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FFmpeg/libavcodec/mpegaudiodec.c

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  1. /*

  2.  * MPEG Audio decoder

  3.  * Copyright (c) 2001, 2002 Fabrice Bellard.

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

  8.  * modify it under the terms of the GNU Lesser General Public

  9.  * License as published by the Free Software Foundation; either

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  15.  * Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. /**

  23.  * @file mpegaudiodec.c

  24.  * MPEG Audio decoder.

  25.  */

  26. 

  27. //#define DEBUG

  28. #include "avcodec.h"

  29. #include "bitstream.h"

  30. #include "dsputil.h"

  31. 

  32. /*

  33.  * TODO:

  34.  *  - in low precision mode, use more 16 bit multiplies in synth filter

  35.  *  - test lsf / mpeg25 extensively.

  36.  */

  37. 

  38. /* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg

  39.    audio decoder */

  40. #ifdef CONFIG_MPEGAUDIO_HP

  41. #   define USE_HIGHPRECISION

  42. #endif

  43. 

  44. #include "mpegaudio.h"

  45. #include "mpegaudiodecheader.h"

  46. 

  47. #include "mathops.h"

  48. 

  49. /* WARNING: only correct for posititive numbers */

  50. #define FIXR(a)   ((int)((a) * FRAC_ONE + 0.5))

  51. #define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)

  52. 

  53. #define FIXHR(a) ((int)((a) * (1LL<<32) + 0.5))

  54. 

  55. /****************/

  56. 

  57. #define HEADER_SIZE 4

  58. 

  59. /**

  60.  * Context for MP3On4 decoder

  61.  */

  62. typedef struct MP3On4DecodeContext {

  63.     int frames;   ///< number of mp3 frames per block (number of mp3 decoder instances)

  64.     int chan_cfg; ///< channel config number

  65.     MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance

  66. } MP3On4DecodeContext;

  67. 

  68. /* layer 3 "granule" */

  69. typedef struct GranuleDef {

  70.     uint8_t scfsi;

  71.     int part2_3_length;

  72.     int big_values;

  73.     int global_gain;

  74.     int scalefac_compress;

  75.     uint8_t block_type;

  76.     uint8_t switch_point;

  77.     int table_select[3];

  78.     int subblock_gain[3];

  79.     uint8_t scalefac_scale;

  80.     uint8_t count1table_select;

  81.     int region_size[3]; /* number of huffman codes in each region */

  82.     int preflag;

  83.     int short_start, long_end; /* long/short band indexes */

  84.     uint8_t scale_factors[40];

  85.     int32_t sb_hybrid[SBLIMIT * 18]; /* 576 samples */

  86. } GranuleDef;

  87. 

  88. #include "mpegaudiodata.h"

  89. #include "mpegaudiodectab.h"

  90. 

  91. static void compute_antialias_integer(MPADecodeContext *s, GranuleDef *g);

  92. static void compute_antialias_float(MPADecodeContext *s, GranuleDef *g);

  93. 

  94. /* vlc structure for decoding layer 3 huffman tables */

  95. static VLC huff_vlc[16];

  96. static VLC huff_quad_vlc[2];

  97. /* computed from band_size_long */

  98. static uint16_t band_index_long[9][23];

  99. /* XXX: free when all decoders are closed */

  100. #define TABLE_4_3_SIZE (8191 + 16)*4

  101. static int8_t  table_4_3_exp[TABLE_4_3_SIZE];

  102. static uint32_t table_4_3_value[TABLE_4_3_SIZE];

  103. static uint32_t exp_table[512];

  104. static uint32_t expval_table[512][16];

  105. /* intensity stereo coef table */

  106. static int32_t is_table[2][16];

  107. static int32_t is_table_lsf[2][2][16];

  108. static int32_t csa_table[8][4];

  109. static float csa_table_float[8][4];

  110. static int32_t mdct_win[8][36];

  111. 

  112. /* lower 2 bits: modulo 3, higher bits: shift */

  113. static uint16_t scale_factor_modshift[64];

  114. /* [i][j]:  2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */

  115. static int32_t scale_factor_mult[15][3];

  116. /* mult table for layer 2 group quantization */

  117. 

  118. #define SCALE_GEN(v) \

  119. { FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }

  120. 

  121. static const int32_t scale_factor_mult2[3][3] = {

  122.     SCALE_GEN(4.0 / 3.0), /* 3 steps */

  123.     SCALE_GEN(4.0 / 5.0), /* 5 steps */

  124.     SCALE_GEN(4.0 / 9.0), /* 9 steps */

  125. };

  126. 

  127. static DECLARE_ALIGNED_16(MPA_INT, window[512]);

  128. 

  129. /**

  130.  * Convert region offsets to region sizes and truncate

  131.  * size to big_values.

  132.  */

  133. void ff_region_offset2size(GranuleDef *g){

  134.     int i, k, j=0;

  135.     g->region_size[2] = (576 / 2);

  136.     for(i=0;i<3;i++) {

  137.         k = FFMIN(g->region_size[i], g->big_values);

  138.         g->region_size[i] = k - j;

  139.         j = k;

  140.     }

  141. }

  142. 

  143. void ff_init_short_region(MPADecodeContext *s, GranuleDef *g){

  144.     if (g->block_type == 2)

  145.         g->region_size[0] = (36 / 2);

  146.     else {

  147.         if (s->sample_rate_index <= 2)

  148.             g->region_size[0] = (36 / 2);

  149.         else if (s->sample_rate_index != 8)

  150.             g->region_size[0] = (54 / 2);

  151.         else

  152.             g->region_size[0] = (108 / 2);

  153.     }

  154.     g->region_size[1] = (576 / 2);

  155. }

  156. 

  157. void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2){

  158.     int l;

  159.     g->region_size[0] =

  160.         band_index_long[s->sample_rate_index][ra1 + 1] >> 1;

  161.     /* should not overflow */

  162.     l = FFMIN(ra1 + ra2 + 2, 22);

  163.     g->region_size[1] =

  164.         band_index_long[s->sample_rate_index][l] >> 1;

  165. }

  166. 

  167. void ff_compute_band_indexes(MPADecodeContext *s, GranuleDef *g){

  168.     if (g->block_type == 2) {

  169.         if (g->switch_point) {

  170.             /* if switched mode, we handle the 36 first samples as

  171.                 long blocks.  For 8000Hz, we handle the 48 first

  172.                 exponents as long blocks (XXX: check this!) */

  173.             if (s->sample_rate_index <= 2)

  174.                 g->long_end = 8;

  175.             else if (s->sample_rate_index != 8)

  176.                 g->long_end = 6;

  177.             else

  178.                 g->long_end = 4; /* 8000 Hz */

  179. 

  180.             g->short_start = 2 + (s->sample_rate_index != 8);

  181.         } else {

  182.             g->long_end = 0;

  183.             g->short_start = 0;

  184.         }

  185.     } else {

  186.         g->short_start = 13;

  187.         g->long_end = 22;

  188.     }

  189. }

  190. 

  191. /* layer 1 unscaling */

  192. /* n = number of bits of the mantissa minus 1 */

  193. static inline int l1_unscale(int n, int mant, int scale_factor)

  194. {

  195.     int shift, mod;

  196.     int64_t val;

  197. 

  198.     shift = scale_factor_modshift[scale_factor];

  199.     mod = shift & 3;

  200.     shift >>= 2;

  201.     val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);

  202.     shift += n;

  203.     /* NOTE: at this point, 1 <= shift >= 21 + 15 */

  204.     return (int)((val + (1LL << (shift - 1))) >> shift);

  205. }

  206. 

  207. static inline int l2_unscale_group(int steps, int mant, int scale_factor)

  208. {

  209.     int shift, mod, val;

  210. 

  211.     shift = scale_factor_modshift[scale_factor];

  212.     mod = shift & 3;

  213.     shift >>= 2;

  214. 

  215.     val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];

  216.     /* NOTE: at this point, 0 <= shift <= 21 */

  217.     if (shift > 0)

  218.         val = (val + (1 << (shift - 1))) >> shift;

  219.     return val;

  220. }

  221. 

  222. /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */

  223. static inline int l3_unscale(int value, int exponent)

  224. {

  225.     unsigned int m;

  226.     int e;

  227. 

  228.     e = table_4_3_exp  [4*value + (exponent&3)];

  229.     m = table_4_3_value[4*value + (exponent&3)];

  230.     e -= (exponent >> 2);

  231.     assert(e>=1);

  232.     if (e > 31)

  233.         return 0;

  234.     m = (m + (1 << (e-1))) >> e;

  235. 

  236.     return m;

  237. }

  238. 

  239. /* all integer n^(4/3) computation code */

  240. #define DEV_ORDER 13

  241. 

  242. #define POW_FRAC_BITS 24

  243. #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)

  244. #define POW_FIX(a)   ((int)((a) * POW_FRAC_ONE))

  245. #define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)

  246. 

  247. static int dev_4_3_coefs[DEV_ORDER];

  248. 

  249. #if 0 /* unused */

  250. static int pow_mult3[3] = {

  251.     POW_FIX(1.0),

  252.     POW_FIX(1.25992104989487316476),

  253.     POW_FIX(1.58740105196819947474),

  254. };

  255. #endif

  256. 

  257. static void int_pow_init(void)

  258. {

  259.     int i, a;

  260. 

  261.     a = POW_FIX(1.0);

  262.     for(i=0;i<DEV_ORDER;i++) {

  263.         a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);

  264.         dev_4_3_coefs[i] = a;

  265.     }

  266. }

  267. 

  268. #if 0 /* unused, remove? */

  269. /* return the mantissa and the binary exponent */

  270. static int int_pow(int i, int *exp_ptr)

  271. {

  272.     int e, er, eq, j;

  273.     int a, a1;

  274. 

  275.     /* renormalize */

  276.     a = i;

  277.     e = POW_FRAC_BITS;

  278.     while (a < (1 << (POW_FRAC_BITS - 1))) {

  279.         a = a << 1;

  280.         e--;

  281.     }

  282.     a -= (1 << POW_FRAC_BITS);

  283.     a1 = 0;

  284.     for(j = DEV_ORDER - 1; j >= 0; j--)

  285.         a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);

  286.     a = (1 << POW_FRAC_BITS) + a1;

  287.     /* exponent compute (exact) */

  288.     e = e * 4;

  289.     er = e % 3;

  290.     eq = e / 3;

  291.     a = POW_MULL(a, pow_mult3[er]);

  292.     while (a >= 2 * POW_FRAC_ONE) {

  293.         a = a >> 1;

  294.         eq++;

  295.     }

  296.     /* convert to float */

  297.     while (a < POW_FRAC_ONE) {

  298.         a = a << 1;

  299.         eq--;

  300.     }

  301.     /* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */

  302. #if POW_FRAC_BITS > FRAC_BITS

  303.     a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);

  304.     /* correct overflow */

  305.     if (a >= 2 * (1 << FRAC_BITS)) {

  306.         a = a >> 1;

  307.         eq++;

  308.     }

  309. #endif

  310.     *exp_ptr = eq;

  311.     return a;

  312. }

  313. #endif

  314. 

  315. static int decode_init(AVCodecContext * avctx)

  316. {

  317.     MPADecodeContext *s = avctx->priv_data;

  318.     static int init=0;

  319.     int i, j, k;

  320. 

  321.     s->avctx = avctx;

  322. 

  323. #if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)

  324.     avctx->sample_fmt= SAMPLE_FMT_S32;

  325. #else

  326.     avctx->sample_fmt= SAMPLE_FMT_S16;

  327. #endif

  328.     s->error_resilience= avctx->error_resilience;

  329. 

  330.     if(avctx->antialias_algo != FF_AA_FLOAT)

  331.         s->compute_antialias= compute_antialias_integer;

  332.     else

  333.         s->compute_antialias= compute_antialias_float;

  334. 

  335.     if (!init && !avctx->parse_only) {

  336.         /* scale factors table for layer 1/2 */

  337.         for(i=0;i<64;i++) {

  338.             int shift, mod;

  339.             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  340.             shift = (i / 3);

  341.             mod = i % 3;

  342.             scale_factor_modshift[i] = mod | (shift << 2);

  343.         }

  344. 

  345.         /* scale factor multiply for layer 1 */

  346.         for(i=0;i<15;i++) {

  347.             int n, norm;

  348.             n = i + 2;

  349.             norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);

  350.             scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);

  351.             scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);

  352.             scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm);

  353.             dprintf(avctx, "%d: norm=%x s=%x %x %x\n",

  354.                     i, norm,

  355.                     scale_factor_mult[i][0],

  356.                     scale_factor_mult[i][1],

  357.                     scale_factor_mult[i][2]);

  358.         }

  359. 

  360.         ff_mpa_synth_init(window);

  361. 

  362.         /* huffman decode tables */

  363.         for(i=1;i<16;i++) {

  364.             const HuffTable *h = &mpa_huff_tables[i];

  365.             int xsize, x, y;

  366.             unsigned int n;

  367.             uint8_t  tmp_bits [512];

  368.             uint16_t tmp_codes[512];

  369. 

  370.             memset(tmp_bits , 0, sizeof(tmp_bits ));

  371.             memset(tmp_codes, 0, sizeof(tmp_codes));

  372. 

  373.             xsize = h->xsize;

  374.             n = xsize * xsize;

  375. 

  376.             j = 0;

  377.             for(x=0;x<xsize;x++) {

  378.                 for(y=0;y<xsize;y++){

  379.                     tmp_bits [(x << 5) | y | ((x&&y)<<4)]= h->bits [j  ];

  380.                     tmp_codes[(x << 5) | y | ((x&&y)<<4)]= h->codes[j++];

  381.                 }

  382.             }

  383. 

  384.             /* XXX: fail test */

  385.             init_vlc(&huff_vlc[i], 7, 512,

  386.                      tmp_bits, 1, 1, tmp_codes, 2, 2, 1);

  387.         }

  388.         for(i=0;i<2;i++) {

  389.             init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,

  390.                      mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1, 1);

  391.         }

  392. 

  393.         for(i=0;i<9;i++) {

  394.             k = 0;

  395.             for(j=0;j<22;j++) {

  396.                 band_index_long[i][j] = k;

  397.                 k += band_size_long[i][j];

  398.             }

  399.             band_index_long[i][22] = k;

  400.         }

  401. 

  402.         /* compute n ^ (4/3) and store it in mantissa/exp format */

  403. 

  404.         int_pow_init();

  405.         for(i=1;i<TABLE_4_3_SIZE;i++) {

  406.             double f, fm;

  407.             int e, m;

  408.             f = pow((double)(i/4), 4.0 / 3.0) * pow(2, (i&3)*0.25);

  409.             fm = frexp(f, &e);

  410.             m = (uint32_t)(fm*(1LL<<31) + 0.5);

  411.             e+= FRAC_BITS - 31 + 5 - 100;

  412. 

  413.             /* normalized to FRAC_BITS */

  414.             table_4_3_value[i] = m;

  415. //            av_log(NULL, AV_LOG_DEBUG, "%d %d %f\n", i, m, pow((double)i, 4.0 / 3.0));

  416.             table_4_3_exp[i] = -e;

  417.         }

  418.         for(i=0; i<512*16; i++){

  419.             int exponent= (i>>4);

  420.             double f= pow(i&15, 4.0 / 3.0) * pow(2, (exponent-400)*0.25 + FRAC_BITS + 5);

  421.             expval_table[exponent][i&15]= llrint(f);

  422.             if((i&15)==1)

  423.                 exp_table[exponent]= llrint(f);

  424.         }

  425. 

  426.         for(i=0;i<7;i++) {

  427.             float f;

  428.             int v;

  429.             if (i != 6) {

  430.                 f = tan((double)i * M_PI / 12.0);

  431.                 v = FIXR(f / (1.0 + f));

  432.             } else {

  433.                 v = FIXR(1.0);

  434.             }

  435.             is_table[0][i] = v;

  436.             is_table[1][6 - i] = v;

  437.         }

  438.         /* invalid values */

  439.         for(i=7;i<16;i++)

  440.             is_table[0][i] = is_table[1][i] = 0.0;

  441. 

  442.         for(i=0;i<16;i++) {

  443.             double f;

  444.             int e, k;

  445. 

  446.             for(j=0;j<2;j++) {

  447.                 e = -(j + 1) * ((i + 1) >> 1);

  448.                 f = pow(2.0, e / 4.0);

  449.                 k = i & 1;

  450.                 is_table_lsf[j][k ^ 1][i] = FIXR(f);

  451.                 is_table_lsf[j][k][i] = FIXR(1.0);

  452.                 dprintf(avctx, "is_table_lsf %d %d: %x %x\n",

  453.                         i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);

  454.             }

  455.         }

  456. 

  457.         for(i=0;i<8;i++) {

  458.             float ci, cs, ca;

  459.             ci = ci_table[i];

  460.             cs = 1.0 / sqrt(1.0 + ci * ci);

  461.             ca = cs * ci;

  462.             csa_table[i][0] = FIXHR(cs/4);

  463.             csa_table[i][1] = FIXHR(ca/4);

  464.             csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);

  465.             csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);

  466.             csa_table_float[i][0] = cs;

  467.             csa_table_float[i][1] = ca;

  468.             csa_table_float[i][2] = ca + cs;

  469.             csa_table_float[i][3] = ca - cs;

  470. //            printf("%d %d %d %d\n", FIX(cs), FIX(cs-1), FIX(ca), FIX(cs)-FIX(ca));

  471. //            av_log(NULL, AV_LOG_DEBUG,"%f %f %f %f\n", cs, ca, ca+cs, ca-cs);

  472.         }

  473. 

  474.         /* compute mdct windows */

  475.         for(i=0;i<36;i++) {

  476.             for(j=0; j<4; j++){

  477.                 double d;

  478. 

  479.                 if(j==2 && i%3 != 1)

  480.                     continue;

  481. 

  482.                 d= sin(M_PI * (i + 0.5) / 36.0);

  483.                 if(j==1){

  484.                     if     (i>=30) d= 0;

  485.                     else if(i>=24) d= sin(M_PI * (i - 18 + 0.5) / 12.0);

  486.                     else if(i>=18) d= 1;

  487.                 }else if(j==3){

  488.                     if     (i<  6) d= 0;

  489.                     else if(i< 12) d= sin(M_PI * (i -  6 + 0.5) / 12.0);

  490.                     else if(i< 18) d= 1;

  491.                 }

  492.                 //merge last stage of imdct into the window coefficients

  493.                 d*= 0.5 / cos(M_PI*(2*i + 19)/72);

  494. 

  495.                 if(j==2)

  496.                     mdct_win[j][i/3] = FIXHR((d / (1<<5)));

  497.                 else

  498.                     mdct_win[j][i  ] = FIXHR((d / (1<<5)));

  499. //                av_log(NULL, AV_LOG_DEBUG, "%2d %d %f\n", i,j,d / (1<<5));

  500.             }

  501.         }

  502. 

  503.         /* NOTE: we do frequency inversion adter the MDCT by changing

  504.            the sign of the right window coefs */

  505.         for(j=0;j<4;j++) {

  506.             for(i=0;i<36;i+=2) {

  507.                 mdct_win[j + 4][i] = mdct_win[j][i];

  508.                 mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];

  509.             }

  510.         }

  511. 

  512. #if defined(DEBUG)

  513.         for(j=0;j<8;j++) {

  514.             av_log(avctx, AV_LOG_DEBUG, "win%d=\n", j);

  515.             for(i=0;i<36;i++)

  516.                 av_log(avctx, AV_LOG_DEBUG, "%f, ", (double)mdct_win[j][i] / FRAC_ONE);

  517.             av_log(avctx, AV_LOG_DEBUG, "\n");

  518.         }

  519. #endif

  520.         init = 1;

  521.     }

  522. 

  523. #ifdef DEBUG

  524.     s->frame_count = 0;

  525. #endif

  526.     if (avctx->codec_id == CODEC_ID_MP3ADU)

  527.         s->adu_mode = 1;

  528.     return 0;

  529. }

  530. 

  531. /* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */

  532. 

  533. /* cos(i*pi/64) */

  534. 

  535. #define COS0_0  FIXHR(0.50060299823519630134/2)

  536. #define COS0_1  FIXHR(0.50547095989754365998/2)

  537. #define COS0_2  FIXHR(0.51544730992262454697/2)

  538. #define COS0_3  FIXHR(0.53104259108978417447/2)

  539. #define COS0_4  FIXHR(0.55310389603444452782/2)

  540. #define COS0_5  FIXHR(0.58293496820613387367/2)

  541. #define COS0_6  FIXHR(0.62250412303566481615/2)

  542. #define COS0_7  FIXHR(0.67480834145500574602/2)

  543. #define COS0_8  FIXHR(0.74453627100229844977/2)

  544. #define COS0_9  FIXHR(0.83934964541552703873/2)

  545. #define COS0_10 FIXHR(0.97256823786196069369/2)

  546. #define COS0_11 FIXHR(1.16943993343288495515/4)

  547. #define COS0_12 FIXHR(1.48416461631416627724/4)

  548. #define COS0_13 FIXHR(2.05778100995341155085/8)

  549. #define COS0_14 FIXHR(3.40760841846871878570/8)

  550. #define COS0_15 FIXHR(10.19000812354805681150/32)

  551. 

  552. #define COS1_0 FIXHR(0.50241928618815570551/2)

  553. #define COS1_1 FIXHR(0.52249861493968888062/2)

  554. #define COS1_2 FIXHR(0.56694403481635770368/2)

  555. #define COS1_3 FIXHR(0.64682178335999012954/2)

  556. #define COS1_4 FIXHR(0.78815462345125022473/2)

  557. #define COS1_5 FIXHR(1.06067768599034747134/4)

  558. #define COS1_6 FIXHR(1.72244709823833392782/4)

  559. #define COS1_7 FIXHR(5.10114861868916385802/16)

  560. 

  561. #define COS2_0 FIXHR(0.50979557910415916894/2)

  562. #define COS2_1 FIXHR(0.60134488693504528054/2)

  563. #define COS2_2 FIXHR(0.89997622313641570463/2)

  564. #define COS2_3 FIXHR(2.56291544774150617881/8)

  565. 

  566. #define COS3_0 FIXHR(0.54119610014619698439/2)

  567. #define COS3_1 FIXHR(1.30656296487637652785/4)

  568. 

  569. #define COS4_0 FIXHR(0.70710678118654752439/2)

  570. 

  571. /* butterfly operator */

  572. #define BF(a, b, c, s)\

  573. {\

  574.     tmp0 = tab[a] + tab[b];\

  575.     tmp1 = tab[a] - tab[b];\

  576.     tab[a] = tmp0;\

  577.     tab[b] = MULH(tmp1<<(s), c);\

  578. }

  579. 

  580. #define BF1(a, b, c, d)\

  581. {\

  582.     BF(a, b, COS4_0, 1);\

  583.     BF(c, d,-COS4_0, 1);\

  584.     tab[c] += tab[d];\

  585. }

  586. 

  587. #define BF2(a, b, c, d)\

  588. {\

  589.     BF(a, b, COS4_0, 1);\

  590.     BF(c, d,-COS4_0, 1);\

  591.     tab[c] += tab[d];\

  592.     tab[a] += tab[c];\

  593.     tab[c] += tab[b];\

  594.     tab[b] += tab[d];\

  595. }

  596. 

  597. #define ADD(a, b) tab[a] += tab[b]

  598. 

  599. /* DCT32 without 1/sqrt(2) coef zero scaling. */

  600. static void dct32(int32_t *out, int32_t *tab)

  601. {

  602.     int tmp0, tmp1;

  603. 

  604.     /* pass 1 */

  605.     BF( 0, 31, COS0_0 , 1);

  606.     BF(15, 16, COS0_15, 5);

  607.     /* pass 2 */

  608.     BF( 0, 15, COS1_0 , 1);

  609.     BF(16, 31,-COS1_0 , 1);

  610.     /* pass 1 */

  611.     BF( 7, 24, COS0_7 , 1);

  612.     BF( 8, 23, COS0_8 , 1);

  613.     /* pass 2 */

  614.     BF( 7,  8, COS1_7 , 4);

  615.     BF(23, 24,-COS1_7 , 4);

  616.     /* pass 3 */

  617.     BF( 0,  7, COS2_0 , 1);

  618.     BF( 8, 15,-COS2_0 , 1);

  619.     BF(16, 23, COS2_0 , 1);

  620.     BF(24, 31,-COS2_0 , 1);

  621.     /* pass 1 */

  622.     BF( 3, 28, COS0_3 , 1);

  623.     BF(12, 19, COS0_12, 2);

  624.     /* pass 2 */

  625.     BF( 3, 12, COS1_3 , 1);

  626.     BF(19, 28,-COS1_3 , 1);

  627.     /* pass 1 */

  628.     BF( 4, 27, COS0_4 , 1);

  629.     BF(11, 20, COS0_11, 2);

  630.     /* pass 2 */

  631.     BF( 4, 11, COS1_4 , 1);

  632.     BF(20, 27,-COS1_4 , 1);

  633.     /* pass 3 */

  634.     BF( 3,  4, COS2_3 , 3);

  635.     BF(11, 12,-COS2_3 , 3);

  636.     BF(19, 20, COS2_3 , 3);

  637.     BF(27, 28,-COS2_3 , 3);

  638.     /* pass 4 */

  639.     BF( 0,  3, COS3_0 , 1);

  640.     BF( 4,  7,-COS3_0 , 1);

  641.     BF( 8, 11, COS3_0 , 1);

  642.     BF(12, 15,-COS3_0 , 1);

  643.     BF(16, 19, COS3_0 , 1);

  644.     BF(20, 23,-COS3_0 , 1);

  645.     BF(24, 27, COS3_0 , 1);

  646.     BF(28, 31,-COS3_0 , 1);

  647. 

  648. 

  649. 

  650.     /* pass 1 */

  651.     BF( 1, 30, COS0_1 , 1);

  652.     BF(14, 17, COS0_14, 3);

  653.     /* pass 2 */

  654.     BF( 1, 14, COS1_1 , 1);

  655.     BF(17, 30,-COS1_1 , 1);

  656.     /* pass 1 */

  657.     BF( 6, 25, COS0_6 , 1);

  658.     BF( 9, 22, COS0_9 , 1);

  659.     /* pass 2 */

  660.     BF( 6,  9, COS1_6 , 2);

  661.     BF(22, 25,-COS1_6 , 2);

  662.     /* pass 3 */

  663.     BF( 1,  6, COS2_1 , 1);

  664.     BF( 9, 14,-COS2_1 , 1);

  665.     BF(17, 22, COS2_1 , 1);

  666.     BF(25, 30,-COS2_1 , 1);

  667. 

  668.     /* pass 1 */

  669.     BF( 2, 29, COS0_2 , 1);

  670.     BF(13, 18, COS0_13, 3);

  671.     /* pass 2 */

  672.     BF( 2, 13, COS1_2 , 1);

  673.     BF(18, 29,-COS1_2 , 1);

  674.     /* pass 1 */

  675.     BF( 5, 26, COS0_5 , 1);

  676.     BF(10, 21, COS0_10, 1);

  677.     /* pass 2 */

  678.     BF( 5, 10, COS1_5 , 2);

  679.     BF(21, 26,-COS1_5 , 2);

  680.     /* pass 3 */

  681.     BF( 2,  5, COS2_2 , 1);

  682.     BF(10, 13,-COS2_2 , 1);

  683.     BF(18, 21, COS2_2 , 1);

  684.     BF(26, 29,-COS2_2 , 1);

  685.     /* pass 4 */

  686.     BF( 1,  2, COS3_1 , 2);

  687.     BF( 5,  6,-COS3_1 , 2);

  688.     BF( 9, 10, COS3_1 , 2);

  689.     BF(13, 14,-COS3_1 , 2);

  690.     BF(17, 18, COS3_1 , 2);

  691.     BF(21, 22,-COS3_1 , 2);

  692.     BF(25, 26, COS3_1 , 2);

  693.     BF(29, 30,-COS3_1 , 2);

  694. 

  695.     /* pass 5 */

  696.     BF1( 0,  1,  2,  3);

  697.     BF2( 4,  5,  6,  7);

  698.     BF1( 8,  9, 10, 11);

  699.     BF2(12, 13, 14, 15);

  700.     BF1(16, 17, 18, 19);

  701.     BF2(20, 21, 22, 23);

  702.     BF1(24, 25, 26, 27);

  703.     BF2(28, 29, 30, 31);

  704. 

  705.     /* pass 6 */

  706. 

  707.     ADD( 8, 12);

  708.     ADD(12, 10);

  709.     ADD(10, 14);

  710.     ADD(14,  9);

  711.     ADD( 9, 13);

  712.     ADD(13, 11);

  713.     ADD(11, 15);

  714. 

  715.     out[ 0] = tab[0];

  716.     out[16] = tab[1];

  717.     out[ 8] = tab[2];

  718.     out[24] = tab[3];

  719.     out[ 4] = tab[4];

  720.     out[20] = tab[5];

  721.     out[12] = tab[6];

  722.     out[28] = tab[7];

  723.     out[ 2] = tab[8];

  724.     out[18] = tab[9];

  725.     out[10] = tab[10];

  726.     out[26] = tab[11];

  727.     out[ 6] = tab[12];

  728.     out[22] = tab[13];

  729.     out[14] = tab[14];

  730.     out[30] = tab[15];

  731. 

  732.     ADD(24, 28);

  733.     ADD(28, 26);

  734.     ADD(26, 30);

  735.     ADD(30, 25);

  736.     ADD(25, 29);

  737.     ADD(29, 27);

  738.     ADD(27, 31);

  739. 

  740.     out[ 1] = tab[16] + tab[24];

  741.     out[17] = tab[17] + tab[25];

  742.     out[ 9] = tab[18] + tab[26];

  743.     out[25] = tab[19] + tab[27];

  744.     out[ 5] = tab[20] + tab[28];

  745.     out[21] = tab[21] + tab[29];

  746.     out[13] = tab[22] + tab[30];

  747.     out[29] = tab[23] + tab[31];

  748.     out[ 3] = tab[24] + tab[20];

  749.     out[19] = tab[25] + tab[21];

  750.     out[11] = tab[26] + tab[22];

  751.     out[27] = tab[27] + tab[23];

  752.     out[ 7] = tab[28] + tab[18];

  753.     out[23] = tab[29] + tab[19];

  754.     out[15] = tab[30] + tab[17];

  755.     out[31] = tab[31];

  756. }

  757. 

  758. #if FRAC_BITS <= 15

  759. 

  760. static inline int round_sample(int *sum)

  761. {

  762.     int sum1;

  763.     sum1 = (*sum) >> OUT_SHIFT;

  764.     *sum &= (1<<OUT_SHIFT)-1;

  765.     if (sum1 < OUT_MIN)

  766.         sum1 = OUT_MIN;

  767.     else if (sum1 > OUT_MAX)

  768.         sum1 = OUT_MAX;

  769.     return sum1;

  770. }

  771. 

  772. /* signed 16x16 -> 32 multiply add accumulate */

  773. #define MACS(rt, ra, rb) MAC16(rt, ra, rb)

  774. 

  775. /* signed 16x16 -> 32 multiply */

  776. #define MULS(ra, rb) MUL16(ra, rb)

  777. 

  778. #else

  779. 

  780. static inline int round_sample(int64_t *sum)

  781. {

  782.     int sum1;

  783.     sum1 = (int)((*sum) >> OUT_SHIFT);

  784.     *sum &= (1<<OUT_SHIFT)-1;

  785.     if (sum1 < OUT_MIN)

  786.         sum1 = OUT_MIN;

  787.     else if (sum1 > OUT_MAX)

  788.         sum1 = OUT_MAX;

  789.     return sum1;

  790. }

  791. 

  792. #   define MULS(ra, rb) MUL64(ra, rb)

  793. #endif

  794. 

  795. #define SUM8(sum, op, w, p) \

  796. {                                               \

  797.     sum op MULS((w)[0 * 64], p[0 * 64]);\

  798.     sum op MULS((w)[1 * 64], p[1 * 64]);\

  799.     sum op MULS((w)[2 * 64], p[2 * 64]);\

  800.     sum op MULS((w)[3 * 64], p[3 * 64]);\

  801.     sum op MULS((w)[4 * 64], p[4 * 64]);\

  802.     sum op MULS((w)[5 * 64], p[5 * 64]);\

  803.     sum op MULS((w)[6 * 64], p[6 * 64]);\

  804.     sum op MULS((w)[7 * 64], p[7 * 64]);\

  805. }

  806. 

  807. #define SUM8P2(sum1, op1, sum2, op2, w1, w2, p) \

  808. {                                               \

  809.     int tmp;\

  810.     tmp = p[0 * 64];\

  811.     sum1 op1 MULS((w1)[0 * 64], tmp);\

  812.     sum2 op2 MULS((w2)[0 * 64], tmp);\

  813.     tmp = p[1 * 64];\

  814.     sum1 op1 MULS((w1)[1 * 64], tmp);\

  815.     sum2 op2 MULS((w2)[1 * 64], tmp);\

  816.     tmp = p[2 * 64];\

  817.     sum1 op1 MULS((w1)[2 * 64], tmp);\

  818.     sum2 op2 MULS((w2)[2 * 64], tmp);\

  819.     tmp = p[3 * 64];\

  820.     sum1 op1 MULS((w1)[3 * 64], tmp);\

  821.     sum2 op2 MULS((w2)[3 * 64], tmp);\

  822.     tmp = p[4 * 64];\

  823.     sum1 op1 MULS((w1)[4 * 64], tmp);\

  824.     sum2 op2 MULS((w2)[4 * 64], tmp);\

  825.     tmp = p[5 * 64];\

  826.     sum1 op1 MULS((w1)[5 * 64], tmp);\

  827.     sum2 op2 MULS((w2)[5 * 64], tmp);\

  828.     tmp = p[6 * 64];\

  829.     sum1 op1 MULS((w1)[6 * 64], tmp);\

  830.     sum2 op2 MULS((w2)[6 * 64], tmp);\

  831.     tmp = p[7 * 64];\

  832.     sum1 op1 MULS((w1)[7 * 64], tmp);\

  833.     sum2 op2 MULS((w2)[7 * 64], tmp);\

  834. }

  835. 

  836. void ff_mpa_synth_init(MPA_INT *window)

  837. {

  838.     int i;

  839. 

  840.     /* max = 18760, max sum over all 16 coefs : 44736 */

  841.     for(i=0;i<257;i++) {

  842.         int v;

  843.         v = ff_mpa_enwindow[i];

  844. #if WFRAC_BITS < 16

  845.         v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);

  846. #endif

  847.         window[i] = v;

  848.         if ((i & 63) != 0)

  849.             v = -v;

  850.         if (i != 0)

  851.             window[512 - i] = v;

  852.     }

  853. }

  854. 

  855. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

  856.    32 samples. */

  857. /* XXX: optimize by avoiding ring buffer usage */

  858. void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,

  859.                          MPA_INT *window, int *dither_state,

  860.                          OUT_INT *samples, int incr,

  861.                          int32_t sb_samples[SBLIMIT])

  862. {

  863.     int32_t tmp[32];

  864.     register MPA_INT *synth_buf;

  865.     register const MPA_INT *w, *w2, *p;

  866.     int j, offset, v;

  867.     OUT_INT *samples2;

  868. #if FRAC_BITS <= 15

  869.     int sum, sum2;

  870. #else

  871.     int64_t sum, sum2;

  872. #endif

  873. 

  874.     dct32(tmp, sb_samples);

  875. 

  876.     offset = *synth_buf_offset;

  877.     synth_buf = synth_buf_ptr + offset;

  878. 

  879.     for(j=0;j<32;j++) {

  880.         v = tmp[j];

  881. #if FRAC_BITS <= 15

  882.         /* NOTE: can cause a loss in precision if very high amplitude

  883.            sound */

  884.         v = av_clip_int16(v);

  885. #endif

  886.         synth_buf[j] = v;

  887.     }

  888.     /* copy to avoid wrap */

  889.     memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));

  890. 

  891.     samples2 = samples + 31 * incr;

  892.     w = window;

  893.     w2 = window + 31;

  894. 

  895.     sum = *dither_state;

  896.     p = synth_buf + 16;

  897.     SUM8(sum, +=, w, p);

  898.     p = synth_buf + 48;

  899.     SUM8(sum, -=, w + 32, p);

  900.     *samples = round_sample(&sum);

  901.     samples += incr;

  902.     w++;

  903. 

  904.     /* we calculate two samples at the same time to avoid one memory

  905.        access per two sample */

  906.     for(j=1;j<16;j++) {

  907.         sum2 = 0;

  908.         p = synth_buf + 16 + j;

  909.         SUM8P2(sum, +=, sum2, -=, w, w2, p);

  910.         p = synth_buf + 48 - j;

  911.         SUM8P2(sum, -=, sum2, -=, w + 32, w2 + 32, p);

  912. 

  913.         *samples = round_sample(&sum);

  914.         samples += incr;

  915.         sum += sum2;

  916.         *samples2 = round_sample(&sum);

  917.         samples2 -= incr;

  918.         w++;

  919.         w2--;

  920.     }

  921. 

  922.     p = synth_buf + 32;

  923.     SUM8(sum, -=, w + 32, p);

  924.     *samples = round_sample(&sum);

  925.     *dither_state= sum;

  926. 

  927.     offset = (offset - 32) & 511;

  928.     *synth_buf_offset = offset;

  929. }

  930. 

  931. #define C3 FIXHR(0.86602540378443864676/2)

  932. 

  933. /* 0.5 / cos(pi*(2*i+1)/36) */

  934. static const int icos36[9] = {

  935.     FIXR(0.50190991877167369479),

  936.     FIXR(0.51763809020504152469), //0

  937.     FIXR(0.55168895948124587824),

  938.     FIXR(0.61038729438072803416),

  939.     FIXR(0.70710678118654752439), //1

  940.     FIXR(0.87172339781054900991),

  941.     FIXR(1.18310079157624925896),

  942.     FIXR(1.93185165257813657349), //2

  943.     FIXR(5.73685662283492756461),

  944. };

  945. 

  946. /* 0.5 / cos(pi*(2*i+1)/36) */

  947. static const int icos36h[9] = {

  948.     FIXHR(0.50190991877167369479/2),

  949.     FIXHR(0.51763809020504152469/2), //0

  950.     FIXHR(0.55168895948124587824/2),

  951.     FIXHR(0.61038729438072803416/2),

  952.     FIXHR(0.70710678118654752439/2), //1

  953.     FIXHR(0.87172339781054900991/2),

  954.     FIXHR(1.18310079157624925896/4),

  955.     FIXHR(1.93185165257813657349/4), //2

  956. //    FIXHR(5.73685662283492756461),

  957. };

  958. 

  959. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  960.    cases. */

  961. static void imdct12(int *out, int *in)

  962. {

  963.     int in0, in1, in2, in3, in4, in5, t1, t2;

  964. 

  965.     in0= in[0*3];

  966.     in1= in[1*3] + in[0*3];

  967.     in2= in[2*3] + in[1*3];

  968.     in3= in[3*3] + in[2*3];

  969.     in4= in[4*3] + in[3*3];

  970.     in5= in[5*3] + in[4*3];

  971.     in5 += in3;

  972.     in3 += in1;

  973. 

  974.     in2= MULH(2*in2, C3);

  975.     in3= MULH(4*in3, C3);

  976. 

  977.     t1 = in0 - in4;

  978.     t2 = MULH(2*(in1 - in5), icos36h[4]);

  979. 

  980.     out[ 7]=

  981.     out[10]= t1 + t2;

  982.     out[ 1]=

  983.     out[ 4]= t1 - t2;

  984. 

  985.     in0 += in4>>1;

  986.     in4 = in0 + in2;

  987.     in5 += 2*in1;

  988.     in1 = MULH(in5 + in3, icos36h[1]);

  989.     out[ 8]=

  990.     out[ 9]= in4 + in1;

  991.     out[ 2]=

  992.     out[ 3]= in4 - in1;

  993. 

  994.     in0 -= in2;

  995.     in5 = MULH(2*(in5 - in3), icos36h[7]);

  996.     out[ 0]=

  997.     out[ 5]= in0 - in5;

  998.     out[ 6]=

  999.     out[11]= in0 + in5;

  1000. }

  1001. 

  1002. /* cos(pi*i/18) */

  1003. #define C1 FIXHR(0.98480775301220805936/2)

  1004. #define C2 FIXHR(0.93969262078590838405/2)

  1005. #define C3 FIXHR(0.86602540378443864676/2)

  1006. #define C4 FIXHR(0.76604444311897803520/2)

  1007. #define C5 FIXHR(0.64278760968653932632/2)

  1008. #define C6 FIXHR(0.5/2)

  1009. #define C7 FIXHR(0.34202014332566873304/2)

  1010. #define C8 FIXHR(0.17364817766693034885/2)

  1011. 

  1012. 

  1013. /* using Lee like decomposition followed by hand coded 9 points DCT */

  1014. static void imdct36(int *out, int *buf, int *in, int *win)

  1015. {

  1016.     int i, j, t0, t1, t2, t3, s0, s1, s2, s3;

  1017.     int tmp[18], *tmp1, *in1;

  1018. 

  1019.     for(i=17;i>=1;i--)

  1020.         in[i] += in[i-1];

  1021.     for(i=17;i>=3;i-=2)

  1022.         in[i] += in[i-2];

  1023. 

  1024.     for(j=0;j<2;j++) {

  1025.         tmp1 = tmp + j;

  1026.         in1 = in + j;

  1027. #if 0

  1028. //more accurate but slower

  1029.         int64_t t0, t1, t2, t3;

  1030.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1031. 

  1032.         t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;

  1033.         t1 = in1[2*0] - in1[2*6];

  1034.         tmp1[ 6] = t1 - (t2>>1);

  1035.         tmp1[16] = t1 + t2;

  1036. 

  1037.         t0 = MUL64(2*(in1[2*2] + in1[2*4]),    C2);

  1038.         t1 = MUL64(   in1[2*4] - in1[2*8] , -2*C8);

  1039.         t2 = MUL64(2*(in1[2*2] + in1[2*8]),   -C4);

  1040. 

  1041.         tmp1[10] = (t3 - t0 - t2) >> 32;

  1042.         tmp1[ 2] = (t3 + t0 + t1) >> 32;

  1043.         tmp1[14] = (t3 + t2 - t1) >> 32;

  1044. 

  1045.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1046.         t2 = MUL64(2*(in1[2*1] + in1[2*5]),    C1);

  1047.         t3 = MUL64(   in1[2*5] - in1[2*7] , -2*C7);

  1048.         t0 = MUL64(2*in1[2*3], C3);

  1049. 

  1050.         t1 = MUL64(2*(in1[2*1] + in1[2*7]),   -C5);

  1051. 

  1052.         tmp1[ 0] = (t2 + t3 + t0) >> 32;

  1053.         tmp1[12] = (t2 + t1 - t0) >> 32;

  1054.         tmp1[ 8] = (t3 - t1 - t0) >> 32;

  1055. #else

  1056.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1057. 

  1058.         t3 = in1[2*0] + (in1[2*6]>>1);

  1059.         t1 = in1[2*0] - in1[2*6];

  1060.         tmp1[ 6] = t1 - (t2>>1);

  1061.         tmp1[16] = t1 + t2;

  1062. 

  1063.         t0 = MULH(2*(in1[2*2] + in1[2*4]),    C2);

  1064.         t1 = MULH(   in1[2*4] - in1[2*8] , -2*C8);

  1065.         t2 = MULH(2*(in1[2*2] + in1[2*8]),   -C4);

  1066. 

  1067.         tmp1[10] = t3 - t0 - t2;

  1068.         tmp1[ 2] = t3 + t0 + t1;

  1069.         tmp1[14] = t3 + t2 - t1;

  1070. 

  1071.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1072.         t2 = MULH(2*(in1[2*1] + in1[2*5]),    C1);

  1073.         t3 = MULH(   in1[2*5] - in1[2*7] , -2*C7);

  1074.         t0 = MULH(2*in1[2*3], C3);

  1075. 

  1076.         t1 = MULH(2*(in1[2*1] + in1[2*7]),   -C5);

  1077. 

  1078.         tmp1[ 0] = t2 + t3 + t0;

  1079.         tmp1[12] = t2 + t1 - t0;

  1080.         tmp1[ 8] = t3 - t1 - t0;

  1081. #endif

  1082.     }

  1083. 

  1084.     i = 0;

  1085.     for(j=0;j<4;j++) {

  1086.         t0 = tmp[i];

  1087.         t1 = tmp[i + 2];

  1088.         s0 = t1 + t0;

  1089.         s2 = t1 - t0;

  1090. 

  1091.         t2 = tmp[i + 1];

  1092.         t3 = tmp[i + 3];

  1093.         s1 = MULH(2*(t3 + t2), icos36h[j]);

  1094.         s3 = MULL(t3 - t2, icos36[8 - j]);

  1095. 

  1096.         t0 = s0 + s1;

  1097.         t1 = s0 - s1;

  1098.         out[(9 + j)*SBLIMIT] =  MULH(t1, win[9 + j]) + buf[9 + j];

  1099.         out[(8 - j)*SBLIMIT] =  MULH(t1, win[8 - j]) + buf[8 - j];

  1100.         buf[9 + j] = MULH(t0, win[18 + 9 + j]);

  1101.         buf[8 - j] = MULH(t0, win[18 + 8 - j]);

  1102. 

  1103.         t0 = s2 + s3;

  1104.         t1 = s2 - s3;

  1105.         out[(9 + 8 - j)*SBLIMIT] =  MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];

  1106.         out[(        j)*SBLIMIT] =  MULH(t1, win[        j]) + buf[        j];

  1107.         buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);

  1108.         buf[      + j] = MULH(t0, win[18         + j]);

  1109.         i += 4;

  1110.     }

  1111. 

  1112.     s0 = tmp[16];

  1113.     s1 = MULH(2*tmp[17], icos36h[4]);

  1114.     t0 = s0 + s1;

  1115.     t1 = s0 - s1;

  1116.     out[(9 + 4)*SBLIMIT] =  MULH(t1, win[9 + 4]) + buf[9 + 4];

  1117.     out[(8 - 4)*SBLIMIT] =  MULH(t1, win[8 - 4]) + buf[8 - 4];

  1118.     buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);

  1119.     buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);

  1120. }

  1121. 

  1122. /* return the number of decoded frames */

  1123. static int mp_decode_layer1(MPADecodeContext *s)

  1124. {

  1125.     int bound, i, v, n, ch, j, mant;

  1126.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  1127.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  1128. 

  1129.     if (s->mode == MPA_JSTEREO)

  1130.         bound = (s->mode_ext + 1) * 4;

  1131.     else

  1132.         bound = SBLIMIT;

  1133. 

  1134.     /* allocation bits */

  1135.     for(i=0;i<bound;i++) {

  1136.         for(ch=0;ch<s->nb_channels;ch++) {

  1137.             allocation[ch][i] = get_bits(&s->gb, 4);

  1138.         }

  1139.     }

  1140.     for(i=bound;i<SBLIMIT;i++) {

  1141.         allocation[0][i] = get_bits(&s->gb, 4);

  1142.     }

  1143. 

  1144.     /* scale factors */

  1145.     for(i=0;i<bound;i++) {

  1146.         for(ch=0;ch<s->nb_channels;ch++) {

  1147.             if (allocation[ch][i])

  1148.                 scale_factors[ch][i] = get_bits(&s->gb, 6);

  1149.         }

  1150.     }

  1151.     for(i=bound;i<SBLIMIT;i++) {

  1152.         if (allocation[0][i]) {

  1153.             scale_factors[0][i] = get_bits(&s->gb, 6);

  1154.             scale_factors[1][i] = get_bits(&s->gb, 6);

  1155.         }

  1156.     }

  1157. 

  1158.     /* compute samples */

  1159.     for(j=0;j<12;j++) {

  1160.         for(i=0;i<bound;i++) {

  1161.             for(ch=0;ch<s->nb_channels;ch++) {

  1162.                 n = allocation[ch][i];

  1163.                 if (n) {

  1164.                     mant = get_bits(&s->gb, n + 1);

  1165.                     v = l1_unscale(n, mant, scale_factors[ch][i]);

  1166.                 } else {

  1167.                     v = 0;

  1168.                 }

  1169.                 s->sb_samples[ch][j][i] = v;

  1170.             }

  1171.         }

  1172.         for(i=bound;i<SBLIMIT;i++) {

  1173.             n = allocation[0][i];

  1174.             if (n) {

  1175.                 mant = get_bits(&s->gb, n + 1);

  1176.                 v = l1_unscale(n, mant, scale_factors[0][i]);

  1177.                 s->sb_samples[0][j][i] = v;

  1178.                 v = l1_unscale(n, mant, scale_factors[1][i]);

  1179.                 s->sb_samples[1][j][i] = v;

  1180.             } else {

  1181.                 s->sb_samples[0][j][i] = 0;

  1182.                 s->sb_samples[1][j][i] = 0;

  1183.             }

  1184.         }

  1185.     }

  1186.     return 12;

  1187. }

  1188. 

  1189. static int mp_decode_layer2(MPADecodeContext *s)

  1190. {

  1191.     int sblimit; /* number of used subbands */

  1192.     const unsigned char *alloc_table;

  1193.     int table, bit_alloc_bits, i, j, ch, bound, v;

  1194.     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];

  1195.     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];

  1196.     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;

  1197.     int scale, qindex, bits, steps, k, l, m, b;

  1198. 

  1199.     /* select decoding table */

  1200.     table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,

  1201.                             s->sample_rate, s->lsf);

  1202.     sblimit = ff_mpa_sblimit_table[table];

  1203.     alloc_table = ff_mpa_alloc_tables[table];

  1204. 

  1205.     if (s->mode == MPA_JSTEREO)

  1206.         bound = (s->mode_ext + 1) * 4;

  1207.     else

  1208.         bound = sblimit;

  1209. 

  1210.     dprintf(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);

  1211. 

  1212.     /* sanity check */

  1213.     if( bound > sblimit ) bound = sblimit;

  1214. 

  1215.     /* parse bit allocation */

  1216.     j = 0;

  1217.     for(i=0;i<bound;i++) {

  1218.         bit_alloc_bits = alloc_table[j];

  1219.         for(ch=0;ch<s->nb_channels;ch++) {

  1220.             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);

  1221.         }

  1222.         j += 1 << bit_alloc_bits;

  1223.     }

  1224.     for(i=bound;i<sblimit;i++) {

  1225.         bit_alloc_bits = alloc_table[j];

  1226.         v = get_bits(&s->gb, bit_alloc_bits);

  1227.         bit_alloc[0][i] = v;

  1228.         bit_alloc[1][i] = v;

  1229.         j += 1 << bit_alloc_bits;

  1230.     }

  1231. 

  1232. #ifdef DEBUG

  1233.     {

  1234.         for(ch=0;ch<s->nb_channels;ch++) {

  1235.             for(i=0;i<sblimit;i++)

  1236.                 dprintf(s->avctx, " %d", bit_alloc[ch][i]);

  1237.             dprintf(s->avctx, "\n");

  1238.         }

  1239.     }

  1240. #endif

  1241. 

  1242.     /* scale codes */

  1243.     for(i=0;i<sblimit;i++) {

  1244.         for(ch=0;ch<s->nb_channels;ch++) {

  1245.             if (bit_alloc[ch][i])

  1246.                 scale_code[ch][i] = get_bits(&s->gb, 2);

  1247.         }

  1248.     }

  1249. 

  1250.     /* scale factors */

  1251.     for(i=0;i<sblimit;i++) {

  1252.         for(ch=0;ch<s->nb_channels;ch++) {

  1253.             if (bit_alloc[ch][i]) {

  1254.                 sf = scale_factors[ch][i];

  1255.                 switch(scale_code[ch][i]) {

  1256.                 default:

  1257.                 case 0:

  1258.                     sf[0] = get_bits(&s->gb, 6);

  1259.                     sf[1] = get_bits(&s->gb, 6);

  1260.                     sf[2] = get_bits(&s->gb, 6);

  1261.                     break;

  1262.                 case 2:

  1263.                     sf[0] = get_bits(&s->gb, 6);

  1264.                     sf[1] = sf[0];

  1265.                     sf[2] = sf[0];

  1266.                     break;

  1267.                 case 1:

  1268.                     sf[0] = get_bits(&s->gb, 6);

  1269.                     sf[2] = get_bits(&s->gb, 6);

  1270.                     sf[1] = sf[0];

  1271.                     break;

  1272.                 case 3:

  1273.                     sf[0] = get_bits(&s->gb, 6);

  1274.                     sf[2] = get_bits(&s->gb, 6);

  1275.                     sf[1] = sf[2];

  1276.                     break;

  1277.                 }

  1278.             }

  1279.         }

  1280.     }

  1281. 

  1282. #ifdef DEBUG

  1283.     for(ch=0;ch<s->nb_channels;ch++) {

  1284.         for(i=0;i<sblimit;i++) {

  1285.             if (bit_alloc[ch][i]) {

  1286.                 sf = scale_factors[ch][i];

  1287.                 dprintf(s->avctx, " %d %d %d", sf[0], sf[1], sf[2]);

  1288.             } else {

  1289.                 dprintf(s->avctx, " -");

  1290.             }

  1291.         }

  1292.         dprintf(s->avctx, "\n");

  1293.     }

  1294. #endif

  1295. 

  1296.     /* samples */

  1297.     for(k=0;k<3;k++) {

  1298.         for(l=0;l<12;l+=3) {

  1299.             j = 0;

  1300.             for(i=0;i<bound;i++) {

  1301.                 bit_alloc_bits = alloc_table[j];

  1302.                 for(ch=0;ch<s->nb_channels;ch++) {

  1303.                     b = bit_alloc[ch][i];

  1304.                     if (b) {

  1305.                         scale = scale_factors[ch][i][k];

  1306.                         qindex = alloc_table[j+b];

  1307.                         bits = ff_mpa_quant_bits[qindex];

  1308.                         if (bits < 0) {

  1309.                             /* 3 values at the same time */

  1310.                             v = get_bits(&s->gb, -bits);

  1311.                             steps = ff_mpa_quant_steps[qindex];

  1312.                             s->sb_samples[ch][k * 12 + l + 0][i] =

  1313.                                 l2_unscale_group(steps, v % steps, scale);

  1314.                             v = v / steps;

  1315.                             s->sb_samples[ch][k * 12 + l + 1][i] =

  1316.                                 l2_unscale_group(steps, v % steps, scale);

  1317.                             v = v / steps;

  1318.                             s->sb_samples[ch][k * 12 + l + 2][i] =

  1319.                                 l2_unscale_group(steps, v, scale);

  1320.                         } else {

  1321.                             for(m=0;m<3;m++) {

  1322.                                 v = get_bits(&s->gb, bits);

  1323.                                 v = l1_unscale(bits - 1, v, scale);

  1324.                                 s->sb_samples[ch][k * 12 + l + m][i] = v;

  1325.                             }

  1326.                         }

  1327.                     } else {

  1328.                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1329.                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1330.                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1331.                     }

  1332.                 }

  1333.                 /* next subband in alloc table */

  1334.                 j += 1 << bit_alloc_bits;

  1335.             }

  1336.             /* XXX: find a way to avoid this duplication of code */

  1337.             for(i=bound;i<sblimit;i++) {

  1338.                 bit_alloc_bits = alloc_table[j];

  1339.                 b = bit_alloc[0][i];

  1340.                 if (b) {

  1341.                     int mant, scale0, scale1;

  1342.                     scale0 = scale_factors[0][i][k];

  1343.                     scale1 = scale_factors[1][i][k];

  1344.                     qindex = alloc_table[j+b];

  1345.                     bits = ff_mpa_quant_bits[qindex];

  1346.                     if (bits < 0) {

  1347.                         /* 3 values at the same time */

  1348.                         v = get_bits(&s->gb, -bits);

  1349.                         steps = ff_mpa_quant_steps[qindex];

  1350.                         mant = v % steps;

  1351.                         v = v / steps;

  1352.                         s->sb_samples[0][k * 12 + l + 0][i] =

  1353.                             l2_unscale_group(steps, mant, scale0);

  1354.                         s->sb_samples[1][k * 12 + l + 0][i] =

  1355.                             l2_unscale_group(steps, mant, scale1);

  1356.                         mant = v % steps;

  1357.                         v = v / steps;

  1358.                         s->sb_samples[0][k * 12 + l + 1][i] =

  1359.                             l2_unscale_group(steps, mant, scale0);

  1360.                         s->sb_samples[1][k * 12 + l + 1][i] =

  1361.                             l2_unscale_group(steps, mant, scale1);

  1362.                         s->sb_samples[0][k * 12 + l + 2][i] =

  1363.                             l2_unscale_group(steps, v, scale0);

  1364.                         s->sb_samples[1][k * 12 + l + 2][i] =

  1365.                             l2_unscale_group(steps, v, scale1);

  1366.                     } else {

  1367.                         for(m=0;m<3;m++) {

  1368.                             mant = get_bits(&s->gb, bits);

  1369.                             s->sb_samples[0][k * 12 + l + m][i] =

  1370.                                 l1_unscale(bits - 1, mant, scale0);

  1371.                             s->sb_samples[1][k * 12 + l + m][i] =

  1372.                                 l1_unscale(bits - 1, mant, scale1);

  1373.                         }

  1374.                     }

  1375.                 } else {

  1376.                     s->sb_samples[0][k * 12 + l + 0][i] = 0;

  1377.                     s->sb_samples[0][k * 12 + l + 1][i] = 0;

  1378.                     s->sb_samples[0][k * 12 + l + 2][i] = 0;

  1379.                     s->sb_samples[1][k * 12 + l + 0][i] = 0;

  1380.                     s->sb_samples[1][k * 12 + l + 1][i] = 0;

  1381.                     s->sb_samples[1][k * 12 + l + 2][i] = 0;

  1382.                 }

  1383.                 /* next subband in alloc table */

  1384.                 j += 1 << bit_alloc_bits;

  1385.             }

  1386.             /* fill remaining samples to zero */

  1387.             for(i=sblimit;i<SBLIMIT;i++) {

  1388.                 for(ch=0;ch<s->nb_channels;ch++) {

  1389.                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1390.                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1391.                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1392.                 }

  1393.             }

  1394.         }

  1395.     }

  1396.     return 3 * 12;

  1397. }

  1398. 

  1399. static inline void lsf_sf_expand(int *slen,

  1400.                                  int sf, int n1, int n2, int n3)

  1401. {

  1402.     if (n3) {

  1403.         slen[3] = sf % n3;

  1404.         sf /= n3;

  1405.     } else {

  1406.         slen[3] = 0;

  1407.     }

  1408.     if (n2) {

  1409.         slen[2] = sf % n2;

  1410.         sf /= n2;

  1411.     } else {

  1412.         slen[2] = 0;

  1413.     }

  1414.     slen[1] = sf % n1;

  1415.     sf /= n1;

  1416.     slen[0] = sf;

  1417. }

  1418. 

  1419. static void exponents_from_scale_factors(MPADecodeContext *s,

  1420.                                          GranuleDef *g,

  1421.                                          int16_t *exponents)

  1422. {

  1423.     const uint8_t *bstab, *pretab;

  1424.     int len, i, j, k, l, v0, shift, gain, gains[3];

  1425.     int16_t *exp_ptr;

  1426. 

  1427.     exp_ptr = exponents;

  1428.     gain = g->global_gain - 210;

  1429.     shift = g->scalefac_scale + 1;

  1430. 

  1431.     bstab = band_size_long[s->sample_rate_index];

  1432.     pretab = mpa_pretab[g->preflag];

  1433.     for(i=0;i<g->long_end;i++) {

  1434.         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;

  1435.         len = bstab[i];

  1436.         for(j=len;j>0;j--)

  1437.             *exp_ptr++ = v0;

  1438.     }

  1439. 

  1440.     if (g->short_start < 13) {

  1441.         bstab = band_size_short[s->sample_rate_index];

  1442.         gains[0] = gain - (g->subblock_gain[0] << 3);

  1443.         gains[1] = gain - (g->subblock_gain[1] << 3);

  1444.         gains[2] = gain - (g->subblock_gain[2] << 3);

  1445.         k = g->long_end;

  1446.         for(i=g->short_start;i<13;i++) {

  1447.             len = bstab[i];

  1448.             for(l=0;l<3;l++) {

  1449.                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;

  1450.                 for(j=len;j>0;j--)

  1451.                 *exp_ptr++ = v0;

  1452.             }

  1453.         }

  1454.     }

  1455. }

  1456. 

  1457. /* handle n = 0 too */

  1458. static inline int get_bitsz(GetBitContext *s, int n)

  1459. {

  1460.     if (n == 0)

  1461.         return 0;

  1462.     else

  1463.         return get_bits(s, n);

  1464. }

  1465. 

  1466. 

  1467. static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos, int *end_pos2){

  1468.     if(s->in_gb.buffer && *pos >= s->gb.size_in_bits){

  1469.         s->gb= s->in_gb;

  1470.         s->in_gb.buffer=NULL;

  1471.         assert((get_bits_count(&s->gb) & 7) == 0);

  1472.         skip_bits_long(&s->gb, *pos - *end_pos);

  1473.         *end_pos2=

  1474.         *end_pos= *end_pos2 + get_bits_count(&s->gb) - *pos;

  1475.         *pos= get_bits_count(&s->gb);

  1476.     }

  1477. }

  1478. 

  1479. static int huffman_decode(MPADecodeContext *s, GranuleDef *g,

  1480.                           int16_t *exponents, int end_pos2)

  1481. {

  1482.     int s_index;

  1483.     int i;

  1484.     int last_pos, bits_left;

  1485.     VLC *vlc;

  1486.     int end_pos= FFMIN(end_pos2, s->gb.size_in_bits);

  1487. 

  1488.     /* low frequencies (called big values) */

  1489.     s_index = 0;

  1490.     for(i=0;i<3;i++) {

  1491.         int j, k, l, linbits;

  1492.         j = g->region_size[i];

  1493.         if (j == 0)

  1494.             continue;

  1495.         /* select vlc table */

  1496.         k = g->table_select[i];

  1497.         l = mpa_huff_data[k][0];

  1498.         linbits = mpa_huff_data[k][1];

  1499.         vlc = &huff_vlc[l];

  1500. 

  1501.         if(!l){

  1502.             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*2*j);

  1503.             s_index += 2*j;

  1504.             continue;

  1505.         }

  1506. 

  1507.         /* read huffcode and compute each couple */

  1508.         for(;j>0;j--) {

  1509.             int exponent, x, y, v;

  1510.             int pos= get_bits_count(&s->gb);

  1511. 

  1512.             if (pos >= end_pos){

  1513. //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1514.                 switch_buffer(s, &pos, &end_pos, &end_pos2);

  1515. //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);

  1516.                 if(pos >= end_pos)

  1517.                     break;

  1518.             }

  1519.             y = get_vlc2(&s->gb, vlc->table, 7, 3);

  1520. 

  1521.             if(!y){

  1522.                 g->sb_hybrid[s_index  ] =

  1523.                 g->sb_hybrid[s_index+1] = 0;

  1524.                 s_index += 2;

  1525.                 continue;

  1526.             }

  1527. 

  1528.             exponent= exponents[s_index];

  1529. 

  1530.             dprintf(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",

  1531.                     i, g->region_size[i] - j, x, y, exponent);

  1532.             if(y&16){

  1533.                 x = y >> 5;

  1534.                 y = y & 0x0f;

  1535.                 if (x < 15){

  1536.                     v = expval_table[ exponent ][ x ];

  1537. //                      v = expval_table[ (exponent&3) ][ x ] >> FFMIN(0 - (exponent>>2), 31);

  1538.                 }else{

  1539.                     x += get_bitsz(&s->gb, linbits);

  1540.                     v = l3_unscale(x, exponent);

  1541.                 }

  1542.                 if (get_bits1(&s->gb))

  1543.                     v = -v;

  1544.                 g->sb_hybrid[s_index] = v;

  1545.                 if (y < 15){

  1546.                     v = expval_table[ exponent ][ y ];

  1547.                 }else{

  1548.                     y += get_bitsz(&s->gb, linbits);

  1549.                     v = l3_unscale(y, exponent);

  1550.                 }

  1551.                 if (get_bits1(&s->gb))

  1552.                     v = -v;

  1553.                 g->sb_hybrid[s_index+1] = v;

  1554.             }else{

  1555.                 x = y >> 5;

  1556.                 y = y & 0x0f;

  1557.                 x += y;

  1558.                 if (x < 15){

  1559.                     v = expval_table[ exponent ][ x ];

  1560.                 }else{

  1561.                     x += get_bitsz(&s->gb, linbits);

  1562.                     v = l3_unscale(x, exponent);

  1563.                 }

  1564.                 if (get_bits1(&s->gb))

  1565.                     v = -v;

  1566.                 g->sb_hybrid[s_index+!!y] = v;

  1567.                 g->sb_hybrid[s_index+ !y] = 0;

  1568.             }

  1569.             s_index+=2;

  1570.         }

  1571.     }

  1572. 

  1573.     /* high frequencies */

  1574.     vlc = &huff_quad_vlc[g->count1table_select];

  1575.     last_pos=0;

  1576.     while (s_index <= 572) {

  1577.         int pos, code;

  1578.         pos = get_bits_count(&s->gb);

  1579.         if (pos >= end_pos) {

  1580.             if (pos > end_pos2 && last_pos){

  1581.                 /* some encoders generate an incorrect size for this

  1582.                    part. We must go back into the data */

  1583.                 s_index -= 4;

  1584.                 skip_bits_long(&s->gb, last_pos - pos);

  1585.                 av_log(NULL, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);

  1586.                 if(s->error_resilience >= FF_ER_COMPLIANT)

  1587.                     s_index=0;

  1588.                 break;

  1589.             }

  1590. //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1591.             switch_buffer(s, &pos, &end_pos, &end_pos2);

  1592. //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);

  1593.             if(pos >= end_pos)

  1594.                 break;

  1595.         }

  1596.         last_pos= pos;

  1597. 

  1598.         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);

  1599.         dprintf(s->avctx, "t=%d code=%d\n", g->count1table_select, code);

  1600.         g->sb_hybrid[s_index+0]=

  1601.         g->sb_hybrid[s_index+1]=

  1602.         g->sb_hybrid[s_index+2]=

  1603.         g->sb_hybrid[s_index+3]= 0;

  1604.         while(code){

  1605.             static const int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};

  1606.             int v;

  1607.             int pos= s_index+idxtab[code];

  1608.             code ^= 8>>idxtab[code];

  1609.             v = exp_table[ exponents[pos] ];

  1610. //            v = exp_table[ (exponents[pos]&3) ] >> FFMIN(0 - (exponents[pos]>>2), 31);

  1611.             if(get_bits1(&s->gb))

  1612.                 v = -v;

  1613.             g->sb_hybrid[pos] = v;

  1614.         }

  1615.         s_index+=4;

  1616.     }

  1617.     /* skip extension bits */

  1618.     bits_left = end_pos2 - get_bits_count(&s->gb);

  1619. //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);

  1620.     if (bits_left < 0/* || bits_left > 500*/) {

  1621.         av_log(NULL, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1622.         s_index=0;

  1623.     }else if(bits_left > 0 && s->error_resilience >= FF_ER_AGGRESSIVE){

  1624.         av_log(NULL, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1625.         s_index=0;

  1626.     }

  1627.     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*(576 - s_index));

  1628.     skip_bits_long(&s->gb, bits_left);

  1629. 

  1630.     i= get_bits_count(&s->gb);

  1631.     switch_buffer(s, &i, &end_pos, &end_pos2);

  1632. 

  1633.     return 0;

  1634. }

  1635. 

  1636. /* Reorder short blocks from bitstream order to interleaved order. It

  1637.    would be faster to do it in parsing, but the code would be far more

  1638.    complicated */

  1639. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1640. {

  1641.     int i, j, len;

  1642.     int32_t *ptr, *dst, *ptr1;

  1643.     int32_t tmp[576];

  1644. 

  1645.     if (g->block_type != 2)

  1646.         return;

  1647. 

  1648.     if (g->switch_point) {

  1649.         if (s->sample_rate_index != 8) {

  1650.             ptr = g->sb_hybrid + 36;

  1651.         } else {

  1652.             ptr = g->sb_hybrid + 48;

  1653.         }

  1654.     } else {

  1655.         ptr = g->sb_hybrid;

  1656.     }

  1657. 

  1658.     for(i=g->short_start;i<13;i++) {

  1659.         len = band_size_short[s->sample_rate_index][i];

  1660.         ptr1 = ptr;

  1661.         dst = tmp;

  1662.         for(j=len;j>0;j--) {

  1663.             *dst++ = ptr[0*len];

  1664.             *dst++ = ptr[1*len];

  1665.             *dst++ = ptr[2*len];

  1666.             ptr++;

  1667.         }

  1668.         ptr+=2*len;

  1669.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1670.     }

  1671. }

  1672. 

  1673. #define ISQRT2 FIXR(0.70710678118654752440)

  1674. 

  1675. static void compute_stereo(MPADecodeContext *s,

  1676.                            GranuleDef *g0, GranuleDef *g1)

  1677. {

  1678.     int i, j, k, l;

  1679.     int32_t v1, v2;

  1680.     int sf_max, tmp0, tmp1, sf, len, non_zero_found;

  1681.     int32_t (*is_tab)[16];

  1682.     int32_t *tab0, *tab1;

  1683.     int non_zero_found_short[3];

  1684. 

  1685.     /* intensity stereo */

  1686.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1687.         if (!s->lsf) {

  1688.             is_tab = is_table;

  1689.             sf_max = 7;

  1690.         } else {

  1691.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1692.             sf_max = 16;

  1693.         }

  1694. 

  1695.         tab0 = g0->sb_hybrid + 576;

  1696.         tab1 = g1->sb_hybrid + 576;

  1697. 

  1698.         non_zero_found_short[0] = 0;

  1699.         non_zero_found_short[1] = 0;

  1700.         non_zero_found_short[2] = 0;

  1701.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1702.         for(i = 12;i >= g1->short_start;i--) {

  1703.             /* for last band, use previous scale factor */

  1704.             if (i != 11)

  1705.                 k -= 3;

  1706.             len = band_size_short[s->sample_rate_index][i];

  1707.             for(l=2;l>=0;l--) {

  1708.                 tab0 -= len;

  1709.                 tab1 -= len;

  1710.                 if (!non_zero_found_short[l]) {

  1711.                     /* test if non zero band. if so, stop doing i-stereo */

  1712.                     for(j=0;j<len;j++) {

  1713.                         if (tab1[j] != 0) {

  1714.                             non_zero_found_short[l] = 1;

  1715.                             goto found1;

  1716.                         }

  1717.                     }

  1718.                     sf = g1->scale_factors[k + l];

  1719.                     if (sf >= sf_max)

  1720.                         goto found1;

  1721. 

  1722.                     v1 = is_tab[0][sf];

  1723.                     v2 = is_tab[1][sf];

  1724.                     for(j=0;j<len;j++) {

  1725.                         tmp0 = tab0[j];

  1726.                         tab0[j] = MULL(tmp0, v1);

  1727.                         tab1[j] = MULL(tmp0, v2);

  1728.                     }

  1729.                 } else {

  1730.                 found1:

  1731.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1732.                         /* lower part of the spectrum : do ms stereo

  1733.                            if enabled */

  1734.                         for(j=0;j<len;j++) {

  1735.                             tmp0 = tab0[j];

  1736.                             tmp1 = tab1[j];

  1737.                             tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1738.                             tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1739.                         }

  1740.                     }

  1741.                 }

  1742.             }

  1743.         }

  1744. 

  1745.         non_zero_found = non_zero_found_short[0] |

  1746.             non_zero_found_short[1] |

  1747.             non_zero_found_short[2];

  1748. 

  1749.         for(i = g1->long_end - 1;i >= 0;i--) {

  1750.             len = band_size_long[s->sample_rate_index][i];

  1751.             tab0 -= len;

  1752.             tab1 -= len;

  1753.             /* test if non zero band. if so, stop doing i-stereo */

  1754.             if (!non_zero_found) {

  1755.                 for(j=0;j<len;j++) {

  1756.                     if (tab1[j] != 0) {

  1757.                         non_zero_found = 1;

  1758.                         goto found2;

  1759.                     }

  1760.                 }

  1761.                 /* for last band, use previous scale factor */

  1762.                 k = (i == 21) ? 20 : i;

  1763.                 sf = g1->scale_factors[k];

  1764.                 if (sf >= sf_max)

  1765.                     goto found2;

  1766.                 v1 = is_tab[0][sf];

  1767.                 v2 = is_tab[1][sf];

  1768.                 for(j=0;j<len;j++) {

  1769.                     tmp0 = tab0[j];

  1770.                     tab0[j] = MULL(tmp0, v1);

  1771.                     tab1[j] = MULL(tmp0, v2);

  1772.                 }

  1773.             } else {

  1774.             found2:

  1775.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1776.                     /* lower part of the spectrum : do ms stereo

  1777.                        if enabled */

  1778.                     for(j=0;j<len;j++) {

  1779.                         tmp0 = tab0[j];

  1780.                         tmp1 = tab1[j];

  1781.                         tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1782.                         tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1783.                     }

  1784.                 }

  1785.             }

  1786.         }

  1787.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1788.         /* ms stereo ONLY */

  1789.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1790.            global gain */

  1791.         tab0 = g0->sb_hybrid;

  1792.         tab1 = g1->sb_hybrid;

  1793.         for(i=0;i<576;i++) {

  1794.             tmp0 = tab0[i];

  1795.             tmp1 = tab1[i];

  1796.             tab0[i] = tmp0 + tmp1;

  1797.             tab1[i] = tmp0 - tmp1;

  1798.         }

  1799.     }

  1800. }

  1801. 

  1802. static void compute_antialias_integer(MPADecodeContext *s,

  1803.                               GranuleDef *g)

  1804. {

  1805.     int32_t *ptr, *csa;

  1806.     int n, i;

  1807. 

  1808.     /* we antialias only "long" bands */

  1809.     if (g->block_type == 2) {

  1810.         if (!g->switch_point)

  1811.             return;

  1812.         /* XXX: check this for 8000Hz case */

  1813.         n = 1;

  1814.     } else {

  1815.         n = SBLIMIT - 1;

  1816.     }

  1817. 

  1818.     ptr = g->sb_hybrid + 18;

  1819.     for(i = n;i > 0;i--) {

  1820.         int tmp0, tmp1, tmp2;

  1821.         csa = &csa_table[0][0];

  1822. #define INT_AA(j) \

  1823.             tmp0 = ptr[-1-j];\

  1824.             tmp1 = ptr[   j];\

  1825.             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\

  1826.             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\

  1827.             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));

  1828. 

  1829.         INT_AA(0)

  1830.         INT_AA(1)

  1831.         INT_AA(2)

  1832.         INT_AA(3)

  1833.         INT_AA(4)

  1834.         INT_AA(5)

  1835.         INT_AA(6)

  1836.         INT_AA(7)

  1837. 

  1838.         ptr += 18;

  1839.     }

  1840. }

  1841. 

  1842. static void compute_antialias_float(MPADecodeContext *s,

  1843.                               GranuleDef *g)

  1844. {

  1845.     int32_t *ptr;

  1846.     int n, i;

  1847. 

  1848.     /* we antialias only "long" bands */

  1849.     if (g->block_type == 2) {

  1850.         if (!g->switch_point)

  1851.             return;

  1852.         /* XXX: check this for 8000Hz case */

  1853.         n = 1;

  1854.     } else {

  1855.         n = SBLIMIT - 1;

  1856.     }

  1857. 

  1858.     ptr = g->sb_hybrid + 18;

  1859.     for(i = n;i > 0;i--) {

  1860.         float tmp0, tmp1;

  1861.         float *csa = &csa_table_float[0][0];

  1862. #define FLOAT_AA(j)\

  1863.         tmp0= ptr[-1-j];\

  1864.         tmp1= ptr[   j];\

  1865.         ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\

  1866.         ptr[   j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);

  1867. 

  1868.         FLOAT_AA(0)

  1869.         FLOAT_AA(1)

  1870.         FLOAT_AA(2)

  1871.         FLOAT_AA(3)

  1872.         FLOAT_AA(4)

  1873.         FLOAT_AA(5)

  1874.         FLOAT_AA(6)

  1875.         FLOAT_AA(7)

  1876. 

  1877.         ptr += 18;

  1878.     }

  1879. }

  1880. 

  1881. static void compute_imdct(MPADecodeContext *s,

  1882.                           GranuleDef *g,

  1883.                           int32_t *sb_samples,

  1884.                           int32_t *mdct_buf)

  1885. {

  1886.     int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;

  1887.     int32_t out2[12];

  1888.     int i, j, mdct_long_end, v, sblimit;

  1889. 

  1890.     /* find last non zero block */

  1891.     ptr = g->sb_hybrid + 576;

  1892.     ptr1 = g->sb_hybrid + 2 * 18;

  1893.     while (ptr >= ptr1) {

  1894.         ptr -= 6;

  1895.         v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];

  1896.         if (v != 0)

  1897.             break;

  1898.     }

  1899.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  1900. 

  1901.     if (g->block_type == 2) {

  1902.         /* XXX: check for 8000 Hz */

  1903.         if (g->switch_point)

  1904.             mdct_long_end = 2;

  1905.         else

  1906.             mdct_long_end = 0;

  1907.     } else {

  1908.         mdct_long_end = sblimit;

  1909.     }

  1910. 

  1911.     buf = mdct_buf;

  1912.     ptr = g->sb_hybrid;

  1913.     for(j=0;j<mdct_long_end;j++) {

  1914.         /* apply window & overlap with previous buffer */

  1915.         out_ptr = sb_samples + j;

  1916.         /* select window */

  1917.         if (g->switch_point && j < 2)

  1918.             win1 = mdct_win[0];

  1919.         else

  1920.             win1 = mdct_win[g->block_type];

  1921.         /* select frequency inversion */

  1922.         win = win1 + ((4 * 36) & -(j & 1));

  1923.         imdct36(out_ptr, buf, ptr, win);

  1924.         out_ptr += 18*SBLIMIT;

  1925.         ptr += 18;

  1926.         buf += 18;

  1927.     }

  1928.     for(j=mdct_long_end;j<sblimit;j++) {

  1929.         /* select frequency inversion */

  1930.         win = mdct_win[2] + ((4 * 36) & -(j & 1));

  1931.         out_ptr = sb_samples + j;

  1932. 

  1933.         for(i=0; i<6; i++){

  1934.             *out_ptr = buf[i];

  1935.             out_ptr += SBLIMIT;

  1936.         }

  1937.         imdct12(out2, ptr + 0);

  1938.         for(i=0;i<6;i++) {

  1939.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];

  1940.             buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);

  1941.             out_ptr += SBLIMIT;

  1942.         }

  1943.         imdct12(out2, ptr + 1);

  1944.         for(i=0;i<6;i++) {

  1945.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];

  1946.             buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);

  1947.             out_ptr += SBLIMIT;

  1948.         }

  1949.         imdct12(out2, ptr + 2);

  1950.         for(i=0;i<6;i++) {

  1951.             buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];

  1952.             buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);

  1953.             buf[i + 6*2] = 0;

  1954.         }

  1955.         ptr += 18;

  1956.         buf += 18;

  1957.     }

  1958.     /* zero bands */

  1959.     for(j=sblimit;j<SBLIMIT;j++) {

  1960.         /* overlap */

  1961.         out_ptr = sb_samples + j;

  1962.         for(i=0;i<18;i++) {

  1963.             *out_ptr = buf[i];

  1964.             buf[i] = 0;

  1965.             out_ptr += SBLIMIT;

  1966.         }

  1967.         buf += 18;

  1968.     }

  1969. }

  1970. 

  1971. #if defined(DEBUG)

  1972. void sample_dump(int fnum, int32_t *tab, int n)

  1973. {

  1974.     static FILE *files[16], *f;

  1975.     char buf[512];

  1976.     int i;

  1977.     int32_t v;

  1978. 

  1979.     f = files[fnum];

  1980.     if (!f) {

  1981.         snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm",

  1982.                 fnum,

  1983. #ifdef USE_HIGHPRECISION

  1984.                 "hp"

  1985. #else

  1986.                 "lp"

  1987. #endif

  1988.                 );

  1989.         f = fopen(buf, "w");

  1990.         if (!f)

  1991.             return;

  1992.         files[fnum] = f;

  1993.     }

  1994. 

  1995.     if (fnum == 0) {

  1996.         static int pos = 0;

  1997.         av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos);

  1998.         for(i=0;i<n;i++) {

  1999.             av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE);

  2000.             if ((i % 18) == 17)

  2001.                 av_log(NULL, AV_LOG_DEBUG, "\n");

  2002.         }

  2003.         pos += n;

  2004.     }

  2005.     for(i=0;i<n;i++) {

  2006.         /* normalize to 23 frac bits */

  2007.         v = tab[i] << (23 - FRAC_BITS);

  2008.         fwrite(&v, 1, sizeof(int32_t), f);

  2009.     }

  2010. }

  2011. #endif

  2012. 

  2013. 

  2014. /* main layer3 decoding function */

  2015. static int mp_decode_layer3(MPADecodeContext *s)

  2016. {

  2017.     int nb_granules, main_data_begin, private_bits;

  2018.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  2019.     GranuleDef granules[2][2], *g;

  2020.     int16_t exponents[576];

  2021. 

  2022.     /* read side info */

  2023.     if (s->lsf) {

  2024.         main_data_begin = get_bits(&s->gb, 8);

  2025.         private_bits = get_bits(&s->gb, s->nb_channels);

  2026.         nb_granules = 1;

  2027.     } else {

  2028.         main_data_begin = get_bits(&s->gb, 9);

  2029.         if (s->nb_channels == 2)

  2030.             private_bits = get_bits(&s->gb, 3);

  2031.         else

  2032.             private_bits = get_bits(&s->gb, 5);

  2033.         nb_granules = 2;

  2034.         for(ch=0;ch<s->nb_channels;ch++) {

  2035.             granules[ch][0].scfsi = 0; /* all scale factors are transmitted */

  2036.             granules[ch][1].scfsi = get_bits(&s->gb, 4);

  2037.         }

  2038.     }

  2039. 

  2040.     for(gr=0;gr<nb_granules;gr++) {

  2041.         for(ch=0;ch<s->nb_channels;ch++) {

  2042.             dprintf(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);

  2043.             g = &granules[ch][gr];

  2044.             g->part2_3_length = get_bits(&s->gb, 12);

  2045.             g->big_values = get_bits(&s->gb, 9);

  2046.             if(g->big_values > 288){

  2047.                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");

  2048.                 return -1;

  2049.             }

  2050. 

  2051.             g->global_gain = get_bits(&s->gb, 8);

  2052.             /* if MS stereo only is selected, we precompute the

  2053.                1/sqrt(2) renormalization factor */

  2054.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  2055.                 MODE_EXT_MS_STEREO)

  2056.                 g->global_gain -= 2;

  2057.             if (s->lsf)

  2058.                 g->scalefac_compress = get_bits(&s->gb, 9);

  2059.             else

  2060.                 g->scalefac_compress = get_bits(&s->gb, 4);

  2061.             blocksplit_flag = get_bits1(&s->gb);

  2062.             if (blocksplit_flag) {

  2063.                 g->block_type = get_bits(&s->gb, 2);

  2064.                 if (g->block_type == 0){

  2065.                     av_log(NULL, AV_LOG_ERROR, "invalid block type\n");

  2066.                     return -1;

  2067.                 }

  2068.                 g->switch_point = get_bits1(&s->gb);

  2069.                 for(i=0;i<2;i++)

  2070.                     g->table_select[i] = get_bits(&s->gb, 5);

  2071.                 for(i=0;i<3;i++)

  2072.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  2073.                 ff_init_short_region(s, g);

  2074.             } else {

  2075.                 int region_address1, region_address2;

  2076.                 g->block_type = 0;

  2077.                 g->switch_point = 0;

  2078.                 for(i=0;i<3;i++)

  2079.                     g->table_select[i] = get_bits(&s->gb, 5);

  2080.                 /* compute huffman coded region sizes */

  2081.                 region_address1 = get_bits(&s->gb, 4);

  2082.                 region_address2 = get_bits(&s->gb, 3);

  2083.                 dprintf(s->avctx, "region1=%d region2=%d\n",

  2084.                         region_address1, region_address2);

  2085.                 ff_init_long_region(s, g, region_address1, region_address2);

  2086.             }

  2087.             ff_region_offset2size(g);

  2088.             ff_compute_band_indexes(s, g);

  2089. 

  2090.             g->preflag = 0;

  2091.             if (!s->lsf)

  2092.                 g->preflag = get_bits1(&s->gb);

  2093.             g->scalefac_scale = get_bits1(&s->gb);

  2094.             g->count1table_select = get_bits1(&s->gb);

  2095.             dprintf(s->avctx, "block_type=%d switch_point=%d\n",

  2096.                     g->block_type, g->switch_point);

  2097.         }

  2098.     }

  2099. 

  2100.   if (!s->adu_mode) {

  2101.     const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  2102.     assert((get_bits_count(&s->gb) & 7) == 0);

  2103.     /* now we get bits from the main_data_begin offset */

  2104.     dprintf(s->avctx, "seekback: %d\n", main_data_begin);

  2105. //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);

  2106. 

  2107.     memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);

  2108.     s->in_gb= s->gb;

  2109.         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);

  2110.         skip_bits_long(&s->gb, 8*(s->last_buf_size - main_data_begin));

  2111.   }

  2112. 

  2113.     for(gr=0;gr<nb_granules;gr++) {

  2114.         for(ch=0;ch<s->nb_channels;ch++) {

  2115.             g = &granules[ch][gr];

  2116.             if(get_bits_count(&s->gb)<0){

  2117.                 av_log(NULL, AV_LOG_ERROR, "mdb:%d, lastbuf:%d skipping granule %d\n",

  2118.                                             main_data_begin, s->last_buf_size, gr);

  2119.                 skip_bits_long(&s->gb, g->part2_3_length);

  2120.                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));

  2121.                 if(get_bits_count(&s->gb) >= s->gb.size_in_bits && s->in_gb.buffer){

  2122.                     skip_bits_long(&s->in_gb, get_bits_count(&s->gb) - s->gb.size_in_bits);

  2123.                     s->gb= s->in_gb;

  2124.                     s->in_gb.buffer=NULL;

  2125.                 }

  2126.                 continue;

  2127.             }

  2128. 

  2129.             bits_pos = get_bits_count(&s->gb);

  2130. 

  2131.             if (!s->lsf) {

  2132.                 uint8_t *sc;

  2133.                 int slen, slen1, slen2;

  2134. 

  2135.                 /* MPEG1 scale factors */

  2136.                 slen1 = slen_table[0][g->scalefac_compress];

  2137.                 slen2 = slen_table[1][g->scalefac_compress];

  2138.                 dprintf(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);

  2139.                 if (g->block_type == 2) {

  2140.                     n = g->switch_point ? 17 : 18;

  2141.                     j = 0;

  2142.                     if(slen1){

  2143.                         for(i=0;i<n;i++)

  2144.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  2145.                     }else{

  2146.                         for(i=0;i<n;i++)

  2147.                             g->scale_factors[j++] = 0;

  2148.                     }

  2149.                     if(slen2){

  2150.                         for(i=0;i<18;i++)

  2151.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  2152.                         for(i=0;i<3;i++)

  2153.                             g->scale_factors[j++] = 0;

  2154.                     }else{

  2155.                         for(i=0;i<21;i++)

  2156.                             g->scale_factors[j++] = 0;

  2157.                     }

  2158.                 } else {

  2159.                     sc = granules[ch][0].scale_factors;

  2160.                     j = 0;

  2161.                     for(k=0;k<4;k++) {

  2162.                         n = (k == 0 ? 6 : 5);

  2163.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  2164.                             slen = (k < 2) ? slen1 : slen2;

  2165.                             if(slen){

  2166.                                 for(i=0;i<n;i++)

  2167.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  2168.                             }else{

  2169.                                 for(i=0;i<n;i++)

  2170.                                     g->scale_factors[j++] = 0;

  2171.                             }

  2172.                         } else {

  2173.                             /* simply copy from last granule */

  2174.                             for(i=0;i<n;i++) {

  2175.                                 g->scale_factors[j] = sc[j];

  2176.                                 j++;

  2177.                             }

  2178.                         }

  2179.                     }

  2180.                     g->scale_factors[j++] = 0;

  2181.                 }

  2182. #if defined(DEBUG)

  2183.                 {

  2184.                     dprintf(s->avctx, "scfsi=%x gr=%d ch=%d scale_factors:\n",

  2185.                            g->scfsi, gr, ch);

  2186.                     for(i=0;i<j;i++)

  2187.                         dprintf(s->avctx, " %d", g->scale_factors[i]);

  2188.                     dprintf(s->avctx, "\n");

  2189.                 }

  2190. #endif

  2191.             } else {

  2192.                 int tindex, tindex2, slen[4], sl, sf;

  2193. 

  2194.                 /* LSF scale factors */

  2195.                 if (g->block_type == 2) {

  2196.                     tindex = g->switch_point ? 2 : 1;

  2197.                 } else {

  2198.                     tindex = 0;

  2199.                 }

  2200.                 sf = g->scalefac_compress;

  2201.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  2202.                     /* intensity stereo case */

  2203.                     sf >>= 1;

  2204.                     if (sf < 180) {

  2205.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  2206.                         tindex2 = 3;

  2207.                     } else if (sf < 244) {

  2208.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  2209.                         tindex2 = 4;

  2210.                     } else {

  2211.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  2212.                         tindex2 = 5;

  2213.                     }

  2214.                 } else {

  2215.                     /* normal case */

  2216.                     if (sf < 400) {

  2217.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  2218.                         tindex2 = 0;

  2219.                     } else if (sf < 500) {

  2220.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  2221.                         tindex2 = 1;

  2222.                     } else {

  2223.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  2224.                         tindex2 = 2;

  2225.                         g->preflag = 1;

  2226.                     }

  2227.                 }

  2228. 

  2229.                 j = 0;

  2230.                 for(k=0;k<4;k++) {

  2231.                     n = lsf_nsf_table[tindex2][tindex][k];

  2232.                     sl = slen[k];

  2233.                     if(sl){

  2234.                         for(i=0;i<n;i++)

  2235.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  2236.                     }else{

  2237.                         for(i=0;i<n;i++)

  2238.                             g->scale_factors[j++] = 0;

  2239.                     }

  2240.                 }

  2241.                 /* XXX: should compute exact size */

  2242.                 for(;j<40;j++)

  2243.                     g->scale_factors[j] = 0;

  2244. #if defined(DEBUG)

  2245.                 {

  2246.                     dprintf(s->avctx, "gr=%d ch=%d scale_factors:\n",

  2247.                            gr, ch);

  2248.                     for(i=0;i<40;i++)

  2249.                         dprintf(s->avctx, " %d", g->scale_factors[i]);

  2250.                     dprintf(s->avctx, "\n");

  2251.                 }

  2252. #endif

  2253.             }

  2254. 

  2255.             exponents_from_scale_factors(s, g, exponents);

  2256. 

  2257.             /* read Huffman coded residue */

  2258.             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);

  2259. #if defined(DEBUG)

  2260.             sample_dump(0, g->sb_hybrid, 576);

  2261. #endif

  2262.         } /* ch */

  2263. 

  2264.         if (s->nb_channels == 2)

  2265.             compute_stereo(s, &granules[0][gr], &granules[1][gr]);

  2266. 

  2267.         for(ch=0;ch<s->nb_channels;ch++) {

  2268.             g = &granules[ch][gr];

  2269. 

  2270.             reorder_block(s, g);

  2271. #if defined(DEBUG)

  2272.             sample_dump(0, g->sb_hybrid, 576);

  2273. #endif

  2274.             s->compute_antialias(s, g);

  2275. #if defined(DEBUG)

  2276.             sample_dump(1, g->sb_hybrid, 576);

  2277. #endif

  2278.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  2279. #if defined(DEBUG)

  2280.             sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);

  2281. #endif

  2282.         }

  2283.     } /* gr */

  2284.     if(get_bits_count(&s->gb)<0)

  2285.         skip_bits_long(&s->gb, -get_bits_count(&s->gb));

  2286.     return nb_granules * 18;

  2287. }

  2288. 

  2289. static int mp_decode_frame(MPADecodeContext *s,

  2290.                            OUT_INT *samples, const uint8_t *buf, int buf_size)

  2291. {

  2292.     int i, nb_frames, ch;

  2293.     OUT_INT *samples_ptr;

  2294. 

  2295.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)*8);

  2296. 

  2297.     /* skip error protection field */

  2298.     if (s->error_protection)

  2299.         skip_bits(&s->gb, 16);

  2300. 

  2301.     dprintf(s->avctx, "frame %d:\n", s->frame_count);

  2302.     switch(s->layer) {

  2303.     case 1:

  2304.         nb_frames = mp_decode_layer1(s);

  2305.         break;

  2306.     case 2:

  2307.         nb_frames = mp_decode_layer2(s);

  2308.         break;

  2309.     case 3:

  2310.     default:

  2311.         nb_frames = mp_decode_layer3(s);

  2312. 

  2313.         s->last_buf_size=0;

  2314.         if(s->in_gb.buffer){

  2315.             align_get_bits(&s->gb);

  2316.             i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;

  2317.             if(i >= 0 && i <= BACKSTEP_SIZE){

  2318.                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);

  2319.                 s->last_buf_size=i;

  2320.             }else

  2321.                 av_log(NULL, AV_LOG_ERROR, "invalid old backstep %d\n", i);

  2322.             s->gb= s->in_gb;

  2323.             s->in_gb.buffer= NULL;

  2324.         }

  2325. 

  2326.         align_get_bits(&s->gb);

  2327.         assert((get_bits_count(&s->gb) & 7) == 0);

  2328.         i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;

  2329. 

  2330.         if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){

  2331.             av_log(NULL, AV_LOG_ERROR, "invalid new backstep %d\n", i);

  2332.             i= FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);

  2333.         }

  2334.         assert(i <= buf_size - HEADER_SIZE && i>= 0);

  2335.         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);

  2336.         s->last_buf_size += i;

  2337. 

  2338.         break;

  2339.     }

  2340. #if defined(DEBUG)

  2341.     for(i=0;i<nb_frames;i++) {

  2342.         for(ch=0;ch<s->nb_channels;ch++) {

  2343.             int j;

  2344.             dprintf(s->avctx, "%d-%d:", i, ch);

  2345.             for(j=0;j<SBLIMIT;j++)

  2346.                 dprintf(s->avctx, " %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);

  2347.             dprintf(s->avctx, "\n");

  2348.         }

  2349.     }

  2350. #endif

  2351.     /* apply the synthesis filter */

  2352.     for(ch=0;ch<s->nb_channels;ch++) {

  2353.         samples_ptr = samples + ch;

  2354.         for(i=0;i<nb_frames;i++) {

  2355.             ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  2356.                          window, &s->dither_state,

  2357.                          samples_ptr, s->nb_channels,

  2358.                          s->sb_samples[ch][i]);

  2359.             samples_ptr += 32 * s->nb_channels;

  2360.         }

  2361.     }

  2362. #ifdef DEBUG

  2363.     s->frame_count++;

  2364. #endif

  2365.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  2366. }

  2367. 

  2368. static int decode_frame(AVCodecContext * avctx,

  2369.                         void *data, int *data_size,

  2370.                         const uint8_t * buf, int buf_size)

  2371. {

  2372.     MPADecodeContext *s = avctx->priv_data;

  2373.     uint32_t header;

  2374.     int out_size;

  2375.     OUT_INT *out_samples = data;

  2376. 

  2377. retry:

  2378.     if(buf_size < HEADER_SIZE)

  2379.         return -1;

  2380. 

  2381.     header = AV_RB32(buf);

  2382.     if(ff_mpa_check_header(header) < 0){

  2383.         buf++;

  2384. //        buf_size--;

  2385.         av_log(avctx, AV_LOG_ERROR, "Header missing skipping one byte.\n");

  2386.         goto retry;

  2387.     }

  2388. 

  2389.     if (ff_mpegaudio_decode_header(s, header) == 1) {

  2390.         /* free format: prepare to compute frame size */

  2391.         s->frame_size = -1;

  2392.         return -1;

  2393.     }

  2394.     /* update codec info */

  2395.     avctx->channels = s->nb_channels;

  2396.     avctx->bit_rate = s->bit_rate;

  2397.     avctx->sub_id = s->layer;

  2398.     switch(s->layer) {

  2399.     case 1:

  2400.         avctx->frame_size = 384;

  2401.         break;

  2402.     case 2:

  2403.         avctx->frame_size = 1152;

  2404.         break;

  2405.     case 3:

  2406.         if (s->lsf)

  2407.             avctx->frame_size = 576;

  2408.         else

  2409.             avctx->frame_size = 1152;

  2410.         break;

  2411.     }

  2412. 

  2413.     if(s->frame_size<=0 || s->frame_size > buf_size){

  2414.         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

  2415.         return -1;

  2416.     }else if(s->frame_size < buf_size){

  2417.         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");

  2418.         buf_size= s->frame_size;

  2419.     }

  2420. 

  2421.     out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2422.     if(out_size>=0){

  2423.         *data_size = out_size;

  2424.         avctx->sample_rate = s->sample_rate;

  2425.         //FIXME maybe move the other codec info stuff from above here too

  2426.     }else

  2427.         av_log(avctx, AV_LOG_DEBUG, "Error while decoding MPEG audio frame.\n"); //FIXME return -1 / but also return the number of bytes consumed

  2428.     s->frame_size = 0;

  2429.     return buf_size;

  2430. }

  2431. 

  2432. static void flush(AVCodecContext *avctx){

  2433.     MPADecodeContext *s = avctx->priv_data;

  2434.     memset(s->synth_buf, 0, sizeof(s->synth_buf));

  2435.     s->last_buf_size= 0;

  2436. }

  2437. 

  2438. #ifdef CONFIG_MP3ADU_DECODER

  2439. static int decode_frame_adu(AVCodecContext * avctx,

  2440.                         void *data, int *data_size,

  2441.                         const uint8_t * buf, int buf_size)

  2442. {

  2443.     MPADecodeContext *s = avctx->priv_data;

  2444.     uint32_t header;

  2445.     int len, out_size;

  2446.     OUT_INT *out_samples = data;

  2447. 

  2448.     len = buf_size;

  2449. 

  2450.     // Discard too short frames

  2451.     if (buf_size < HEADER_SIZE) {

  2452.         *data_size = 0;

  2453.         return buf_size;

  2454.     }

  2455. 

  2456. 

  2457.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  2458.         len = MPA_MAX_CODED_FRAME_SIZE;

  2459. 

  2460.     // Get header and restore sync word

  2461.     header = AV_RB32(buf) | 0xffe00000;

  2462. 

  2463.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  2464.         *data_size = 0;

  2465.         return buf_size;

  2466.     }

  2467. 

  2468.     ff_mpegaudio_decode_header(s, header);

  2469.     /* update codec info */

  2470.     avctx->sample_rate = s->sample_rate;

  2471.     avctx->channels = s->nb_channels;

  2472.     avctx->bit_rate = s->bit_rate;

  2473.     avctx->sub_id = s->layer;

  2474. 

  2475.     avctx->frame_size=s->frame_size = len;

  2476. 

  2477.     if (avctx->parse_only) {

  2478.         out_size = buf_size;

  2479.     } else {

  2480.         out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2481.     }

  2482. 

  2483.     *data_size = out_size;

  2484.     return buf_size;

  2485. }

  2486. #endif /* CONFIG_MP3ADU_DECODER */

  2487. 

  2488. #ifdef CONFIG_MP3ON4_DECODER

  2489. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  2490. static int mp3Frames[16] = {0,1,1,2,3,3,4,5,2};   /* number of mp3 decoder instances */

  2491. static int mp3Channels[16] = {0,1,2,3,4,5,6,8,4}; /* total output channels */

  2492. /* offsets into output buffer, assume output order is FL FR BL BR C LFE */

  2493. static int chan_offset[9][5] = {

  2494.     {0},

  2495.     {0},            // C

  2496.     {0},            // FLR

  2497.     {2,0},          // C FLR

  2498.     {2,0,3},        // C FLR BS

  2499.     {4,0,2},        // C FLR BLRS

  2500.     {4,0,2,5},      // C FLR BLRS LFE

  2501.     {4,0,2,6,5},    // C FLR BLRS BLR LFE

  2502.     {0,2}           // FLR BLRS

  2503. };

  2504. 

  2505. 

  2506. static int decode_init_mp3on4(AVCodecContext * avctx)

  2507. {

  2508.     MP3On4DecodeContext *s = avctx->priv_data;

  2509.     int i;

  2510. 

  2511.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  2512.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  2513.         return -1;

  2514.     }

  2515. 

  2516.     s->chan_cfg = (((unsigned char *)avctx->extradata)[1] >> 3) & 0x0f;

  2517.     s->frames = mp3Frames[s->chan_cfg];

  2518.     if(!s->frames) {

  2519.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  2520.         return -1;

  2521.     }

  2522.     avctx->channels = mp3Channels[s->chan_cfg];

  2523. 

  2524.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  2525.      * We replace avctx->priv_data with the context of the first decoder so that

  2526.      * decode_init() does not have to be changed.

  2527.      * Other decoders will be initialized here copying data from the first context

  2528.      */

  2529.     // Allocate zeroed memory for the first decoder context

  2530.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  2531.     // Put decoder context in place to make init_decode() happy

  2532.     avctx->priv_data = s->mp3decctx[0];

  2533.     decode_init(avctx);

  2534.     // Restore mp3on4 context pointer

  2535.     avctx->priv_data = s;

  2536.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  2537. 

  2538.     /* Create a separate codec/context for each frame (first is already ok).

  2539.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  2540.      */

  2541.     for (i = 1; i < s->frames; i++) {

  2542.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  2543.         s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;

  2544.         s->mp3decctx[i]->adu_mode = 1;

  2545.         s->mp3decctx[i]->avctx = avctx;

  2546.     }

  2547. 

  2548.     return 0;

  2549. }

  2550. 

  2551. 

  2552. static int decode_close_mp3on4(AVCodecContext * avctx)

  2553. {

  2554.     MP3On4DecodeContext *s = avctx->priv_data;

  2555.     int i;

  2556. 

  2557.     for (i = 0; i < s->frames; i++)

  2558.         if (s->mp3decctx[i])

  2559.             av_free(s->mp3decctx[i]);

  2560. 

  2561.     return 0;

  2562. }

  2563. 

  2564. 

  2565. static int decode_frame_mp3on4(AVCodecContext * avctx,

  2566.                         void *data, int *data_size,

  2567.                         const uint8_t * buf, int buf_size)

  2568. {

  2569.     MP3On4DecodeContext *s = avctx->priv_data;

  2570.     MPADecodeContext *m;

  2571.     int len, out_size = 0;

  2572.     uint32_t header;

  2573.     OUT_INT *out_samples = data;

  2574.     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];

  2575.     OUT_INT *outptr, *bp;

  2576.     int fsize;

  2577.     const unsigned char *start2 = buf, *start;

  2578.     int fr, i, j, n;

  2579.     int off = avctx->channels;

  2580.     int *coff = chan_offset[s->chan_cfg];

  2581. 

  2582.     len = buf_size;

  2583. 

  2584.     // Discard too short frames

  2585.     if (buf_size < HEADER_SIZE) {

  2586.         *data_size = 0;

  2587.         return buf_size;

  2588.     }

  2589. 

  2590.     // If only one decoder interleave is not needed

  2591.     outptr = s->frames == 1 ? out_samples : decoded_buf;

  2592. 

  2593.     for (fr = 0; fr < s->frames; fr++) {

  2594.         start = start2;

  2595.         fsize = (start[0] << 4) | (start[1] >> 4);

  2596.         start2 += fsize;

  2597.         if (fsize > len)

  2598.             fsize = len;

  2599.         len -= fsize;

  2600.         if (fsize > MPA_MAX_CODED_FRAME_SIZE)

  2601.             fsize = MPA_MAX_CODED_FRAME_SIZE;

  2602.         m = s->mp3decctx[fr];

  2603.         assert (m != NULL);

  2604. 

  2605.         // Get header

  2606.         header = AV_RB32(start) | 0xfff00000;

  2607. 

  2608.         if (ff_mpa_check_header(header) < 0) { // Bad header, discard block

  2609.             *data_size = 0;

  2610.             return buf_size;

  2611.         }

  2612. 

  2613.         ff_mpegaudio_decode_header(m, header);

  2614.         mp_decode_frame(m, decoded_buf, start, fsize);

  2615. 

  2616.         n = MPA_FRAME_SIZE * m->nb_channels;

  2617.         out_size += n * sizeof(OUT_INT);

  2618.         if(s->frames > 1) {

  2619.             /* interleave output data */

  2620.             bp = out_samples + coff[fr];

  2621.             if(m->nb_channels == 1) {

  2622.                 for(j = 0; j < n; j++) {

  2623.                     *bp = decoded_buf[j];

  2624.                     bp += off;

  2625.                 }

  2626.             } else {

  2627.                 for(j = 0; j < n; j++) {

  2628.                     bp[0] = decoded_buf[j++];

  2629.                     bp[1] = decoded_buf[j];

  2630.                     bp += off;

  2631.                 }

  2632.             }

  2633.         }

  2634.     }

  2635. 

  2636.     /* update codec info */

  2637.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  2638.     avctx->frame_size= buf_size;

  2639.     avctx->bit_rate = 0;

  2640.     for (i = 0; i < s->frames; i++)

  2641.         avctx->bit_rate += s->mp3decctx[i]->bit_rate;

  2642. 

  2643.     *data_size = out_size;

  2644.     return buf_size;

  2645. }

  2646. #endif /* CONFIG_MP3ON4_DECODER */

  2647. 

  2648. #ifdef CONFIG_MP2_DECODER

  2649. AVCodec mp2_decoder =

  2650. {

  2651.     "mp2",

  2652.     CODEC_TYPE_AUDIO,

  2653.     CODEC_ID_MP2,

  2654.     sizeof(MPADecodeContext),

  2655.     decode_init,

  2656.     NULL,

  2657.     NULL,

  2658.     decode_frame,

  2659.     CODEC_CAP_PARSE_ONLY,

  2660.     .flush= flush,

  2661. };

  2662. #endif

  2663. #ifdef CONFIG_MP3_DECODER

  2664. AVCodec mp3_decoder =

  2665. {

  2666.     "mp3",

  2667.     CODEC_TYPE_AUDIO,

  2668.     CODEC_ID_MP3,

  2669.     sizeof(MPADecodeContext),

  2670.     decode_init,

  2671.     NULL,

  2672.     NULL,

  2673.     decode_frame,

  2674.     CODEC_CAP_PARSE_ONLY,

  2675.     .flush= flush,

  2676. };

  2677. #endif

  2678. #ifdef CONFIG_MP3ADU_DECODER

  2679. AVCodec mp3adu_decoder =

  2680. {

  2681.     "mp3adu",

  2682.     CODEC_TYPE_AUDIO,

  2683.     CODEC_ID_MP3ADU,

  2684.     sizeof(MPADecodeContext),

  2685.     decode_init,

  2686.     NULL,

  2687.     NULL,

  2688.     decode_frame_adu,

  2689.     CODEC_CAP_PARSE_ONLY,

  2690.     .flush= flush,

  2691. };

  2692. #endif

  2693. #ifdef CONFIG_MP3ON4_DECODER

  2694. AVCodec mp3on4_decoder =

  2695. {

  2696.     "mp3on4",

  2697.     CODEC_TYPE_AUDIO,

  2698.     CODEC_ID_MP3ON4,

  2699.     sizeof(MP3On4DecodeContext),

  2700.     decode_init_mp3on4,

  2701.     NULL,

  2702.     decode_close_mp3on4,

  2703.     decode_frame_mp3on4,

  2704.     .flush= flush,

  2705. };

  2706. #endif