  = 0;
1213 
  }
1214 
 
1215 
  f = sfbwidth[sfbi];
1216 
  w = 0;
1217 
 
1218 
  for (l = 18 * sb; l < 576; ++l) {
1219 
    tmp[sbw[w]][w][sw[w]++] = xr[l];
1220 
 
1221 
    if (sw[w] == 6) {
1222 
      sw[w] = 0;
1223 
      ++sbw[w];
1224 
    }
1225 
 
1226 
    if (--f == 0) {
1227 
      if (++w == 3)
1228 
        w = 0;
1229 
 
1230 
      f = sfbwidth[++sfbi];
1231 
    }
1232 
  }
1233 
 
1234 
  memcpy(&xr[18 * sb], &tmp[sb], (576 - 18 * sb) * sizeof(mad_fixed_t));
1235 
}
1236 
 
1237 
/*
1238 
 * NAME:        III_stereo()
1239 
 * DESCRIPTION: perform joint stereo processing on a granule
1240 
 */
1241 
static
1242 
enum mad_error III_stereo(mad_fixed_t xr[2][576],
1243 
                          struct granule const *granule,
1244 
                          struct mad_header *header,
1245 
                          unsigned char const *sfbwidth)
1246 
{
1247 
  short modes[39];
1248 
  unsigned int sfbi, l, n, i;
1249 
 
1250 
  enum {
1251 
    i_stereo  = 0x1,
1252 
    ms_stereo = 0x2
1253 
  };
1254 
 
1255 
  if (granule->ch[0].block_type !=
1256 
      granule->ch[1].block_type ||
1257 
      (granule->ch[0].flags & mixed_block_flag) !=
1258 
      (granule->ch[1].flags & mixed_block_flag))
1259 
    return MAD_ERROR_BADSTEREO;
1260 
 
1261 
  for (i = 0; i < 39; ++i)
1262 
    modes[i] = header->mode_extension;
1263 
 
1264 
  /* intensity stereo */
1265 
 
1266 
  if (header->mode_extension & i_stereo) {
1267 
    struct channel const *right_ch = &granule->ch[1];
1268 
    mad_fixed_t const *right_xr = xr[1];
1269 
    unsigned int is_pos;
1270 
 
1271 
    header->flags |= MAD_FLAG_I_STEREO;
1272 
 
1273 
    /* first determine which scalefactor bands are to be processed */
1274 
 
1275 
    if (right_ch->block_type == 2) {
1276 
      unsigned int lower, start, max, bound[3], w;
1277 
 
1278 
      lower = start = max = bound[0] = bound[1] = bound[2] = 0;
1279 
 
1280 
      sfbi = l = 0;
1281 
 
1282 
      if (right_ch->flags & mixed_block_flag) {
1283 
        while (l < 36) {
1284 
          n = sfbwidth[sfbi++];
1285 
 
1286 
          for (i = 0; i < n; ++i) {
1287 
            if (right_xr[i]) {
1288 
              lower = sfbi;
1289 
              break;
1290 
            }
1291 
          }
1292 
 
1293 
          right_xr += n;
1294 
          l += n;
1295 
        }
1296 
 
1297 
        start = sfbi;
1298 
      }
1299 
 
1300 
      w = 0;
1301 
      while (l < 576) {
1302 
        n = sfbwidth[sfbi++];
1303 
 
1304 
        for (i = 0; i < n; ++i) {
1305 
          if (right_xr[i]) {
1306 
            max = bound[w] = sfbi;
1307 
            break;
1308 
          }
1309 
        }
1310 
 
1311 
        right_xr += n;
1312 
        l += n;
1313 
        w = (w + 1) % 3;
1314 
      }
1315 
 
1316 
      if (max)
1317 
        lower = start;
1318 
 
1319 
      /* long blocks */
1320 
 
1321 
      for (i = 0; i < lower; ++i)
1322 
        modes[i] = header->mode_extension & ~i_stereo;
1323 
 
1324 
      /* short blocks */
1325 
 
1326 
      w = 0;
1327 
      for (i = start; i < max; ++i) {
1328 
        if (i < bound[w])
1329 
          modes[i] = header->mode_extension & ~i_stereo;
1330 
 
1331 
        w = (w + 1) % 3;
1332 
      }
1333 
    }
1334 
    else {  /* right_ch->block_type != 2 */
1335 
      unsigned int bound;
1336 
 
1337 
      bound = 0;
1338 
      for (sfbi = l = 0; l < 576; l += n) {
1339 
        n = sfbwidth[sfbi++];
1340 
 
1341 
        for (i = 0; i < n; ++i) {
1342 
          if (right_xr[i]) {
1343 
            bound = sfbi;
1344 
            break;
1345 
          }
1346 
        }
1347 
 
1348 
        right_xr += n;
1349 
      }
1350 
 
1351 
      for (i = 0; i < bound; ++i)
1352 
        modes[i] = header->mode_extension & ~i_stereo;
1353 
    }
1354 
 
1355 
    /* now do the actual processing */
1356 
 
1357 
    if (header->flags & MAD_FLAG_LSF_EXT) {
1358 
      unsigned char const *illegal_pos = granule[1].ch[1].scalefac;
1359 
      mad_fixed_t const *lsf_scale;
1360 
 
1361 
      /* intensity_scale */
1362 
      lsf_scale = is_lsf_table[right_ch->scalefac_compress & 0x1];
1363 
 
1364 
      for (sfbi = l = 0; l < 576; ++sfbi, l += n) {
1365 
        n = sfbwidth[sfbi];
1366 
 
1367 
        if (!(modes[sfbi] & i_stereo))
1368 
          continue;
1369 
 
1370 
        if (illegal_pos[sfbi]) {
1371 
          modes[sfbi] &= ~i_stereo;
1372 
          continue;
1373 
        }
1374 
 
1375 
        is_pos = right_ch->scalefac[sfbi];
1376 
 
1377 
        for (i = 0; i < n; ++i) {
1378 
          register mad_fixed_t left;
1379 
 
1380 
          left = xr[0][l + i];
1381 
 
1382 
          if (is_pos == 0)
1383 
            xr[1][l + i] = left;
1384 
          else {
1385 
            register mad_fixed_t opposite;
1386 
 
1387 
            opposite = mad_f_mul(left, lsf_scale[(is_pos - 1) / 2]);
1388 
 
1389 
            if (is_pos & 1) {
1390 
              xr[0][l + i] = opposite;
1391 
              xr[1][l + i] = left;
1392 
            }
1393 
            else
1394 
              xr[1][l + i] = opposite;
1395 
          }
1396 
        }
1397 
      }
1398 
    }
1399 
    else {  /* !(header->flags & MAD_FLAG_LSF_EXT) */
1400 
      for (sfbi = l = 0; l < 576; ++sfbi, l += n) {
1401 
        n = sfbwidth[sfbi];
1402 
 
1403 
        if (!(modes[sfbi] & i_stereo))
1404 
          continue;
1405 
 
1406 
        is_pos = right_ch->scalefac[sfbi];
1407 
 
1408 
        if (is_pos >= 7) {  /* illegal intensity position */
1409 
          modes[sfbi] &= ~i_stereo;
1410 
          continue;
1411 
        }
1412 
 
1413 
        for (i = 0; i < n; ++i) {
1414 
          register mad_fixed_t left;
1415 
 
1416 
          left = xr[0][l + i];
1417 
 
1418 
          xr[0][l + i] = mad_f_mul(left, is_table[    is_pos]);
1419 
          xr[1][l + i] = mad_f_mul(left, is_table[6 - is_pos]);
1420 
        }
1421 
      }
1422 
    }
1423 
  }
1424 
 
1425 
  /* middle/side stereo */
1426 
 
1427 
  if (header->mode_extension & ms_stereo) {
1428 
    register mad_fixed_t invsqrt2;
1429 
 
1430 
    header->flags |= MAD_FLAG_MS_STEREO;
1431 
 
1432 
    invsqrt2 = root_table[3 + -2];
1433 
 
1434 
    for (sfbi = l = 0; l < 576; ++sfbi, l += n) {
1435 
      n = sfbwidth[sfbi];
1436 
 
1437 
      if (modes[sfbi] != ms_stereo)
1438 
        continue;
1439 
 
1440 
      for (i = 0; i < n; ++i) {
1441 
        register mad_fixed_t m, s;
1442 
 
1443 
        m = xr[0][l + i];
1444 
        s = xr[1][l + i];
1445 
 
1446 
        xr[0][l + i] = mad_f_mul(m + s, invsqrt2);  /* l = (m + s) / sqrt(2) */
1447 
        xr[1][l + i] = mad_f_mul(m - s, invsqrt2);  /* r = (m - s) / sqrt(2) */
1448 
      }
1449 
    }
1450 
  }
1451 
 
1452 
  return 0;
1453 
}
1454 
 
1455 
/*
1456 
 * NAME:        III_aliasreduce()
1457 
 * DESCRIPTION: perform frequency line alias reduction
1458 
 */
1459 
static
1460 
void III_aliasreduce(mad_fixed_t xr[576], int lines)
1461 
{
1462 
  mad_fixed_t const *bound;
1463 
  int i;
1464 
 
1465 
  bound = &xr[lines];
1466 
  for (xr += 18; xr < bound; xr += 18) {
1467 
    for (i = 0; i < 8; ++i) {
1468 
      register mad_fixed_t *aptr, *bptr, a, b;
1469 
      register mad_fixed64hi_t hi;
1470 
      register mad_fixed64lo_t lo;
1471 
 
1472 
      aptr = &xr[-1 - i];
1473 
      bptr = &xr[     i];
1474 
 
1475 
      a = *aptr;
1476 
      b = *bptr;
1477 
 
1478 
# if defined(ASO_ZEROCHECK)
1479 
      if (a | b) {
1480 
# endif
1481 
        MAD_F_ML0(hi, lo,  a, cs[i]);
1482 
        MAD_F_MLA(hi, lo, -b, ca[i]);
1483 
 
1484 
        *aptr = MAD_F_MLZ(hi, lo);
1485 
 
1486 
        MAD_F_ML0(hi, lo,  b, cs[i]);
1487 
        MAD_F_MLA(hi, lo,  a, ca[i]);
1488 
 
1489 
        *bptr = MAD_F_MLZ(hi, lo);
1490 
# if defined(ASO_ZEROCHECK)
1491 
      }
1492 
# endif
1493 
    }
1494 
  }
1495 
}
1496 
 
1497 
# if defined(ASO_IMDCT)
1498 
void III_imdct_l(mad_fixed_t const [18], mad_fixed_t [36], unsigned int);
1499 
# else
1500 
/*
1501 
 * NAME:        imdct36
1502 
 * DESCRIPTION: perform X[18]->x[36] IMDCT
1503 
 */
1504 
static inline
1505 
void imdct36(mad_fixed_t const X[18], mad_fixed_t x[36])
1506 
{
1507 
  mad_fixed_t t0, t1, t2,  t3,  t4,  t5,  t6,  t7;
1508 
  mad_fixed_t t8, t9, t10, t11, t12, t13, t14, t15;
1509 
  register mad_fixed64hi_t hi;
1510 
  register mad_fixed64lo_t lo;
1511 
 
1512 
  MAD_F_ML0(hi, lo, X[4],  MAD_F(0x0ec835e8));
1513 
  MAD_F_MLA(hi, lo, X[13], MAD_F(0x061f78aa));
1514 
 
1515 
  t6 = MAD_F_MLZ(hi, lo);
1516 
 
1517 
  MAD_F_MLA(hi, lo, (t14 = X[1] - X[10]), -MAD_F(0x061f78aa));
1518 
  MAD_F_MLA(hi, lo, (t15 = X[7] + X[16]), -MAD_F(0x0ec835e8));
1519 
 
1520 
  t0 = MAD_F_MLZ(hi, lo);
1521 
 
1522 
  MAD_F_MLA(hi, lo, (t8  = X[0] - X[11] - X[12]),  MAD_F(0x0216a2a2));
1523 
  MAD_F_MLA(hi, lo, (t9  = X[2] - X[9]  - X[14]),  MAD_F(0x09bd7ca0));
1524 
  MAD_F_MLA(hi, lo, (t10 = X[3] - X[8]  - X[15]), -MAD_F(0x0cb19346));
1525 
  MAD_F_MLA(hi, lo, (t11 = X[5] - X[6]  - X[17]), -MAD_F(0x0fdcf549));
1526 
 
1527 
  x[7]  = MAD_F_MLZ(hi, lo);
1528 
  x[10] = -x[7];
1529 
 
1530 
  MAD_F_ML0(hi, lo, t8,  -MAD_F(0x0cb19346));
1531 
  MAD_F_MLA(hi, lo, t9,   MAD_F(0x0fdcf549));
1532 
  MAD_F_MLA(hi, lo, t10,  MAD_F(0x0216a2a2));
1533 
  MAD_F_MLA(hi, lo, t11, -MAD_F(0x09bd7ca0));
1534 
 
1535 
  x[19] = x[34] = MAD_F_MLZ(hi, lo) - t0;
1536 
 
1537 
  t12 = X[0] - X[3] + X[8] - X[11] - X[12] + X[15];
1538 
  t13 = X[2] + X[5] - X[6] - X[9]  - X[14] - X[17];
1539 
 
1540 
  MAD_F_ML0(hi, lo, t12, -MAD_F(0x0ec835e8));
1541 
  MAD_F_MLA(hi, lo, t13,  MAD_F(0x061f78aa));
1542 
 
1543 
  x[22] = x[31] = MAD_F_MLZ(hi, lo) + t0;
1544 
 
1545 
  MAD_F_ML0(hi, lo, X[1],  -MAD_F(0x09bd7ca0));
1546 
  MAD_F_MLA(hi, lo, X[7],   MAD_F(0x0216a2a2));
1547 
  MAD_F_MLA(hi, lo, X[10], -MAD_F(0x0fdcf549));
1548 
  MAD_F_MLA(hi, lo, X[16],  MAD_F(0x0cb19346));
1549 
 
1550 
  t1 = MAD_F_MLZ(hi, lo) + t6;
1551 
 
1552 
  MAD_F_ML0(hi, lo, X[0],   MAD_F(0x03768962));
1553 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x0e313245));
1554 
  MAD_F_MLA(hi, lo, X[3],  -MAD_F(0x0ffc19fd));
1555 
  MAD_F_MLA(hi, lo, X[5],  -MAD_F(0x0acf37ad));
1556 
  MAD_F_MLA(hi, lo, X[6],   MAD_F(0x04cfb0e2));
1557 
  MAD_F_MLA(hi, lo, X[8],  -MAD_F(0x0898c779));
1558 
  MAD_F_MLA(hi, lo, X[9],   MAD_F(0x0d7e8807));
1559 
  MAD_F_MLA(hi, lo, X[11],  MAD_F(0x0f426cb5));
1560 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0bcbe352));
1561 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x00b2aa3e));
1562 
  MAD_F_MLA(hi, lo, X[15], -MAD_F(0x07635284));
1563 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0f9ee890));
1564 
 
1565 
  x[6]  = MAD_F_MLZ(hi, lo) + t1;
1566 
  x[11] = -x[6];
1567 
 
1568 
  MAD_F_ML0(hi, lo, X[0],  -MAD_F(0x0f426cb5));
1569 
  MAD_F_MLA(hi, lo, X[2],  -MAD_F(0x00b2aa3e));
1570 
  MAD_F_MLA(hi, lo, X[3],   MAD_F(0x0898c779));
1571 
  MAD_F_MLA(hi, lo, X[5],   MAD_F(0x0f9ee890));
1572 
  MAD_F_MLA(hi, lo, X[6],   MAD_F(0x0acf37ad));
1573 
  MAD_F_MLA(hi, lo, X[8],  -MAD_F(0x07635284));
1574 
  MAD_F_MLA(hi, lo, X[9],  -MAD_F(0x0e313245));
1575 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0bcbe352));
1576 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x03768962));
1577 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x0d7e8807));
1578 
  MAD_F_MLA(hi, lo, X[15],  MAD_F(0x0ffc19fd));
1579 
  MAD_F_MLA(hi, lo, X[17],  MAD_F(0x04cfb0e2));
1580 
 
1581 
  x[23] = x[30] = MAD_F_MLZ(hi, lo) + t1;
1582 
 
1583 
  MAD_F_ML0(hi, lo, X[0],  -MAD_F(0x0bcbe352));
1584 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x0d7e8807));
1585 
  MAD_F_MLA(hi, lo, X[3],  -MAD_F(0x07635284));
1586 
  MAD_F_MLA(hi, lo, X[5],   MAD_F(0x04cfb0e2));
1587 
  MAD_F_MLA(hi, lo, X[6],   MAD_F(0x0f9ee890));
1588 
  MAD_F_MLA(hi, lo, X[8],  -MAD_F(0x0ffc19fd));
1589 
  MAD_F_MLA(hi, lo, X[9],  -MAD_F(0x00b2aa3e));
1590 
  MAD_F_MLA(hi, lo, X[11],  MAD_F(0x03768962));
1591 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0f426cb5));
1592 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x0e313245));
1593 
  MAD_F_MLA(hi, lo, X[15],  MAD_F(0x0898c779));
1594 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0acf37ad));
1595 
 
1596 
  x[18] = x[35] = MAD_F_MLZ(hi, lo) - t1;
1597 
 
1598 
  MAD_F_ML0(hi, lo, X[4],   MAD_F(0x061f78aa));
1599 
  MAD_F_MLA(hi, lo, X[13], -MAD_F(0x0ec835e8));
1600 
 
1601 
  t7 = MAD_F_MLZ(hi, lo);
1602 
 
1603 
  MAD_F_MLA(hi, lo, X[1],  -MAD_F(0x0cb19346));
1604 
  MAD_F_MLA(hi, lo, X[7],   MAD_F(0x0fdcf549));
1605 
  MAD_F_MLA(hi, lo, X[10],  MAD_F(0x0216a2a2));
1606 
  MAD_F_MLA(hi, lo, X[16], -MAD_F(0x09bd7ca0));
1607 
 
1608 
  t2 = MAD_F_MLZ(hi, lo);
1609 
 
1610 
  MAD_F_MLA(hi, lo, X[0],   MAD_F(0x04cfb0e2));
1611 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x0ffc19fd));
1612 
  MAD_F_MLA(hi, lo, X[3],  -MAD_F(0x0d7e8807));
1613 
  MAD_F_MLA(hi, lo, X[5],   MAD_F(0x03768962));
1614 
  MAD_F_MLA(hi, lo, X[6],  -MAD_F(0x0bcbe352));
1615 
  MAD_F_MLA(hi, lo, X[8],  -MAD_F(0x0e313245));
1616 
  MAD_F_MLA(hi, lo, X[9],   MAD_F(0x07635284));
1617 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0acf37ad));
1618 
  MAD_F_MLA(hi, lo, X[12],  MAD_F(0x0f9ee890));
1619 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x0898c779));
1620 
  MAD_F_MLA(hi, lo, X[15],  MAD_F(0x00b2aa3e));
1621 
  MAD_F_MLA(hi, lo, X[17],  MAD_F(0x0f426cb5));
1622 
 
1623 
  x[5]  = MAD_F_MLZ(hi, lo);
1624 
  x[12] = -x[5];
1625 
 
1626 
  MAD_F_ML0(hi, lo, X[0],   MAD_F(0x0acf37ad));
1627 
  MAD_F_MLA(hi, lo, X[2],  -MAD_F(0x0898c779));
1628 
  MAD_F_MLA(hi, lo, X[3],   MAD_F(0x0e313245));
1629 
  MAD_F_MLA(hi, lo, X[5],  -MAD_F(0x0f426cb5));
1630 
  MAD_F_MLA(hi, lo, X[6],  -MAD_F(0x03768962));
1631 
  MAD_F_MLA(hi, lo, X[8],   MAD_F(0x00b2aa3e));
1632 
  MAD_F_MLA(hi, lo, X[9],  -MAD_F(0x0ffc19fd));
1633 
  MAD_F_MLA(hi, lo, X[11],  MAD_F(0x0f9ee890));
1634 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x04cfb0e2));
1635 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x07635284));
1636 
  MAD_F_MLA(hi, lo, X[15],  MAD_F(0x0d7e8807));
1637 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0bcbe352));
1638 
 
1639 
  x[0]  = MAD_F_MLZ(hi, lo) + t2;
1640 
  x[17] = -x[0];
1641 
 
1642 
  MAD_F_ML0(hi, lo, X[0],  -MAD_F(0x0f9ee890));
1643 
  MAD_F_MLA(hi, lo, X[2],  -MAD_F(0x07635284));
1644 
  MAD_F_MLA(hi, lo, X[3],  -MAD_F(0x00b2aa3e));
1645 
  MAD_F_MLA(hi, lo, X[5],   MAD_F(0x0bcbe352));
1646 
  MAD_F_MLA(hi, lo, X[6],   MAD_F(0x0f426cb5));
1647 
  MAD_F_MLA(hi, lo, X[8],   MAD_F(0x0d7e8807));
1648 
  MAD_F_MLA(hi, lo, X[9],   MAD_F(0x0898c779));
1649 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x04cfb0e2));
1650 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0acf37ad));
1651 
  MAD_F_MLA(hi, lo, X[14], -MAD_F(0x0ffc19fd));
1652 
  MAD_F_MLA(hi, lo, X[15], -MAD_F(0x0e313245));
1653 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x03768962));
1654 
 
1655 
  x[24] = x[29] = MAD_F_MLZ(hi, lo) + t2;
1656 
 
1657 
  MAD_F_ML0(hi, lo, X[1],  -MAD_F(0x0216a2a2));
1658 
  MAD_F_MLA(hi, lo, X[7],  -MAD_F(0x09bd7ca0));
1659 
  MAD_F_MLA(hi, lo, X[10],  MAD_F(0x0cb19346));
1660 
  MAD_F_MLA(hi, lo, X[16],  MAD_F(0x0fdcf549));
1661 
 
1662 
  t3 = MAD_F_MLZ(hi, lo) + t7;
1663 
 
1664 
  MAD_F_ML0(hi, lo, X[0],   MAD_F(0x00b2aa3e));
1665 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x03768962));
1666 
  MAD_F_MLA(hi, lo, X[3],  -MAD_F(0x04cfb0e2));
1667 
  MAD_F_MLA(hi, lo, X[5],  -MAD_F(0x07635284));
1668 
  MAD_F_MLA(hi, lo, X[6],   MAD_F(0x0898c779));
1669 
  MAD_F_MLA(hi, lo, X[8],   MAD_F(0x0acf37ad));
1670 
  MAD_F_MLA(hi, lo, X[9],  -MAD_F(0x0bcbe352));
1671 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0d7e8807));
1672 
  MAD_F_MLA(hi, lo, X[12],  MAD_F(0x0e313245));
1673 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x0f426cb5));
1674 
  MAD_F_MLA(hi, lo, X[15], -MAD_F(0x0f9ee890));
1675 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0ffc19fd));
1676 
 
1677 
  x[8] = MAD_F_MLZ(hi, lo) + t3;
1678 
  x[9] = -x[8];
1679 
 
1680 
  MAD_F_ML0(hi, lo, X[0],  -MAD_F(0x0e313245));
1681 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x0bcbe352));
1682 
  MAD_F_MLA(hi, lo, X[3],   MAD_F(0x0f9ee890));
1683 
  MAD_F_MLA(hi, lo, X[5],  -MAD_F(0x0898c779));
1684 
  MAD_F_MLA(hi, lo, X[6],  -MAD_F(0x0ffc19fd));
1685 
  MAD_F_MLA(hi, lo, X[8],   MAD_F(0x04cfb0e2));
1686 
  MAD_F_MLA(hi, lo, X[9],   MAD_F(0x0f426cb5));
1687 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x00b2aa3e));
1688 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0d7e8807));
1689 
  MAD_F_MLA(hi, lo, X[14], -MAD_F(0x03768962));
1690 
  MAD_F_MLA(hi, lo, X[15],  MAD_F(0x0acf37ad));
1691 
  MAD_F_MLA(hi, lo, X[17],  MAD_F(0x07635284));
1692 
 
1693 
  x[21] = x[32] = MAD_F_MLZ(hi, lo) + t3;
1694 
 
1695 
  MAD_F_ML0(hi, lo, X[0],  -MAD_F(0x0d7e8807));
1696 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x0f426cb5));
1697 
  MAD_F_MLA(hi, lo, X[3],   MAD_F(0x0acf37ad));
1698 
  MAD_F_MLA(hi, lo, X[5],  -MAD_F(0x0ffc19fd));
1699 
  MAD_F_MLA(hi, lo, X[6],  -MAD_F(0x07635284));
1700 
  MAD_F_MLA(hi, lo, X[8],   MAD_F(0x0f9ee890));
1701 
  MAD_F_MLA(hi, lo, X[9],   MAD_F(0x03768962));
1702 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0e313245));
1703 
  MAD_F_MLA(hi, lo, X[12],  MAD_F(0x00b2aa3e));
1704 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x0bcbe352));
1705 
  MAD_F_MLA(hi, lo, X[15], -MAD_F(0x04cfb0e2));
1706 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0898c779));
1707 
 
1708 
  x[20] = x[33] = MAD_F_MLZ(hi, lo) - t3;
1709 
 
1710 
  MAD_F_ML0(hi, lo, t14, -MAD_F(0x0ec835e8));
1711 
  MAD_F_MLA(hi, lo, t15,  MAD_F(0x061f78aa));
1712 
 
1713 
  t4 = MAD_F_MLZ(hi, lo) - t7;
1714 
 
1715 
  MAD_F_ML0(hi, lo, t12, MAD_F(0x061f78aa));
1716 
  MAD_F_MLA(hi, lo, t13, MAD_F(0x0ec835e8));
1717 
 
1718 
  x[4]  = MAD_F_MLZ(hi, lo) + t4;
1719 
  x[13] = -x[4];
1720 
 
1721 
  MAD_F_ML0(hi, lo, t8,   MAD_F(0x09bd7ca0));
1722 
  MAD_F_MLA(hi, lo, t9,  -MAD_F(0x0216a2a2));
1723 
  MAD_F_MLA(hi, lo, t10,  MAD_F(0x0fdcf549));
1724 
  MAD_F_MLA(hi, lo, t11, -MAD_F(0x0cb19346));
1725 
 
1726 
  x[1]  = MAD_F_MLZ(hi, lo) + t4;
1727 
  x[16] = -x[1];
1728 
 
1729 
  MAD_F_ML0(hi, lo, t8,  -MAD_F(0x0fdcf549));
1730 
  MAD_F_MLA(hi, lo, t9,  -MAD_F(0x0cb19346));
1731 
  MAD_F_MLA(hi, lo, t10, -MAD_F(0x09bd7ca0));
1732 
  MAD_F_MLA(hi, lo, t11, -MAD_F(0x0216a2a2));
1733 
 
1734 
  x[25] = x[28] = MAD_F_MLZ(hi, lo) + t4;
1735 
 
1736 
  MAD_F_ML0(hi, lo, X[1],  -MAD_F(0x0fdcf549));
1737 
  MAD_F_MLA(hi, lo, X[7],  -MAD_F(0x0cb19346));
1738 
  MAD_F_MLA(hi, lo, X[10], -MAD_F(0x09bd7ca0));
1739 
  MAD_F_MLA(hi, lo, X[16], -MAD_F(0x0216a2a2));
1740 
 
1741 
  t5 = MAD_F_MLZ(hi, lo) - t6;
1742 
 
1743 
  MAD_F_ML0(hi, lo, X[0],   MAD_F(0x0898c779));
1744 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x04cfb0e2));
1745 
  MAD_F_MLA(hi, lo, X[3],   MAD_F(0x0bcbe352));
1746 
  MAD_F_MLA(hi, lo, X[5],   MAD_F(0x00b2aa3e));
1747 
  MAD_F_MLA(hi, lo, X[6],   MAD_F(0x0e313245));
1748 
  MAD_F_MLA(hi, lo, X[8],  -MAD_F(0x03768962));
1749 
  MAD_F_MLA(hi, lo, X[9],   MAD_F(0x0f9ee890));
1750 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x07635284));
1751 
  MAD_F_MLA(hi, lo, X[12],  MAD_F(0x0ffc19fd));
1752 
  MAD_F_MLA(hi, lo, X[14], -MAD_F(0x0acf37ad));
1753 
  MAD_F_MLA(hi, lo, X[15],  MAD_F(0x0f426cb5));
1754 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0d7e8807));
1755 
 
1756 
  x[2]  = MAD_F_MLZ(hi, lo) + t5;
1757 
  x[15] = -x[2];
1758 
 
1759 
  MAD_F_ML0(hi, lo, X[0],   MAD_F(0x07635284));
1760 
  MAD_F_MLA(hi, lo, X[2],   MAD_F(0x0acf37ad));
1761 
  MAD_F_MLA(hi, lo, X[3],   MAD_F(0x03768962));
1762 
  MAD_F_MLA(hi, lo, X[5],   MAD_F(0x0d7e8807));
1763 
  MAD_F_MLA(hi, lo, X[6],  -MAD_F(0x00b2aa3e));
1764 
  MAD_F_MLA(hi, lo, X[8],   MAD_F(0x0f426cb5));
1765 
  MAD_F_MLA(hi, lo, X[9],  -MAD_F(0x04cfb0e2));
1766 
  MAD_F_MLA(hi, lo, X[11],  MAD_F(0x0ffc19fd));
1767 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0898c779));
1768 
  MAD_F_MLA(hi, lo, X[14],  MAD_F(0x0f9ee890));
1769 
  MAD_F_MLA(hi, lo, X[15], -MAD_F(0x0bcbe352));
1770 
  MAD_F_MLA(hi, lo, X[17],  MAD_F(0x0e313245));
1771 
 
1772 
  x[3]  = MAD_F_MLZ(hi, lo) + t5;
1773 
  x[14] = -x[3];
1774 
 
1775 
  MAD_F_ML0(hi, lo, X[0],  -MAD_F(0x0ffc19fd));
1776 
  MAD_F_MLA(hi, lo, X[2],  -MAD_F(0x0f9ee890));
1777 
  MAD_F_MLA(hi, lo, X[3],  -MAD_F(0x0f426cb5));
1778 
  MAD_F_MLA(hi, lo, X[5],  -MAD_F(0x0e313245));
1779 
  MAD_F_MLA(hi, lo, X[6],  -MAD_F(0x0d7e8807));
1780 
  MAD_F_MLA(hi, lo, X[8],  -MAD_F(0x0bcbe352));
1781 
  MAD_F_MLA(hi, lo, X[9],  -MAD_F(0x0acf37ad));
1782 
  MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0898c779));
1783 
  MAD_F_MLA(hi, lo, X[12], -MAD_F(0x07635284));
1784 
  MAD_F_MLA(hi, lo, X[14], -MAD_F(0x04cfb0e2));
1785 
  MAD_F_MLA(hi, lo, X[15], -MAD_F(0x03768962));
1786 
  MAD_F_MLA(hi, lo, X[17], -MAD_F(0x00b2aa3e));
1787 
 
1788 
  x[26] = x[27] = MAD_F_MLZ(hi, lo) + t5;
1789 
}
1790 
 
1791 
/*
1792 
 * NAME:        III_imdct_l()
1793 
 * DESCRIPTION: perform IMDCT and windowing for long blocks
1794 
 */
1795 
static
1796 
void III_imdct_l(mad_fixed_t const X[18], mad_fixed_t z[36],
1797 
                 unsigned int block_type)
1798 
{
1799 
  unsigned int i;
1800 
 
1801 
  /* IMDCT */
1802 
 
1803 
  imdct36(X, z);
1804 
 
1805 
  /* windowing */
1806 
 
1807 
  switch (block_type) {
1808 
  case 0:  /* normal window */
1809 
# if defined(ASO_INTERLEAVE1)
1810 
    {
1811 
      register mad_fixed_t tmp1, tmp2;
1812 
 
1813 
      tmp1 = window_l[0];
1814 
      tmp2 = window_l[1];
1815 
 
1816 
      for (i = 0; i < 34; i += 2) {
1817 
        z[i + 0] = mad_f_mul(z[i + 0], tmp1);
1818 
        tmp1 = window_l[i + 2];
1819 
        z[i + 1] = mad_f_mul(z[i + 1], tmp2);
1820 
        tmp2 = window_l[i + 3];
1821 
      }
1822 
 
1823 
      z[34] = mad_f_mul(z[34], tmp1);
1824 
      z[35] = mad_f_mul(z[35], tmp2);
1825 
    }
1826 
# elif defined(ASO_INTERLEAVE2)
1827 
    {
1828 
      register mad_fixed_t tmp1, tmp2;
1829 
 
1830 
      tmp1 = z[0];
1831 
      tmp2 = window_l[0];
1832 
 
1833 
      for (i = 0; i < 35; ++i) {
1834 
        z[i] = mad_f_mul(tmp1, tmp2);
1835 
        tmp1 = z[i + 1];
1836 
        tmp2 = window_l[i + 1];
1837 
      }
1838 
 
1839 
      z[35] = mad_f_mul(tmp1, tmp2);
1840 
    }
1841 
# elif 1
1842 
    for (i = 0; i < 36; i += 4) {
1843 
      z[i + 0] = mad_f_mul(z[i + 0], window_l[i + 0]);
1844 
      z[i + 1] = mad_f_mul(z[i + 1], window_l[i + 1]);
1845 
      z[i + 2] = mad_f_mul(z[i + 2], window_l[i + 2]);
1846 
      z[i + 3] = mad_f_mul(z[i + 3], window_l[i + 3]);
1847 
    }
1848 
# else
1849 
    for (i =  0; i < 36; ++i) z[i] = mad_f_mul(z[i], window_l[i]);
1850 
# endif
1851 
    break;
1852 
 
1853 
  case 1:  /* start block */
1854 
    for (i =  0; i < 18; ++i) z[i] = mad_f_mul(z[i], window_l[i]);
1855 
    /*  (i = 18; i < 24; ++i) z[i] unchanged */
1856 
    for (i = 24; i < 30; ++i) z[i] = mad_f_mul(z[i], window_s[i - 18]);
1857 
    for (i = 30; i < 36; ++i) z[i] = 0;
1858 
    break;
1859 
 
1860 
  case 3:  /* stop block */
1861 
    for (i =  0; i <  6; ++i) z[i] = 0;
1862 
    for (i =  6; i < 12; ++i) z[i] = mad_f_mul(z[i], window_s[i - 6]);
1863 
    /*  (i = 12; i < 18; ++i) z[i] unchanged */
1864 
    for (i = 18; i < 36; ++i) z[i] = mad_f_mul(z[i], window_l[i]);
1865 
    break;
1866 
  }
1867 
}
1868 
# endif  /* ASO_IMDCT */
1869 
 
1870 
/*
1871 
 * NAME:        III_imdct_s()
1872 
 * DESCRIPTION: perform IMDCT and windowing for short blocks
1873 
 */
1874 
static
1875 
void III_imdct_s(mad_fixed_t const X[18], mad_fixed_t z[36])
1876 
{
1877 
  mad_fixed_t y[36], *yptr;
1878 
  mad_fixed_t const *wptr;
1879 
  int w, i;
1880 
  register mad_fixed64hi_t hi;
1881 
  register mad_fixed64lo_t lo;
1882 
 
1883 
  /* IMDCT */
1884 
 
1885 
  yptr = &y[0];
1886 
 
1887 
  for (w = 0; w < 3; ++w) {
1888 
    register mad_fixed_t const (*s)[6];
1889 
 
1890 
    s = imdct_s;
1891 
 
1892 
    for (i = 0; i < 3; ++i) {
1893 
      MAD_F_ML0(hi, lo, X[0], (*s)[0]);
1894 
      MAD_F_MLA(hi, lo, X[1], (*s)[1]);
1895 
      MAD_F_MLA(hi, lo, X[2], (*s)[2]);
1896 
      MAD_F_MLA(hi, lo, X[3], (*s)[3]);
1897 
      MAD_F_MLA(hi, lo, X[4], (*s)[4]);
1898 
      MAD_F_MLA(hi, lo, X[5], (*s)[5]);
1899 
 
1900 
      yptr[i + 0] = MAD_F_MLZ(hi, lo);
1901 
      yptr[5 - i] = -yptr[i + 0];
1902 
 
1903 
      ++s;
1904 
 
1905 
      MAD_F_ML0(hi, lo, X[0], (*s)[0]);
1906 
      MAD_F_MLA(hi, lo, X[1], (*s)[1]);
1907 
      MAD_F_MLA(hi, lo, X[2], (*s)[2]);
1908 
      MAD_F_MLA(hi, lo, X[3], (*s)[3]);
1909 
      MAD_F_MLA(hi, lo, X[4], (*s)[4]);
1910 
      MAD_F_MLA(hi, lo, X[5], (*s)[5]);
1911 
 
1912 
      yptr[ i + 6] = MAD_F_MLZ(hi, lo);
1913 
      yptr[11 - i] = yptr[i + 6];
1914 
 
1915 
      ++s;
1916 
    }
1917 
 
1918 
    yptr += 12;
1919 
    X    += 6;
1920 
  }
1921 
 
1922 
  /* windowing, overlapping and concatenation */
1923 
 
1924 
  yptr = &y[0];
1925 
  wptr = &window_s[0];
1926 
 
1927 
  for (i = 0; i < 6; ++i) {
1928 
    z[i +  0] = 0;
1929 
    z[i +  6] = mad_f_mul(yptr[ 0 + 0], wptr[0]);
1930 
 
1931 
    MAD_F_ML0(hi, lo, yptr[ 0 + 6], wptr[6]);
1932 
    MAD_F_MLA(hi, lo, yptr[12 + 0], wptr[0]);
1933 
 
1934 
    z[i + 12] = MAD_F_MLZ(hi, lo);
1935 
 
1936 
    MAD_F_ML0(hi, lo, yptr[12 + 6], wptr[6]);
1937 
    MAD_F_MLA(hi, lo, yptr[24 + 0], wptr[0]);
1938 
 
1939 
    z[i + 18] = MAD_F_MLZ(hi, lo);
1940 
 
1941 
    z[i + 24] = mad_f_mul(yptr[24 + 6], wptr[6]);
1942 
    z[i + 30] = 0;
1943 
 
1944 
    ++yptr;
1945 
    ++wptr;
1946 
  }
1947 
}
1948 
 
1949 
/*
1950 
 * NAME:        III_overlap()
1951 
 * DESCRIPTION: perform overlap-add of windowed IMDCT outputs
1952 
 */
1953 
static
1954 
void III_overlap(mad_fixed_t const output[36], mad_fixed_t overlap[18],
1955 
                 mad_fixed_t sample[18][32], unsigned int sb)
1956 
{
1957 
  unsigned int i;
1958 
 
1959 
# if defined(ASO_INTERLEAVE2)
1960 
  {
1961 
    register mad_fixed_t tmp1, tmp2;
1962 
 
1963 
    tmp1 = overlap[0];
1964 
    tmp2 = overlap[1];
1965 
 
1966 
    for (i = 0; i < 16; i += 2) {
1967 
      sample[i + 0][sb] = output[i + 0] + tmp1;
1968 
      overlap[i + 0]    = output[i + 0 + 18];
1969 
      tmp1 = overlap[i + 2];
1970 
 
1971 
      sample[i + 1][sb] = output[i + 1] + tmp2;
1972 
      overlap[i + 1]    = output[i + 1 + 18];
1973 
      tmp2 = overlap[i + 3];
1974 
    }
1975 
 
1976 
    sample[16][sb] = output[16] + tmp1;
1977 
    overlap[16]    = output[16 + 18];
1978 
    sample[17][sb] = output[17] + tmp2;
1979 
    overlap[17]    = output[17 + 18];
1980 
  }
1981 
# elif 0
1982 
  for (i = 0; i < 18; i += 2) {
1983 
    sample[i + 0][sb] = output[i + 0] + overlap[i + 0];
1984 
    overlap[i + 0]    = output[i + 0 + 18];
1985 
 
1986 
    sample[i + 1][sb] = output[i + 1] + overlap[i + 1];
1987 
    overlap[i + 1]    = output[i + 1 + 18];
1988 
  }
1989 
# else
1990 
  for (i = 0; i < 18; ++i) {
1991 
    sample[i][sb] = output[i] + overlap[i];
1992 
    overlap[i]    = output[i + 18];
1993 
  }
1994 
# endif
1995 
}
1996 
 
1997 
/*
1998 
 * NAME:        III_overlap_z()
1999 
 * DESCRIPTION: perform "overlap-add" of zero IMDCT outputs
2000 
 */
2001 
static inline
2002 
void III_overlap_z(mad_fixed_t overlap[18],
2003 
                   mad_fixed_t sample[18][32], unsigned int sb)
2004 
{
2005 
  unsigned int i;
2006 
 
2007 
# if defined(ASO_INTERLEAVE2)
2008 
  {
2009 
    register mad_fixed_t tmp1, tmp2;
2010 
 
2011 
    tmp1 = overlap[0];
2012 
    tmp2 = overlap[1];
2013 
 
2014 
    for (i = 0; i < 16; i += 2) {
2015 
      sample[i + 0][sb] = tmp1;
2016 
      overlap[i + 0]    = 0;
2017 
      tmp1 = overlap[i + 2];
2018 
 
2019 
      sample[i + 1][sb] = tmp2;
2020 
      overlap[i + 1]    = 0;
2021 
      tmp2 = overlap[i + 3];
2022 
    }
2023 
 
2024 
    sample[16][sb] = tmp1;
2025 
    overlap[16]    = 0;
2026 
    sample[17][sb] = tmp2;
2027 
    overlap[17]    = 0;
2028 
  }
2029 
# else
2030 
  for (i = 0; i < 18; ++i) {
2031 
    sample[i][sb] = overlap[i];
2032 
    overlap[i]    = 0;
2033 
  }
2034 
# endif
2035 
}
2036 
 
2037 
/*
2038 
 * NAME:        III_freqinver()
2039 
 * DESCRIPTION: perform subband frequency inversion for odd sample lines
2040 
 */
2041 
static
2042 
void III_freqinver(mad_fixed_t sample[18][32], unsigned int sb)
2043 
{
2044 
  unsigned int i;
2045 
 
2046 
# if 1 || defined(ASO_INTERLEAVE1) || defined(ASO_INTERLEAVE2)
2047 
  {
2048 
    register mad_fixed_t tmp1, tmp2;
2049 
 
2050 
    tmp1 = sample[1][sb];
2051 
    tmp2 = sample[3][sb];
2052 
 
2053 
    for (i = 1; i < 13; i += 4) {
2054 
      sample[i + 0][sb] = -tmp1;
2055 
      tmp1 = sample[i + 4][sb];
2056 
      sample[i + 2][sb] = -tmp2;
2057 
      tmp2 = sample[i + 6][sb];
2058 
    }
2059 
 
2060 
    sample[13][sb] = -tmp1;
2061 
    tmp1 = sample[17][sb];
2062 
    sample[15][sb] = -tmp2;
2063 
    sample[17][sb] = -tmp1;
2064 
  }
2065 
# else
2066 
  for (i = 1; i < 18; i += 2)
2067 
    sample[i][sb] = -sample[i][sb];
2068 
# endif
2069 
}
2070 
 
2071 
/*
2072 
 * NAME:        III_decode()
2073 
 * DESCRIPTION: decode frame main_data
2074 
 */
2075 
static
2076 
int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame,
2077 
                struct sideinfo *si, unsigned int nch)
2078 
{
2079 
  struct mad_header *header = &frame->header;
2080 
  unsigned int sfreqi, ngr, gr;
2081 
 
2082 
  {
2083 
    unsigned int sfreq;
2084 
 
2085 
    sfreq = header->samplerate;
2086 
    if (header->flags & MAD_FLAG_MPEG_2_5_EXT)
2087 
      sfreq *= 2;
2088 
 
2089 
    /* 48000 => 0, 44100 => 1, 32000 => 2,
2090 
       24000 => 3, 22050 => 4, 16000 => 5 */
2091 
    sfreqi = ((sfreq >>  7) & 0x000f) +
2092 
             ((sfreq >> 15) & 0x0001) - 8;
2093 
 
2094 
    if (header->flags & MAD_FLAG_MPEG_2_5_EXT)
2095 
      sfreqi += 3;
2096 
  }
2097 
 
2098 
  /* scalefactors, Huffman decoding, requantization */
2099 
 
2100 
  ngr = (header->flags & MAD_FLAG_LSF_EXT) ? 1 : 2;
2101 
 
2102 
  for (gr = 0; gr < ngr; ++gr) {
2103 
    struct granule *granule = &si->gr[gr];
2104 
    unsigned char const *sfbwidth = 0;
2105 
    mad_fixed_t xr[2][576];
2106 
    unsigned int ch;
2107 
    enum mad_error error;
2108 
 
2109 
    for (ch = 0; ch < nch; ++ch) {
2110 
      struct channel *channel = &granule->ch[ch];
2111 
      unsigned int part2_length;
2112 
 
2113 
      sfbwidth = sfbwidth_table[sfreqi].l;
2114 
      if (channel->block_type == 2) {
2115 
        sfbwidth = (channel->flags & mixed_block_flag) ?
2116 
          sfbwidth_table[sfreqi].m : sfbwidth_table[sfreqi].s;
2117 
      }
2118 
 
2119 
      if (header->flags & MAD_FLAG_LSF_EXT) {
2120 
        part2_length = III_scalefactors_lsf(ptr, channel,
2121 
                                            ch == 0 ? 0 : &si->gr[1].ch[1],
2122 
                                            header->mode_extension);
2123 
      }
2124 
      else {
2125 
        part2_length = III_scalefactors(ptr, channel, &si->gr[0].ch[ch],
2126 
                                        gr == 0 ? 0 : si->scfsi[ch]);
2127 
      }
2128 
 
2129 
      error = III_huffdecode(ptr, xr[ch], channel, sfbwidth, part2_length);
2130 
      if (error)
2131 
        return error;
2132 
    }
2133 
 
2134 
    /* joint stereo processing */
2135 
 
2136 
    if (header->mode == MAD_MODE_JOINT_STEREO && header->mode_extension) {
2137 
      error = III_stereo(xr, granule, header, sfbwidth);
2138 
      if (error)
2139 
        return error;
2140 
    }
2141 
 
2142 
    /* reordering, alias reduction, IMDCT, overlap-add, frequency inversion */
2143 
 
2144 
    for (ch = 0; ch < nch; ++ch) {
2145 
      struct channel const *channel = &granule->ch[ch];
2146 
      mad_fixed_t (*sample)[32] = &frame->sbsample[ch][18 * gr];
2147 
      unsigned int sb, l, i, sblimit;
2148 
      mad_fixed_t output[36];
2149 
 
2150 
      if (channel->block_type == 2) {
2151 
        III_reorder(xr[ch], channel, sfbwidth_table[sfreqi].s);
2152 
 
2153 
# if !defined(OPT_STRICT)
2154 
        /*
2155 
         * According to ISO/IEC 11172-3, "Alias reduction is not applied for
2156 
         * granules with block_type == 2 (short block)." However, other
2157 
         * sources suggest alias reduction should indeed be performed on the
2158 
         * lower two subbands of mixed blocks. Most other implementations do
2159 
         * this, so by default we will too.
2160 
         */
2161 
        if (channel->flags & mixed_block_flag)
2162 
          III_aliasreduce(xr[ch], 36);
2163 
# endif
2164 
      }
2165 
      else
2166 
        III_aliasreduce(xr[ch], 576);
2167 
 
2168 
      l = 0;
2169 
 
2170 
      /* subbands 0-1 */
2171 
 
2172 
      if (channel->block_type != 2 || (channel->flags & mixed_block_flag)) {
2173 
        unsigned int block_type;
2174 
 
2175 
        block_type = channel->block_type;
2176 
        if (channel->flags & mixed_block_flag)
2177 
          block_type = 0;
2178 
 
2179 
        /* long blocks */
2180 
        for (sb = 0; sb < 2; ++sb, l += 18) {
2181 
          III_imdct_l(&xr[ch][l], output, block_type);
2182 
          III_overlap(output, (*frame->overlap)[ch][sb], sample, sb);
2183 
        }
2184 
      }
2185 
      else {
2186 
        /* short blocks */
2187 
        for (sb = 0; sb < 2; ++sb, l += 18) {
2188 
          III_imdct_s(&xr[ch][l], output);
2189 
          III_overlap(output, (*frame->overlap)[ch][sb], sample, sb);
2190 
        }
2191 
      }
2192 
 
2193 
      III_freqinver(sample, 1);
2194 
 
2195 
      /* (nonzero) subbands 2-31 */
2196 
 
2197 
      i = 576;
2198 
      while (i > 36 && xr[ch][i - 1] == 0)
2199 
        --i;
2200 
 
2201 
      sblimit = 32 - (576 - i) / 18;
2202 
 
2203 
      if (channel->block_type != 2) {
2204 
        /* long blocks */
2205 
        for (sb = 2; sb < sblimit; ++sb, l += 18) {
2206 
          III_imdct_l(&xr[ch][l], output, channel->block_type);
2207 
          III_overlap(output, (*frame->overlap)[ch][sb], sample, sb);
2208 
 
2209 
          if (sb & 1)
2210 
            III_freqinver(sample, sb);
2211 
        }
2212 
      }
2213 
      else {
2214 
        /* short blocks */
2215 
        for (sb = 2; sb < sblimit; ++sb, l += 18) {
2216 
          III_imdct_s(&xr[ch][l], output);
2217 
          III_overlap(output, (*frame->overlap)[ch][sb], sample, sb);
2218 
 
2219 
          if (sb & 1)
2220 
            III_freqinver(sample, sb);
2221 
        }
2222 
      }
2223 
 
2224 
      /* remaining (zero) subbands */
2225 
 
2226 
      for (sb = sblimit; sb < 32; ++sb) {
2227 
        III_overlap_z((*frame->overlap)[ch][sb], sample, sb);
2228 
 
2229 
        if (sb & 1)
2230 
          III_freqinver(sample, sb);
2231 
      }
2232 
    }
2233 
  }
2234 
 
2235 
  return 0;
2236 
}
2237 
 
2238 
unsigned char g_main_data[MAD_BUFFER_MDLEN];
2239 
mad_fixed_t g_frame_overlap [2][32][18];
2240 
 
2241 
/*
2242 
 * NAME:        layer->III()
2243 
 * DESCRIPTION: decode a single Layer III frame
2244 
 */
2245 
int mad_layer_III(struct mad_stream *stream, struct mad_frame *frame)
2246 
{
2247 
  struct mad_header *header = &frame->header;
2248 
  unsigned int nch, priv_bitlen, next_md_begin = 0;
2249 
  unsigned int si_len, data_bitlen, md_len;
2250 
  unsigned int frame_space, frame_used, frame_free;
2251 
  struct mad_bitptr ptr;
2252 
  struct sideinfo si;
2253 
  enum mad_error error;
2254 
  int result = 0;
2255 
 
2256 
  /* allocate Layer III dynamic structures */
2257 
 
2258 
  if (!stream->main_data)
2259 
    stream->main_data = (unsigned char *)stream->buffer; //&g_main_data;
2260 
  frame->overlap = &g_frame_overlap;
2261 
 
2262 
  nch = MAD_NCHANNELS(header);
2263 
  si_len = (header->flags & MAD_FLAG_LSF_EXT) ?
2264 
    (nch == 1 ? 9 : 17) : (nch == 1 ? 17 : 32);
2265 
 
2266 
  /* check frame sanity */
2267 
 
2268 
  if (stream->next_frame - mad_bit_nextbyte(&stream->ptr) <
2269 
      (signed int) si_len) {
2270 
    stream->error = MAD_ERROR_BADFRAMELEN;
2271 
    stream->md_len = 0;
2272 
    return -1;
2273 
  }
2274 
 
2275 
  /* check CRC word */
2276 
 
2277 
  if (header->flags & MAD_FLAG_PROTECTION) {
2278 
    header->crc_check =
2279 
      mad_bit_crc(stream->ptr, si_len * CHAR_BIT, header->crc_check);
2280 
 
2281 
    if (header->crc_check != header->crc_target &&
2282 
        !(frame->options & MAD_OPTION_IGNORECRC)) {
2283 
      stream->error = MAD_ERROR_BADCRC;
2284 
      result = -1;
2285 
    }
2286 
  }
2287 
 
2288 
  /* decode frame side information */
2289 
 
2290 
  error = III_sideinfo(&stream->ptr, nch, header->flags & MAD_FLAG_LSF_EXT,
2291 
                       &si, &data_bitlen, &priv_bitlen);
2292 
  if (error && result == 0) {
2293 
    stream->error = error;
2294 
    result = -1;
2295 
  }
2296 
 
2297 
  header->flags        |= priv_bitlen;
2298 
  header->private_bits |= si.private_bits;
2299 
 
2300 
  /* find main_data of next frame */
2301 
 
2302 
  {
2303 
    struct mad_bitptr peek;
2304 
    unsigned long header;
2305 
 
2306 
    mad_bit_init(&peek, stream->next_frame);
2307 
 
2308 
    header = mad_bit_read(&peek, 32);
2309 
    if ((header & 0xffe60000L) /* syncword | layer */ == 0xffe20000L) {
2310 
      if (!(header & 0x00010000L))  /* protection_bit */
2311 
        mad_bit_skip(&peek, 16);  /* crc_check */
2312 
 
2313 
      next_md_begin =
2314 
        mad_bit_read(&peek, (header & 0x00080000L) /* ID */ ? 9 : 8);
2315 
    }
2316 
 
2317 
    mad_bit_finish(&peek);
2318 
  }
2319 
 
2320 
  /* find main_data of this frame */
2321 
 
2322 
  frame_space = stream->next_frame - mad_bit_nextbyte(&stream->ptr);
2323 
 
2324 
  if (next_md_begin > si.main_data_begin + frame_space)
2325 
    next_md_begin = 0;
2326 
 
2327 
  md_len = si.main_data_begin + frame_space - next_md_begin;
2328 
 
2329 
  frame_used = 0;
2330 
 
2331 
  if (si.main_data_begin == 0) {
2332 
    ptr = stream->ptr;
2333 
    stream->md_len = 0;
2334 
 
2335 
    frame_used = md_len;
2336 
  }
2337 
  else {
2338 
    if (si.main_data_begin > stream->md_len) {
2339 
      if (result == 0) {
2340 
        stream->error = MAD_ERROR_BADDATAPTR;
2341 
        result = -1;
2342 
      }
2343 
    }
2344 
    else {
2345 
       mad_bit_init(&ptr,
2346 
                   stream->main_data + stream->md_len - si.main_data_begin);
2347 
 
2348 
      if (md_len > si.main_data_begin) {
2349 
        assert(stream->md_len + md_len -
2350 
               si.main_data_begin <= MAD_BUFFER_MDLEN);
2351 
 
2352 
        memcpy(stream->main_data + stream->md_len,
2353 
               mad_bit_nextbyte(&stream->ptr),
2354 
               frame_used = md_len - si.main_data_begin);
2355 
        stream->md_len += frame_used;
2356 
      }
2357 
    }
2358 
  }
2359 
 
2360 
  frame_free = frame_space - frame_used;
2361 
 
2362 
  /* decode main_data */
2363 
 
2364 
  if (result == 0) {
2365 
    error = III_decode(&ptr, frame, &si, nch);
2366 
    if (error) {
2367 
      stream->error = error;
2368 
      result = -1;
2369 
    }
2370 
  }
2371 
 
2372 
  /* designate ancillary bits */
2373 
 
2374 
  stream->anc_ptr    = ptr;
2375 
  stream->anc_bitlen = md_len * CHAR_BIT - data_bitlen;
2376 
 
2377 
  /*  fprintf(stderr,
2378 
          "main_data_begin:%u, md_len:%u, frame_free:%u, "
2379 
          "data_bitlen:%u, anc_bitlen: %u\n",
2380 
          si.main_data_begin, md_len, frame_free,
2381 
          data_bitlen, stream->anc_bitlen);*/
2382 
 
2383 
  /* preload main_data buffer with up to 511 bytes for next frame(s) */
2384 
 
2385 
  if (frame_free >= next_md_begin) {
2386 
    memcpy(stream->main_data,
2387 
           stream->next_frame - next_md_begin, next_md_begin);
2388 
 
2389 
    stream->md_len = next_md_begin;
2390 
  }
2391 
  else {
2392 
    if (md_len < si.main_data_begin) {
2393 
      unsigned int extra;
2394 
      extra = si.main_data_begin - md_len;
2395 
      if (extra + frame_free > next_md_begin)
2396 
        extra = next_md_begin - frame_free;
2397 
 
2398 
      if (extra < stream->md_len) {
2399 
        memmove(stream->main_data,
2400 
                stream->main_data + stream->md_len - extra, extra);
2401 
        stream->md_len = extra;
2402 
      }
2403 
    }
2404 
    else
2405 
      stream->md_len = 0;
2406 
 
2407 
    memcpy(stream->main_data + stream->md_len,
2408 
      stream->next_frame - frame_free, frame_free);
2409 
    stream->md_len += frame_free;
2410 
  }
2411 
  return result;
2412 
}

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