falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
14494 Commits
32 Branches
449MB
Tree: f67a10cd0c
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from 'f67a10cd0c'
${ noResults }
FFmpeg/libavcodec/mpegaudiodec.c

2693 lines
80KB
Raw Blame History 

  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. /* layer 3 "granule" */

  60. typedef struct GranuleDef {

  61.     uint8_t scfsi;

  62.     int part2_3_length;

  63.     int big_values;

  64.     int global_gain;

  65.     int scalefac_compress;

  66.     uint8_t block_type;

  67.     uint8_t switch_point;

  68.     int table_select[3];

  69.     int subblock_gain[3];

  70.     uint8_t scalefac_scale;

  71.     uint8_t count1table_select;

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

  73.     int preflag;

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

  75.     uint8_t scale_factors[40];

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

  77. } GranuleDef;

  78. 

  79. #include "mpegaudiodata.h"

  80. #include "mpegaudiodectab.h"

  81. 

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

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

  84. 

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

  86. static VLC huff_vlc[16];

  87. static VLC huff_quad_vlc[2];

  88. /* computed from band_size_long */

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

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

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

  92. static int8_t  table_4_3_exp[TABLE_4_3_SIZE];

  93. static uint32_t table_4_3_value[TABLE_4_3_SIZE];

  94. static uint32_t exp_table[512];

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

  96. /* intensity stereo coef table */

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

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

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

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

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

  102. 

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

  104. static uint16_t scale_factor_modshift[64];

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

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

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

  108. 

  109. #define SCALE_GEN(v) \

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

  111. 

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

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

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

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

  116. };

  117. 

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

  119. 

  120. /**

  121.  * Convert region offsets to region sizes and truncate

  122.  * size to big_values.

  123.  */

  124. void ff_region_offset2size(GranuleDef *g){

  125.     int i, k, j=0;

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

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

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

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

  130.         j = k;

  131.     }

  132. }

  133. 

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

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

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

  137.     else {

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

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

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

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

  142.         else

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

  144.     }

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

  146. }

  147. 

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

  149.     int l;

  150.     g->region_size[0] =

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

  152.     /* should not overflow */

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

  154.     g->region_size[1] =

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

  156. }

  157. 

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

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

  160.         if (g->switch_point) {

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

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

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

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

  165.                 g->long_end = 8;

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

  167.                 g->long_end = 6;

  168.             else

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

  170. 

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

  172.         } else {

  173.             g->long_end = 0;

  174.             g->short_start = 0;

  175.         }

  176.     } else {

  177.         g->short_start = 13;

  178.         g->long_end = 22;

  179.     }

  180. }

  181. 

  182. /* layer 1 unscaling */

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

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

  185. {

  186.     int shift, mod;

  187.     int64_t val;

  188. 

  189.     shift = scale_factor_modshift[scale_factor];

  190.     mod = shift & 3;

  191.     shift >>= 2;

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

  193.     shift += n;

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

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

  196. }

  197. 

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

  199. {

  200.     int shift, mod, val;

  201. 

  202.     shift = scale_factor_modshift[scale_factor];

  203.     mod = shift & 3;

  204.     shift >>= 2;

  205. 

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

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

  208.     if (shift > 0)

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

  210.     return val;

  211. }

  212. 

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

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

  215. {

  216.     unsigned int m;

  217.     int e;

  218. 

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

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

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

  222.     assert(e>=1);

  223.     if (e > 31)

  224.         return 0;

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

  226. 

  227.     return m;

  228. }

  229. 

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

  231. #define DEV_ORDER 13

  232. 

  233. #define POW_FRAC_BITS 24

  234. #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)

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

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

  237. 

  238. static int dev_4_3_coefs[DEV_ORDER];

  239. 

  240. #if 0 /* unused */

  241. static int pow_mult3[3] = {

  242.     POW_FIX(1.0),

  243.     POW_FIX(1.25992104989487316476),

  244.     POW_FIX(1.58740105196819947474),

  245. };

  246. #endif

  247. 

  248. static void int_pow_init(void)

  249. {

  250.     int i, a;

  251. 

  252.     a = POW_FIX(1.0);

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

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

  255.         dev_4_3_coefs[i] = a;

  256.     }

  257. }

  258. 

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

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

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

  262. {

  263.     int e, er, eq, j;

  264.     int a, a1;

  265. 

  266.     /* renormalize */

  267.     a = i;

  268.     e = POW_FRAC_BITS;

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

  270.         a = a << 1;

  271.         e--;

  272.     }

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

  274.     a1 = 0;

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

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

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

  278.     /* exponent compute (exact) */

  279.     e = e * 4;

  280.     er = e % 3;

  281.     eq = e / 3;

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

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

  284.         a = a >> 1;

  285.         eq++;

  286.     }

  287.     /* convert to float */

  288.     while (a < POW_FRAC_ONE) {

  289.         a = a << 1;

  290.         eq--;

  291.     }

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

  293. #if POW_FRAC_BITS > FRAC_BITS

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

  295.     /* correct overflow */

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

  297.         a = a >> 1;

  298.         eq++;

  299.     }

  300. #endif

  301.     *exp_ptr = eq;

  302.     return a;

  303. }

  304. #endif

  305. 

  306. static int decode_init(AVCodecContext * avctx)

  307. {

  308.     MPADecodeContext *s = avctx->priv_data;

  309.     static int init=0;

  310.     int i, j, k;

  311. 

  312.     s->avctx = avctx;

  313. 

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

  315.     avctx->sample_fmt= SAMPLE_FMT_S32;

  316. #else

  317.     avctx->sample_fmt= SAMPLE_FMT_S16;

  318. #endif

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

  320. 

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

  322.         s->compute_antialias= compute_antialias_integer;

  323.     else

  324.         s->compute_antialias= compute_antialias_float;

  325. 

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

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

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

  329.             int shift, mod;

  330.             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  331.             shift = (i / 3);

  332.             mod = i % 3;

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

  334.         }

  335. 

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

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

  338.             int n, norm;

  339.             n = i + 2;

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

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

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

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

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

  345.                     i, norm,

  346.                     scale_factor_mult[i][0],

  347.                     scale_factor_mult[i][1],

  348.                     scale_factor_mult[i][2]);

  349.         }

  350. 

  351.         ff_mpa_synth_init(window);

  352. 

  353.         /* huffman decode tables */

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

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

  356.             int xsize, x, y;

  357.             unsigned int n;

  358.             uint8_t  tmp_bits [512];

  359.             uint16_t tmp_codes[512];

  360. 

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

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

  363. 

  364.             xsize = h->xsize;

  365.             n = xsize * xsize;

  366. 

  367.             j = 0;

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

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

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

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

  372.                 }

  373.             }

  374. 

  375.             /* XXX: fail test */

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

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

  378.         }

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

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

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

  382.         }

  383. 

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

  385.             k = 0;

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

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

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

  389.             }

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

  391.         }

  392. 

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

  394. 

  395.         int_pow_init();

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

  397.             double f, fm;

  398.             int e, m;

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

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

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

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

  403. 

  404.             /* normalized to FRAC_BITS */

  405.             table_4_3_value[i] = m;

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

  407.             table_4_3_exp[i] = -e;

  408.         }

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

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

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

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

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

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

  415.         }

  416. 

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

  418.             float f;

  419.             int v;

  420.             if (i != 6) {

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

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

  423.             } else {

  424.                 v = FIXR(1.0);

  425.             }

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

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

  428.         }

  429.         /* invalid values */

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

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

  432. 

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

  434.             double f;

  435.             int e, k;

  436. 

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

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

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

  440.                 k = i & 1;

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

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

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

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

  445.             }

  446.         }

  447. 

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

  449.             float ci, cs, ca;

  450.             ci = ci_table[i];

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

  452.             ca = cs * ci;

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

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

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

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

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

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

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

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

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

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

  463.         }

  464. 

  465.         /* compute mdct windows */

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

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

  468.                 double d;

  469. 

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

  471.                     continue;

  472. 

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

  474.                 if(j==1){

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

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

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

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

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

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

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

  482.                 }

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

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

  485. 

  486.                 if(j==2)

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

  488.                 else

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

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

  491.             }

  492.         }

  493. 

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

  495.            the sign of the right window coefs */

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

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

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

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

  500.             }

  501.         }

  502. 

  503. #if defined(DEBUG)

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

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

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

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

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

  509.         }

  510. #endif

  511.         init = 1;

  512.     }

  513. 

  514. #ifdef DEBUG

  515.     s->frame_count = 0;

  516. #endif

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

  518.         s->adu_mode = 1;

  519.     return 0;

  520. }

  521. 

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

  523. 

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

  525. 

  526. #define COS0_0  FIXHR(0.50060299823519630134/2)

  527. #define COS0_1  FIXHR(0.50547095989754365998/2)

  528. #define COS0_2  FIXHR(0.51544730992262454697/2)

  529. #define COS0_3  FIXHR(0.53104259108978417447/2)

  530. #define COS0_4  FIXHR(0.55310389603444452782/2)

  531. #define COS0_5  FIXHR(0.58293496820613387367/2)

  532. #define COS0_6  FIXHR(0.62250412303566481615/2)

  533. #define COS0_7  FIXHR(0.67480834145500574602/2)

  534. #define COS0_8  FIXHR(0.74453627100229844977/2)

  535. #define COS0_9  FIXHR(0.83934964541552703873/2)

  536. #define COS0_10 FIXHR(0.97256823786196069369/2)

  537. #define COS0_11 FIXHR(1.16943993343288495515/4)

  538. #define COS0_12 FIXHR(1.48416461631416627724/4)

  539. #define COS0_13 FIXHR(2.05778100995341155085/8)

  540. #define COS0_14 FIXHR(3.40760841846871878570/8)

  541. #define COS0_15 FIXHR(10.19000812354805681150/32)

  542. 

  543. #define COS1_0 FIXHR(0.50241928618815570551/2)

  544. #define COS1_1 FIXHR(0.52249861493968888062/2)

  545. #define COS1_2 FIXHR(0.56694403481635770368/2)

  546. #define COS1_3 FIXHR(0.64682178335999012954/2)

  547. #define COS1_4 FIXHR(0.78815462345125022473/2)

  548. #define COS1_5 FIXHR(1.06067768599034747134/4)

  549. #define COS1_6 FIXHR(1.72244709823833392782/4)

  550. #define COS1_7 FIXHR(5.10114861868916385802/16)

  551. 

  552. #define COS2_0 FIXHR(0.50979557910415916894/2)

  553. #define COS2_1 FIXHR(0.60134488693504528054/2)

  554. #define COS2_2 FIXHR(0.89997622313641570463/2)

  555. #define COS2_3 FIXHR(2.56291544774150617881/8)

  556. 

  557. #define COS3_0 FIXHR(0.54119610014619698439/2)

  558. #define COS3_1 FIXHR(1.30656296487637652785/4)

  559. 

  560. #define COS4_0 FIXHR(0.70710678118654752439/2)

  561. 

  562. /* butterfly operator */

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

  564. {\

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

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

  567.     tab[a] = tmp0;\

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

  569. }

  570. 

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

  572. {\

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

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

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

  576. }

  577. 

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

  579. {\

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

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

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

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

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

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

  586. }

  587. 

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

  589. 

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

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

  592. {

  593.     int tmp0, tmp1;

  594. 

  595.     /* pass 1 */

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

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

  598.     /* pass 2 */

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

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

  601.     /* pass 1 */

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

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

  604.     /* pass 2 */

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

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

  607.     /* pass 3 */

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

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

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

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

  612.     /* pass 1 */

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

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

  615.     /* pass 2 */

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

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

  618.     /* pass 1 */

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

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

  621.     /* pass 2 */

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

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

  624.     /* pass 3 */

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

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

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

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

  629.     /* pass 4 */

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

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

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

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

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

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

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

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

  638. 

  639. 

  640. 

  641.     /* pass 1 */

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

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

  644.     /* pass 2 */

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

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

  647.     /* pass 1 */

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

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

  650.     /* pass 2 */

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

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

  653.     /* pass 3 */

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

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

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

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

  658. 

  659.     /* pass 1 */

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

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

  662.     /* pass 2 */

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

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

  665.     /* pass 1 */

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

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

  668.     /* pass 2 */

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

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

  671.     /* pass 3 */

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

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

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

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

  676.     /* pass 4 */

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

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

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

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

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

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

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

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

  685. 

  686.     /* pass 5 */

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

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

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

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

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

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

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

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

  695. 

  696.     /* pass 6 */

  697. 

  698.     ADD( 8, 12);

  699.     ADD(12, 10);

  700.     ADD(10, 14);

  701.     ADD(14,  9);

  702.     ADD( 9, 13);

  703.     ADD(13, 11);

  704.     ADD(11, 15);

  705. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  722. 

  723.     ADD(24, 28);

  724.     ADD(28, 26);

  725.     ADD(26, 30);

  726.     ADD(30, 25);

  727.     ADD(25, 29);

  728.     ADD(29, 27);

  729.     ADD(27, 31);

  730. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  747. }

  748. 

  749. #if FRAC_BITS <= 15

  750. 

  751. static inline int round_sample(int *sum)

  752. {

  753.     int sum1;

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

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

  756.     if (sum1 < OUT_MIN)

  757.         sum1 = OUT_MIN;

  758.     else if (sum1 > OUT_MAX)

  759.         sum1 = OUT_MAX;

  760.     return sum1;

  761. }

  762. 

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

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

  765. 

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

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

  768. 

  769. #else

  770. 

  771. static inline int round_sample(int64_t *sum)

  772. {

  773.     int sum1;

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

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

  776.     if (sum1 < OUT_MIN)

  777.         sum1 = OUT_MIN;

  778.     else if (sum1 > OUT_MAX)

  779.         sum1 = OUT_MAX;

  780.     return sum1;

  781. }

  782. 

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

  784. #endif

  785. 

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

  787. {                                               \

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

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

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

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

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

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

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

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

  796. }

  797. 

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

  799. {                                               \

  800.     int tmp;\

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  825. }

  826. 

  827. void ff_mpa_synth_init(MPA_INT *window)

  828. {

  829.     int i;

  830. 

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

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

  833.         int v;

  834.         v = ff_mpa_enwindow[i];

  835. #if WFRAC_BITS < 16

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

  837. #endif

  838.         window[i] = v;

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

  840.             v = -v;

  841.         if (i != 0)

  842.             window[512 - i] = v;

  843.     }

  844. }

  845. 

  846. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

  847.    32 samples. */

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

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

  850.                          MPA_INT *window, int *dither_state,

  851.                          OUT_INT *samples, int incr,

  852.                          int32_t sb_samples[SBLIMIT])

  853. {

  854.     int32_t tmp[32];

  855.     register MPA_INT *synth_buf;

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

  857.     int j, offset, v;

  858.     OUT_INT *samples2;

  859. #if FRAC_BITS <= 15

  860.     int sum, sum2;

  861. #else

  862.     int64_t sum, sum2;

  863. #endif

  864. 

  865.     dct32(tmp, sb_samples);

  866. 

  867.     offset = *synth_buf_offset;

  868.     synth_buf = synth_buf_ptr + offset;

  869. 

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

  871.         v = tmp[j];

  872. #if FRAC_BITS <= 15

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

  874.            sound */

  875.         v = av_clip_int16(v);

  876. #endif

  877.         synth_buf[j] = v;

  878.     }

  879.     /* copy to avoid wrap */

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

  881. 

  882.     samples2 = samples + 31 * incr;

  883.     w = window;

  884.     w2 = window + 31;

  885. 

  886.     sum = *dither_state;

  887.     p = synth_buf + 16;

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

  889.     p = synth_buf + 48;

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

  891.     *samples = round_sample(&sum);

  892.     samples += incr;

  893.     w++;

  894. 

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

  896.        access per two sample */

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

  898.         sum2 = 0;

  899.         p = synth_buf + 16 + j;

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

  901.         p = synth_buf + 48 - j;

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

  903. 

  904.         *samples = round_sample(&sum);

  905.         samples += incr;

  906.         sum += sum2;

  907.         *samples2 = round_sample(&sum);

  908.         samples2 -= incr;

  909.         w++;

  910.         w2--;

  911.     }

  912. 

  913.     p = synth_buf + 32;

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

  915.     *samples = round_sample(&sum);

  916.     *dither_state= sum;

  917. 

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

  919.     *synth_buf_offset = offset;

  920. }

  921. 

  922. #define C3 FIXHR(0.86602540378443864676/2)

  923. 

  924. /* 0.5 / cos(pi*(2*i+1)/36) */

  925. static const int icos36[9] = {

  926.     FIXR(0.50190991877167369479),

  927.     FIXR(0.51763809020504152469), //0

  928.     FIXR(0.55168895948124587824),

  929.     FIXR(0.61038729438072803416),

  930.     FIXR(0.70710678118654752439), //1

  931.     FIXR(0.87172339781054900991),

  932.     FIXR(1.18310079157624925896),

  933.     FIXR(1.93185165257813657349), //2

  934.     FIXR(5.73685662283492756461),

  935. };

  936. 

  937. /* 0.5 / cos(pi*(2*i+1)/36) */

  938. static const int icos36h[9] = {

  939.     FIXHR(0.50190991877167369479/2),

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

  941.     FIXHR(0.55168895948124587824/2),

  942.     FIXHR(0.61038729438072803416/2),

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

  944.     FIXHR(0.87172339781054900991/2),

  945.     FIXHR(1.18310079157624925896/4),

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

  947. //    FIXHR(5.73685662283492756461),

  948. };

  949. 

  950. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  951.    cases. */

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

  953. {

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

  955. 

  956.     in0= in[0*3];

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

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

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

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

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

  962.     in5 += in3;

  963.     in3 += in1;

  964. 

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

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

  967. 

  968.     t1 = in0 - in4;

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

  970. 

  971.     out[ 7]=

  972.     out[10]= t1 + t2;

  973.     out[ 1]=

  974.     out[ 4]= t1 - t2;

  975. 

  976.     in0 += in4>>1;

  977.     in4 = in0 + in2;

  978.     in5 += 2*in1;

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

  980.     out[ 8]=

  981.     out[ 9]= in4 + in1;

  982.     out[ 2]=

  983.     out[ 3]= in4 - in1;

  984. 

  985.     in0 -= in2;

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

  987.     out[ 0]=

  988.     out[ 5]= in0 - in5;

  989.     out[ 6]=

  990.     out[11]= in0 + in5;

  991. }

  992. 

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

  994. #define C1 FIXHR(0.98480775301220805936/2)

  995. #define C2 FIXHR(0.93969262078590838405/2)

  996. #define C3 FIXHR(0.86602540378443864676/2)

  997. #define C4 FIXHR(0.76604444311897803520/2)

  998. #define C5 FIXHR(0.64278760968653932632/2)

  999. #define C6 FIXHR(0.5/2)

  1000. #define C7 FIXHR(0.34202014332566873304/2)

  1001. #define C8 FIXHR(0.17364817766693034885/2)

  1002. 

  1003. 

  1004. /* using Lee like decomposition followed by hand coded 9 points DCT */

  1005. static void imdct36(int *out, int *buf, int *in, int *win)

  1006. {

  1007.     int i, j, t0, t1, t2, t3, s0, s1, s2, s3;

  1008.     int tmp[18], *tmp1, *in1;

  1009. 

  1010.     for(i=17;i>=1;i--)

  1011.         in[i] += in[i-1];

  1012.     for(i=17;i>=3;i-=2)

  1013.         in[i] += in[i-2];

  1014. 

  1015.     for(j=0;j<2;j++) {

  1016.         tmp1 = tmp + j;

  1017.         in1 = in + j;

  1018. #if 0

  1019. //more accurate but slower

  1020.         int64_t t0, t1, t2, t3;

  1021.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1022. 

  1023.         t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;

  1024.         t1 = in1[2*0] - in1[2*6];

  1025.         tmp1[ 6] = t1 - (t2>>1);

  1026.         tmp1[16] = t1 + t2;

  1027. 

  1028.         t0 = MUL64(2*(in1[2*2] + in1[2*4]),    C2);

  1029.         t1 = MUL64(   in1[2*4] - in1[2*8] , -2*C8);

  1030.         t2 = MUL64(2*(in1[2*2] + in1[2*8]),   -C4);

  1031. 

  1032.         tmp1[10] = (t3 - t0 - t2) >> 32;

  1033.         tmp1[ 2] = (t3 + t0 + t1) >> 32;

  1034.         tmp1[14] = (t3 + t2 - t1) >> 32;

  1035. 

  1036.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1037.         t2 = MUL64(2*(in1[2*1] + in1[2*5]),    C1);

  1038.         t3 = MUL64(   in1[2*5] - in1[2*7] , -2*C7);

  1039.         t0 = MUL64(2*in1[2*3], C3);

  1040. 

  1041.         t1 = MUL64(2*(in1[2*1] + in1[2*7]),   -C5);

  1042. 

  1043.         tmp1[ 0] = (t2 + t3 + t0) >> 32;

  1044.         tmp1[12] = (t2 + t1 - t0) >> 32;

  1045.         tmp1[ 8] = (t3 - t1 - t0) >> 32;

  1046. #else

  1047.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1048. 

  1049.         t3 = in1[2*0] + (in1[2*6]>>1);

  1050.         t1 = in1[2*0] - in1[2*6];

  1051.         tmp1[ 6] = t1 - (t2>>1);

  1052.         tmp1[16] = t1 + t2;

  1053. 

  1054.         t0 = MULH(2*(in1[2*2] + in1[2*4]),    C2);

  1055.         t1 = MULH(   in1[2*4] - in1[2*8] , -2*C8);

  1056.         t2 = MULH(2*(in1[2*2] + in1[2*8]),   -C4);

  1057. 

  1058.         tmp1[10] = t3 - t0 - t2;

  1059.         tmp1[ 2] = t3 + t0 + t1;

  1060.         tmp1[14] = t3 + t2 - t1;

  1061. 

  1062.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1063.         t2 = MULH(2*(in1[2*1] + in1[2*5]),    C1);

  1064.         t3 = MULH(   in1[2*5] - in1[2*7] , -2*C7);

  1065.         t0 = MULH(2*in1[2*3], C3);

  1066. 

  1067.         t1 = MULH(2*(in1[2*1] + in1[2*7]),   -C5);

  1068. 

  1069.         tmp1[ 0] = t2 + t3 + t0;

  1070.         tmp1[12] = t2 + t1 - t0;

  1071.         tmp1[ 8] = t3 - t1 - t0;

  1072. #endif

  1073.     }

  1074. 

  1075.     i = 0;

  1076.     for(j=0;j<4;j++) {

  1077.         t0 = tmp[i];

  1078.         t1 = tmp[i + 2];

  1079.         s0 = t1 + t0;

  1080.         s2 = t1 - t0;

  1081. 

  1082.         t2 = tmp[i + 1];

  1083.         t3 = tmp[i + 3];

  1084.         s1 = MULH(2*(t3 + t2), icos36h[j]);

  1085.         s3 = MULL(t3 - t2, icos36[8 - j]);

  1086. 

  1087.         t0 = s0 + s1;

  1088.         t1 = s0 - s1;

  1089.         out[(9 + j)*SBLIMIT] =  MULH(t1, win[9 + j]) + buf[9 + j];

  1090.         out[(8 - j)*SBLIMIT] =  MULH(t1, win[8 - j]) + buf[8 - j];

  1091.         buf[9 + j] = MULH(t0, win[18 + 9 + j]);

  1092.         buf[8 - j] = MULH(t0, win[18 + 8 - j]);

  1093. 

  1094.         t0 = s2 + s3;

  1095.         t1 = s2 - s3;

  1096.         out[(9 + 8 - j)*SBLIMIT] =  MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];

  1097.         out[(        j)*SBLIMIT] =  MULH(t1, win[        j]) + buf[        j];

  1098.         buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);

  1099.         buf[      + j] = MULH(t0, win[18         + j]);

  1100.         i += 4;

  1101.     }

  1102. 

  1103.     s0 = tmp[16];

  1104.     s1 = MULH(2*tmp[17], icos36h[4]);

  1105.     t0 = s0 + s1;

  1106.     t1 = s0 - s1;

  1107.     out[(9 + 4)*SBLIMIT] =  MULH(t1, win[9 + 4]) + buf[9 + 4];

  1108.     out[(8 - 4)*SBLIMIT] =  MULH(t1, win[8 - 4]) + buf[8 - 4];

  1109.     buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);

  1110.     buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);

  1111. }

  1112. 

  1113. /* return the number of decoded frames */

  1114. static int mp_decode_layer1(MPADecodeContext *s)

  1115. {

  1116.     int bound, i, v, n, ch, j, mant;

  1117.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  1118.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  1119. 

  1120.     if (s->mode == MPA_JSTEREO)

  1121.         bound = (s->mode_ext + 1) * 4;

  1122.     else

  1123.         bound = SBLIMIT;

  1124. 

  1125.     /* allocation bits */

  1126.     for(i=0;i<bound;i++) {

  1127.         for(ch=0;ch<s->nb_channels;ch++) {

  1128.             allocation[ch][i] = get_bits(&s->gb, 4);

  1129.         }

  1130.     }

  1131.     for(i=bound;i<SBLIMIT;i++) {

  1132.         allocation[0][i] = get_bits(&s->gb, 4);

  1133.     }

  1134. 

  1135.     /* scale factors */

  1136.     for(i=0;i<bound;i++) {

  1137.         for(ch=0;ch<s->nb_channels;ch++) {

  1138.             if (allocation[ch][i])

  1139.                 scale_factors[ch][i] = get_bits(&s->gb, 6);

  1140.         }

  1141.     }

  1142.     for(i=bound;i<SBLIMIT;i++) {

  1143.         if (allocation[0][i]) {

  1144.             scale_factors[0][i] = get_bits(&s->gb, 6);

  1145.             scale_factors[1][i] = get_bits(&s->gb, 6);

  1146.         }

  1147.     }

  1148. 

  1149.     /* compute samples */

  1150.     for(j=0;j<12;j++) {

  1151.         for(i=0;i<bound;i++) {

  1152.             for(ch=0;ch<s->nb_channels;ch++) {

  1153.                 n = allocation[ch][i];

  1154.                 if (n) {

  1155.                     mant = get_bits(&s->gb, n + 1);

  1156.                     v = l1_unscale(n, mant, scale_factors[ch][i]);

  1157.                 } else {

  1158.                     v = 0;

  1159.                 }

  1160.                 s->sb_samples[ch][j][i] = v;

  1161.             }

  1162.         }

  1163.         for(i=bound;i<SBLIMIT;i++) {

  1164.             n = allocation[0][i];

  1165.             if (n) {

  1166.                 mant = get_bits(&s->gb, n + 1);

  1167.                 v = l1_unscale(n, mant, scale_factors[0][i]);

  1168.                 s->sb_samples[0][j][i] = v;

  1169.                 v = l1_unscale(n, mant, scale_factors[1][i]);

  1170.                 s->sb_samples[1][j][i] = v;

  1171.             } else {

  1172.                 s->sb_samples[0][j][i] = 0;

  1173.                 s->sb_samples[1][j][i] = 0;

  1174.             }

  1175.         }

  1176.     }

  1177.     return 12;

  1178. }

  1179. 

  1180. static int mp_decode_layer2(MPADecodeContext *s)

  1181. {

  1182.     int sblimit; /* number of used subbands */

  1183.     const unsigned char *alloc_table;

  1184.     int table, bit_alloc_bits, i, j, ch, bound, v;

  1185.     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];

  1186.     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];

  1187.     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;

  1188.     int scale, qindex, bits, steps, k, l, m, b;

  1189. 

  1190.     /* select decoding table */

  1191.     table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,

  1192.                             s->sample_rate, s->lsf);

  1193.     sblimit = ff_mpa_sblimit_table[table];

  1194.     alloc_table = ff_mpa_alloc_tables[table];

  1195. 

  1196.     if (s->mode == MPA_JSTEREO)

  1197.         bound = (s->mode_ext + 1) * 4;

  1198.     else

  1199.         bound = sblimit;

  1200. 

  1201.     dprintf(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);

  1202. 

  1203.     /* sanity check */

  1204.     if( bound > sblimit ) bound = sblimit;

  1205. 

  1206.     /* parse bit allocation */

  1207.     j = 0;

  1208.     for(i=0;i<bound;i++) {

  1209.         bit_alloc_bits = alloc_table[j];

  1210.         for(ch=0;ch<s->nb_channels;ch++) {

  1211.             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);

  1212.         }

  1213.         j += 1 << bit_alloc_bits;

  1214.     }

  1215.     for(i=bound;i<sblimit;i++) {

  1216.         bit_alloc_bits = alloc_table[j];

  1217.         v = get_bits(&s->gb, bit_alloc_bits);

  1218.         bit_alloc[0][i] = v;

  1219.         bit_alloc[1][i] = v;

  1220.         j += 1 << bit_alloc_bits;

  1221.     }

  1222. 

  1223. #ifdef DEBUG

  1224.     {

  1225.         for(ch=0;ch<s->nb_channels;ch++) {

  1226.             for(i=0;i<sblimit;i++)

  1227.                 dprintf(s->avctx, " %d", bit_alloc[ch][i]);

  1228.             dprintf(s->avctx, "\n");

  1229.         }

  1230.     }

  1231. #endif

  1232. 

  1233.     /* scale codes */

  1234.     for(i=0;i<sblimit;i++) {

  1235.         for(ch=0;ch<s->nb_channels;ch++) {

  1236.             if (bit_alloc[ch][i])

  1237.                 scale_code[ch][i] = get_bits(&s->gb, 2);

  1238.         }

  1239.     }

  1240. 

  1241.     /* scale factors */

  1242.     for(i=0;i<sblimit;i++) {

  1243.         for(ch=0;ch<s->nb_channels;ch++) {

  1244.             if (bit_alloc[ch][i]) {

  1245.                 sf = scale_factors[ch][i];

  1246.                 switch(scale_code[ch][i]) {

  1247.                 default:

  1248.                 case 0:

  1249.                     sf[0] = get_bits(&s->gb, 6);

  1250.                     sf[1] = get_bits(&s->gb, 6);

  1251.                     sf[2] = get_bits(&s->gb, 6);

  1252.                     break;

  1253.                 case 2:

  1254.                     sf[0] = get_bits(&s->gb, 6);

  1255.                     sf[1] = sf[0];

  1256.                     sf[2] = sf[0];

  1257.                     break;

  1258.                 case 1:

  1259.                     sf[0] = get_bits(&s->gb, 6);

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

  1261.                     sf[1] = sf[0];

  1262.                     break;

  1263.                 case 3:

  1264.                     sf[0] = get_bits(&s->gb, 6);

  1265.                     sf[2] = get_bits(&s->gb, 6);

  1266.                     sf[1] = sf[2];

  1267.                     break;

  1268.                 }

  1269.             }

  1270.         }

  1271.     }

  1272. 

  1273. #ifdef DEBUG

  1274.     for(ch=0;ch<s->nb_channels;ch++) {

  1275.         for(i=0;i<sblimit;i++) {

  1276.             if (bit_alloc[ch][i]) {

  1277.                 sf = scale_factors[ch][i];

  1278.                 dprintf(s->avctx, " %d %d %d", sf[0], sf[1], sf[2]);

  1279.             } else {

  1280.                 dprintf(s->avctx, " -");

  1281.             }

  1282.         }

  1283.         dprintf(s->avctx, "\n");

  1284.     }

  1285. #endif

  1286. 

  1287.     /* samples */

  1288.     for(k=0;k<3;k++) {

  1289.         for(l=0;l<12;l+=3) {

  1290.             j = 0;

  1291.             for(i=0;i<bound;i++) {

  1292.                 bit_alloc_bits = alloc_table[j];

  1293.                 for(ch=0;ch<s->nb_channels;ch++) {

  1294.                     b = bit_alloc[ch][i];

  1295.                     if (b) {

  1296.                         scale = scale_factors[ch][i][k];

  1297.                         qindex = alloc_table[j+b];

  1298.                         bits = ff_mpa_quant_bits[qindex];

  1299.                         if (bits < 0) {

  1300.                             /* 3 values at the same time */

  1301.                             v = get_bits(&s->gb, -bits);

  1302.                             steps = ff_mpa_quant_steps[qindex];

  1303.                             s->sb_samples[ch][k * 12 + l + 0][i] =

  1304.                                 l2_unscale_group(steps, v % steps, scale);

  1305.                             v = v / steps;

  1306.                             s->sb_samples[ch][k * 12 + l + 1][i] =

  1307.                                 l2_unscale_group(steps, v % steps, scale);

  1308.                             v = v / steps;

  1309.                             s->sb_samples[ch][k * 12 + l + 2][i] =

  1310.                                 l2_unscale_group(steps, v, scale);

  1311.                         } else {

  1312.                             for(m=0;m<3;m++) {

  1313.                                 v = get_bits(&s->gb, bits);

  1314.                                 v = l1_unscale(bits - 1, v, scale);

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

  1316.                             }

  1317.                         }

  1318.                     } else {

  1319.                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1320.                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1321.                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1322.                     }

  1323.                 }

  1324.                 /* next subband in alloc table */

  1325.                 j += 1 << bit_alloc_bits;

  1326.             }

  1327.             /* XXX: find a way to avoid this duplication of code */

  1328.             for(i=bound;i<sblimit;i++) {

  1329.                 bit_alloc_bits = alloc_table[j];

  1330.                 b = bit_alloc[0][i];

  1331.                 if (b) {

  1332.                     int mant, scale0, scale1;

  1333.                     scale0 = scale_factors[0][i][k];

  1334.                     scale1 = scale_factors[1][i][k];

  1335.                     qindex = alloc_table[j+b];

  1336.                     bits = ff_mpa_quant_bits[qindex];

  1337.                     if (bits < 0) {

  1338.                         /* 3 values at the same time */

  1339.                         v = get_bits(&s->gb, -bits);

  1340.                         steps = ff_mpa_quant_steps[qindex];

  1341.                         mant = v % steps;

  1342.                         v = v / steps;

  1343.                         s->sb_samples[0][k * 12 + l + 0][i] =

  1344.                             l2_unscale_group(steps, mant, scale0);

  1345.                         s->sb_samples[1][k * 12 + l + 0][i] =

  1346.                             l2_unscale_group(steps, mant, scale1);

  1347.                         mant = v % steps;

  1348.                         v = v / steps;

  1349.                         s->sb_samples[0][k * 12 + l + 1][i] =

  1350.                             l2_unscale_group(steps, mant, scale0);

  1351.                         s->sb_samples[1][k * 12 + l + 1][i] =

  1352.                             l2_unscale_group(steps, mant, scale1);

  1353.                         s->sb_samples[0][k * 12 + l + 2][i] =

  1354.                             l2_unscale_group(steps, v, scale0);

  1355.                         s->sb_samples[1][k * 12 + l + 2][i] =

  1356.                             l2_unscale_group(steps, v, scale1);

  1357.                     } else {

  1358.                         for(m=0;m<3;m++) {

  1359.                             mant = get_bits(&s->gb, bits);

  1360.                             s->sb_samples[0][k * 12 + l + m][i] =

  1361.                                 l1_unscale(bits - 1, mant, scale0);

  1362.                             s->sb_samples[1][k * 12 + l + m][i] =

  1363.                                 l1_unscale(bits - 1, mant, scale1);

  1364.                         }

  1365.                     }

  1366.                 } else {

  1367.                     s->sb_samples[0][k * 12 + l + 0][i] = 0;

  1368.                     s->sb_samples[0][k * 12 + l + 1][i] = 0;

  1369.                     s->sb_samples[0][k * 12 + l + 2][i] = 0;

  1370.                     s->sb_samples[1][k * 12 + l + 0][i] = 0;

  1371.                     s->sb_samples[1][k * 12 + l + 1][i] = 0;

  1372.                     s->sb_samples[1][k * 12 + l + 2][i] = 0;

  1373.                 }

  1374.                 /* next subband in alloc table */

  1375.                 j += 1 << bit_alloc_bits;

  1376.             }

  1377.             /* fill remaining samples to zero */

  1378.             for(i=sblimit;i<SBLIMIT;i++) {

  1379.                 for(ch=0;ch<s->nb_channels;ch++) {

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

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

  1382.                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1383.                 }

  1384.             }

  1385.         }

  1386.     }

  1387.     return 3 * 12;

  1388. }

  1389. 

  1390. static inline void lsf_sf_expand(int *slen,

  1391.                                  int sf, int n1, int n2, int n3)

  1392. {

  1393.     if (n3) {

  1394.         slen[3] = sf % n3;

  1395.         sf /= n3;

  1396.     } else {

  1397.         slen[3] = 0;

  1398.     }

  1399.     if (n2) {

  1400.         slen[2] = sf % n2;

  1401.         sf /= n2;

  1402.     } else {

  1403.         slen[2] = 0;

  1404.     }

  1405.     slen[1] = sf % n1;

  1406.     sf /= n1;

  1407.     slen[0] = sf;

  1408. }

  1409. 

  1410. static void exponents_from_scale_factors(MPADecodeContext *s,

  1411.                                          GranuleDef *g,

  1412.                                          int16_t *exponents)

  1413. {

  1414.     const uint8_t *bstab, *pretab;

  1415.     int len, i, j, k, l, v0, shift, gain, gains[3];

  1416.     int16_t *exp_ptr;

  1417. 

  1418.     exp_ptr = exponents;

  1419.     gain = g->global_gain - 210;

  1420.     shift = g->scalefac_scale + 1;

  1421. 

  1422.     bstab = band_size_long[s->sample_rate_index];

  1423.     pretab = mpa_pretab[g->preflag];

  1424.     for(i=0;i<g->long_end;i++) {

  1425.         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;

  1426.         len = bstab[i];

  1427.         for(j=len;j>0;j--)

  1428.             *exp_ptr++ = v0;

  1429.     }

  1430. 

  1431.     if (g->short_start < 13) {

  1432.         bstab = band_size_short[s->sample_rate_index];

  1433.         gains[0] = gain - (g->subblock_gain[0] << 3);

  1434.         gains[1] = gain - (g->subblock_gain[1] << 3);

  1435.         gains[2] = gain - (g->subblock_gain[2] << 3);

  1436.         k = g->long_end;

  1437.         for(i=g->short_start;i<13;i++) {

  1438.             len = bstab[i];

  1439.             for(l=0;l<3;l++) {

  1440.                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;

  1441.                 for(j=len;j>0;j--)

  1442.                 *exp_ptr++ = v0;

  1443.             }

  1444.         }

  1445.     }

  1446. }

  1447. 

  1448. /* handle n = 0 too */

  1449. static inline int get_bitsz(GetBitContext *s, int n)

  1450. {

  1451.     if (n == 0)

  1452.         return 0;

  1453.     else

  1454.         return get_bits(s, n);

  1455. }

  1456. 

  1457. 

  1458. static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos, int *end_pos2){

  1459.     if(s->in_gb.buffer && *pos >= s->gb.size_in_bits){

  1460.         s->gb= s->in_gb;

  1461.         s->in_gb.buffer=NULL;

  1462.         assert((get_bits_count(&s->gb) & 7) == 0);

  1463.         skip_bits_long(&s->gb, *pos - *end_pos);

  1464.         *end_pos2=

  1465.         *end_pos= *end_pos2 + get_bits_count(&s->gb) - *pos;

  1466.         *pos= get_bits_count(&s->gb);

  1467.     }

  1468. }

  1469. 

  1470. static int huffman_decode(MPADecodeContext *s, GranuleDef *g,

  1471.                           int16_t *exponents, int end_pos2)

  1472. {

  1473.     int s_index;

  1474.     int i;

  1475.     int last_pos, bits_left;

  1476.     VLC *vlc;

  1477.     int end_pos= FFMIN(end_pos2, s->gb.size_in_bits);

  1478. 

  1479.     /* low frequencies (called big values) */

  1480.     s_index = 0;

  1481.     for(i=0;i<3;i++) {

  1482.         int j, k, l, linbits;

  1483.         j = g->region_size[i];

  1484.         if (j == 0)

  1485.             continue;

  1486.         /* select vlc table */

  1487.         k = g->table_select[i];

  1488.         l = mpa_huff_data[k][0];

  1489.         linbits = mpa_huff_data[k][1];

  1490.         vlc = &huff_vlc[l];

  1491. 

  1492.         if(!l){

  1493.             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*2*j);

  1494.             s_index += 2*j;

  1495.             continue;

  1496.         }

  1497. 

  1498.         /* read huffcode and compute each couple */

  1499.         for(;j>0;j--) {

  1500.             int exponent, x, y, v;

  1501.             int pos= get_bits_count(&s->gb);

  1502. 

  1503.             if (pos >= end_pos){

  1504. //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1505.                 switch_buffer(s, &pos, &end_pos, &end_pos2);

  1506. //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);

  1507.                 if(pos >= end_pos)

  1508.                     break;

  1509.             }

  1510.             y = get_vlc2(&s->gb, vlc->table, 7, 3);

  1511. 

  1512.             if(!y){

  1513.                 g->sb_hybrid[s_index  ] =

  1514.                 g->sb_hybrid[s_index+1] = 0;

  1515.                 s_index += 2;

  1516.                 continue;

  1517.             }

  1518. 

  1519.             exponent= exponents[s_index];

  1520. 

  1521.             dprintf(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",

  1522.                     i, g->region_size[i] - j, x, y, exponent);

  1523.             if(y&16){

  1524.                 x = y >> 5;

  1525.                 y = y & 0x0f;

  1526.                 if (x < 15){

  1527.                     v = expval_table[ exponent ][ x ];

  1528. //                      v = expval_table[ (exponent&3) ][ x ] >> FFMIN(0 - (exponent>>2), 31);

  1529.                 }else{

  1530.                     x += get_bitsz(&s->gb, linbits);

  1531.                     v = l3_unscale(x, exponent);

  1532.                 }

  1533.                 if (get_bits1(&s->gb))

  1534.                     v = -v;

  1535.                 g->sb_hybrid[s_index] = v;

  1536.                 if (y < 15){

  1537.                     v = expval_table[ exponent ][ y ];

  1538.                 }else{

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

  1540.                     v = l3_unscale(y, exponent);

  1541.                 }

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

  1543.                     v = -v;

  1544.                 g->sb_hybrid[s_index+1] = v;

  1545.             }else{

  1546.                 x = y >> 5;

  1547.                 y = y & 0x0f;

  1548.                 x += y;

  1549.                 if (x < 15){

  1550.                     v = expval_table[ exponent ][ x ];

  1551.                 }else{

  1552.                     x += get_bitsz(&s->gb, linbits);

  1553.                     v = l3_unscale(x, exponent);

  1554.                 }

  1555.                 if (get_bits1(&s->gb))

  1556.                     v = -v;

  1557.                 g->sb_hybrid[s_index+!!y] = v;

  1558.                 g->sb_hybrid[s_index+ !y] = 0;

  1559.             }

  1560.             s_index+=2;

  1561.         }

  1562.     }

  1563. 

  1564.     /* high frequencies */

  1565.     vlc = &huff_quad_vlc[g->count1table_select];

  1566.     last_pos=0;

  1567.     while (s_index <= 572) {

  1568.         int pos, code;

  1569.         pos = get_bits_count(&s->gb);

  1570.         if (pos >= end_pos) {

  1571.             if (pos > end_pos2 && last_pos){

  1572.                 /* some encoders generate an incorrect size for this

  1573.                    part. We must go back into the data */

  1574.                 s_index -= 4;

  1575.                 skip_bits_long(&s->gb, last_pos - pos);

  1576.                 av_log(NULL, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);

  1577.                 if(s->error_resilience >= FF_ER_COMPLIANT)

  1578.                     s_index=0;

  1579.                 break;

  1580.             }

  1581. //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1582.             switch_buffer(s, &pos, &end_pos, &end_pos2);

  1583. //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);

  1584.             if(pos >= end_pos)

  1585.                 break;

  1586.         }

  1587.         last_pos= pos;

  1588. 

  1589.         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);

  1590.         dprintf(s->avctx, "t=%d code=%d\n", g->count1table_select, code);

  1591.         g->sb_hybrid[s_index+0]=

  1592.         g->sb_hybrid[s_index+1]=

  1593.         g->sb_hybrid[s_index+2]=

  1594.         g->sb_hybrid[s_index+3]= 0;

  1595.         while(code){

  1596.             static const int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};

  1597.             int v;

  1598.             int pos= s_index+idxtab[code];

  1599.             code ^= 8>>idxtab[code];

  1600.             v = exp_table[ exponents[pos] ];

  1601. //            v = exp_table[ (exponents[pos]&3) ] >> FFMIN(0 - (exponents[pos]>>2), 31);

  1602.             if(get_bits1(&s->gb))

  1603.                 v = -v;

  1604.             g->sb_hybrid[pos] = v;

  1605.         }

  1606.         s_index+=4;

  1607.     }

  1608.     /* skip extension bits */

  1609.     bits_left = end_pos2 - get_bits_count(&s->gb);

  1610. //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);

  1611.     if (bits_left < 0/* || bits_left > 500*/) {

  1612.         av_log(NULL, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1613.         s_index=0;

  1614.     }else if(bits_left > 0 && s->error_resilience >= FF_ER_AGGRESSIVE){

  1615.         av_log(NULL, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1616.         s_index=0;

  1617.     }

  1618.     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*(576 - s_index));

  1619.     skip_bits_long(&s->gb, bits_left);

  1620. 

  1621.     i= get_bits_count(&s->gb);

  1622.     switch_buffer(s, &i, &end_pos, &end_pos2);

  1623. 

  1624.     return 0;

  1625. }

  1626. 

  1627. /* Reorder short blocks from bitstream order to interleaved order. It

  1628.    would be faster to do it in parsing, but the code would be far more

  1629.    complicated */

  1630. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1631. {

  1632.     int i, j, len;

  1633.     int32_t *ptr, *dst, *ptr1;

  1634.     int32_t tmp[576];

  1635. 

  1636.     if (g->block_type != 2)

  1637.         return;

  1638. 

  1639.     if (g->switch_point) {

  1640.         if (s->sample_rate_index != 8) {

  1641.             ptr = g->sb_hybrid + 36;

  1642.         } else {

  1643.             ptr = g->sb_hybrid + 48;

  1644.         }

  1645.     } else {

  1646.         ptr = g->sb_hybrid;

  1647.     }

  1648. 

  1649.     for(i=g->short_start;i<13;i++) {

  1650.         len = band_size_short[s->sample_rate_index][i];

  1651.         ptr1 = ptr;

  1652.         dst = tmp;

  1653.         for(j=len;j>0;j--) {

  1654.             *dst++ = ptr[0*len];

  1655.             *dst++ = ptr[1*len];

  1656.             *dst++ = ptr[2*len];

  1657.             ptr++;

  1658.         }

  1659.         ptr+=2*len;

  1660.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1661.     }

  1662. }

  1663. 

  1664. #define ISQRT2 FIXR(0.70710678118654752440)

  1665. 

  1666. static void compute_stereo(MPADecodeContext *s,

  1667.                            GranuleDef *g0, GranuleDef *g1)

  1668. {

  1669.     int i, j, k, l;

  1670.     int32_t v1, v2;

  1671.     int sf_max, tmp0, tmp1, sf, len, non_zero_found;

  1672.     int32_t (*is_tab)[16];

  1673.     int32_t *tab0, *tab1;

  1674.     int non_zero_found_short[3];

  1675. 

  1676.     /* intensity stereo */

  1677.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1678.         if (!s->lsf) {

  1679.             is_tab = is_table;

  1680.             sf_max = 7;

  1681.         } else {

  1682.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1683.             sf_max = 16;

  1684.         }

  1685. 

  1686.         tab0 = g0->sb_hybrid + 576;

  1687.         tab1 = g1->sb_hybrid + 576;

  1688. 

  1689.         non_zero_found_short[0] = 0;

  1690.         non_zero_found_short[1] = 0;

  1691.         non_zero_found_short[2] = 0;

  1692.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1693.         for(i = 12;i >= g1->short_start;i--) {

  1694.             /* for last band, use previous scale factor */

  1695.             if (i != 11)

  1696.                 k -= 3;

  1697.             len = band_size_short[s->sample_rate_index][i];

  1698.             for(l=2;l>=0;l--) {

  1699.                 tab0 -= len;

  1700.                 tab1 -= len;

  1701.                 if (!non_zero_found_short[l]) {

  1702.                     /* test if non zero band. if so, stop doing i-stereo */

  1703.                     for(j=0;j<len;j++) {

  1704.                         if (tab1[j] != 0) {

  1705.                             non_zero_found_short[l] = 1;

  1706.                             goto found1;

  1707.                         }

  1708.                     }

  1709.                     sf = g1->scale_factors[k + l];

  1710.                     if (sf >= sf_max)

  1711.                         goto found1;

  1712. 

  1713.                     v1 = is_tab[0][sf];

  1714.                     v2 = is_tab[1][sf];

  1715.                     for(j=0;j<len;j++) {

  1716.                         tmp0 = tab0[j];

  1717.                         tab0[j] = MULL(tmp0, v1);

  1718.                         tab1[j] = MULL(tmp0, v2);

  1719.                     }

  1720.                 } else {

  1721.                 found1:

  1722.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1723.                         /* lower part of the spectrum : do ms stereo

  1724.                            if enabled */

  1725.                         for(j=0;j<len;j++) {

  1726.                             tmp0 = tab0[j];

  1727.                             tmp1 = tab1[j];

  1728.                             tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1729.                             tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1730.                         }

  1731.                     }

  1732.                 }

  1733.             }

  1734.         }

  1735. 

  1736.         non_zero_found = non_zero_found_short[0] |

  1737.             non_zero_found_short[1] |

  1738.             non_zero_found_short[2];

  1739. 

  1740.         for(i = g1->long_end - 1;i >= 0;i--) {

  1741.             len = band_size_long[s->sample_rate_index][i];

  1742.             tab0 -= len;

  1743.             tab1 -= len;

  1744.             /* test if non zero band. if so, stop doing i-stereo */

  1745.             if (!non_zero_found) {

  1746.                 for(j=0;j<len;j++) {

  1747.                     if (tab1[j] != 0) {

  1748.                         non_zero_found = 1;

  1749.                         goto found2;

  1750.                     }

  1751.                 }

  1752.                 /* for last band, use previous scale factor */

  1753.                 k = (i == 21) ? 20 : i;

  1754.                 sf = g1->scale_factors[k];

  1755.                 if (sf >= sf_max)

  1756.                     goto found2;

  1757.                 v1 = is_tab[0][sf];

  1758.                 v2 = is_tab[1][sf];

  1759.                 for(j=0;j<len;j++) {

  1760.                     tmp0 = tab0[j];

  1761.                     tab0[j] = MULL(tmp0, v1);

  1762.                     tab1[j] = MULL(tmp0, v2);

  1763.                 }

  1764.             } else {

  1765.             found2:

  1766.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1767.                     /* lower part of the spectrum : do ms stereo

  1768.                        if enabled */

  1769.                     for(j=0;j<len;j++) {

  1770.                         tmp0 = tab0[j];

  1771.                         tmp1 = tab1[j];

  1772.                         tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1773.                         tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1774.                     }

  1775.                 }

  1776.             }

  1777.         }

  1778.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1779.         /* ms stereo ONLY */

  1780.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1781.            global gain */

  1782.         tab0 = g0->sb_hybrid;

  1783.         tab1 = g1->sb_hybrid;

  1784.         for(i=0;i<576;i++) {

  1785.             tmp0 = tab0[i];

  1786.             tmp1 = tab1[i];

  1787.             tab0[i] = tmp0 + tmp1;

  1788.             tab1[i] = tmp0 - tmp1;

  1789.         }

  1790.     }

  1791. }

  1792. 

  1793. static void compute_antialias_integer(MPADecodeContext *s,

  1794.                               GranuleDef *g)

  1795. {

  1796.     int32_t *ptr, *csa;

  1797.     int n, i;

  1798. 

  1799.     /* we antialias only "long" bands */

  1800.     if (g->block_type == 2) {

  1801.         if (!g->switch_point)

  1802.             return;

  1803.         /* XXX: check this for 8000Hz case */

  1804.         n = 1;

  1805.     } else {

  1806.         n = SBLIMIT - 1;

  1807.     }

  1808. 

  1809.     ptr = g->sb_hybrid + 18;

  1810.     for(i = n;i > 0;i--) {

  1811.         int tmp0, tmp1, tmp2;

  1812.         csa = &csa_table[0][0];

  1813. #define INT_AA(j) \

  1814.             tmp0 = ptr[-1-j];\

  1815.             tmp1 = ptr[   j];\

  1816.             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\

  1817.             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\

  1818.             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));

  1819. 

  1820.         INT_AA(0)

  1821.         INT_AA(1)

  1822.         INT_AA(2)

  1823.         INT_AA(3)

  1824.         INT_AA(4)

  1825.         INT_AA(5)

  1826.         INT_AA(6)

  1827.         INT_AA(7)

  1828. 

  1829.         ptr += 18;

  1830.     }

  1831. }

  1832. 

  1833. static void compute_antialias_float(MPADecodeContext *s,

  1834.                               GranuleDef *g)

  1835. {

  1836.     int32_t *ptr;

  1837.     int n, i;

  1838. 

  1839.     /* we antialias only "long" bands */

  1840.     if (g->block_type == 2) {

  1841.         if (!g->switch_point)

  1842.             return;

  1843.         /* XXX: check this for 8000Hz case */

  1844.         n = 1;

  1845.     } else {

  1846.         n = SBLIMIT - 1;

  1847.     }

  1848. 

  1849.     ptr = g->sb_hybrid + 18;

  1850.     for(i = n;i > 0;i--) {

  1851.         float tmp0, tmp1;

  1852.         float *csa = &csa_table_float[0][0];

  1853. #define FLOAT_AA(j)\

  1854.         tmp0= ptr[-1-j];\

  1855.         tmp1= ptr[   j];\

  1856.         ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\

  1857.         ptr[   j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);

  1858. 

  1859.         FLOAT_AA(0)

  1860.         FLOAT_AA(1)

  1861.         FLOAT_AA(2)

  1862.         FLOAT_AA(3)

  1863.         FLOAT_AA(4)

  1864.         FLOAT_AA(5)

  1865.         FLOAT_AA(6)

  1866.         FLOAT_AA(7)

  1867. 

  1868.         ptr += 18;

  1869.     }

  1870. }

  1871. 

  1872. static void compute_imdct(MPADecodeContext *s,

  1873.                           GranuleDef *g,

  1874.                           int32_t *sb_samples,

  1875.                           int32_t *mdct_buf)

  1876. {

  1877.     int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;

  1878.     int32_t out2[12];

  1879.     int i, j, mdct_long_end, v, sblimit;

  1880. 

  1881.     /* find last non zero block */

  1882.     ptr = g->sb_hybrid + 576;

  1883.     ptr1 = g->sb_hybrid + 2 * 18;

  1884.     while (ptr >= ptr1) {

  1885.         ptr -= 6;

  1886.         v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];

  1887.         if (v != 0)

  1888.             break;

  1889.     }

  1890.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  1891. 

  1892.     if (g->block_type == 2) {

  1893.         /* XXX: check for 8000 Hz */

  1894.         if (g->switch_point)

  1895.             mdct_long_end = 2;

  1896.         else

  1897.             mdct_long_end = 0;

  1898.     } else {

  1899.         mdct_long_end = sblimit;

  1900.     }

  1901. 

  1902.     buf = mdct_buf;

  1903.     ptr = g->sb_hybrid;

  1904.     for(j=0;j<mdct_long_end;j++) {

  1905.         /* apply window & overlap with previous buffer */

  1906.         out_ptr = sb_samples + j;

  1907.         /* select window */

  1908.         if (g->switch_point && j < 2)

  1909.             win1 = mdct_win[0];

  1910.         else

  1911.             win1 = mdct_win[g->block_type];

  1912.         /* select frequency inversion */

  1913.         win = win1 + ((4 * 36) & -(j & 1));

  1914.         imdct36(out_ptr, buf, ptr, win);

  1915.         out_ptr += 18*SBLIMIT;

  1916.         ptr += 18;

  1917.         buf += 18;

  1918.     }

  1919.     for(j=mdct_long_end;j<sblimit;j++) {

  1920.         /* select frequency inversion */

  1921.         win = mdct_win[2] + ((4 * 36) & -(j & 1));

  1922.         out_ptr = sb_samples + j;

  1923. 

  1924.         for(i=0; i<6; i++){

  1925.             *out_ptr = buf[i];

  1926.             out_ptr += SBLIMIT;

  1927.         }

  1928.         imdct12(out2, ptr + 0);

  1929.         for(i=0;i<6;i++) {

  1930.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];

  1931.             buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);

  1932.             out_ptr += SBLIMIT;

  1933.         }

  1934.         imdct12(out2, ptr + 1);

  1935.         for(i=0;i<6;i++) {

  1936.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];

  1937.             buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);

  1938.             out_ptr += SBLIMIT;

  1939.         }

  1940.         imdct12(out2, ptr + 2);

  1941.         for(i=0;i<6;i++) {

  1942.             buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];

  1943.             buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);

  1944.             buf[i + 6*2] = 0;

  1945.         }

  1946.         ptr += 18;

  1947.         buf += 18;

  1948.     }

  1949.     /* zero bands */

  1950.     for(j=sblimit;j<SBLIMIT;j++) {

  1951.         /* overlap */

  1952.         out_ptr = sb_samples + j;

  1953.         for(i=0;i<18;i++) {

  1954.             *out_ptr = buf[i];

  1955.             buf[i] = 0;

  1956.             out_ptr += SBLIMIT;

  1957.         }

  1958.         buf += 18;

  1959.     }

  1960. }

  1961. 

  1962. #if defined(DEBUG)

  1963. void sample_dump(int fnum, int32_t *tab, int n)

  1964. {

  1965.     static FILE *files[16], *f;

  1966.     char buf[512];

  1967.     int i;

  1968.     int32_t v;

  1969. 

  1970.     f = files[fnum];

  1971.     if (!f) {

  1972.         snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm",

  1973.                 fnum,

  1974. #ifdef USE_HIGHPRECISION

  1975.                 "hp"

  1976. #else

  1977.                 "lp"

  1978. #endif

  1979.                 );

  1980.         f = fopen(buf, "w");

  1981.         if (!f)

  1982.             return;

  1983.         files[fnum] = f;

  1984.     }

  1985. 

  1986.     if (fnum == 0) {

  1987.         static int pos = 0;

  1988.         av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos);

  1989.         for(i=0;i<n;i++) {

  1990.             av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE);

  1991.             if ((i % 18) == 17)

  1992.                 av_log(NULL, AV_LOG_DEBUG, "\n");

  1993.         }

  1994.         pos += n;

  1995.     }

  1996.     for(i=0;i<n;i++) {

  1997.         /* normalize to 23 frac bits */

  1998.         v = tab[i] << (23 - FRAC_BITS);

  1999.         fwrite(&v, 1, sizeof(int32_t), f);

  2000.     }

  2001. }

  2002. #endif

  2003. 

  2004. 

  2005. /* main layer3 decoding function */

  2006. static int mp_decode_layer3(MPADecodeContext *s)

  2007. {

  2008.     int nb_granules, main_data_begin, private_bits;

  2009.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  2010.     GranuleDef granules[2][2], *g;

  2011.     int16_t exponents[576];

  2012. 

  2013.     /* read side info */

  2014.     if (s->lsf) {

  2015.         main_data_begin = get_bits(&s->gb, 8);

  2016.         private_bits = get_bits(&s->gb, s->nb_channels);

  2017.         nb_granules = 1;

  2018.     } else {

  2019.         main_data_begin = get_bits(&s->gb, 9);

  2020.         if (s->nb_channels == 2)

  2021.             private_bits = get_bits(&s->gb, 3);

  2022.         else

  2023.             private_bits = get_bits(&s->gb, 5);

  2024.         nb_granules = 2;

  2025.         for(ch=0;ch<s->nb_channels;ch++) {

  2026.             granules[ch][0].scfsi = 0; /* all scale factors are transmitted */

  2027.             granules[ch][1].scfsi = get_bits(&s->gb, 4);

  2028.         }

  2029.     }

  2030. 

  2031.     for(gr=0;gr<nb_granules;gr++) {

  2032.         for(ch=0;ch<s->nb_channels;ch++) {

  2033.             dprintf(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);

  2034.             g = &granules[ch][gr];

  2035.             g->part2_3_length = get_bits(&s->gb, 12);

  2036.             g->big_values = get_bits(&s->gb, 9);

  2037.             if(g->big_values > 288){

  2038.                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");

  2039.                 return -1;

  2040.             }

  2041. 

  2042.             g->global_gain = get_bits(&s->gb, 8);

  2043.             /* if MS stereo only is selected, we precompute the

  2044.                1/sqrt(2) renormalization factor */

  2045.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  2046.                 MODE_EXT_MS_STEREO)

  2047.                 g->global_gain -= 2;

  2048.             if (s->lsf)

  2049.                 g->scalefac_compress = get_bits(&s->gb, 9);

  2050.             else

  2051.                 g->scalefac_compress = get_bits(&s->gb, 4);

  2052.             blocksplit_flag = get_bits1(&s->gb);

  2053.             if (blocksplit_flag) {

  2054.                 g->block_type = get_bits(&s->gb, 2);

  2055.                 if (g->block_type == 0){

  2056.                     av_log(NULL, AV_LOG_ERROR, "invalid block type\n");

  2057.                     return -1;

  2058.                 }

  2059.                 g->switch_point = get_bits1(&s->gb);

  2060.                 for(i=0;i<2;i++)

  2061.                     g->table_select[i] = get_bits(&s->gb, 5);

  2062.                 for(i=0;i<3;i++)

  2063.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  2064.                 ff_init_short_region(s, g);

  2065.             } else {

  2066.                 int region_address1, region_address2;

  2067.                 g->block_type = 0;

  2068.                 g->switch_point = 0;

  2069.                 for(i=0;i<3;i++)

  2070.                     g->table_select[i] = get_bits(&s->gb, 5);

  2071.                 /* compute huffman coded region sizes */

  2072.                 region_address1 = get_bits(&s->gb, 4);

  2073.                 region_address2 = get_bits(&s->gb, 3);

  2074.                 dprintf(s->avctx, "region1=%d region2=%d\n",

  2075.                         region_address1, region_address2);

  2076.                 ff_init_long_region(s, g, region_address1, region_address2);

  2077.             }

  2078.             ff_region_offset2size(g);

  2079.             ff_compute_band_indexes(s, g);

  2080. 

  2081.             g->preflag = 0;

  2082.             if (!s->lsf)

  2083.                 g->preflag = get_bits1(&s->gb);

  2084.             g->scalefac_scale = get_bits1(&s->gb);

  2085.             g->count1table_select = get_bits1(&s->gb);

  2086.             dprintf(s->avctx, "block_type=%d switch_point=%d\n",

  2087.                     g->block_type, g->switch_point);

  2088.         }

  2089.     }

  2090. 

  2091.   if (!s->adu_mode) {

  2092.     const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  2093.     assert((get_bits_count(&s->gb) & 7) == 0);

  2094.     /* now we get bits from the main_data_begin offset */

  2095.     dprintf(s->avctx, "seekback: %d\n", main_data_begin);

  2096. //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);

  2097. 

  2098.     memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);

  2099.     s->in_gb= s->gb;

  2100.         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);

  2101.         skip_bits_long(&s->gb, 8*(s->last_buf_size - main_data_begin));

  2102.   }

  2103. 

  2104.     for(gr=0;gr<nb_granules;gr++) {

  2105.         for(ch=0;ch<s->nb_channels;ch++) {

  2106.             g = &granules[ch][gr];

  2107.             if(get_bits_count(&s->gb)<0){

  2108.                 av_log(NULL, AV_LOG_ERROR, "mdb:%d, lastbuf:%d skipping granule %d\n",

  2109.                                             main_data_begin, s->last_buf_size, gr);

  2110.                 skip_bits_long(&s->gb, g->part2_3_length);

  2111.                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));

  2112.                 if(get_bits_count(&s->gb) >= s->gb.size_in_bits && s->in_gb.buffer){

  2113.                     skip_bits_long(&s->in_gb, get_bits_count(&s->gb) - s->gb.size_in_bits);

  2114.                     s->gb= s->in_gb;

  2115.                     s->in_gb.buffer=NULL;

  2116.                 }

  2117.                 continue;

  2118.             }

  2119. 

  2120.             bits_pos = get_bits_count(&s->gb);

  2121. 

  2122.             if (!s->lsf) {

  2123.                 uint8_t *sc;

  2124.                 int slen, slen1, slen2;

  2125. 

  2126.                 /* MPEG1 scale factors */

  2127.                 slen1 = slen_table[0][g->scalefac_compress];

  2128.                 slen2 = slen_table[1][g->scalefac_compress];

  2129.                 dprintf(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);

  2130.                 if (g->block_type == 2) {

  2131.                     n = g->switch_point ? 17 : 18;

  2132.                     j = 0;

  2133.                     if(slen1){

  2134.                         for(i=0;i<n;i++)

  2135.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  2136.                     }else{

  2137.                         for(i=0;i<n;i++)

  2138.                             g->scale_factors[j++] = 0;

  2139.                     }

  2140.                     if(slen2){

  2141.                         for(i=0;i<18;i++)

  2142.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  2143.                         for(i=0;i<3;i++)

  2144.                             g->scale_factors[j++] = 0;

  2145.                     }else{

  2146.                         for(i=0;i<21;i++)

  2147.                             g->scale_factors[j++] = 0;

  2148.                     }

  2149.                 } else {

  2150.                     sc = granules[ch][0].scale_factors;

  2151.                     j = 0;

  2152.                     for(k=0;k<4;k++) {

  2153.                         n = (k == 0 ? 6 : 5);

  2154.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  2155.                             slen = (k < 2) ? slen1 : slen2;

  2156.                             if(slen){

  2157.                                 for(i=0;i<n;i++)

  2158.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  2159.                             }else{

  2160.                                 for(i=0;i<n;i++)

  2161.                                     g->scale_factors[j++] = 0;

  2162.                             }

  2163.                         } else {

  2164.                             /* simply copy from last granule */

  2165.                             for(i=0;i<n;i++) {

  2166.                                 g->scale_factors[j] = sc[j];

  2167.                                 j++;

  2168.                             }

  2169.                         }

  2170.                     }

  2171.                     g->scale_factors[j++] = 0;

  2172.                 }

  2173. #if defined(DEBUG)

  2174.                 {

  2175.                     dprintf(s->avctx, "scfsi=%x gr=%d ch=%d scale_factors:\n",

  2176.                            g->scfsi, gr, ch);

  2177.                     for(i=0;i<j;i++)

  2178.                         dprintf(s->avctx, " %d", g->scale_factors[i]);

  2179.                     dprintf(s->avctx, "\n");

  2180.                 }

  2181. #endif

  2182.             } else {

  2183.                 int tindex, tindex2, slen[4], sl, sf;

  2184. 

  2185.                 /* LSF scale factors */

  2186.                 if (g->block_type == 2) {

  2187.                     tindex = g->switch_point ? 2 : 1;

  2188.                 } else {

  2189.                     tindex = 0;

  2190.                 }

  2191.                 sf = g->scalefac_compress;

  2192.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  2193.                     /* intensity stereo case */

  2194.                     sf >>= 1;

  2195.                     if (sf < 180) {

  2196.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  2197.                         tindex2 = 3;

  2198.                     } else if (sf < 244) {

  2199.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  2200.                         tindex2 = 4;

  2201.                     } else {

  2202.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  2203.                         tindex2 = 5;

  2204.                     }

  2205.                 } else {

  2206.                     /* normal case */

  2207.                     if (sf < 400) {

  2208.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  2209.                         tindex2 = 0;

  2210.                     } else if (sf < 500) {

  2211.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  2212.                         tindex2 = 1;

  2213.                     } else {

  2214.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  2215.                         tindex2 = 2;

  2216.                         g->preflag = 1;

  2217.                     }

  2218.                 }

  2219. 

  2220.                 j = 0;

  2221.                 for(k=0;k<4;k++) {

  2222.                     n = lsf_nsf_table[tindex2][tindex][k];

  2223.                     sl = slen[k];

  2224.                     if(sl){

  2225.                         for(i=0;i<n;i++)

  2226.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  2227.                     }else{

  2228.                         for(i=0;i<n;i++)

  2229.                             g->scale_factors[j++] = 0;

  2230.                     }

  2231.                 }

  2232.                 /* XXX: should compute exact size */

  2233.                 for(;j<40;j++)

  2234.                     g->scale_factors[j] = 0;

  2235. #if defined(DEBUG)

  2236.                 {

  2237.                     dprintf(s->avctx, "gr=%d ch=%d scale_factors:\n",

  2238.                            gr, ch);

  2239.                     for(i=0;i<40;i++)

  2240.                         dprintf(s->avctx, " %d", g->scale_factors[i]);

  2241.                     dprintf(s->avctx, "\n");

  2242.                 }

  2243. #endif

  2244.             }

  2245. 

  2246.             exponents_from_scale_factors(s, g, exponents);

  2247. 

  2248.             /* read Huffman coded residue */

  2249.             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);

  2250. #if defined(DEBUG)

  2251.             sample_dump(0, g->sb_hybrid, 576);

  2252. #endif

  2253.         } /* ch */

  2254. 

  2255.         if (s->nb_channels == 2)

  2256.             compute_stereo(s, &granules[0][gr], &granules[1][gr]);

  2257. 

  2258.         for(ch=0;ch<s->nb_channels;ch++) {

  2259.             g = &granules[ch][gr];

  2260. 

  2261.             reorder_block(s, g);

  2262. #if defined(DEBUG)

  2263.             sample_dump(0, g->sb_hybrid, 576);

  2264. #endif

  2265.             s->compute_antialias(s, g);

  2266. #if defined(DEBUG)

  2267.             sample_dump(1, g->sb_hybrid, 576);

  2268. #endif

  2269.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  2270. #if defined(DEBUG)

  2271.             sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);

  2272. #endif

  2273.         }

  2274.     } /* gr */

  2275.     if(get_bits_count(&s->gb)<0)

  2276.         skip_bits_long(&s->gb, -get_bits_count(&s->gb));

  2277.     return nb_granules * 18;

  2278. }

  2279. 

  2280. static int mp_decode_frame(MPADecodeContext *s,

  2281.                            OUT_INT *samples, const uint8_t *buf, int buf_size)

  2282. {

  2283.     int i, nb_frames, ch;

  2284.     OUT_INT *samples_ptr;

  2285. 

  2286.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)*8);

  2287. 

  2288.     /* skip error protection field */

  2289.     if (s->error_protection)

  2290.         skip_bits(&s->gb, 16);

  2291. 

  2292.     dprintf(s->avctx, "frame %d:\n", s->frame_count);

  2293.     switch(s->layer) {

  2294.     case 1:

  2295.         s->avctx->frame_size = 384;

  2296.         nb_frames = mp_decode_layer1(s);

  2297.         break;

  2298.     case 2:

  2299.         s->avctx->frame_size = 1152;

  2300.         nb_frames = mp_decode_layer2(s);

  2301.         break;

  2302.     case 3:

  2303.         s->avctx->frame_size = s->lsf ? 576 : 1152;

  2304.     default:

  2305.         nb_frames = mp_decode_layer3(s);

  2306. 

  2307.         s->last_buf_size=0;

  2308.         if(s->in_gb.buffer){

  2309.             align_get_bits(&s->gb);

  2310.             i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;

  2311.             if(i >= 0 && i <= BACKSTEP_SIZE){

  2312.                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);

  2313.                 s->last_buf_size=i;

  2314.             }else

  2315.                 av_log(NULL, AV_LOG_ERROR, "invalid old backstep %d\n", i);

  2316.             s->gb= s->in_gb;

  2317.             s->in_gb.buffer= NULL;

  2318.         }

  2319. 

  2320.         align_get_bits(&s->gb);

  2321.         assert((get_bits_count(&s->gb) & 7) == 0);

  2322.         i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;

  2323. 

  2324.         if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){

  2325.             av_log(NULL, AV_LOG_ERROR, "invalid new backstep %d\n", i);

  2326.             i= FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);

  2327.         }

  2328.         assert(i <= buf_size - HEADER_SIZE && i>= 0);

  2329.         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);

  2330.         s->last_buf_size += i;

  2331. 

  2332.         break;

  2333.     }

  2334. #if defined(DEBUG)

  2335.     for(i=0;i<nb_frames;i++) {

  2336.         for(ch=0;ch<s->nb_channels;ch++) {

  2337.             int j;

  2338.             dprintf(s->avctx, "%d-%d:", i, ch);

  2339.             for(j=0;j<SBLIMIT;j++)

  2340.                 dprintf(s->avctx, " %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);

  2341.             dprintf(s->avctx, "\n");

  2342.         }

  2343.     }

  2344. #endif

  2345.     /* apply the synthesis filter */

  2346.     for(ch=0;ch<s->nb_channels;ch++) {

  2347.         samples_ptr = samples + ch;

  2348.         for(i=0;i<nb_frames;i++) {

  2349.             ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  2350.                          window, &s->dither_state,

  2351.                          samples_ptr, s->nb_channels,

  2352.                          s->sb_samples[ch][i]);

  2353.             samples_ptr += 32 * s->nb_channels;

  2354.         }

  2355.     }

  2356. #ifdef DEBUG

  2357.     s->frame_count++;

  2358. #endif

  2359.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  2360. }

  2361. 

  2362. static int decode_frame(AVCodecContext * avctx,

  2363.                         void *data, int *data_size,

  2364.                         const uint8_t * buf, int buf_size)

  2365. {

  2366.     MPADecodeContext *s = avctx->priv_data;

  2367.     uint32_t header;

  2368.     int out_size;

  2369.     OUT_INT *out_samples = data;

  2370. 

  2371. retry:

  2372.     if(buf_size < HEADER_SIZE)

  2373.         return -1;

  2374. 

  2375.     header = AV_RB32(buf);

  2376.     if(ff_mpa_check_header(header) < 0){

  2377.         buf++;

  2378. //        buf_size--;

  2379.         av_log(avctx, AV_LOG_ERROR, "Header missing skipping one byte.\n");

  2380.         goto retry;

  2381.     }

  2382. 

  2383.     if (ff_mpegaudio_decode_header(s, header) == 1) {

  2384.         /* free format: prepare to compute frame size */

  2385.         s->frame_size = -1;

  2386.         return -1;

  2387.     }

  2388.     /* update codec info */

  2389.     avctx->channels = s->nb_channels;

  2390.     avctx->bit_rate = s->bit_rate;

  2391.     avctx->sub_id = s->layer;

  2392. 

  2393.     if(s->frame_size<=0 || s->frame_size > buf_size){

  2394.         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

  2395.         return -1;

  2396.     }else if(s->frame_size < buf_size){

  2397.         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");

  2398.         buf_size= s->frame_size;

  2399.     }

  2400. 

  2401.     out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2402.     if(out_size>=0){

  2403.         *data_size = out_size;

  2404.         avctx->sample_rate = s->sample_rate;

  2405.         //FIXME maybe move the other codec info stuff from above here too

  2406.     }else

  2407.         av_log(avctx, AV_LOG_DEBUG, "Error while decoding MPEG audio frame.\n"); //FIXME return -1 / but also return the number of bytes consumed

  2408.     s->frame_size = 0;

  2409.     return buf_size;

  2410. }

  2411. 

  2412. static void flush(AVCodecContext *avctx){

  2413.     MPADecodeContext *s = avctx->priv_data;

  2414.     memset(s->synth_buf, 0, sizeof(s->synth_buf));

  2415.     s->last_buf_size= 0;

  2416. }

  2417. 

  2418. #ifdef CONFIG_MP3ADU_DECODER

  2419. static int decode_frame_adu(AVCodecContext * avctx,

  2420.                         void *data, int *data_size,

  2421.                         const uint8_t * buf, int buf_size)

  2422. {

  2423.     MPADecodeContext *s = avctx->priv_data;

  2424.     uint32_t header;

  2425.     int len, out_size;

  2426.     OUT_INT *out_samples = data;

  2427. 

  2428.     len = buf_size;

  2429. 

  2430.     // Discard too short frames

  2431.     if (buf_size < HEADER_SIZE) {

  2432.         *data_size = 0;

  2433.         return buf_size;

  2434.     }

  2435. 

  2436. 

  2437.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  2438.         len = MPA_MAX_CODED_FRAME_SIZE;

  2439. 

  2440.     // Get header and restore sync word

  2441.     header = AV_RB32(buf) | 0xffe00000;

  2442. 

  2443.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  2444.         *data_size = 0;

  2445.         return buf_size;

  2446.     }

  2447. 

  2448.     ff_mpegaudio_decode_header(s, header);

  2449.     /* update codec info */

  2450.     avctx->sample_rate = s->sample_rate;

  2451.     avctx->channels = s->nb_channels;

  2452.     avctx->bit_rate = s->bit_rate;

  2453.     avctx->sub_id = s->layer;

  2454. 

  2455.     s->frame_size = len;

  2456. 

  2457.     if (avctx->parse_only) {

  2458.         out_size = buf_size;

  2459.     } else {

  2460.         out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2461.     }

  2462. 

  2463.     *data_size = out_size;

  2464.     return buf_size;

  2465. }

  2466. #endif /* CONFIG_MP3ADU_DECODER */

  2467. 

  2468. #ifdef CONFIG_MP3ON4_DECODER

  2469. 

  2470. /**

  2471.  * Context for MP3On4 decoder

  2472.  */

  2473. typedef struct MP3On4DecodeContext {

  2474.     int frames;   ///< number of mp3 frames per block (number of mp3 decoder instances)

  2475.     int syncword; ///< syncword patch

  2476.     const uint8_t *coff; ///< channels offsets in output buffer

  2477.     MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance

  2478. } MP3On4DecodeContext;

  2479. 

  2480. #include "mpeg4audio.h"

  2481. 

  2482. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  2483. static const uint8_t mp3Frames[8] = {0,1,1,2,3,3,4,5};   /* number of mp3 decoder instances */

  2484. /* offsets into output buffer, assume output order is FL FR BL BR C LFE */

  2485. static const uint8_t chan_offset[8][5] = {

  2486.     {0},

  2487.     {0},            // C

  2488.     {0},            // FLR

  2489.     {2,0},          // C FLR

  2490.     {2,0,3},        // C FLR BS

  2491.     {4,0,2},        // C FLR BLRS

  2492.     {4,0,2,5},      // C FLR BLRS LFE

  2493.     {4,0,2,6,5},    // C FLR BLRS BLR LFE

  2494. };

  2495. 

  2496. 

  2497. static int decode_init_mp3on4(AVCodecContext * avctx)

  2498. {

  2499.     MP3On4DecodeContext *s = avctx->priv_data;

  2500.     MPEG4AudioConfig cfg;

  2501.     int i;

  2502. 

  2503.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  2504.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  2505.         return -1;

  2506.     }

  2507. 

  2508.     ff_mpeg4audio_get_config(&cfg, avctx->extradata, avctx->extradata_size);

  2509.     if (!cfg.chan_config || cfg.chan_config > 7) {

  2510.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  2511.         return -1;

  2512.     }

  2513.     s->frames = mp3Frames[cfg.chan_config];

  2514.     s->coff = chan_offset[cfg.chan_config];

  2515.     avctx->channels = ff_mpeg4audio_channels[cfg.chan_config];

  2516. 

  2517.     if (cfg.sample_rate < 16000)

  2518.         s->syncword = 0xffe00000;

  2519.     else

  2520.         s->syncword = 0xfff00000;

  2521. 

  2522.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  2523.      * We replace avctx->priv_data with the context of the first decoder so that

  2524.      * decode_init() does not have to be changed.

  2525.      * Other decoders will be initialized here copying data from the first context

  2526.      */

  2527.     // Allocate zeroed memory for the first decoder context

  2528.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  2529.     // Put decoder context in place to make init_decode() happy

  2530.     avctx->priv_data = s->mp3decctx[0];

  2531.     decode_init(avctx);

  2532.     // Restore mp3on4 context pointer

  2533.     avctx->priv_data = s;

  2534.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  2535. 

  2536.     /* Create a separate codec/context for each frame (first is already ok).

  2537.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  2538.      */

  2539.     for (i = 1; i < s->frames; i++) {

  2540.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  2541.         s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;

  2542.         s->mp3decctx[i]->adu_mode = 1;

  2543.         s->mp3decctx[i]->avctx = avctx;

  2544.     }

  2545. 

  2546.     return 0;

  2547. }

  2548. 

  2549. 

  2550. static int decode_close_mp3on4(AVCodecContext * avctx)

  2551. {

  2552.     MP3On4DecodeContext *s = avctx->priv_data;

  2553.     int i;

  2554. 

  2555.     for (i = 0; i < s->frames; i++)

  2556.         if (s->mp3decctx[i])

  2557.             av_free(s->mp3decctx[i]);

  2558. 

  2559.     return 0;

  2560. }

  2561. 

  2562. 

  2563. static int decode_frame_mp3on4(AVCodecContext * avctx,

  2564.                         void *data, int *data_size,

  2565.                         const uint8_t * buf, int buf_size)

  2566. {

  2567.     MP3On4DecodeContext *s = avctx->priv_data;

  2568.     MPADecodeContext *m;

  2569.     int fsize, len = buf_size, out_size = 0;

  2570.     uint32_t header;

  2571.     OUT_INT *out_samples = data;

  2572.     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];

  2573.     OUT_INT *outptr, *bp;

  2574.     int fr, j, n;

  2575. 

  2576.     *data_size = 0;

  2577.     // Discard too short frames

  2578.     if (buf_size < HEADER_SIZE)

  2579.         return -1;

  2580. 

  2581.     // If only one decoder interleave is not needed

  2582.     outptr = s->frames == 1 ? out_samples : decoded_buf;

  2583. 

  2584.     avctx->bit_rate = 0;

  2585. 

  2586.     for (fr = 0; fr < s->frames; fr++) {

  2587.         fsize = AV_RB16(buf) >> 4;

  2588.         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);

  2589.         m = s->mp3decctx[fr];

  2590.         assert (m != NULL);

  2591. 

  2592.         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header

  2593. 

  2594.         if (ff_mpa_check_header(header) < 0) // Bad header, discard block

  2595.             break;

  2596. 

  2597.         ff_mpegaudio_decode_header(m, header);

  2598.         out_size += mp_decode_frame(m, outptr, buf, fsize);

  2599.         buf += fsize;

  2600.         len -= fsize;

  2601. 

  2602.         if(s->frames > 1) {

  2603.             n = m->avctx->frame_size*m->nb_channels;

  2604.             /* interleave output data */

  2605.             bp = out_samples + s->coff[fr];

  2606.             if(m->nb_channels == 1) {

  2607.                 for(j = 0; j < n; j++) {

  2608.                     *bp = decoded_buf[j];

  2609.                     bp += avctx->channels;

  2610.                 }

  2611.             } else {

  2612.                 for(j = 0; j < n; j++) {

  2613.                     bp[0] = decoded_buf[j++];

  2614.                     bp[1] = decoded_buf[j];

  2615.                     bp += avctx->channels;

  2616.                 }

  2617.             }

  2618.         }

  2619.         avctx->bit_rate += m->bit_rate;

  2620.     }

  2621. 

  2622.     /* update codec info */

  2623.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  2624. 

  2625.     *data_size = out_size;

  2626.     return buf_size;

  2627. }

  2628. #endif /* CONFIG_MP3ON4_DECODER */

  2629. 

  2630. #ifdef CONFIG_MP2_DECODER

  2631. AVCodec mp2_decoder =

  2632. {

  2633.     "mp2",

  2634.     CODEC_TYPE_AUDIO,

  2635.     CODEC_ID_MP2,

  2636.     sizeof(MPADecodeContext),

  2637.     decode_init,

  2638.     NULL,

  2639.     NULL,

  2640.     decode_frame,

  2641.     CODEC_CAP_PARSE_ONLY,

  2642.     .flush= flush,

  2643.     .long_name= NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),

  2644. };

  2645. #endif

  2646. #ifdef CONFIG_MP3_DECODER

  2647. AVCodec mp3_decoder =

  2648. {

  2649.     "mp3",

  2650.     CODEC_TYPE_AUDIO,

  2651.     CODEC_ID_MP3,

  2652.     sizeof(MPADecodeContext),

  2653.     decode_init,

  2654.     NULL,

  2655.     NULL,

  2656.     decode_frame,

  2657.     CODEC_CAP_PARSE_ONLY,

  2658.     .flush= flush,

  2659.     .long_name= NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),

  2660. };

  2661. #endif

  2662. #ifdef CONFIG_MP3ADU_DECODER

  2663. AVCodec mp3adu_decoder =

  2664. {

  2665.     "mp3adu",

  2666.     CODEC_TYPE_AUDIO,

  2667.     CODEC_ID_MP3ADU,

  2668.     sizeof(MPADecodeContext),

  2669.     decode_init,

  2670.     NULL,

  2671.     NULL,

  2672.     decode_frame_adu,

  2673.     CODEC_CAP_PARSE_ONLY,

  2674.     .flush= flush,

  2675.     .long_name= NULL_IF_CONFIG_SMALL("ADU (Application Data Unit) MP3 (MPEG audio layer 3)"),

  2676. };

  2677. #endif

  2678. #ifdef CONFIG_MP3ON4_DECODER

  2679. AVCodec mp3on4_decoder =

  2680. {

  2681.     "mp3on4",

  2682.     CODEC_TYPE_AUDIO,

  2683.     CODEC_ID_MP3ON4,

  2684.     sizeof(MP3On4DecodeContext),

  2685.     decode_init_mp3on4,

  2686.     NULL,

  2687.     decode_close_mp3on4,

  2688.     decode_frame_mp3on4,

  2689.     .flush= flush,

  2690.     .long_name= NULL_IF_CONFIG_SMALL("MP3onMP4"),

  2691. };

  2692. #endif