You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

2507 lines
74KB

  1. /*
  2. * MPEG Audio decoder
  3. * Copyright (c) 2001, 2002 Fabrice Bellard.
  4. *
  5. * This library is free software; you can redistribute it and/or
  6. * modify it under the terms of the GNU Lesser General Public
  7. * License as published by the Free Software Foundation; either
  8. * version 2 of the License, or (at your option) any later version.
  9. *
  10. * This library 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 GNU
  13. * Lesser General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU Lesser General Public
  16. * License along with this library; if not, write to the Free Software
  17. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18. */
  19. /**
  20. * @file mpegaudiodec.c
  21. * MPEG Audio decoder.
  22. */
  23. //#define DEBUG
  24. #include "avcodec.h"
  25. #include "mpegaudio.h"
  26. /*
  27. * TODO:
  28. * - in low precision mode, use more 16 bit multiplies in synth filter
  29. * - test lsf / mpeg25 extensively.
  30. */
  31. /* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
  32. audio decoder */
  33. #ifdef CONFIG_MPEGAUDIO_HP
  34. #define USE_HIGHPRECISION
  35. #endif
  36. #ifdef USE_HIGHPRECISION
  37. #define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
  38. #define WFRAC_BITS 16 /* fractional bits for window */
  39. #else
  40. #define FRAC_BITS 15 /* fractional bits for sb_samples and dct */
  41. #define WFRAC_BITS 14 /* fractional bits for window */
  42. #endif
  43. #define FRAC_ONE (1 << FRAC_BITS)
  44. #define MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
  45. #define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
  46. #define FIX(a) ((int)((a) * FRAC_ONE))
  47. /* WARNING: only correct for posititive numbers */
  48. #define FIXR(a) ((int)((a) * FRAC_ONE + 0.5))
  49. #define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)
  50. #if FRAC_BITS <= 15
  51. typedef int16_t MPA_INT;
  52. #else
  53. typedef int32_t MPA_INT;
  54. #endif
  55. /****************/
  56. #define HEADER_SIZE 4
  57. #define BACKSTEP_SIZE 512
  58. typedef struct MPADecodeContext {
  59. uint8_t inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE]; /* input buffer */
  60. int inbuf_index;
  61. uint8_t *inbuf_ptr, *inbuf;
  62. int frame_size;
  63. int free_format_frame_size; /* frame size in case of free format
  64. (zero if currently unknown) */
  65. /* next header (used in free format parsing) */
  66. uint32_t free_format_next_header;
  67. int error_protection;
  68. int layer;
  69. int sample_rate;
  70. int sample_rate_index; /* between 0 and 8 */
  71. int bit_rate;
  72. int old_frame_size;
  73. GetBitContext gb;
  74. int nb_channels;
  75. int mode;
  76. int mode_ext;
  77. int lsf;
  78. MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2] __attribute__((aligned(16)));
  79. int synth_buf_offset[MPA_MAX_CHANNELS];
  80. int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT] __attribute__((aligned(16)));
  81. int32_t mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
  82. #ifdef DEBUG
  83. int frame_count;
  84. #endif
  85. } MPADecodeContext;
  86. /* layer 3 "granule" */
  87. typedef struct GranuleDef {
  88. uint8_t scfsi;
  89. int part2_3_length;
  90. int big_values;
  91. int global_gain;
  92. int scalefac_compress;
  93. uint8_t block_type;
  94. uint8_t switch_point;
  95. int table_select[3];
  96. int subblock_gain[3];
  97. uint8_t scalefac_scale;
  98. uint8_t count1table_select;
  99. int region_size[3]; /* number of huffman codes in each region */
  100. int preflag;
  101. int short_start, long_end; /* long/short band indexes */
  102. uint8_t scale_factors[40];
  103. int32_t sb_hybrid[SBLIMIT * 18]; /* 576 samples */
  104. } GranuleDef;
  105. #define MODE_EXT_MS_STEREO 2
  106. #define MODE_EXT_I_STEREO 1
  107. /* layer 3 huffman tables */
  108. typedef struct HuffTable {
  109. int xsize;
  110. const uint8_t *bits;
  111. const uint16_t *codes;
  112. } HuffTable;
  113. #include "mpegaudiodectab.h"
  114. /* vlc structure for decoding layer 3 huffman tables */
  115. static VLC huff_vlc[16];
  116. static uint8_t *huff_code_table[16];
  117. static VLC huff_quad_vlc[2];
  118. /* computed from band_size_long */
  119. static uint16_t band_index_long[9][23];
  120. /* XXX: free when all decoders are closed */
  121. #define TABLE_4_3_SIZE (8191 + 16)
  122. static int8_t *table_4_3_exp;
  123. #if FRAC_BITS <= 15
  124. static uint16_t *table_4_3_value;
  125. #else
  126. static uint32_t *table_4_3_value;
  127. #endif
  128. /* intensity stereo coef table */
  129. static int32_t is_table[2][16];
  130. static int32_t is_table_lsf[2][2][16];
  131. static int32_t csa_table[8][2];
  132. static int32_t mdct_win[8][36];
  133. /* lower 2 bits: modulo 3, higher bits: shift */
  134. static uint16_t scale_factor_modshift[64];
  135. /* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
  136. static int32_t scale_factor_mult[15][3];
  137. /* mult table for layer 2 group quantization */
  138. #define SCALE_GEN(v) \
  139. { FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
  140. static int32_t scale_factor_mult2[3][3] = {
  141. SCALE_GEN(4.0 / 3.0), /* 3 steps */
  142. SCALE_GEN(4.0 / 5.0), /* 5 steps */
  143. SCALE_GEN(4.0 / 9.0), /* 9 steps */
  144. };
  145. /* 2^(n/4) */
  146. static uint32_t scale_factor_mult3[4] = {
  147. FIXR(1.0),
  148. FIXR(1.18920711500272106671),
  149. FIXR(1.41421356237309504880),
  150. FIXR(1.68179283050742908605),
  151. };
  152. static MPA_INT window[512] __attribute__((aligned(16)));
  153. /* layer 1 unscaling */
  154. /* n = number of bits of the mantissa minus 1 */
  155. static inline int l1_unscale(int n, int mant, int scale_factor)
  156. {
  157. int shift, mod;
  158. int64_t val;
  159. shift = scale_factor_modshift[scale_factor];
  160. mod = shift & 3;
  161. shift >>= 2;
  162. val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
  163. shift += n;
  164. /* NOTE: at this point, 1 <= shift >= 21 + 15 */
  165. return (int)((val + (1LL << (shift - 1))) >> shift);
  166. }
  167. static inline int l2_unscale_group(int steps, int mant, int scale_factor)
  168. {
  169. int shift, mod, val;
  170. shift = scale_factor_modshift[scale_factor];
  171. mod = shift & 3;
  172. shift >>= 2;
  173. val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
  174. /* NOTE: at this point, 0 <= shift <= 21 */
  175. if (shift > 0)
  176. val = (val + (1 << (shift - 1))) >> shift;
  177. return val;
  178. }
  179. /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
  180. static inline int l3_unscale(int value, int exponent)
  181. {
  182. #if FRAC_BITS <= 15
  183. unsigned int m;
  184. #else
  185. uint64_t m;
  186. #endif
  187. int e;
  188. e = table_4_3_exp[value];
  189. e += (exponent >> 2);
  190. e = FRAC_BITS - e;
  191. #if FRAC_BITS <= 15
  192. if (e > 31)
  193. e = 31;
  194. #endif
  195. m = table_4_3_value[value];
  196. #if FRAC_BITS <= 15
  197. m = (m * scale_factor_mult3[exponent & 3]);
  198. m = (m + (1 << (e-1))) >> e;
  199. return m;
  200. #else
  201. m = MUL64(m, scale_factor_mult3[exponent & 3]);
  202. m = (m + (uint64_t_C(1) << (e-1))) >> e;
  203. return m;
  204. #endif
  205. }
  206. /* all integer n^(4/3) computation code */
  207. #define DEV_ORDER 13
  208. #define POW_FRAC_BITS 24
  209. #define POW_FRAC_ONE (1 << POW_FRAC_BITS)
  210. #define POW_FIX(a) ((int)((a) * POW_FRAC_ONE))
  211. #define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)
  212. static int dev_4_3_coefs[DEV_ORDER];
  213. static int pow_mult3[3] = {
  214. POW_FIX(1.0),
  215. POW_FIX(1.25992104989487316476),
  216. POW_FIX(1.58740105196819947474),
  217. };
  218. static void int_pow_init(void)
  219. {
  220. int i, a;
  221. a = POW_FIX(1.0);
  222. for(i=0;i<DEV_ORDER;i++) {
  223. a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);
  224. dev_4_3_coefs[i] = a;
  225. }
  226. }
  227. /* return the mantissa and the binary exponent */
  228. static int int_pow(int i, int *exp_ptr)
  229. {
  230. int e, er, eq, j;
  231. int a, a1;
  232. /* renormalize */
  233. a = i;
  234. e = POW_FRAC_BITS;
  235. while (a < (1 << (POW_FRAC_BITS - 1))) {
  236. a = a << 1;
  237. e--;
  238. }
  239. a -= (1 << POW_FRAC_BITS);
  240. a1 = 0;
  241. for(j = DEV_ORDER - 1; j >= 0; j--)
  242. a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);
  243. a = (1 << POW_FRAC_BITS) + a1;
  244. /* exponent compute (exact) */
  245. e = e * 4;
  246. er = e % 3;
  247. eq = e / 3;
  248. a = POW_MULL(a, pow_mult3[er]);
  249. while (a >= 2 * POW_FRAC_ONE) {
  250. a = a >> 1;
  251. eq++;
  252. }
  253. /* convert to float */
  254. while (a < POW_FRAC_ONE) {
  255. a = a << 1;
  256. eq--;
  257. }
  258. /* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
  259. #if POW_FRAC_BITS > FRAC_BITS
  260. a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
  261. /* correct overflow */
  262. if (a >= 2 * (1 << FRAC_BITS)) {
  263. a = a >> 1;
  264. eq++;
  265. }
  266. #endif
  267. *exp_ptr = eq;
  268. return a;
  269. }
  270. static int decode_init(AVCodecContext * avctx)
  271. {
  272. MPADecodeContext *s = avctx->priv_data;
  273. static int init=0;
  274. int i, j, k;
  275. if(!init) {
  276. /* scale factors table for layer 1/2 */
  277. for(i=0;i<64;i++) {
  278. int shift, mod;
  279. /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
  280. shift = (i / 3);
  281. mod = i % 3;
  282. scale_factor_modshift[i] = mod | (shift << 2);
  283. }
  284. /* scale factor multiply for layer 1 */
  285. for(i=0;i<15;i++) {
  286. int n, norm;
  287. n = i + 2;
  288. norm = ((int64_t_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
  289. scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);
  290. scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);
  291. scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm);
  292. dprintf("%d: norm=%x s=%x %x %x\n",
  293. i, norm,
  294. scale_factor_mult[i][0],
  295. scale_factor_mult[i][1],
  296. scale_factor_mult[i][2]);
  297. }
  298. /* window */
  299. /* max = 18760, max sum over all 16 coefs : 44736 */
  300. for(i=0;i<257;i++) {
  301. int v;
  302. v = mpa_enwindow[i];
  303. #if WFRAC_BITS < 16
  304. v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
  305. #endif
  306. window[i] = v;
  307. if ((i & 63) != 0)
  308. v = -v;
  309. if (i != 0)
  310. window[512 - i] = v;
  311. }
  312. /* huffman decode tables */
  313. huff_code_table[0] = NULL;
  314. for(i=1;i<16;i++) {
  315. const HuffTable *h = &mpa_huff_tables[i];
  316. int xsize, x, y;
  317. unsigned int n;
  318. uint8_t *code_table;
  319. xsize = h->xsize;
  320. n = xsize * xsize;
  321. /* XXX: fail test */
  322. init_vlc(&huff_vlc[i], 8, n,
  323. h->bits, 1, 1, h->codes, 2, 2);
  324. code_table = av_mallocz(n);
  325. j = 0;
  326. for(x=0;x<xsize;x++) {
  327. for(y=0;y<xsize;y++)
  328. code_table[j++] = (x << 4) | y;
  329. }
  330. huff_code_table[i] = code_table;
  331. }
  332. for(i=0;i<2;i++) {
  333. init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
  334. mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1);
  335. }
  336. for(i=0;i<9;i++) {
  337. k = 0;
  338. for(j=0;j<22;j++) {
  339. band_index_long[i][j] = k;
  340. k += band_size_long[i][j];
  341. }
  342. band_index_long[i][22] = k;
  343. }
  344. /* compute n ^ (4/3) and store it in mantissa/exp format */
  345. if (!av_mallocz_static(&table_4_3_exp,
  346. TABLE_4_3_SIZE * sizeof(table_4_3_exp[0])))
  347. return -1;
  348. if (!av_mallocz_static(&table_4_3_value,
  349. TABLE_4_3_SIZE * sizeof(table_4_3_value[0])))
  350. return -1;
  351. int_pow_init();
  352. for(i=1;i<TABLE_4_3_SIZE;i++) {
  353. int e, m;
  354. m = int_pow(i, &e);
  355. #if 0
  356. /* test code */
  357. {
  358. double f, fm;
  359. int e1, m1;
  360. f = pow((double)i, 4.0 / 3.0);
  361. fm = frexp(f, &e1);
  362. m1 = FIXR(2 * fm);
  363. #if FRAC_BITS <= 15
  364. if ((unsigned short)m1 != m1) {
  365. m1 = m1 >> 1;
  366. e1++;
  367. }
  368. #endif
  369. e1--;
  370. if (m != m1 || e != e1) {
  371. printf("%4d: m=%x m1=%x e=%d e1=%d\n",
  372. i, m, m1, e, e1);
  373. }
  374. }
  375. #endif
  376. /* normalized to FRAC_BITS */
  377. table_4_3_value[i] = m;
  378. table_4_3_exp[i] = e;
  379. }
  380. for(i=0;i<7;i++) {
  381. float f;
  382. int v;
  383. if (i != 6) {
  384. f = tan((double)i * M_PI / 12.0);
  385. v = FIXR(f / (1.0 + f));
  386. } else {
  387. v = FIXR(1.0);
  388. }
  389. is_table[0][i] = v;
  390. is_table[1][6 - i] = v;
  391. }
  392. /* invalid values */
  393. for(i=7;i<16;i++)
  394. is_table[0][i] = is_table[1][i] = 0.0;
  395. for(i=0;i<16;i++) {
  396. double f;
  397. int e, k;
  398. for(j=0;j<2;j++) {
  399. e = -(j + 1) * ((i + 1) >> 1);
  400. f = pow(2.0, e / 4.0);
  401. k = i & 1;
  402. is_table_lsf[j][k ^ 1][i] = FIXR(f);
  403. is_table_lsf[j][k][i] = FIXR(1.0);
  404. dprintf("is_table_lsf %d %d: %x %x\n",
  405. i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);
  406. }
  407. }
  408. for(i=0;i<8;i++) {
  409. float ci, cs, ca;
  410. ci = ci_table[i];
  411. cs = 1.0 / sqrt(1.0 + ci * ci);
  412. ca = cs * ci;
  413. csa_table[i][0] = FIX(cs);
  414. csa_table[i][1] = FIX(ca);
  415. }
  416. /* compute mdct windows */
  417. for(i=0;i<36;i++) {
  418. int v;
  419. v = FIXR(sin(M_PI * (i + 0.5) / 36.0));
  420. mdct_win[0][i] = v;
  421. mdct_win[1][i] = v;
  422. mdct_win[3][i] = v;
  423. }
  424. for(i=0;i<6;i++) {
  425. mdct_win[1][18 + i] = FIXR(1.0);
  426. mdct_win[1][24 + i] = FIXR(sin(M_PI * ((i + 6) + 0.5) / 12.0));
  427. mdct_win[1][30 + i] = FIXR(0.0);
  428. mdct_win[3][i] = FIXR(0.0);
  429. mdct_win[3][6 + i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
  430. mdct_win[3][12 + i] = FIXR(1.0);
  431. }
  432. for(i=0;i<12;i++)
  433. mdct_win[2][i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
  434. /* NOTE: we do frequency inversion adter the MDCT by changing
  435. the sign of the right window coefs */
  436. for(j=0;j<4;j++) {
  437. for(i=0;i<36;i+=2) {
  438. mdct_win[j + 4][i] = mdct_win[j][i];
  439. mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];
  440. }
  441. }
  442. #if defined(DEBUG)
  443. for(j=0;j<8;j++) {
  444. printf("win%d=\n", j);
  445. for(i=0;i<36;i++)
  446. printf("%f, ", (double)mdct_win[j][i] / FRAC_ONE);
  447. printf("\n");
  448. }
  449. #endif
  450. init = 1;
  451. }
  452. s->inbuf_index = 0;
  453. s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
  454. s->inbuf_ptr = s->inbuf;
  455. #ifdef DEBUG
  456. s->frame_count = 0;
  457. #endif
  458. return 0;
  459. }
  460. /* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */
  461. /* cos(i*pi/64) */
  462. #define COS0_0 FIXR(0.50060299823519630134)
  463. #define COS0_1 FIXR(0.50547095989754365998)
  464. #define COS0_2 FIXR(0.51544730992262454697)
  465. #define COS0_3 FIXR(0.53104259108978417447)
  466. #define COS0_4 FIXR(0.55310389603444452782)
  467. #define COS0_5 FIXR(0.58293496820613387367)
  468. #define COS0_6 FIXR(0.62250412303566481615)
  469. #define COS0_7 FIXR(0.67480834145500574602)
  470. #define COS0_8 FIXR(0.74453627100229844977)
  471. #define COS0_9 FIXR(0.83934964541552703873)
  472. #define COS0_10 FIXR(0.97256823786196069369)
  473. #define COS0_11 FIXR(1.16943993343288495515)
  474. #define COS0_12 FIXR(1.48416461631416627724)
  475. #define COS0_13 FIXR(2.05778100995341155085)
  476. #define COS0_14 FIXR(3.40760841846871878570)
  477. #define COS0_15 FIXR(10.19000812354805681150)
  478. #define COS1_0 FIXR(0.50241928618815570551)
  479. #define COS1_1 FIXR(0.52249861493968888062)
  480. #define COS1_2 FIXR(0.56694403481635770368)
  481. #define COS1_3 FIXR(0.64682178335999012954)
  482. #define COS1_4 FIXR(0.78815462345125022473)
  483. #define COS1_5 FIXR(1.06067768599034747134)
  484. #define COS1_6 FIXR(1.72244709823833392782)
  485. #define COS1_7 FIXR(5.10114861868916385802)
  486. #define COS2_0 FIXR(0.50979557910415916894)
  487. #define COS2_1 FIXR(0.60134488693504528054)
  488. #define COS2_2 FIXR(0.89997622313641570463)
  489. #define COS2_3 FIXR(2.56291544774150617881)
  490. #define COS3_0 FIXR(0.54119610014619698439)
  491. #define COS3_1 FIXR(1.30656296487637652785)
  492. #define COS4_0 FIXR(0.70710678118654752439)
  493. /* butterfly operator */
  494. #define BF(a, b, c)\
  495. {\
  496. tmp0 = tab[a] + tab[b];\
  497. tmp1 = tab[a] - tab[b];\
  498. tab[a] = tmp0;\
  499. tab[b] = MULL(tmp1, c);\
  500. }
  501. #define BF1(a, b, c, d)\
  502. {\
  503. BF(a, b, COS4_0);\
  504. BF(c, d, -COS4_0);\
  505. tab[c] += tab[d];\
  506. }
  507. #define BF2(a, b, c, d)\
  508. {\
  509. BF(a, b, COS4_0);\
  510. BF(c, d, -COS4_0);\
  511. tab[c] += tab[d];\
  512. tab[a] += tab[c];\
  513. tab[c] += tab[b];\
  514. tab[b] += tab[d];\
  515. }
  516. #define ADD(a, b) tab[a] += tab[b]
  517. /* DCT32 without 1/sqrt(2) coef zero scaling. */
  518. static void dct32(int32_t *out, int32_t *tab)
  519. {
  520. int tmp0, tmp1;
  521. /* pass 1 */
  522. BF(0, 31, COS0_0);
  523. BF(1, 30, COS0_1);
  524. BF(2, 29, COS0_2);
  525. BF(3, 28, COS0_3);
  526. BF(4, 27, COS0_4);
  527. BF(5, 26, COS0_5);
  528. BF(6, 25, COS0_6);
  529. BF(7, 24, COS0_7);
  530. BF(8, 23, COS0_8);
  531. BF(9, 22, COS0_9);
  532. BF(10, 21, COS0_10);
  533. BF(11, 20, COS0_11);
  534. BF(12, 19, COS0_12);
  535. BF(13, 18, COS0_13);
  536. BF(14, 17, COS0_14);
  537. BF(15, 16, COS0_15);
  538. /* pass 2 */
  539. BF(0, 15, COS1_0);
  540. BF(1, 14, COS1_1);
  541. BF(2, 13, COS1_2);
  542. BF(3, 12, COS1_3);
  543. BF(4, 11, COS1_4);
  544. BF(5, 10, COS1_5);
  545. BF(6, 9, COS1_6);
  546. BF(7, 8, COS1_7);
  547. BF(16, 31, -COS1_0);
  548. BF(17, 30, -COS1_1);
  549. BF(18, 29, -COS1_2);
  550. BF(19, 28, -COS1_3);
  551. BF(20, 27, -COS1_4);
  552. BF(21, 26, -COS1_5);
  553. BF(22, 25, -COS1_6);
  554. BF(23, 24, -COS1_7);
  555. /* pass 3 */
  556. BF(0, 7, COS2_0);
  557. BF(1, 6, COS2_1);
  558. BF(2, 5, COS2_2);
  559. BF(3, 4, COS2_3);
  560. BF(8, 15, -COS2_0);
  561. BF(9, 14, -COS2_1);
  562. BF(10, 13, -COS2_2);
  563. BF(11, 12, -COS2_3);
  564. BF(16, 23, COS2_0);
  565. BF(17, 22, COS2_1);
  566. BF(18, 21, COS2_2);
  567. BF(19, 20, COS2_3);
  568. BF(24, 31, -COS2_0);
  569. BF(25, 30, -COS2_1);
  570. BF(26, 29, -COS2_2);
  571. BF(27, 28, -COS2_3);
  572. /* pass 4 */
  573. BF(0, 3, COS3_0);
  574. BF(1, 2, COS3_1);
  575. BF(4, 7, -COS3_0);
  576. BF(5, 6, -COS3_1);
  577. BF(8, 11, COS3_0);
  578. BF(9, 10, COS3_1);
  579. BF(12, 15, -COS3_0);
  580. BF(13, 14, -COS3_1);
  581. BF(16, 19, COS3_0);
  582. BF(17, 18, COS3_1);
  583. BF(20, 23, -COS3_0);
  584. BF(21, 22, -COS3_1);
  585. BF(24, 27, COS3_0);
  586. BF(25, 26, COS3_1);
  587. BF(28, 31, -COS3_0);
  588. BF(29, 30, -COS3_1);
  589. /* pass 5 */
  590. BF1(0, 1, 2, 3);
  591. BF2(4, 5, 6, 7);
  592. BF1(8, 9, 10, 11);
  593. BF2(12, 13, 14, 15);
  594. BF1(16, 17, 18, 19);
  595. BF2(20, 21, 22, 23);
  596. BF1(24, 25, 26, 27);
  597. BF2(28, 29, 30, 31);
  598. /* pass 6 */
  599. ADD( 8, 12);
  600. ADD(12, 10);
  601. ADD(10, 14);
  602. ADD(14, 9);
  603. ADD( 9, 13);
  604. ADD(13, 11);
  605. ADD(11, 15);
  606. out[ 0] = tab[0];
  607. out[16] = tab[1];
  608. out[ 8] = tab[2];
  609. out[24] = tab[3];
  610. out[ 4] = tab[4];
  611. out[20] = tab[5];
  612. out[12] = tab[6];
  613. out[28] = tab[7];
  614. out[ 2] = tab[8];
  615. out[18] = tab[9];
  616. out[10] = tab[10];
  617. out[26] = tab[11];
  618. out[ 6] = tab[12];
  619. out[22] = tab[13];
  620. out[14] = tab[14];
  621. out[30] = tab[15];
  622. ADD(24, 28);
  623. ADD(28, 26);
  624. ADD(26, 30);
  625. ADD(30, 25);
  626. ADD(25, 29);
  627. ADD(29, 27);
  628. ADD(27, 31);
  629. out[ 1] = tab[16] + tab[24];
  630. out[17] = tab[17] + tab[25];
  631. out[ 9] = tab[18] + tab[26];
  632. out[25] = tab[19] + tab[27];
  633. out[ 5] = tab[20] + tab[28];
  634. out[21] = tab[21] + tab[29];
  635. out[13] = tab[22] + tab[30];
  636. out[29] = tab[23] + tab[31];
  637. out[ 3] = tab[24] + tab[20];
  638. out[19] = tab[25] + tab[21];
  639. out[11] = tab[26] + tab[22];
  640. out[27] = tab[27] + tab[23];
  641. out[ 7] = tab[28] + tab[18];
  642. out[23] = tab[29] + tab[19];
  643. out[15] = tab[30] + tab[17];
  644. out[31] = tab[31];
  645. }
  646. #define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
  647. #if FRAC_BITS <= 15
  648. #define OUT_SAMPLE(sum)\
  649. {\
  650. int sum1;\
  651. sum1 = (sum + (1 << (OUT_SHIFT - 1))) >> OUT_SHIFT;\
  652. if (sum1 < -32768)\
  653. sum1 = -32768;\
  654. else if (sum1 > 32767)\
  655. sum1 = 32767;\
  656. *samples = sum1;\
  657. samples += incr;\
  658. }
  659. #define SUM8(off, op) \
  660. { \
  661. sum op w[0 * 64 + off] * p[0 * 64];\
  662. sum op w[1 * 64 + off] * p[1 * 64];\
  663. sum op w[2 * 64 + off] * p[2 * 64];\
  664. sum op w[3 * 64 + off] * p[3 * 64];\
  665. sum op w[4 * 64 + off] * p[4 * 64];\
  666. sum op w[5 * 64 + off] * p[5 * 64];\
  667. sum op w[6 * 64 + off] * p[6 * 64];\
  668. sum op w[7 * 64 + off] * p[7 * 64];\
  669. }
  670. #else
  671. #define OUT_SAMPLE(sum)\
  672. {\
  673. int sum1;\
  674. sum1 = (int)((sum + (int64_t_C(1) << (OUT_SHIFT - 1))) >> OUT_SHIFT);\
  675. if (sum1 < -32768)\
  676. sum1 = -32768;\
  677. else if (sum1 > 32767)\
  678. sum1 = 32767;\
  679. *samples = sum1;\
  680. samples += incr;\
  681. }
  682. #define SUM8(off, op) \
  683. { \
  684. sum op MUL64(w[0 * 64 + off], p[0 * 64]);\
  685. sum op MUL64(w[1 * 64 + off], p[1 * 64]);\
  686. sum op MUL64(w[2 * 64 + off], p[2 * 64]);\
  687. sum op MUL64(w[3 * 64 + off], p[3 * 64]);\
  688. sum op MUL64(w[4 * 64 + off], p[4 * 64]);\
  689. sum op MUL64(w[5 * 64 + off], p[5 * 64]);\
  690. sum op MUL64(w[6 * 64 + off], p[6 * 64]);\
  691. sum op MUL64(w[7 * 64 + off], p[7 * 64]);\
  692. }
  693. #endif
  694. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
  695. 32 samples. */
  696. /* XXX: optimize by avoiding ring buffer usage */
  697. static void synth_filter(MPADecodeContext *s1,
  698. int ch, int16_t *samples, int incr,
  699. int32_t sb_samples[SBLIMIT])
  700. {
  701. int32_t tmp[32];
  702. register MPA_INT *synth_buf, *p;
  703. register MPA_INT *w;
  704. int j, offset, v;
  705. #if FRAC_BITS <= 15
  706. int sum;
  707. #else
  708. int64_t sum;
  709. #endif
  710. dct32(tmp, sb_samples);
  711. offset = s1->synth_buf_offset[ch];
  712. synth_buf = s1->synth_buf[ch] + offset;
  713. for(j=0;j<32;j++) {
  714. v = tmp[j];
  715. #if FRAC_BITS <= 15
  716. /* NOTE: can cause a loss in precision if very high amplitude
  717. sound */
  718. if (v > 32767)
  719. v = 32767;
  720. else if (v < -32768)
  721. v = -32768;
  722. #endif
  723. synth_buf[j] = v;
  724. }
  725. /* copy to avoid wrap */
  726. memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
  727. w = window;
  728. for(j=0;j<16;j++) {
  729. sum = 0;
  730. p = synth_buf + 16 + j; /* 0-15 */
  731. SUM8(0, +=);
  732. p = synth_buf + 48 - j; /* 32-47 */
  733. SUM8(32, -=);
  734. OUT_SAMPLE(sum);
  735. w++;
  736. }
  737. p = synth_buf + 32; /* 48 */
  738. sum = 0;
  739. SUM8(32, -=);
  740. OUT_SAMPLE(sum);
  741. w++;
  742. for(j=17;j<32;j++) {
  743. sum = 0;
  744. p = synth_buf + 48 - j; /* 17-31 */
  745. SUM8(0, -=);
  746. p = synth_buf + 16 + j; /* 49-63 */
  747. SUM8(32, -=);
  748. OUT_SAMPLE(sum);
  749. w++;
  750. }
  751. offset = (offset - 32) & 511;
  752. s1->synth_buf_offset[ch] = offset;
  753. }
  754. /* cos(pi*i/24) */
  755. #define C1 FIXR(0.99144486137381041114)
  756. #define C3 FIXR(0.92387953251128675612)
  757. #define C5 FIXR(0.79335334029123516458)
  758. #define C7 FIXR(0.60876142900872063941)
  759. #define C9 FIXR(0.38268343236508977173)
  760. #define C11 FIXR(0.13052619222005159154)
  761. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
  762. cases. */
  763. static void imdct12(int *out, int *in)
  764. {
  765. int tmp;
  766. int64_t in1_3, in1_9, in4_3, in4_9;
  767. in1_3 = MUL64(in[1], C3);
  768. in1_9 = MUL64(in[1], C9);
  769. in4_3 = MUL64(in[4], C3);
  770. in4_9 = MUL64(in[4], C9);
  771. tmp = FRAC_RND(MUL64(in[0], C7) - in1_3 - MUL64(in[2], C11) +
  772. MUL64(in[3], C1) - in4_9 - MUL64(in[5], C5));
  773. out[0] = tmp;
  774. out[5] = -tmp;
  775. tmp = FRAC_RND(MUL64(in[0] - in[3], C9) - in1_3 +
  776. MUL64(in[2] + in[5], C3) - in4_9);
  777. out[1] = tmp;
  778. out[4] = -tmp;
  779. tmp = FRAC_RND(MUL64(in[0], C11) - in1_9 + MUL64(in[2], C7) -
  780. MUL64(in[3], C5) + in4_3 - MUL64(in[5], C1));
  781. out[2] = tmp;
  782. out[3] = -tmp;
  783. tmp = FRAC_RND(MUL64(-in[0], C5) + in1_9 + MUL64(in[2], C1) +
  784. MUL64(in[3], C11) - in4_3 - MUL64(in[5], C7));
  785. out[6] = tmp;
  786. out[11] = tmp;
  787. tmp = FRAC_RND(MUL64(-in[0] + in[3], C3) - in1_9 +
  788. MUL64(in[2] + in[5], C9) + in4_3);
  789. out[7] = tmp;
  790. out[10] = tmp;
  791. tmp = FRAC_RND(-MUL64(in[0], C1) - in1_3 - MUL64(in[2], C5) -
  792. MUL64(in[3], C7) - in4_9 - MUL64(in[5], C11));
  793. out[8] = tmp;
  794. out[9] = tmp;
  795. }
  796. #undef C1
  797. #undef C3
  798. #undef C5
  799. #undef C7
  800. #undef C9
  801. #undef C11
  802. /* cos(pi*i/18) */
  803. #define C1 FIXR(0.98480775301220805936)
  804. #define C2 FIXR(0.93969262078590838405)
  805. #define C3 FIXR(0.86602540378443864676)
  806. #define C4 FIXR(0.76604444311897803520)
  807. #define C5 FIXR(0.64278760968653932632)
  808. #define C6 FIXR(0.5)
  809. #define C7 FIXR(0.34202014332566873304)
  810. #define C8 FIXR(0.17364817766693034885)
  811. /* 0.5 / cos(pi*(2*i+1)/36) */
  812. static const int icos36[9] = {
  813. FIXR(0.50190991877167369479),
  814. FIXR(0.51763809020504152469),
  815. FIXR(0.55168895948124587824),
  816. FIXR(0.61038729438072803416),
  817. FIXR(0.70710678118654752439),
  818. FIXR(0.87172339781054900991),
  819. FIXR(1.18310079157624925896),
  820. FIXR(1.93185165257813657349),
  821. FIXR(5.73685662283492756461),
  822. };
  823. static const int icos72[18] = {
  824. /* 0.5 / cos(pi*(2*i+19)/72) */
  825. FIXR(0.74009361646113053152),
  826. FIXR(0.82133981585229078570),
  827. FIXR(0.93057949835178895673),
  828. FIXR(1.08284028510010010928),
  829. FIXR(1.30656296487637652785),
  830. FIXR(1.66275476171152078719),
  831. FIXR(2.31011315767264929558),
  832. FIXR(3.83064878777019433457),
  833. FIXR(11.46279281302667383546),
  834. /* 0.5 / cos(pi*(2*(i + 18) +19)/72) */
  835. FIXR(-0.67817085245462840086),
  836. FIXR(-0.63023620700513223342),
  837. FIXR(-0.59284452371708034528),
  838. FIXR(-0.56369097343317117734),
  839. FIXR(-0.54119610014619698439),
  840. FIXR(-0.52426456257040533932),
  841. FIXR(-0.51213975715725461845),
  842. FIXR(-0.50431448029007636036),
  843. FIXR(-0.50047634258165998492),
  844. };
  845. /* using Lee like decomposition followed by hand coded 9 points DCT */
  846. static void imdct36(int *out, int *in)
  847. {
  848. int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
  849. int tmp[18], *tmp1, *in1;
  850. int64_t in3_3, in6_6;
  851. for(i=17;i>=1;i--)
  852. in[i] += in[i-1];
  853. for(i=17;i>=3;i-=2)
  854. in[i] += in[i-2];
  855. for(j=0;j<2;j++) {
  856. tmp1 = tmp + j;
  857. in1 = in + j;
  858. in3_3 = MUL64(in1[2*3], C3);
  859. in6_6 = MUL64(in1[2*6], C6);
  860. tmp1[0] = FRAC_RND(MUL64(in1[2*1], C1) + in3_3 +
  861. MUL64(in1[2*5], C5) + MUL64(in1[2*7], C7));
  862. tmp1[2] = in1[2*0] + FRAC_RND(MUL64(in1[2*2], C2) +
  863. MUL64(in1[2*4], C4) + in6_6 +
  864. MUL64(in1[2*8], C8));
  865. tmp1[4] = FRAC_RND(MUL64(in1[2*1] - in1[2*5] - in1[2*7], C3));
  866. tmp1[6] = FRAC_RND(MUL64(in1[2*2] - in1[2*4] - in1[2*8], C6)) -
  867. in1[2*6] + in1[2*0];
  868. tmp1[8] = FRAC_RND(MUL64(in1[2*1], C5) - in3_3 -
  869. MUL64(in1[2*5], C7) + MUL64(in1[2*7], C1));
  870. tmp1[10] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C8) -
  871. MUL64(in1[2*4], C2) + in6_6 +
  872. MUL64(in1[2*8], C4));
  873. tmp1[12] = FRAC_RND(MUL64(in1[2*1], C7) - in3_3 +
  874. MUL64(in1[2*5], C1) -
  875. MUL64(in1[2*7], C5));
  876. tmp1[14] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C4) +
  877. MUL64(in1[2*4], C8) + in6_6 -
  878. MUL64(in1[2*8], C2));
  879. tmp1[16] = in1[2*0] - in1[2*2] + in1[2*4] - in1[2*6] + in1[2*8];
  880. }
  881. i = 0;
  882. for(j=0;j<4;j++) {
  883. t0 = tmp[i];
  884. t1 = tmp[i + 2];
  885. s0 = t1 + t0;
  886. s2 = t1 - t0;
  887. t2 = tmp[i + 1];
  888. t3 = tmp[i + 3];
  889. s1 = MULL(t3 + t2, icos36[j]);
  890. s3 = MULL(t3 - t2, icos36[8 - j]);
  891. t0 = MULL(s0 + s1, icos72[9 + 8 - j]);
  892. t1 = MULL(s0 - s1, icos72[8 - j]);
  893. out[18 + 9 + j] = t0;
  894. out[18 + 8 - j] = t0;
  895. out[9 + j] = -t1;
  896. out[8 - j] = t1;
  897. t0 = MULL(s2 + s3, icos72[9+j]);
  898. t1 = MULL(s2 - s3, icos72[j]);
  899. out[18 + 9 + (8 - j)] = t0;
  900. out[18 + j] = t0;
  901. out[9 + (8 - j)] = -t1;
  902. out[j] = t1;
  903. i += 4;
  904. }
  905. s0 = tmp[16];
  906. s1 = MULL(tmp[17], icos36[4]);
  907. t0 = MULL(s0 + s1, icos72[9 + 4]);
  908. t1 = MULL(s0 - s1, icos72[4]);
  909. out[18 + 9 + 4] = t0;
  910. out[18 + 8 - 4] = t0;
  911. out[9 + 4] = -t1;
  912. out[8 - 4] = t1;
  913. }
  914. /* fast header check for resync */
  915. static int check_header(uint32_t header)
  916. {
  917. /* header */
  918. if ((header & 0xffe00000) != 0xffe00000)
  919. return -1;
  920. /* layer check */
  921. if (((header >> 17) & 3) == 0)
  922. return -1;
  923. /* bit rate */
  924. if (((header >> 12) & 0xf) == 0xf)
  925. return -1;
  926. /* frequency */
  927. if (((header >> 10) & 3) == 3)
  928. return -1;
  929. return 0;
  930. }
  931. /* header + layer + bitrate + freq + lsf/mpeg25 */
  932. #define SAME_HEADER_MASK \
  933. (0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
  934. /* header decoding. MUST check the header before because no
  935. consistency check is done there. Return 1 if free format found and
  936. that the frame size must be computed externally */
  937. static int decode_header(MPADecodeContext *s, uint32_t header)
  938. {
  939. int sample_rate, frame_size, mpeg25, padding;
  940. int sample_rate_index, bitrate_index;
  941. if (header & (1<<20)) {
  942. s->lsf = (header & (1<<19)) ? 0 : 1;
  943. mpeg25 = 0;
  944. } else {
  945. s->lsf = 1;
  946. mpeg25 = 1;
  947. }
  948. s->layer = 4 - ((header >> 17) & 3);
  949. /* extract frequency */
  950. sample_rate_index = (header >> 10) & 3;
  951. sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
  952. sample_rate_index += 3 * (s->lsf + mpeg25);
  953. s->sample_rate_index = sample_rate_index;
  954. s->error_protection = ((header >> 16) & 1) ^ 1;
  955. s->sample_rate = sample_rate;
  956. bitrate_index = (header >> 12) & 0xf;
  957. padding = (header >> 9) & 1;
  958. //extension = (header >> 8) & 1;
  959. s->mode = (header >> 6) & 3;
  960. s->mode_ext = (header >> 4) & 3;
  961. //copyright = (header >> 3) & 1;
  962. //original = (header >> 2) & 1;
  963. //emphasis = header & 3;
  964. if (s->mode == MPA_MONO)
  965. s->nb_channels = 1;
  966. else
  967. s->nb_channels = 2;
  968. if (bitrate_index != 0) {
  969. frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
  970. s->bit_rate = frame_size * 1000;
  971. switch(s->layer) {
  972. case 1:
  973. frame_size = (frame_size * 12000) / sample_rate;
  974. frame_size = (frame_size + padding) * 4;
  975. break;
  976. case 2:
  977. frame_size = (frame_size * 144000) / sample_rate;
  978. frame_size += padding;
  979. break;
  980. default:
  981. case 3:
  982. frame_size = (frame_size * 144000) / (sample_rate << s->lsf);
  983. frame_size += padding;
  984. break;
  985. }
  986. s->frame_size = frame_size;
  987. } else {
  988. /* if no frame size computed, signal it */
  989. if (!s->free_format_frame_size)
  990. return 1;
  991. /* free format: compute bitrate and real frame size from the
  992. frame size we extracted by reading the bitstream */
  993. s->frame_size = s->free_format_frame_size;
  994. switch(s->layer) {
  995. case 1:
  996. s->frame_size += padding * 4;
  997. s->bit_rate = (s->frame_size * sample_rate) / 48000;
  998. break;
  999. case 2:
  1000. s->frame_size += padding;
  1001. s->bit_rate = (s->frame_size * sample_rate) / 144000;
  1002. break;
  1003. default:
  1004. case 3:
  1005. s->frame_size += padding;
  1006. s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;
  1007. break;
  1008. }
  1009. }
  1010. #if defined(DEBUG)
  1011. printf("layer%d, %d Hz, %d kbits/s, ",
  1012. s->layer, s->sample_rate, s->bit_rate);
  1013. if (s->nb_channels == 2) {
  1014. if (s->layer == 3) {
  1015. if (s->mode_ext & MODE_EXT_MS_STEREO)
  1016. printf("ms-");
  1017. if (s->mode_ext & MODE_EXT_I_STEREO)
  1018. printf("i-");
  1019. }
  1020. printf("stereo");
  1021. } else {
  1022. printf("mono");
  1023. }
  1024. printf("\n");
  1025. #endif
  1026. return 0;
  1027. }
  1028. /* return the number of decoded frames */
  1029. static int mp_decode_layer1(MPADecodeContext *s)
  1030. {
  1031. int bound, i, v, n, ch, j, mant;
  1032. uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
  1033. uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
  1034. if (s->mode == MPA_JSTEREO)
  1035. bound = (s->mode_ext + 1) * 4;
  1036. else
  1037. bound = SBLIMIT;
  1038. /* allocation bits */
  1039. for(i=0;i<bound;i++) {
  1040. for(ch=0;ch<s->nb_channels;ch++) {
  1041. allocation[ch][i] = get_bits(&s->gb, 4);
  1042. }
  1043. }
  1044. for(i=bound;i<SBLIMIT;i++) {
  1045. allocation[0][i] = get_bits(&s->gb, 4);
  1046. }
  1047. /* scale factors */
  1048. for(i=0;i<bound;i++) {
  1049. for(ch=0;ch<s->nb_channels;ch++) {
  1050. if (allocation[ch][i])
  1051. scale_factors[ch][i] = get_bits(&s->gb, 6);
  1052. }
  1053. }
  1054. for(i=bound;i<SBLIMIT;i++) {
  1055. if (allocation[0][i]) {
  1056. scale_factors[0][i] = get_bits(&s->gb, 6);
  1057. scale_factors[1][i] = get_bits(&s->gb, 6);
  1058. }
  1059. }
  1060. /* compute samples */
  1061. for(j=0;j<12;j++) {
  1062. for(i=0;i<bound;i++) {
  1063. for(ch=0;ch<s->nb_channels;ch++) {
  1064. n = allocation[ch][i];
  1065. if (n) {
  1066. mant = get_bits(&s->gb, n + 1);
  1067. v = l1_unscale(n, mant, scale_factors[ch][i]);
  1068. } else {
  1069. v = 0;
  1070. }
  1071. s->sb_samples[ch][j][i] = v;
  1072. }
  1073. }
  1074. for(i=bound;i<SBLIMIT;i++) {
  1075. n = allocation[0][i];
  1076. if (n) {
  1077. mant = get_bits(&s->gb, n + 1);
  1078. v = l1_unscale(n, mant, scale_factors[0][i]);
  1079. s->sb_samples[0][j][i] = v;
  1080. v = l1_unscale(n, mant, scale_factors[1][i]);
  1081. s->sb_samples[1][j][i] = v;
  1082. } else {
  1083. s->sb_samples[0][j][i] = 0;
  1084. s->sb_samples[1][j][i] = 0;
  1085. }
  1086. }
  1087. }
  1088. return 12;
  1089. }
  1090. /* bitrate is in kb/s */
  1091. int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
  1092. {
  1093. int ch_bitrate, table;
  1094. ch_bitrate = bitrate / nb_channels;
  1095. if (!lsf) {
  1096. if ((freq == 48000 && ch_bitrate >= 56) ||
  1097. (ch_bitrate >= 56 && ch_bitrate <= 80))
  1098. table = 0;
  1099. else if (freq != 48000 && ch_bitrate >= 96)
  1100. table = 1;
  1101. else if (freq != 32000 && ch_bitrate <= 48)
  1102. table = 2;
  1103. else
  1104. table = 3;
  1105. } else {
  1106. table = 4;
  1107. }
  1108. return table;
  1109. }
  1110. static int mp_decode_layer2(MPADecodeContext *s)
  1111. {
  1112. int sblimit; /* number of used subbands */
  1113. const unsigned char *alloc_table;
  1114. int table, bit_alloc_bits, i, j, ch, bound, v;
  1115. unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
  1116. unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
  1117. unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
  1118. int scale, qindex, bits, steps, k, l, m, b;
  1119. /* select decoding table */
  1120. table = l2_select_table(s->bit_rate / 1000, s->nb_channels,
  1121. s->sample_rate, s->lsf);
  1122. sblimit = sblimit_table[table];
  1123. alloc_table = alloc_tables[table];
  1124. if (s->mode == MPA_JSTEREO)
  1125. bound = (s->mode_ext + 1) * 4;
  1126. else
  1127. bound = sblimit;
  1128. dprintf("bound=%d sblimit=%d\n", bound, sblimit);
  1129. /* parse bit allocation */
  1130. j = 0;
  1131. for(i=0;i<bound;i++) {
  1132. bit_alloc_bits = alloc_table[j];
  1133. for(ch=0;ch<s->nb_channels;ch++) {
  1134. bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
  1135. }
  1136. j += 1 << bit_alloc_bits;
  1137. }
  1138. for(i=bound;i<sblimit;i++) {
  1139. bit_alloc_bits = alloc_table[j];
  1140. v = get_bits(&s->gb, bit_alloc_bits);
  1141. bit_alloc[0][i] = v;
  1142. bit_alloc[1][i] = v;
  1143. j += 1 << bit_alloc_bits;
  1144. }
  1145. #ifdef DEBUG
  1146. {
  1147. for(ch=0;ch<s->nb_channels;ch++) {
  1148. for(i=0;i<sblimit;i++)
  1149. printf(" %d", bit_alloc[ch][i]);
  1150. printf("\n");
  1151. }
  1152. }
  1153. #endif
  1154. /* scale codes */
  1155. for(i=0;i<sblimit;i++) {
  1156. for(ch=0;ch<s->nb_channels;ch++) {
  1157. if (bit_alloc[ch][i])
  1158. scale_code[ch][i] = get_bits(&s->gb, 2);
  1159. }
  1160. }
  1161. /* scale factors */
  1162. for(i=0;i<sblimit;i++) {
  1163. for(ch=0;ch<s->nb_channels;ch++) {
  1164. if (bit_alloc[ch][i]) {
  1165. sf = scale_factors[ch][i];
  1166. switch(scale_code[ch][i]) {
  1167. default:
  1168. case 0:
  1169. sf[0] = get_bits(&s->gb, 6);
  1170. sf[1] = get_bits(&s->gb, 6);
  1171. sf[2] = get_bits(&s->gb, 6);
  1172. break;
  1173. case 2:
  1174. sf[0] = get_bits(&s->gb, 6);
  1175. sf[1] = sf[0];
  1176. sf[2] = sf[0];
  1177. break;
  1178. case 1:
  1179. sf[0] = get_bits(&s->gb, 6);
  1180. sf[2] = get_bits(&s->gb, 6);
  1181. sf[1] = sf[0];
  1182. break;
  1183. case 3:
  1184. sf[0] = get_bits(&s->gb, 6);
  1185. sf[2] = get_bits(&s->gb, 6);
  1186. sf[1] = sf[2];
  1187. break;
  1188. }
  1189. }
  1190. }
  1191. }
  1192. #ifdef DEBUG
  1193. for(ch=0;ch<s->nb_channels;ch++) {
  1194. for(i=0;i<sblimit;i++) {
  1195. if (bit_alloc[ch][i]) {
  1196. sf = scale_factors[ch][i];
  1197. printf(" %d %d %d", sf[0], sf[1], sf[2]);
  1198. } else {
  1199. printf(" -");
  1200. }
  1201. }
  1202. printf("\n");
  1203. }
  1204. #endif
  1205. /* samples */
  1206. for(k=0;k<3;k++) {
  1207. for(l=0;l<12;l+=3) {
  1208. j = 0;
  1209. for(i=0;i<bound;i++) {
  1210. bit_alloc_bits = alloc_table[j];
  1211. for(ch=0;ch<s->nb_channels;ch++) {
  1212. b = bit_alloc[ch][i];
  1213. if (b) {
  1214. scale = scale_factors[ch][i][k];
  1215. qindex = alloc_table[j+b];
  1216. bits = quant_bits[qindex];
  1217. if (bits < 0) {
  1218. /* 3 values at the same time */
  1219. v = get_bits(&s->gb, -bits);
  1220. steps = quant_steps[qindex];
  1221. s->sb_samples[ch][k * 12 + l + 0][i] =
  1222. l2_unscale_group(steps, v % steps, scale);
  1223. v = v / steps;
  1224. s->sb_samples[ch][k * 12 + l + 1][i] =
  1225. l2_unscale_group(steps, v % steps, scale);
  1226. v = v / steps;
  1227. s->sb_samples[ch][k * 12 + l + 2][i] =
  1228. l2_unscale_group(steps, v, scale);
  1229. } else {
  1230. for(m=0;m<3;m++) {
  1231. v = get_bits(&s->gb, bits);
  1232. v = l1_unscale(bits - 1, v, scale);
  1233. s->sb_samples[ch][k * 12 + l + m][i] = v;
  1234. }
  1235. }
  1236. } else {
  1237. s->sb_samples[ch][k * 12 + l + 0][i] = 0;
  1238. s->sb_samples[ch][k * 12 + l + 1][i] = 0;
  1239. s->sb_samples[ch][k * 12 + l + 2][i] = 0;
  1240. }
  1241. }
  1242. /* next subband in alloc table */
  1243. j += 1 << bit_alloc_bits;
  1244. }
  1245. /* XXX: find a way to avoid this duplication of code */
  1246. for(i=bound;i<sblimit;i++) {
  1247. bit_alloc_bits = alloc_table[j];
  1248. b = bit_alloc[0][i];
  1249. if (b) {
  1250. int mant, scale0, scale1;
  1251. scale0 = scale_factors[0][i][k];
  1252. scale1 = scale_factors[1][i][k];
  1253. qindex = alloc_table[j+b];
  1254. bits = quant_bits[qindex];
  1255. if (bits < 0) {
  1256. /* 3 values at the same time */
  1257. v = get_bits(&s->gb, -bits);
  1258. steps = quant_steps[qindex];
  1259. mant = v % steps;
  1260. v = v / steps;
  1261. s->sb_samples[0][k * 12 + l + 0][i] =
  1262. l2_unscale_group(steps, mant, scale0);
  1263. s->sb_samples[1][k * 12 + l + 0][i] =
  1264. l2_unscale_group(steps, mant, scale1);
  1265. mant = v % steps;
  1266. v = v / steps;
  1267. s->sb_samples[0][k * 12 + l + 1][i] =
  1268. l2_unscale_group(steps, mant, scale0);
  1269. s->sb_samples[1][k * 12 + l + 1][i] =
  1270. l2_unscale_group(steps, mant, scale1);
  1271. s->sb_samples[0][k * 12 + l + 2][i] =
  1272. l2_unscale_group(steps, v, scale0);
  1273. s->sb_samples[1][k * 12 + l + 2][i] =
  1274. l2_unscale_group(steps, v, scale1);
  1275. } else {
  1276. for(m=0;m<3;m++) {
  1277. mant = get_bits(&s->gb, bits);
  1278. s->sb_samples[0][k * 12 + l + m][i] =
  1279. l1_unscale(bits - 1, mant, scale0);
  1280. s->sb_samples[1][k * 12 + l + m][i] =
  1281. l1_unscale(bits - 1, mant, scale1);
  1282. }
  1283. }
  1284. } else {
  1285. s->sb_samples[0][k * 12 + l + 0][i] = 0;
  1286. s->sb_samples[0][k * 12 + l + 1][i] = 0;
  1287. s->sb_samples[0][k * 12 + l + 2][i] = 0;
  1288. s->sb_samples[1][k * 12 + l + 0][i] = 0;
  1289. s->sb_samples[1][k * 12 + l + 1][i] = 0;
  1290. s->sb_samples[1][k * 12 + l + 2][i] = 0;
  1291. }
  1292. /* next subband in alloc table */
  1293. j += 1 << bit_alloc_bits;
  1294. }
  1295. /* fill remaining samples to zero */
  1296. for(i=sblimit;i<SBLIMIT;i++) {
  1297. for(ch=0;ch<s->nb_channels;ch++) {
  1298. s->sb_samples[ch][k * 12 + l + 0][i] = 0;
  1299. s->sb_samples[ch][k * 12 + l + 1][i] = 0;
  1300. s->sb_samples[ch][k * 12 + l + 2][i] = 0;
  1301. }
  1302. }
  1303. }
  1304. }
  1305. return 3 * 12;
  1306. }
  1307. /*
  1308. * Seek back in the stream for backstep bytes (at most 511 bytes)
  1309. */
  1310. static void seek_to_maindata(MPADecodeContext *s, unsigned int backstep)
  1311. {
  1312. uint8_t *ptr;
  1313. /* compute current position in stream */
  1314. ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
  1315. /* copy old data before current one */
  1316. ptr -= backstep;
  1317. memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] +
  1318. BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);
  1319. /* init get bits again */
  1320. init_get_bits(&s->gb, ptr, (s->frame_size + backstep)*8);
  1321. /* prepare next buffer */
  1322. s->inbuf_index ^= 1;
  1323. s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
  1324. s->old_frame_size = s->frame_size;
  1325. }
  1326. static inline void lsf_sf_expand(int *slen,
  1327. int sf, int n1, int n2, int n3)
  1328. {
  1329. if (n3) {
  1330. slen[3] = sf % n3;
  1331. sf /= n3;
  1332. } else {
  1333. slen[3] = 0;
  1334. }
  1335. if (n2) {
  1336. slen[2] = sf % n2;
  1337. sf /= n2;
  1338. } else {
  1339. slen[2] = 0;
  1340. }
  1341. slen[1] = sf % n1;
  1342. sf /= n1;
  1343. slen[0] = sf;
  1344. }
  1345. static void exponents_from_scale_factors(MPADecodeContext *s,
  1346. GranuleDef *g,
  1347. int16_t *exponents)
  1348. {
  1349. const uint8_t *bstab, *pretab;
  1350. int len, i, j, k, l, v0, shift, gain, gains[3];
  1351. int16_t *exp_ptr;
  1352. exp_ptr = exponents;
  1353. gain = g->global_gain - 210;
  1354. shift = g->scalefac_scale + 1;
  1355. bstab = band_size_long[s->sample_rate_index];
  1356. pretab = mpa_pretab[g->preflag];
  1357. for(i=0;i<g->long_end;i++) {
  1358. v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift);
  1359. len = bstab[i];
  1360. for(j=len;j>0;j--)
  1361. *exp_ptr++ = v0;
  1362. }
  1363. if (g->short_start < 13) {
  1364. bstab = band_size_short[s->sample_rate_index];
  1365. gains[0] = gain - (g->subblock_gain[0] << 3);
  1366. gains[1] = gain - (g->subblock_gain[1] << 3);
  1367. gains[2] = gain - (g->subblock_gain[2] << 3);
  1368. k = g->long_end;
  1369. for(i=g->short_start;i<13;i++) {
  1370. len = bstab[i];
  1371. for(l=0;l<3;l++) {
  1372. v0 = gains[l] - (g->scale_factors[k++] << shift);
  1373. for(j=len;j>0;j--)
  1374. *exp_ptr++ = v0;
  1375. }
  1376. }
  1377. }
  1378. }
  1379. /* handle n = 0 too */
  1380. static inline int get_bitsz(GetBitContext *s, int n)
  1381. {
  1382. if (n == 0)
  1383. return 0;
  1384. else
  1385. return get_bits(s, n);
  1386. }
  1387. static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
  1388. int16_t *exponents, int end_pos)
  1389. {
  1390. int s_index;
  1391. int linbits, code, x, y, l, v, i, j, k, pos;
  1392. GetBitContext last_gb;
  1393. VLC *vlc;
  1394. uint8_t *code_table;
  1395. /* low frequencies (called big values) */
  1396. s_index = 0;
  1397. for(i=0;i<3;i++) {
  1398. j = g->region_size[i];
  1399. if (j == 0)
  1400. continue;
  1401. /* select vlc table */
  1402. k = g->table_select[i];
  1403. l = mpa_huff_data[k][0];
  1404. linbits = mpa_huff_data[k][1];
  1405. vlc = &huff_vlc[l];
  1406. code_table = huff_code_table[l];
  1407. /* read huffcode and compute each couple */
  1408. for(;j>0;j--) {
  1409. if (get_bits_count(&s->gb) >= end_pos)
  1410. break;
  1411. if (code_table) {
  1412. code = get_vlc(&s->gb, vlc);
  1413. if (code < 0)
  1414. return -1;
  1415. y = code_table[code];
  1416. x = y >> 4;
  1417. y = y & 0x0f;
  1418. } else {
  1419. x = 0;
  1420. y = 0;
  1421. }
  1422. dprintf("region=%d n=%d x=%d y=%d exp=%d\n",
  1423. i, g->region_size[i] - j, x, y, exponents[s_index]);
  1424. if (x) {
  1425. if (x == 15)
  1426. x += get_bitsz(&s->gb, linbits);
  1427. v = l3_unscale(x, exponents[s_index]);
  1428. if (get_bits1(&s->gb))
  1429. v = -v;
  1430. } else {
  1431. v = 0;
  1432. }
  1433. g->sb_hybrid[s_index++] = v;
  1434. if (y) {
  1435. if (y == 15)
  1436. y += get_bitsz(&s->gb, linbits);
  1437. v = l3_unscale(y, exponents[s_index]);
  1438. if (get_bits1(&s->gb))
  1439. v = -v;
  1440. } else {
  1441. v = 0;
  1442. }
  1443. g->sb_hybrid[s_index++] = v;
  1444. }
  1445. }
  1446. /* high frequencies */
  1447. vlc = &huff_quad_vlc[g->count1table_select];
  1448. last_gb.buffer = NULL;
  1449. while (s_index <= 572) {
  1450. pos = get_bits_count(&s->gb);
  1451. if (pos >= end_pos) {
  1452. if (pos > end_pos && last_gb.buffer != NULL) {
  1453. /* some encoders generate an incorrect size for this
  1454. part. We must go back into the data */
  1455. s_index -= 4;
  1456. s->gb = last_gb;
  1457. }
  1458. break;
  1459. }
  1460. last_gb= s->gb;
  1461. code = get_vlc(&s->gb, vlc);
  1462. dprintf("t=%d code=%d\n", g->count1table_select, code);
  1463. if (code < 0)
  1464. return -1;
  1465. for(i=0;i<4;i++) {
  1466. if (code & (8 >> i)) {
  1467. /* non zero value. Could use a hand coded function for
  1468. 'one' value */
  1469. v = l3_unscale(1, exponents[s_index]);
  1470. if(get_bits1(&s->gb))
  1471. v = -v;
  1472. } else {
  1473. v = 0;
  1474. }
  1475. g->sb_hybrid[s_index++] = v;
  1476. }
  1477. }
  1478. while (s_index < 576)
  1479. g->sb_hybrid[s_index++] = 0;
  1480. return 0;
  1481. }
  1482. /* Reorder short blocks from bitstream order to interleaved order. It
  1483. would be faster to do it in parsing, but the code would be far more
  1484. complicated */
  1485. static void reorder_block(MPADecodeContext *s, GranuleDef *g)
  1486. {
  1487. int i, j, k, len;
  1488. int32_t *ptr, *dst, *ptr1;
  1489. int32_t tmp[576];
  1490. if (g->block_type != 2)
  1491. return;
  1492. if (g->switch_point) {
  1493. if (s->sample_rate_index != 8) {
  1494. ptr = g->sb_hybrid + 36;
  1495. } else {
  1496. ptr = g->sb_hybrid + 48;
  1497. }
  1498. } else {
  1499. ptr = g->sb_hybrid;
  1500. }
  1501. for(i=g->short_start;i<13;i++) {
  1502. len = band_size_short[s->sample_rate_index][i];
  1503. ptr1 = ptr;
  1504. for(k=0;k<3;k++) {
  1505. dst = tmp + k;
  1506. for(j=len;j>0;j--) {
  1507. *dst = *ptr++;
  1508. dst += 3;
  1509. }
  1510. }
  1511. memcpy(ptr1, tmp, len * 3 * sizeof(int32_t));
  1512. }
  1513. }
  1514. #define ISQRT2 FIXR(0.70710678118654752440)
  1515. static void compute_stereo(MPADecodeContext *s,
  1516. GranuleDef *g0, GranuleDef *g1)
  1517. {
  1518. int i, j, k, l;
  1519. int32_t v1, v2;
  1520. int sf_max, tmp0, tmp1, sf, len, non_zero_found;
  1521. int32_t (*is_tab)[16];
  1522. int32_t *tab0, *tab1;
  1523. int non_zero_found_short[3];
  1524. /* intensity stereo */
  1525. if (s->mode_ext & MODE_EXT_I_STEREO) {
  1526. if (!s->lsf) {
  1527. is_tab = is_table;
  1528. sf_max = 7;
  1529. } else {
  1530. is_tab = is_table_lsf[g1->scalefac_compress & 1];
  1531. sf_max = 16;
  1532. }
  1533. tab0 = g0->sb_hybrid + 576;
  1534. tab1 = g1->sb_hybrid + 576;
  1535. non_zero_found_short[0] = 0;
  1536. non_zero_found_short[1] = 0;
  1537. non_zero_found_short[2] = 0;
  1538. k = (13 - g1->short_start) * 3 + g1->long_end - 3;
  1539. for(i = 12;i >= g1->short_start;i--) {
  1540. /* for last band, use previous scale factor */
  1541. if (i != 11)
  1542. k -= 3;
  1543. len = band_size_short[s->sample_rate_index][i];
  1544. for(l=2;l>=0;l--) {
  1545. tab0 -= len;
  1546. tab1 -= len;
  1547. if (!non_zero_found_short[l]) {
  1548. /* test if non zero band. if so, stop doing i-stereo */
  1549. for(j=0;j<len;j++) {
  1550. if (tab1[j] != 0) {
  1551. non_zero_found_short[l] = 1;
  1552. goto found1;
  1553. }
  1554. }
  1555. sf = g1->scale_factors[k + l];
  1556. if (sf >= sf_max)
  1557. goto found1;
  1558. v1 = is_tab[0][sf];
  1559. v2 = is_tab[1][sf];
  1560. for(j=0;j<len;j++) {
  1561. tmp0 = tab0[j];
  1562. tab0[j] = MULL(tmp0, v1);
  1563. tab1[j] = MULL(tmp0, v2);
  1564. }
  1565. } else {
  1566. found1:
  1567. if (s->mode_ext & MODE_EXT_MS_STEREO) {
  1568. /* lower part of the spectrum : do ms stereo
  1569. if enabled */
  1570. for(j=0;j<len;j++) {
  1571. tmp0 = tab0[j];
  1572. tmp1 = tab1[j];
  1573. tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
  1574. tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
  1575. }
  1576. }
  1577. }
  1578. }
  1579. }
  1580. non_zero_found = non_zero_found_short[0] |
  1581. non_zero_found_short[1] |
  1582. non_zero_found_short[2];
  1583. for(i = g1->long_end - 1;i >= 0;i--) {
  1584. len = band_size_long[s->sample_rate_index][i];
  1585. tab0 -= len;
  1586. tab1 -= len;
  1587. /* test if non zero band. if so, stop doing i-stereo */
  1588. if (!non_zero_found) {
  1589. for(j=0;j<len;j++) {
  1590. if (tab1[j] != 0) {
  1591. non_zero_found = 1;
  1592. goto found2;
  1593. }
  1594. }
  1595. /* for last band, use previous scale factor */
  1596. k = (i == 21) ? 20 : i;
  1597. sf = g1->scale_factors[k];
  1598. if (sf >= sf_max)
  1599. goto found2;
  1600. v1 = is_tab[0][sf];
  1601. v2 = is_tab[1][sf];
  1602. for(j=0;j<len;j++) {
  1603. tmp0 = tab0[j];
  1604. tab0[j] = MULL(tmp0, v1);
  1605. tab1[j] = MULL(tmp0, v2);
  1606. }
  1607. } else {
  1608. found2:
  1609. if (s->mode_ext & MODE_EXT_MS_STEREO) {
  1610. /* lower part of the spectrum : do ms stereo
  1611. if enabled */
  1612. for(j=0;j<len;j++) {
  1613. tmp0 = tab0[j];
  1614. tmp1 = tab1[j];
  1615. tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
  1616. tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
  1617. }
  1618. }
  1619. }
  1620. }
  1621. } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
  1622. /* ms stereo ONLY */
  1623. /* NOTE: the 1/sqrt(2) normalization factor is included in the
  1624. global gain */
  1625. tab0 = g0->sb_hybrid;
  1626. tab1 = g1->sb_hybrid;
  1627. for(i=0;i<576;i++) {
  1628. tmp0 = tab0[i];
  1629. tmp1 = tab1[i];
  1630. tab0[i] = tmp0 + tmp1;
  1631. tab1[i] = tmp0 - tmp1;
  1632. }
  1633. }
  1634. }
  1635. static void compute_antialias(MPADecodeContext *s,
  1636. GranuleDef *g)
  1637. {
  1638. int32_t *ptr, *p0, *p1, *csa;
  1639. int n, tmp0, tmp1, i, j;
  1640. /* we antialias only "long" bands */
  1641. if (g->block_type == 2) {
  1642. if (!g->switch_point)
  1643. return;
  1644. /* XXX: check this for 8000Hz case */
  1645. n = 1;
  1646. } else {
  1647. n = SBLIMIT - 1;
  1648. }
  1649. ptr = g->sb_hybrid + 18;
  1650. for(i = n;i > 0;i--) {
  1651. p0 = ptr - 1;
  1652. p1 = ptr;
  1653. csa = &csa_table[0][0];
  1654. for(j=0;j<8;j++) {
  1655. tmp0 = *p0;
  1656. tmp1 = *p1;
  1657. *p0 = FRAC_RND(MUL64(tmp0, csa[0]) - MUL64(tmp1, csa[1]));
  1658. *p1 = FRAC_RND(MUL64(tmp0, csa[1]) + MUL64(tmp1, csa[0]));
  1659. p0--;
  1660. p1++;
  1661. csa += 2;
  1662. }
  1663. ptr += 18;
  1664. }
  1665. }
  1666. static void compute_imdct(MPADecodeContext *s,
  1667. GranuleDef *g,
  1668. int32_t *sb_samples,
  1669. int32_t *mdct_buf)
  1670. {
  1671. int32_t *ptr, *win, *win1, *buf, *buf2, *out_ptr, *ptr1;
  1672. int32_t in[6];
  1673. int32_t out[36];
  1674. int32_t out2[12];
  1675. int i, j, k, mdct_long_end, v, sblimit;
  1676. /* find last non zero block */
  1677. ptr = g->sb_hybrid + 576;
  1678. ptr1 = g->sb_hybrid + 2 * 18;
  1679. while (ptr >= ptr1) {
  1680. ptr -= 6;
  1681. v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];
  1682. if (v != 0)
  1683. break;
  1684. }
  1685. sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
  1686. if (g->block_type == 2) {
  1687. /* XXX: check for 8000 Hz */
  1688. if (g->switch_point)
  1689. mdct_long_end = 2;
  1690. else
  1691. mdct_long_end = 0;
  1692. } else {
  1693. mdct_long_end = sblimit;
  1694. }
  1695. buf = mdct_buf;
  1696. ptr = g->sb_hybrid;
  1697. for(j=0;j<mdct_long_end;j++) {
  1698. imdct36(out, ptr);
  1699. /* apply window & overlap with previous buffer */
  1700. out_ptr = sb_samples + j;
  1701. /* select window */
  1702. if (g->switch_point && j < 2)
  1703. win1 = mdct_win[0];
  1704. else
  1705. win1 = mdct_win[g->block_type];
  1706. /* select frequency inversion */
  1707. win = win1 + ((4 * 36) & -(j & 1));
  1708. for(i=0;i<18;i++) {
  1709. *out_ptr = MULL(out[i], win[i]) + buf[i];
  1710. buf[i] = MULL(out[i + 18], win[i + 18]);
  1711. out_ptr += SBLIMIT;
  1712. }
  1713. ptr += 18;
  1714. buf += 18;
  1715. }
  1716. for(j=mdct_long_end;j<sblimit;j++) {
  1717. for(i=0;i<6;i++) {
  1718. out[i] = 0;
  1719. out[6 + i] = 0;
  1720. out[30+i] = 0;
  1721. }
  1722. /* select frequency inversion */
  1723. win = mdct_win[2] + ((4 * 36) & -(j & 1));
  1724. buf2 = out + 6;
  1725. for(k=0;k<3;k++) {
  1726. /* reorder input for short mdct */
  1727. ptr1 = ptr + k;
  1728. for(i=0;i<6;i++) {
  1729. in[i] = *ptr1;
  1730. ptr1 += 3;
  1731. }
  1732. imdct12(out2, in);
  1733. /* apply 12 point window and do small overlap */
  1734. for(i=0;i<6;i++) {
  1735. buf2[i] = MULL(out2[i], win[i]) + buf2[i];
  1736. buf2[i + 6] = MULL(out2[i + 6], win[i + 6]);
  1737. }
  1738. buf2 += 6;
  1739. }
  1740. /* overlap */
  1741. out_ptr = sb_samples + j;
  1742. for(i=0;i<18;i++) {
  1743. *out_ptr = out[i] + buf[i];
  1744. buf[i] = out[i + 18];
  1745. out_ptr += SBLIMIT;
  1746. }
  1747. ptr += 18;
  1748. buf += 18;
  1749. }
  1750. /* zero bands */
  1751. for(j=sblimit;j<SBLIMIT;j++) {
  1752. /* overlap */
  1753. out_ptr = sb_samples + j;
  1754. for(i=0;i<18;i++) {
  1755. *out_ptr = buf[i];
  1756. buf[i] = 0;
  1757. out_ptr += SBLIMIT;
  1758. }
  1759. buf += 18;
  1760. }
  1761. }
  1762. #if defined(DEBUG)
  1763. void sample_dump(int fnum, int32_t *tab, int n)
  1764. {
  1765. static FILE *files[16], *f;
  1766. char buf[512];
  1767. int i;
  1768. int32_t v;
  1769. f = files[fnum];
  1770. if (!f) {
  1771. sprintf(buf, "/tmp/out%d.%s.pcm",
  1772. fnum,
  1773. #ifdef USE_HIGHPRECISION
  1774. "hp"
  1775. #else
  1776. "lp"
  1777. #endif
  1778. );
  1779. f = fopen(buf, "w");
  1780. if (!f)
  1781. return;
  1782. files[fnum] = f;
  1783. }
  1784. if (fnum == 0) {
  1785. static int pos = 0;
  1786. printf("pos=%d\n", pos);
  1787. for(i=0;i<n;i++) {
  1788. printf(" %0.4f", (double)tab[i] / FRAC_ONE);
  1789. if ((i % 18) == 17)
  1790. printf("\n");
  1791. }
  1792. pos += n;
  1793. }
  1794. for(i=0;i<n;i++) {
  1795. /* normalize to 23 frac bits */
  1796. v = tab[i] << (23 - FRAC_BITS);
  1797. fwrite(&v, 1, sizeof(int32_t), f);
  1798. }
  1799. }
  1800. #endif
  1801. /* main layer3 decoding function */
  1802. static int mp_decode_layer3(MPADecodeContext *s)
  1803. {
  1804. int nb_granules, main_data_begin, private_bits;
  1805. int gr, ch, blocksplit_flag, i, j, k, n, bits_pos, bits_left;
  1806. GranuleDef granules[2][2], *g;
  1807. int16_t exponents[576];
  1808. /* read side info */
  1809. if (s->lsf) {
  1810. main_data_begin = get_bits(&s->gb, 8);
  1811. if (s->nb_channels == 2)
  1812. private_bits = get_bits(&s->gb, 2);
  1813. else
  1814. private_bits = get_bits(&s->gb, 1);
  1815. nb_granules = 1;
  1816. } else {
  1817. main_data_begin = get_bits(&s->gb, 9);
  1818. if (s->nb_channels == 2)
  1819. private_bits = get_bits(&s->gb, 3);
  1820. else
  1821. private_bits = get_bits(&s->gb, 5);
  1822. nb_granules = 2;
  1823. for(ch=0;ch<s->nb_channels;ch++) {
  1824. granules[ch][0].scfsi = 0; /* all scale factors are transmitted */
  1825. granules[ch][1].scfsi = get_bits(&s->gb, 4);
  1826. }
  1827. }
  1828. for(gr=0;gr<nb_granules;gr++) {
  1829. for(ch=0;ch<s->nb_channels;ch++) {
  1830. dprintf("gr=%d ch=%d: side_info\n", gr, ch);
  1831. g = &granules[ch][gr];
  1832. g->part2_3_length = get_bits(&s->gb, 12);
  1833. g->big_values = get_bits(&s->gb, 9);
  1834. g->global_gain = get_bits(&s->gb, 8);
  1835. /* if MS stereo only is selected, we precompute the
  1836. 1/sqrt(2) renormalization factor */
  1837. if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
  1838. MODE_EXT_MS_STEREO)
  1839. g->global_gain -= 2;
  1840. if (s->lsf)
  1841. g->scalefac_compress = get_bits(&s->gb, 9);
  1842. else
  1843. g->scalefac_compress = get_bits(&s->gb, 4);
  1844. blocksplit_flag = get_bits(&s->gb, 1);
  1845. if (blocksplit_flag) {
  1846. g->block_type = get_bits(&s->gb, 2);
  1847. if (g->block_type == 0)
  1848. return -1;
  1849. g->switch_point = get_bits(&s->gb, 1);
  1850. for(i=0;i<2;i++)
  1851. g->table_select[i] = get_bits(&s->gb, 5);
  1852. for(i=0;i<3;i++)
  1853. g->subblock_gain[i] = get_bits(&s->gb, 3);
  1854. /* compute huffman coded region sizes */
  1855. if (g->block_type == 2)
  1856. g->region_size[0] = (36 / 2);
  1857. else {
  1858. if (s->sample_rate_index <= 2)
  1859. g->region_size[0] = (36 / 2);
  1860. else if (s->sample_rate_index != 8)
  1861. g->region_size[0] = (54 / 2);
  1862. else
  1863. g->region_size[0] = (108 / 2);
  1864. }
  1865. g->region_size[1] = (576 / 2);
  1866. } else {
  1867. int region_address1, region_address2, l;
  1868. g->block_type = 0;
  1869. g->switch_point = 0;
  1870. for(i=0;i<3;i++)
  1871. g->table_select[i] = get_bits(&s->gb, 5);
  1872. /* compute huffman coded region sizes */
  1873. region_address1 = get_bits(&s->gb, 4);
  1874. region_address2 = get_bits(&s->gb, 3);
  1875. dprintf("region1=%d region2=%d\n",
  1876. region_address1, region_address2);
  1877. g->region_size[0] =
  1878. band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;
  1879. l = region_address1 + region_address2 + 2;
  1880. /* should not overflow */
  1881. if (l > 22)
  1882. l = 22;
  1883. g->region_size[1] =
  1884. band_index_long[s->sample_rate_index][l] >> 1;
  1885. }
  1886. /* convert region offsets to region sizes and truncate
  1887. size to big_values */
  1888. g->region_size[2] = (576 / 2);
  1889. j = 0;
  1890. for(i=0;i<3;i++) {
  1891. k = g->region_size[i];
  1892. if (k > g->big_values)
  1893. k = g->big_values;
  1894. g->region_size[i] = k - j;
  1895. j = k;
  1896. }
  1897. /* compute band indexes */
  1898. if (g->block_type == 2) {
  1899. if (g->switch_point) {
  1900. /* if switched mode, we handle the 36 first samples as
  1901. long blocks. For 8000Hz, we handle the 48 first
  1902. exponents as long blocks (XXX: check this!) */
  1903. if (s->sample_rate_index <= 2)
  1904. g->long_end = 8;
  1905. else if (s->sample_rate_index != 8)
  1906. g->long_end = 6;
  1907. else
  1908. g->long_end = 4; /* 8000 Hz */
  1909. if (s->sample_rate_index != 8)
  1910. g->short_start = 3;
  1911. else
  1912. g->short_start = 2;
  1913. } else {
  1914. g->long_end = 0;
  1915. g->short_start = 0;
  1916. }
  1917. } else {
  1918. g->short_start = 13;
  1919. g->long_end = 22;
  1920. }
  1921. g->preflag = 0;
  1922. if (!s->lsf)
  1923. g->preflag = get_bits(&s->gb, 1);
  1924. g->scalefac_scale = get_bits(&s->gb, 1);
  1925. g->count1table_select = get_bits(&s->gb, 1);
  1926. dprintf("block_type=%d switch_point=%d\n",
  1927. g->block_type, g->switch_point);
  1928. }
  1929. }
  1930. /* now we get bits from the main_data_begin offset */
  1931. dprintf("seekback: %d\n", main_data_begin);
  1932. seek_to_maindata(s, main_data_begin);
  1933. for(gr=0;gr<nb_granules;gr++) {
  1934. for(ch=0;ch<s->nb_channels;ch++) {
  1935. g = &granules[ch][gr];
  1936. bits_pos = get_bits_count(&s->gb);
  1937. if (!s->lsf) {
  1938. uint8_t *sc;
  1939. int slen, slen1, slen2;
  1940. /* MPEG1 scale factors */
  1941. slen1 = slen_table[0][g->scalefac_compress];
  1942. slen2 = slen_table[1][g->scalefac_compress];
  1943. dprintf("slen1=%d slen2=%d\n", slen1, slen2);
  1944. if (g->block_type == 2) {
  1945. n = g->switch_point ? 17 : 18;
  1946. j = 0;
  1947. for(i=0;i<n;i++)
  1948. g->scale_factors[j++] = get_bitsz(&s->gb, slen1);
  1949. for(i=0;i<18;i++)
  1950. g->scale_factors[j++] = get_bitsz(&s->gb, slen2);
  1951. for(i=0;i<3;i++)
  1952. g->scale_factors[j++] = 0;
  1953. } else {
  1954. sc = granules[ch][0].scale_factors;
  1955. j = 0;
  1956. for(k=0;k<4;k++) {
  1957. n = (k == 0 ? 6 : 5);
  1958. if ((g->scfsi & (0x8 >> k)) == 0) {
  1959. slen = (k < 2) ? slen1 : slen2;
  1960. for(i=0;i<n;i++)
  1961. g->scale_factors[j++] = get_bitsz(&s->gb, slen);
  1962. } else {
  1963. /* simply copy from last granule */
  1964. for(i=0;i<n;i++) {
  1965. g->scale_factors[j] = sc[j];
  1966. j++;
  1967. }
  1968. }
  1969. }
  1970. g->scale_factors[j++] = 0;
  1971. }
  1972. #if defined(DEBUG)
  1973. {
  1974. printf("scfsi=%x gr=%d ch=%d scale_factors:\n",
  1975. g->scfsi, gr, ch);
  1976. for(i=0;i<j;i++)
  1977. printf(" %d", g->scale_factors[i]);
  1978. printf("\n");
  1979. }
  1980. #endif
  1981. } else {
  1982. int tindex, tindex2, slen[4], sl, sf;
  1983. /* LSF scale factors */
  1984. if (g->block_type == 2) {
  1985. tindex = g->switch_point ? 2 : 1;
  1986. } else {
  1987. tindex = 0;
  1988. }
  1989. sf = g->scalefac_compress;
  1990. if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
  1991. /* intensity stereo case */
  1992. sf >>= 1;
  1993. if (sf < 180) {
  1994. lsf_sf_expand(slen, sf, 6, 6, 0);
  1995. tindex2 = 3;
  1996. } else if (sf < 244) {
  1997. lsf_sf_expand(slen, sf - 180, 4, 4, 0);
  1998. tindex2 = 4;
  1999. } else {
  2000. lsf_sf_expand(slen, sf - 244, 3, 0, 0);
  2001. tindex2 = 5;
  2002. }
  2003. } else {
  2004. /* normal case */
  2005. if (sf < 400) {
  2006. lsf_sf_expand(slen, sf, 5, 4, 4);
  2007. tindex2 = 0;
  2008. } else if (sf < 500) {
  2009. lsf_sf_expand(slen, sf - 400, 5, 4, 0);
  2010. tindex2 = 1;
  2011. } else {
  2012. lsf_sf_expand(slen, sf - 500, 3, 0, 0);
  2013. tindex2 = 2;
  2014. g->preflag = 1;
  2015. }
  2016. }
  2017. j = 0;
  2018. for(k=0;k<4;k++) {
  2019. n = lsf_nsf_table[tindex2][tindex][k];
  2020. sl = slen[k];
  2021. for(i=0;i<n;i++)
  2022. g->scale_factors[j++] = get_bitsz(&s->gb, sl);
  2023. }
  2024. /* XXX: should compute exact size */
  2025. for(;j<40;j++)
  2026. g->scale_factors[j] = 0;
  2027. #if defined(DEBUG)
  2028. {
  2029. printf("gr=%d ch=%d scale_factors:\n",
  2030. gr, ch);
  2031. for(i=0;i<40;i++)
  2032. printf(" %d", g->scale_factors[i]);
  2033. printf("\n");
  2034. }
  2035. #endif
  2036. }
  2037. exponents_from_scale_factors(s, g, exponents);
  2038. /* read Huffman coded residue */
  2039. if (huffman_decode(s, g, exponents,
  2040. bits_pos + g->part2_3_length) < 0)
  2041. return -1;
  2042. #if defined(DEBUG)
  2043. sample_dump(0, g->sb_hybrid, 576);
  2044. #endif
  2045. /* skip extension bits */
  2046. bits_left = g->part2_3_length - (get_bits_count(&s->gb) - bits_pos);
  2047. if (bits_left < 0) {
  2048. dprintf("bits_left=%d\n", bits_left);
  2049. return -1;
  2050. }
  2051. while (bits_left >= 16) {
  2052. skip_bits(&s->gb, 16);
  2053. bits_left -= 16;
  2054. }
  2055. if (bits_left > 0)
  2056. skip_bits(&s->gb, bits_left);
  2057. } /* ch */
  2058. if (s->nb_channels == 2)
  2059. compute_stereo(s, &granules[0][gr], &granules[1][gr]);
  2060. for(ch=0;ch<s->nb_channels;ch++) {
  2061. g = &granules[ch][gr];
  2062. reorder_block(s, g);
  2063. #if defined(DEBUG)
  2064. sample_dump(0, g->sb_hybrid, 576);
  2065. #endif
  2066. compute_antialias(s, g);
  2067. #if defined(DEBUG)
  2068. sample_dump(1, g->sb_hybrid, 576);
  2069. #endif
  2070. compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
  2071. #if defined(DEBUG)
  2072. sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);
  2073. #endif
  2074. }
  2075. } /* gr */
  2076. return nb_granules * 18;
  2077. }
  2078. static int mp_decode_frame(MPADecodeContext *s,
  2079. short *samples)
  2080. {
  2081. int i, nb_frames, ch;
  2082. short *samples_ptr;
  2083. init_get_bits(&s->gb, s->inbuf + HEADER_SIZE,
  2084. (s->inbuf_ptr - s->inbuf - HEADER_SIZE)*8);
  2085. /* skip error protection field */
  2086. if (s->error_protection)
  2087. get_bits(&s->gb, 16);
  2088. dprintf("frame %d:\n", s->frame_count);
  2089. switch(s->layer) {
  2090. case 1:
  2091. nb_frames = mp_decode_layer1(s);
  2092. break;
  2093. case 2:
  2094. nb_frames = mp_decode_layer2(s);
  2095. break;
  2096. case 3:
  2097. default:
  2098. nb_frames = mp_decode_layer3(s);
  2099. break;
  2100. }
  2101. #if defined(DEBUG)
  2102. for(i=0;i<nb_frames;i++) {
  2103. for(ch=0;ch<s->nb_channels;ch++) {
  2104. int j;
  2105. printf("%d-%d:", i, ch);
  2106. for(j=0;j<SBLIMIT;j++)
  2107. printf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);
  2108. printf("\n");
  2109. }
  2110. }
  2111. #endif
  2112. /* apply the synthesis filter */
  2113. for(ch=0;ch<s->nb_channels;ch++) {
  2114. samples_ptr = samples + ch;
  2115. for(i=0;i<nb_frames;i++) {
  2116. synth_filter(s, ch, samples_ptr, s->nb_channels,
  2117. s->sb_samples[ch][i]);
  2118. samples_ptr += 32 * s->nb_channels;
  2119. }
  2120. }
  2121. #ifdef DEBUG
  2122. s->frame_count++;
  2123. #endif
  2124. return nb_frames * 32 * sizeof(short) * s->nb_channels;
  2125. }
  2126. static int decode_frame(AVCodecContext * avctx,
  2127. void *data, int *data_size,
  2128. uint8_t * buf, int buf_size)
  2129. {
  2130. MPADecodeContext *s = avctx->priv_data;
  2131. uint32_t header;
  2132. uint8_t *buf_ptr;
  2133. int len, out_size;
  2134. short *out_samples = data;
  2135. *data_size = 0;
  2136. buf_ptr = buf;
  2137. while (buf_size > 0) {
  2138. len = s->inbuf_ptr - s->inbuf;
  2139. if (s->frame_size == 0) {
  2140. /* special case for next header for first frame in free
  2141. format case (XXX: find a simpler method) */
  2142. if (s->free_format_next_header != 0) {
  2143. s->inbuf[0] = s->free_format_next_header >> 24;
  2144. s->inbuf[1] = s->free_format_next_header >> 16;
  2145. s->inbuf[2] = s->free_format_next_header >> 8;
  2146. s->inbuf[3] = s->free_format_next_header;
  2147. s->inbuf_ptr = s->inbuf + 4;
  2148. s->free_format_next_header = 0;
  2149. goto got_header;
  2150. }
  2151. /* no header seen : find one. We need at least HEADER_SIZE
  2152. bytes to parse it */
  2153. len = HEADER_SIZE - len;
  2154. if (len > buf_size)
  2155. len = buf_size;
  2156. if (len > 0) {
  2157. memcpy(s->inbuf_ptr, buf_ptr, len);
  2158. buf_ptr += len;
  2159. buf_size -= len;
  2160. s->inbuf_ptr += len;
  2161. }
  2162. if ((s->inbuf_ptr - s->inbuf) >= HEADER_SIZE) {
  2163. got_header:
  2164. header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
  2165. (s->inbuf[2] << 8) | s->inbuf[3];
  2166. if (check_header(header) < 0) {
  2167. /* no sync found : move by one byte (inefficient, but simple!) */
  2168. memcpy(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
  2169. s->inbuf_ptr--;
  2170. dprintf("skip %x\n", header);
  2171. /* reset free format frame size to give a chance
  2172. to get a new bitrate */
  2173. s->free_format_frame_size = 0;
  2174. } else {
  2175. if (decode_header(s, header) == 1) {
  2176. /* free format: prepare to compute frame size */
  2177. s->frame_size = -1;
  2178. }
  2179. /* update codec info */
  2180. avctx->sample_rate = s->sample_rate;
  2181. avctx->channels = s->nb_channels;
  2182. avctx->bit_rate = s->bit_rate;
  2183. avctx->frame_size = s->frame_size;
  2184. }
  2185. }
  2186. } else if (s->frame_size == -1) {
  2187. /* free format : find next sync to compute frame size */
  2188. len = MPA_MAX_CODED_FRAME_SIZE - len;
  2189. if (len > buf_size)
  2190. len = buf_size;
  2191. if (len == 0) {
  2192. /* frame too long: resync */
  2193. s->frame_size = 0;
  2194. memcpy(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
  2195. s->inbuf_ptr--;
  2196. } else {
  2197. uint8_t *p, *pend;
  2198. uint32_t header1;
  2199. int padding;
  2200. memcpy(s->inbuf_ptr, buf_ptr, len);
  2201. /* check for header */
  2202. p = s->inbuf_ptr - 3;
  2203. pend = s->inbuf_ptr + len - 4;
  2204. while (p <= pend) {
  2205. header = (p[0] << 24) | (p[1] << 16) |
  2206. (p[2] << 8) | p[3];
  2207. header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
  2208. (s->inbuf[2] << 8) | s->inbuf[3];
  2209. /* check with high probability that we have a
  2210. valid header */
  2211. if ((header & SAME_HEADER_MASK) ==
  2212. (header1 & SAME_HEADER_MASK)) {
  2213. /* header found: update pointers */
  2214. len = (p + 4) - s->inbuf_ptr;
  2215. buf_ptr += len;
  2216. buf_size -= len;
  2217. s->inbuf_ptr = p;
  2218. /* compute frame size */
  2219. s->free_format_next_header = header;
  2220. s->free_format_frame_size = s->inbuf_ptr - s->inbuf;
  2221. padding = (header1 >> 9) & 1;
  2222. if (s->layer == 1)
  2223. s->free_format_frame_size -= padding * 4;
  2224. else
  2225. s->free_format_frame_size -= padding;
  2226. dprintf("free frame size=%d padding=%d\n",
  2227. s->free_format_frame_size, padding);
  2228. decode_header(s, header1);
  2229. goto next_data;
  2230. }
  2231. p++;
  2232. }
  2233. /* not found: simply increase pointers */
  2234. buf_ptr += len;
  2235. s->inbuf_ptr += len;
  2236. buf_size -= len;
  2237. }
  2238. } else if (len < s->frame_size) {
  2239. if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)
  2240. s->frame_size = MPA_MAX_CODED_FRAME_SIZE;
  2241. len = s->frame_size - len;
  2242. if (len > buf_size)
  2243. len = buf_size;
  2244. memcpy(s->inbuf_ptr, buf_ptr, len);
  2245. buf_ptr += len;
  2246. s->inbuf_ptr += len;
  2247. buf_size -= len;
  2248. } else {
  2249. out_size = mp_decode_frame(s, out_samples);
  2250. s->inbuf_ptr = s->inbuf;
  2251. s->frame_size = 0;
  2252. *data_size = out_size;
  2253. break;
  2254. }
  2255. next_data:
  2256. ;
  2257. }
  2258. return buf_ptr - buf;
  2259. }
  2260. AVCodec mp2_decoder =
  2261. {
  2262. "mp2",
  2263. CODEC_TYPE_AUDIO,
  2264. CODEC_ID_MP2,
  2265. sizeof(MPADecodeContext),
  2266. decode_init,
  2267. NULL,
  2268. NULL,
  2269. decode_frame,
  2270. };
  2271. AVCodec mp3_decoder =
  2272. {
  2273. "mp3",
  2274. CODEC_TYPE_AUDIO,
  2275. CODEC_ID_MP3LAME,
  2276. sizeof(MPADecodeContext),
  2277. decode_init,
  2278. NULL,
  2279. NULL,
  2280. decode_frame,
  2281. };
  2282. #undef C1
  2283. #undef C2
  2284. #undef C3
  2285. #undef C4
  2286. #undef C5
  2287. #undef C6
  2288. #undef C7
  2289. #undef C8
  2290. #undef FRAC_BITS
  2291. #undef HEADER_SIZE