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FFmpeg/libavcodec/mpegaudiodec.c

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  1. /*

  2.  * MPEG Audio decoder

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

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

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

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

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

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

  11.  *

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

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

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

  15.  * Lesser General Public License for more details.

  16.  *

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

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

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

  20.  */

  21. 

  22. /**

  23.  * @file

  24.  * MPEG Audio decoder.

  25.  */

  26. 

  27. #include "libavutil/audioconvert.h"

  28. #include "avcodec.h"

  29. #include "get_bits.h"

  30. #include "dsputil.h"

  31. #include "mathops.h"

  32. #include "dct32.h"

  33. 

  34. /*

  35.  * TODO:

  36.  *  - test lsf / mpeg25 extensively.

  37.  */

  38. 

  39. #include "mpegaudio.h"

  40. #include "mpegaudiodecheader.h"

  41. 

  42. #if CONFIG_FLOAT

  43. #   define SHR(a,b)       ((a)*(1.0f/(1<<(b))))

  44. #   define FIXR_OLD(a)    ((int)((a) * FRAC_ONE + 0.5))

  45. #   define FIXR(x)        ((float)(x))

  46. #   define FIXHR(x)       ((float)(x))

  47. #   define MULH3(x, y, s) ((s)*(y)*(x))

  48. #   define MULLx(x, y, s) ((y)*(x))

  49. #   define RENAME(a) a ## _float

  50. #   define OUT_FMT AV_SAMPLE_FMT_FLT

  51. #else

  52. #   define SHR(a,b)       ((a)>>(b))

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

  54. #   define FIXR_OLD(a)    ((int)((a) * FRAC_ONE + 0.5))

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

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

  57. #   define MULH3(x, y, s) MULH((s)*(x), y)

  58. #   define MULLx(x, y, s) MULL(x,y,s)

  59. #   define RENAME(a)      a ## _fixed

  60. #   define OUT_FMT AV_SAMPLE_FMT_S16

  61. #endif

  62. 

  63. /****************/

  64. 

  65. #define HEADER_SIZE 4

  66. 

  67. #include "mpegaudiodata.h"

  68. #include "mpegaudiodectab.h"

  69. 

  70. static void RENAME(compute_antialias)(MPADecodeContext *s, GranuleDef *g);

  71. static void apply_window_mp3_c(MPA_INT *synth_buf, MPA_INT *window,

  72.                                int *dither_state, OUT_INT *samples, int incr);

  73. 

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

  75. static VLC huff_vlc[16];

  76. static VLC_TYPE huff_vlc_tables[

  77.   0+128+128+128+130+128+154+166+

  78.   142+204+190+170+542+460+662+414

  79.   ][2];

  80. static const int huff_vlc_tables_sizes[16] = {

  81.   0, 128, 128, 128, 130, 128, 154, 166,

  82.   142, 204, 190, 170, 542, 460, 662, 414

  83. };

  84. static VLC huff_quad_vlc[2];

  85. static VLC_TYPE huff_quad_vlc_tables[128+16][2];

  86. static const int huff_quad_vlc_tables_sizes[2] = {

  87.   128, 16

  88. };

  89. /* computed from band_size_long */

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

  91. #include "mpegaudio_tablegen.h"

  92. /* intensity stereo coef table */

  93. static INTFLOAT is_table[2][16];

  94. static INTFLOAT is_table_lsf[2][2][16];

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

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

  97. static INTFLOAT mdct_win[8][36];

  98. 

  99. static int16_t division_tab3[1<<6 ];

  100. static int16_t division_tab5[1<<8 ];

  101. static int16_t division_tab9[1<<11];

  102. 

  103. static int16_t * const division_tabs[4] = {

  104.     division_tab3, division_tab5, NULL, division_tab9

  105. };

  106. 

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

  108. static uint16_t scale_factor_modshift[64];

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

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

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

  112. 

  113. #define SCALE_GEN(v) \

  114. { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }

  115. 

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

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

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

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

  120. };

  121. 

  122. DECLARE_ALIGNED(16, MPA_INT, RENAME(ff_mpa_synth_window))[512+256];

  123. 

  124. /**

  125.  * Convert region offsets to region sizes and truncate

  126.  * size to big_values.

  127.  */

  128. static void ff_region_offset2size(GranuleDef *g){

  129.     int i, k, j=0;

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

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

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

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

  134.         j = k;

  135.     }

  136. }

  137. 

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

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

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

  141.     else {

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

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

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

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

  146.         else

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

  148.     }

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

  150. }

  151. 

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

  153.     int l;

  154.     g->region_size[0] =

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

  156.     /* should not overflow */

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

  158.     g->region_size[1] =

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

  160. }

  161. 

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

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

  164.         if (g->switch_point) {

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

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

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

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

  169.                 g->long_end = 8;

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

  171.                 g->long_end = 6;

  172.             else

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

  174. 

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

  176.         } else {

  177.             g->long_end = 0;

  178.             g->short_start = 0;

  179.         }

  180.     } else {

  181.         g->short_start = 13;

  182.         g->long_end = 22;

  183.     }

  184. }

  185. 

  186. /* layer 1 unscaling */

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

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

  189. {

  190.     int shift, mod;

  191.     int64_t val;

  192. 

  193.     shift = scale_factor_modshift[scale_factor];

  194.     mod = shift & 3;

  195.     shift >>= 2;

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

  197.     shift += n;

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

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

  200. }

  201. 

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

  203. {

  204.     int shift, mod, val;

  205. 

  206.     shift = scale_factor_modshift[scale_factor];

  207.     mod = shift & 3;

  208.     shift >>= 2;

  209. 

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

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

  212.     if (shift > 0)

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

  214.     return val;

  215. }

  216. 

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

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

  219. {

  220.     unsigned int m;

  221.     int e;

  222. 

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

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

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

  226.     assert(e>=1);

  227.     if (e > 31)

  228.         return 0;

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

  230. 

  231.     return m;

  232. }

  233. 

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

  235. #define DEV_ORDER 13

  236. 

  237. #define POW_FRAC_BITS 24

  238. #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)

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

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

  241. 

  242. static int dev_4_3_coefs[DEV_ORDER];

  243. 

  244. static av_cold void int_pow_init(void)

  245. {

  246.     int i, a;

  247. 

  248.     a = POW_FIX(1.0);

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

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

  251.         dev_4_3_coefs[i] = a;

  252.     }

  253. }

  254. 

  255. static av_cold int decode_init(AVCodecContext * avctx)

  256. {

  257.     MPADecodeContext *s = avctx->priv_data;

  258.     static int init=0;

  259.     int i, j, k;

  260. 

  261.     s->avctx = avctx;

  262.     s->apply_window_mp3 = apply_window_mp3_c;

  263. #if HAVE_MMX && CONFIG_FLOAT

  264.     ff_mpegaudiodec_init_mmx(s);

  265. #endif

  266. #if CONFIG_FLOAT

  267.     ff_dct_init(&s->dct, 5, DCT_II);

  268. #endif

  269.     if (HAVE_ALTIVEC && CONFIG_FLOAT) ff_mpegaudiodec_init_altivec(s);

  270. 

  271.     avctx->sample_fmt= OUT_FMT;

  272.     s->error_recognition= avctx->error_recognition;

  273. 

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

  275.         int offset;

  276. 

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

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

  279.             int shift, mod;

  280.             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  281.             shift = (i / 3);

  282.             mod = i % 3;

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

  284.         }

  285. 

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

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

  288.             int n, norm;

  289.             n = i + 2;

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

  291.             scale_factor_mult[i][0] = MULLx(norm, FIXR(1.0          * 2.0), FRAC_BITS);

  292.             scale_factor_mult[i][1] = MULLx(norm, FIXR(0.7937005259 * 2.0), FRAC_BITS);

  293.             scale_factor_mult[i][2] = MULLx(norm, FIXR(0.6299605249 * 2.0), FRAC_BITS);

  294.             av_dlog(avctx, "%d: norm=%x s=%x %x %x\n",

  295.                     i, norm,

  296.                     scale_factor_mult[i][0],

  297.                     scale_factor_mult[i][1],

  298.                     scale_factor_mult[i][2]);

  299.         }

  300. 

  301.         RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));

  302. 

  303.         /* huffman decode tables */

  304.         offset = 0;

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

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

  307.             int xsize, x, y;

  308.             uint8_t  tmp_bits [512];

  309.             uint16_t tmp_codes[512];

  310. 

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

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

  313. 

  314.             xsize = h->xsize;

  315. 

  316.             j = 0;

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

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

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

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

  321.                 }

  322.             }

  323. 

  324.             /* XXX: fail test */

  325.             huff_vlc[i].table = huff_vlc_tables+offset;

  326.             huff_vlc[i].table_allocated = huff_vlc_tables_sizes[i];

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

  328.                      tmp_bits, 1, 1, tmp_codes, 2, 2,

  329.                      INIT_VLC_USE_NEW_STATIC);

  330.             offset += huff_vlc_tables_sizes[i];

  331.         }

  332.         assert(offset == FF_ARRAY_ELEMS(huff_vlc_tables));

  333. 

  334.         offset = 0;

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

  336.             huff_quad_vlc[i].table = huff_quad_vlc_tables+offset;

  337.             huff_quad_vlc[i].table_allocated = huff_quad_vlc_tables_sizes[i];

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

  339.                      mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1,

  340.                      INIT_VLC_USE_NEW_STATIC);

  341.             offset += huff_quad_vlc_tables_sizes[i];

  342.         }

  343.         assert(offset == FF_ARRAY_ELEMS(huff_quad_vlc_tables));

  344. 

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

  346.             k = 0;

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

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

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

  350.             }

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

  352.         }

  353. 

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

  355. 

  356.         int_pow_init();

  357.         mpegaudio_tableinit();

  358. 

  359.         for (i = 0; i < 4; i++)

  360.             if (ff_mpa_quant_bits[i] < 0)

  361.                 for (j = 0; j < (1<<(-ff_mpa_quant_bits[i]+1)); j++) {

  362.                     int val1, val2, val3, steps;

  363.                     int val = j;

  364.                     steps  = ff_mpa_quant_steps[i];

  365.                     val1 = val % steps;

  366.                     val /= steps;

  367.                     val2 = val % steps;

  368.                     val3 = val / steps;

  369.                     division_tabs[i][j] = val1 + (val2 << 4) + (val3 << 8);

  370.                 }

  371. 

  372. 

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

  374.             float f;

  375.             INTFLOAT v;

  376.             if (i != 6) {

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

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

  379.             } else {

  380.                 v = FIXR(1.0);

  381.             }

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

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

  384.         }

  385.         /* invalid values */

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

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

  388. 

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

  390.             double f;

  391.             int e, k;

  392. 

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

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

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

  396.                 k = i & 1;

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

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

  399.                 av_dlog(avctx, "is_table_lsf %d %d: %x %x\n",

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

  401.             }

  402.         }

  403. 

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

  405.             float ci, cs, ca;

  406.             ci = ci_table[i];

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

  408.             ca = cs * ci;

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

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

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

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

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

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

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

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

  417.         }

  418. 

  419.         /* compute mdct windows */

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

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

  422.                 double d;

  423. 

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

  425.                     continue;

  426. 

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

  428.                 if(j==1){

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

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

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

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

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

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

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

  436.                 }

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

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

  439. 

  440.                 if(j==2)

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

  442.                 else

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

  444.             }

  445.         }

  446. 

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

  448.            the sign of the right window coefs */

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

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

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

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

  453.             }

  454.         }

  455. 

  456.         init = 1;

  457.     }

  458. 

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

  460.         s->adu_mode = 1;

  461.     return 0;

  462. }

  463. 

  464. 

  465. #if CONFIG_FLOAT

  466. static inline float round_sample(float *sum)

  467. {

  468.     float sum1=*sum;

  469.     *sum = 0;

  470.     return sum1;

  471. }

  472. 

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

  474. #define MACS(rt, ra, rb) rt+=(ra)*(rb)

  475. 

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

  477. #define MULS(ra, rb) ((ra)*(rb))

  478. 

  479. #define MLSS(rt, ra, rb) rt-=(ra)*(rb)

  480. 

  481. #else

  482. 

  483. static inline int round_sample(int64_t *sum)

  484. {

  485.     int sum1;

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

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

  488.     return av_clip_int16(sum1);

  489. }

  490. 

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

  492. #   define MACS(rt, ra, rb) MAC64(rt, ra, rb)

  493. #   define MLSS(rt, ra, rb) MLS64(rt, ra, rb)

  494. #endif

  495. 

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

  497. {                                         \

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

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

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

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

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

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

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

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

  506. }

  507. 

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

  509. {                                               \

  510.     INTFLOAT tmp;\

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  535. }

  536. 

  537. void av_cold RENAME(ff_mpa_synth_init)(MPA_INT *window)

  538. {

  539.     int i, j;

  540. 

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

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

  543.         INTFLOAT v;

  544.         v = ff_mpa_enwindow[i];

  545. #if CONFIG_FLOAT

  546.         v *= 1.0 / (1LL<<(16 + FRAC_BITS));

  547. #endif

  548.         window[i] = v;

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

  550.             v = -v;

  551.         if (i != 0)

  552.             window[512 - i] = v;

  553.     }

  554. 

  555.     // Needed for avoiding shuffles in ASM implementations

  556.     for(i=0; i < 8; i++)

  557.         for(j=0; j < 16; j++)

  558.             window[512+16*i+j] = window[64*i+32-j];

  559. 

  560.     for(i=0; i < 8; i++)

  561.         for(j=0; j < 16; j++)

  562.             window[512+128+16*i+j] = window[64*i+48-j];

  563. }

  564. 

  565. static void apply_window_mp3_c(MPA_INT *synth_buf, MPA_INT *window,

  566.                                int *dither_state, OUT_INT *samples, int incr)

  567. {

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

  569.     int j;

  570.     OUT_INT *samples2;

  571. #if CONFIG_FLOAT

  572.     float sum, sum2;

  573. #else

  574.     int64_t sum, sum2;

  575. #endif

  576. 

  577.     /* copy to avoid wrap */

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

  579. 

  580.     samples2 = samples + 31 * incr;

  581.     w = window;

  582.     w2 = window + 31;

  583. 

  584.     sum = *dither_state;

  585.     p = synth_buf + 16;

  586.     SUM8(MACS, sum, w, p);

  587.     p = synth_buf + 48;

  588.     SUM8(MLSS, sum, w + 32, p);

  589.     *samples = round_sample(&sum);

  590.     samples += incr;

  591.     w++;

  592. 

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

  594.        access per two sample */

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

  596.         sum2 = 0;

  597.         p = synth_buf + 16 + j;

  598.         SUM8P2(sum, MACS, sum2, MLSS, w, w2, p);

  599.         p = synth_buf + 48 - j;

  600.         SUM8P2(sum, MLSS, sum2, MLSS, w + 32, w2 + 32, p);

  601. 

  602.         *samples = round_sample(&sum);

  603.         samples += incr;

  604.         sum += sum2;

  605.         *samples2 = round_sample(&sum);

  606.         samples2 -= incr;

  607.         w++;

  608.         w2--;

  609.     }

  610. 

  611.     p = synth_buf + 32;

  612.     SUM8(MLSS, sum, w + 32, p);

  613.     *samples = round_sample(&sum);

  614.     *dither_state= sum;

  615. }

  616. 

  617. 

  618. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

  619.    32 samples. */

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

  621. #if !CONFIG_FLOAT

  622. void ff_mpa_synth_filter_fixed(MPA_INT *synth_buf_ptr, int *synth_buf_offset,

  623.                          MPA_INT *window, int *dither_state,

  624.                          OUT_INT *samples, int incr,

  625.                          INTFLOAT sb_samples[SBLIMIT])

  626. {

  627.     register MPA_INT *synth_buf;

  628.     int offset;

  629. 

  630.     offset = *synth_buf_offset;

  631.     synth_buf = synth_buf_ptr + offset;

  632. 

  633.     ff_dct32_fixed(synth_buf, sb_samples);

  634.     apply_window_mp3_c(synth_buf, window, dither_state, samples, incr);

  635. 

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

  637.     *synth_buf_offset = offset;

  638. }

  639. #endif

  640. 

  641. #define C3 FIXHR(0.86602540378443864676/2)

  642. 

  643. /* 0.5 / cos(pi*(2*i+1)/36) */

  644. static const INTFLOAT icos36[9] = {

  645.     FIXR(0.50190991877167369479),

  646.     FIXR(0.51763809020504152469), //0

  647.     FIXR(0.55168895948124587824),

  648.     FIXR(0.61038729438072803416),

  649.     FIXR(0.70710678118654752439), //1

  650.     FIXR(0.87172339781054900991),

  651.     FIXR(1.18310079157624925896),

  652.     FIXR(1.93185165257813657349), //2

  653.     FIXR(5.73685662283492756461),

  654. };

  655. 

  656. /* 0.5 / cos(pi*(2*i+1)/36) */

  657. static const INTFLOAT icos36h[9] = {

  658.     FIXHR(0.50190991877167369479/2),

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

  660.     FIXHR(0.55168895948124587824/2),

  661.     FIXHR(0.61038729438072803416/2),

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

  663.     FIXHR(0.87172339781054900991/2),

  664.     FIXHR(1.18310079157624925896/4),

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

  666. //    FIXHR(5.73685662283492756461),

  667. };

  668. 

  669. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  670.    cases. */

  671. static void imdct12(INTFLOAT *out, INTFLOAT *in)

  672. {

  673.     INTFLOAT in0, in1, in2, in3, in4, in5, t1, t2;

  674. 

  675.     in0= in[0*3];

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

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

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

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

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

  681.     in5 += in3;

  682.     in3 += in1;

  683. 

  684.     in2= MULH3(in2, C3, 2);

  685.     in3= MULH3(in3, C3, 4);

  686. 

  687.     t1 = in0 - in4;

  688.     t2 = MULH3(in1 - in5, icos36h[4], 2);

  689. 

  690.     out[ 7]=

  691.     out[10]= t1 + t2;

  692.     out[ 1]=

  693.     out[ 4]= t1 - t2;

  694. 

  695.     in0 += SHR(in4, 1);

  696.     in4 = in0 + in2;

  697.     in5 += 2*in1;

  698.     in1 = MULH3(in5 + in3, icos36h[1], 1);

  699.     out[ 8]=

  700.     out[ 9]= in4 + in1;

  701.     out[ 2]=

  702.     out[ 3]= in4 - in1;

  703. 

  704.     in0 -= in2;

  705.     in5 = MULH3(in5 - in3, icos36h[7], 2);

  706.     out[ 0]=

  707.     out[ 5]= in0 - in5;

  708.     out[ 6]=

  709.     out[11]= in0 + in5;

  710. }

  711. 

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

  713. #define C1 FIXHR(0.98480775301220805936/2)

  714. #define C2 FIXHR(0.93969262078590838405/2)

  715. #define C3 FIXHR(0.86602540378443864676/2)

  716. #define C4 FIXHR(0.76604444311897803520/2)

  717. #define C5 FIXHR(0.64278760968653932632/2)

  718. #define C6 FIXHR(0.5/2)

  719. #define C7 FIXHR(0.34202014332566873304/2)

  720. #define C8 FIXHR(0.17364817766693034885/2)

  721. 

  722. 

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

  724. static void imdct36(INTFLOAT *out, INTFLOAT *buf, INTFLOAT *in, INTFLOAT *win)

  725. {

  726.     int i, j;

  727.     INTFLOAT t0, t1, t2, t3, s0, s1, s2, s3;

  728.     INTFLOAT tmp[18], *tmp1, *in1;

  729. 

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

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

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

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

  734. 

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

  736.         tmp1 = tmp + j;

  737.         in1 = in + j;

  738. 

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

  740. 

  741.         t3 = in1[2*0] + SHR(in1[2*6],1);

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

  743.         tmp1[ 6] = t1 - SHR(t2,1);

  744.         tmp1[16] = t1 + t2;

  745. 

  746.         t0 = MULH3(in1[2*2] + in1[2*4] ,    C2, 2);

  747.         t1 = MULH3(in1[2*4] - in1[2*8] , -2*C8, 1);

  748.         t2 = MULH3(in1[2*2] + in1[2*8] ,   -C4, 2);

  749. 

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

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

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

  753. 

  754.         tmp1[ 4] = MULH3(in1[2*5] + in1[2*7] - in1[2*1], -C3, 2);

  755.         t2 = MULH3(in1[2*1] + in1[2*5],    C1, 2);

  756.         t3 = MULH3(in1[2*5] - in1[2*7], -2*C7, 1);

  757.         t0 = MULH3(in1[2*3], C3, 2);

  758. 

  759.         t1 = MULH3(in1[2*1] + in1[2*7],   -C5, 2);

  760. 

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

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

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

  764.     }

  765. 

  766.     i = 0;

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

  768.         t0 = tmp[i];

  769.         t1 = tmp[i + 2];

  770.         s0 = t1 + t0;

  771.         s2 = t1 - t0;

  772. 

  773.         t2 = tmp[i + 1];

  774.         t3 = tmp[i + 3];

  775.         s1 = MULH3(t3 + t2, icos36h[j], 2);

  776.         s3 = MULLx(t3 - t2, icos36[8 - j], FRAC_BITS);

  777. 

  778.         t0 = s0 + s1;

  779.         t1 = s0 - s1;

  780.         out[(9 + j)*SBLIMIT] =  MULH3(t1, win[9 + j], 1) + buf[9 + j];

  781.         out[(8 - j)*SBLIMIT] =  MULH3(t1, win[8 - j], 1) + buf[8 - j];

  782.         buf[9 + j] = MULH3(t0, win[18 + 9 + j], 1);

  783.         buf[8 - j] = MULH3(t0, win[18 + 8 - j], 1);

  784. 

  785.         t0 = s2 + s3;

  786.         t1 = s2 - s3;

  787.         out[(9 + 8 - j)*SBLIMIT] =  MULH3(t1, win[9 + 8 - j], 1) + buf[9 + 8 - j];

  788.         out[(        j)*SBLIMIT] =  MULH3(t1, win[        j], 1) + buf[        j];

  789.         buf[9 + 8 - j] = MULH3(t0, win[18 + 9 + 8 - j], 1);

  790.         buf[      + j] = MULH3(t0, win[18         + j], 1);

  791.         i += 4;

  792.     }

  793. 

  794.     s0 = tmp[16];

  795.     s1 = MULH3(tmp[17], icos36h[4], 2);

  796.     t0 = s0 + s1;

  797.     t1 = s0 - s1;

  798.     out[(9 + 4)*SBLIMIT] =  MULH3(t1, win[9 + 4], 1) + buf[9 + 4];

  799.     out[(8 - 4)*SBLIMIT] =  MULH3(t1, win[8 - 4], 1) + buf[8 - 4];

  800.     buf[9 + 4] = MULH3(t0, win[18 + 9 + 4], 1);

  801.     buf[8 - 4] = MULH3(t0, win[18 + 8 - 4], 1);

  802. }

  803. 

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

  805. static int mp_decode_layer1(MPADecodeContext *s)

  806. {

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

  808.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  809.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  810. 

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

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

  813.     else

  814.         bound = SBLIMIT;

  815. 

  816.     /* allocation bits */

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

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

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

  820.         }

  821.     }

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

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

  824.     }

  825. 

  826.     /* scale factors */

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

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

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

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

  831.         }

  832.     }

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

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

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

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

  837.         }

  838.     }

  839. 

  840.     /* compute samples */

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

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

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

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

  845.                 if (n) {

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

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

  848.                 } else {

  849.                     v = 0;

  850.                 }

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

  852.             }

  853.         }

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

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

  856.             if (n) {

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

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

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

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

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

  862.             } else {

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

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

  865.             }

  866.         }

  867.     }

  868.     return 12;

  869. }

  870. 

  871. static int mp_decode_layer2(MPADecodeContext *s)

  872. {

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

  874.     const unsigned char *alloc_table;

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

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

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

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

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

  880. 

  881.     /* select decoding table */

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

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

  884.     sblimit = ff_mpa_sblimit_table[table];

  885.     alloc_table = ff_mpa_alloc_tables[table];

  886. 

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

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

  889.     else

  890.         bound = sblimit;

  891. 

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

  893. 

  894.     /* sanity check */

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

  896. 

  897.     /* parse bit allocation */

  898.     j = 0;

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

  900.         bit_alloc_bits = alloc_table[j];

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

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

  903.         }

  904.         j += 1 << bit_alloc_bits;

  905.     }

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

  907.         bit_alloc_bits = alloc_table[j];

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

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

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

  911.         j += 1 << bit_alloc_bits;

  912.     }

  913. 

  914.     /* scale codes */

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

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

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

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

  919.         }

  920.     }

  921. 

  922.     /* scale factors */

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

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

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

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

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

  928.                 default:

  929.                 case 0:

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

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

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

  933.                     break;

  934.                 case 2:

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

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

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

  938.                     break;

  939.                 case 1:

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

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

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

  943.                     break;

  944.                 case 3:

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

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

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

  948.                     break;

  949.                 }

  950.             }

  951.         }

  952.     }

  953. 

  954.     /* samples */

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

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

  957.             j = 0;

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

  959.                 bit_alloc_bits = alloc_table[j];

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

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

  962.                     if (b) {

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

  964.                         qindex = alloc_table[j+b];

  965.                         bits = ff_mpa_quant_bits[qindex];

  966.                         if (bits < 0) {

  967.                             int v2;

  968.                             /* 3 values at the same time */

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

  970.                             v2 = division_tabs[qindex][v];

  971.                             steps  = ff_mpa_quant_steps[qindex];

  972. 

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

  974.                                 l2_unscale_group(steps, v2        & 15, scale);

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

  976.                                 l2_unscale_group(steps, (v2 >> 4) & 15, scale);

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

  978.                                 l2_unscale_group(steps,  v2 >> 8      , scale);

  979.                         } else {

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

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

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

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

  984.                             }

  985.                         }

  986.                     } else {

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

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

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

  990.                     }

  991.                 }

  992.                 /* next subband in alloc table */

  993.                 j += 1 << bit_alloc_bits;

  994.             }

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

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

  997.                 bit_alloc_bits = alloc_table[j];

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

  999.                 if (b) {

  1000.                     int mant, scale0, scale1;

  1001.                     scale0 = scale_factors[0][i][k];

  1002.                     scale1 = scale_factors[1][i][k];

  1003.                     qindex = alloc_table[j+b];

  1004.                     bits = ff_mpa_quant_bits[qindex];

  1005.                     if (bits < 0) {

  1006.                         /* 3 values at the same time */

  1007.                         v = get_bits(&s->gb, -bits);

  1008.                         steps = ff_mpa_quant_steps[qindex];

  1009.                         mant = v % steps;

  1010.                         v = v / steps;

  1011.                         s->sb_samples[0][k * 12 + l + 0][i] =

  1012.                             l2_unscale_group(steps, mant, scale0);

  1013.                         s->sb_samples[1][k * 12 + l + 0][i] =

  1014.                             l2_unscale_group(steps, mant, scale1);

  1015.                         mant = v % steps;

  1016.                         v = v / steps;

  1017.                         s->sb_samples[0][k * 12 + l + 1][i] =

  1018.                             l2_unscale_group(steps, mant, scale0);

  1019.                         s->sb_samples[1][k * 12 + l + 1][i] =

  1020.                             l2_unscale_group(steps, mant, scale1);

  1021.                         s->sb_samples[0][k * 12 + l + 2][i] =

  1022.                             l2_unscale_group(steps, v, scale0);

  1023.                         s->sb_samples[1][k * 12 + l + 2][i] =

  1024.                             l2_unscale_group(steps, v, scale1);

  1025.                     } else {

  1026.                         for(m=0;m<3;m++) {

  1027.                             mant = get_bits(&s->gb, bits);

  1028.                             s->sb_samples[0][k * 12 + l + m][i] =

  1029.                                 l1_unscale(bits - 1, mant, scale0);

  1030.                             s->sb_samples[1][k * 12 + l + m][i] =

  1031.                                 l1_unscale(bits - 1, mant, scale1);

  1032.                         }

  1033.                     }

  1034.                 } else {

  1035.                     s->sb_samples[0][k * 12 + l + 0][i] = 0;

  1036.                     s->sb_samples[0][k * 12 + l + 1][i] = 0;

  1037.                     s->sb_samples[0][k * 12 + l + 2][i] = 0;

  1038.                     s->sb_samples[1][k * 12 + l + 0][i] = 0;

  1039.                     s->sb_samples[1][k * 12 + l + 1][i] = 0;

  1040.                     s->sb_samples[1][k * 12 + l + 2][i] = 0;

  1041.                 }

  1042.                 /* next subband in alloc table */

  1043.                 j += 1 << bit_alloc_bits;

  1044.             }

  1045.             /* fill remaining samples to zero */

  1046.             for(i=sblimit;i<SBLIMIT;i++) {

  1047.                 for(ch=0;ch<s->nb_channels;ch++) {

  1048.                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1049.                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1050.                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1051.                 }

  1052.             }

  1053.         }

  1054.     }

  1055.     return 3 * 12;

  1056. }

  1057. 

  1058. #define SPLIT(dst,sf,n)\

  1059.     if(n==3){\

  1060.         int m= (sf*171)>>9;\

  1061.         dst= sf - 3*m;\

  1062.         sf=m;\

  1063.     }else if(n==4){\

  1064.         dst= sf&3;\

  1065.         sf>>=2;\

  1066.     }else if(n==5){\

  1067.         int m= (sf*205)>>10;\

  1068.         dst= sf - 5*m;\

  1069.         sf=m;\

  1070.     }else if(n==6){\

  1071.         int m= (sf*171)>>10;\

  1072.         dst= sf - 6*m;\

  1073.         sf=m;\

  1074.     }else{\

  1075.         dst=0;\

  1076.     }

  1077. 

  1078. static av_always_inline void lsf_sf_expand(int *slen,

  1079.                                  int sf, int n1, int n2, int n3)

  1080. {

  1081.     SPLIT(slen[3], sf, n3)

  1082.     SPLIT(slen[2], sf, n2)

  1083.     SPLIT(slen[1], sf, n1)

  1084.     slen[0] = sf;

  1085. }

  1086. 

  1087. static void exponents_from_scale_factors(MPADecodeContext *s,

  1088.                                          GranuleDef *g,

  1089.                                          int16_t *exponents)

  1090. {

  1091.     const uint8_t *bstab, *pretab;

  1092.     int len, i, j, k, l, v0, shift, gain, gains[3];

  1093.     int16_t *exp_ptr;

  1094. 

  1095.     exp_ptr = exponents;

  1096.     gain = g->global_gain - 210;

  1097.     shift = g->scalefac_scale + 1;

  1098. 

  1099.     bstab = band_size_long[s->sample_rate_index];

  1100.     pretab = mpa_pretab[g->preflag];

  1101.     for(i=0;i<g->long_end;i++) {

  1102.         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;

  1103.         len = bstab[i];

  1104.         for(j=len;j>0;j--)

  1105.             *exp_ptr++ = v0;

  1106.     }

  1107. 

  1108.     if (g->short_start < 13) {

  1109.         bstab = band_size_short[s->sample_rate_index];

  1110.         gains[0] = gain - (g->subblock_gain[0] << 3);

  1111.         gains[1] = gain - (g->subblock_gain[1] << 3);

  1112.         gains[2] = gain - (g->subblock_gain[2] << 3);

  1113.         k = g->long_end;

  1114.         for(i=g->short_start;i<13;i++) {

  1115.             len = bstab[i];

  1116.             for(l=0;l<3;l++) {

  1117.                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;

  1118.                 for(j=len;j>0;j--)

  1119.                 *exp_ptr++ = v0;

  1120.             }

  1121.         }

  1122.     }

  1123. }

  1124. 

  1125. /* handle n = 0 too */

  1126. static inline int get_bitsz(GetBitContext *s, int n)

  1127. {

  1128.     if (n == 0)

  1129.         return 0;

  1130.     else

  1131.         return get_bits(s, n);

  1132. }

  1133. 

  1134. 

  1135. static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos, int *end_pos2){

  1136.     if(s->in_gb.buffer && *pos >= s->gb.size_in_bits){

  1137.         s->gb= s->in_gb;

  1138.         s->in_gb.buffer=NULL;

  1139.         assert((get_bits_count(&s->gb) & 7) == 0);

  1140.         skip_bits_long(&s->gb, *pos - *end_pos);

  1141.         *end_pos2=

  1142.         *end_pos= *end_pos2 + get_bits_count(&s->gb) - *pos;

  1143.         *pos= get_bits_count(&s->gb);

  1144.     }

  1145. }

  1146. 

  1147. /* Following is a optimized code for

  1148.             INTFLOAT v = *src

  1149.             if(get_bits1(&s->gb))

  1150.                 v = -v;

  1151.             *dst = v;

  1152. */

  1153. #if CONFIG_FLOAT

  1154. #define READ_FLIP_SIGN(dst,src)\

  1155.             v = AV_RN32A(src) ^ (get_bits1(&s->gb)<<31);\

  1156.             AV_WN32A(dst, v);

  1157. #else

  1158. #define READ_FLIP_SIGN(dst,src)\

  1159.             v= -get_bits1(&s->gb);\

  1160.             *(dst) = (*(src) ^ v) - v;

  1161. #endif

  1162. 

  1163. static int huffman_decode(MPADecodeContext *s, GranuleDef *g,

  1164.                           int16_t *exponents, int end_pos2)

  1165. {

  1166.     int s_index;

  1167.     int i;

  1168.     int last_pos, bits_left;

  1169.     VLC *vlc;

  1170.     int end_pos= FFMIN(end_pos2, s->gb.size_in_bits);

  1171. 

  1172.     /* low frequencies (called big values) */

  1173.     s_index = 0;

  1174.     for(i=0;i<3;i++) {

  1175.         int j, k, l, linbits;

  1176.         j = g->region_size[i];

  1177.         if (j == 0)

  1178.             continue;

  1179.         /* select vlc table */

  1180.         k = g->table_select[i];

  1181.         l = mpa_huff_data[k][0];

  1182.         linbits = mpa_huff_data[k][1];

  1183.         vlc = &huff_vlc[l];

  1184. 

  1185.         if(!l){

  1186.             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*2*j);

  1187.             s_index += 2*j;

  1188.             continue;

  1189.         }

  1190. 

  1191.         /* read huffcode and compute each couple */

  1192.         for(;j>0;j--) {

  1193.             int exponent, x, y;

  1194.             int v;

  1195.             int pos= get_bits_count(&s->gb);

  1196. 

  1197.             if (pos >= end_pos){

  1198. //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1199.                 switch_buffer(s, &pos, &end_pos, &end_pos2);

  1200. //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);

  1201.                 if(pos >= end_pos)

  1202.                     break;

  1203.             }

  1204.             y = get_vlc2(&s->gb, vlc->table, 7, 3);

  1205. 

  1206.             if(!y){

  1207.                 g->sb_hybrid[s_index  ] =

  1208.                 g->sb_hybrid[s_index+1] = 0;

  1209.                 s_index += 2;

  1210.                 continue;

  1211.             }

  1212. 

  1213.             exponent= exponents[s_index];

  1214. 

  1215.             av_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",

  1216.                     i, g->region_size[i] - j, x, y, exponent);

  1217.             if(y&16){

  1218.                 x = y >> 5;

  1219.                 y = y & 0x0f;

  1220.                 if (x < 15){

  1221.                     READ_FLIP_SIGN(g->sb_hybrid+s_index, RENAME(expval_table)[ exponent ]+x)

  1222.                 }else{

  1223.                     x += get_bitsz(&s->gb, linbits);

  1224.                     v = l3_unscale(x, exponent);

  1225.                     if (get_bits1(&s->gb))

  1226.                         v = -v;

  1227.                     g->sb_hybrid[s_index] = v;

  1228.                 }

  1229.                 if (y < 15){

  1230.                     READ_FLIP_SIGN(g->sb_hybrid+s_index+1, RENAME(expval_table)[ exponent ]+y)

  1231.                 }else{

  1232.                     y += get_bitsz(&s->gb, linbits);

  1233.                     v = l3_unscale(y, exponent);

  1234.                     if (get_bits1(&s->gb))

  1235.                         v = -v;

  1236.                     g->sb_hybrid[s_index+1] = v;

  1237.                 }

  1238.             }else{

  1239.                 x = y >> 5;

  1240.                 y = y & 0x0f;

  1241.                 x += y;

  1242.                 if (x < 15){

  1243.                     READ_FLIP_SIGN(g->sb_hybrid+s_index+!!y, RENAME(expval_table)[ exponent ]+x)

  1244.                 }else{

  1245.                     x += get_bitsz(&s->gb, linbits);

  1246.                     v = l3_unscale(x, exponent);

  1247.                     if (get_bits1(&s->gb))

  1248.                         v = -v;

  1249.                     g->sb_hybrid[s_index+!!y] = v;

  1250.                 }

  1251.                 g->sb_hybrid[s_index+ !y] = 0;

  1252.             }

  1253.             s_index+=2;

  1254.         }

  1255.     }

  1256. 

  1257.     /* high frequencies */

  1258.     vlc = &huff_quad_vlc[g->count1table_select];

  1259.     last_pos=0;

  1260.     while (s_index <= 572) {

  1261.         int pos, code;

  1262.         pos = get_bits_count(&s->gb);

  1263.         if (pos >= end_pos) {

  1264.             if (pos > end_pos2 && last_pos){

  1265.                 /* some encoders generate an incorrect size for this

  1266.                    part. We must go back into the data */

  1267.                 s_index -= 4;

  1268.                 skip_bits_long(&s->gb, last_pos - pos);

  1269.                 av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);

  1270.                 if(s->error_recognition >= FF_ER_COMPLIANT)

  1271.                     s_index=0;

  1272.                 break;

  1273.             }

  1274. //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1275.             switch_buffer(s, &pos, &end_pos, &end_pos2);

  1276. //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);

  1277.             if(pos >= end_pos)

  1278.                 break;

  1279.         }

  1280.         last_pos= pos;

  1281. 

  1282.         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);

  1283.         av_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);

  1284.         g->sb_hybrid[s_index+0]=

  1285.         g->sb_hybrid[s_index+1]=

  1286.         g->sb_hybrid[s_index+2]=

  1287.         g->sb_hybrid[s_index+3]= 0;

  1288.         while(code){

  1289.             static const int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};

  1290.             int v;

  1291.             int pos= s_index+idxtab[code];

  1292.             code ^= 8>>idxtab[code];

  1293.             READ_FLIP_SIGN(g->sb_hybrid+pos, RENAME(exp_table)+exponents[pos])

  1294.         }

  1295.         s_index+=4;

  1296.     }

  1297.     /* skip extension bits */

  1298.     bits_left = end_pos2 - get_bits_count(&s->gb);

  1299. //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);

  1300.     if (bits_left < 0 && s->error_recognition >= FF_ER_COMPLIANT) {

  1301.         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1302.         s_index=0;

  1303.     }else if(bits_left > 0 && s->error_recognition >= FF_ER_AGGRESSIVE){

  1304.         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1305.         s_index=0;

  1306.     }

  1307.     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*(576 - s_index));

  1308.     skip_bits_long(&s->gb, bits_left);

  1309. 

  1310.     i= get_bits_count(&s->gb);

  1311.     switch_buffer(s, &i, &end_pos, &end_pos2);

  1312. 

  1313.     return 0;

  1314. }

  1315. 

  1316. /* Reorder short blocks from bitstream order to interleaved order. It

  1317.    would be faster to do it in parsing, but the code would be far more

  1318.    complicated */

  1319. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1320. {

  1321.     int i, j, len;

  1322.     INTFLOAT *ptr, *dst, *ptr1;

  1323.     INTFLOAT tmp[576];

  1324. 

  1325.     if (g->block_type != 2)

  1326.         return;

  1327. 

  1328.     if (g->switch_point) {

  1329.         if (s->sample_rate_index != 8) {

  1330.             ptr = g->sb_hybrid + 36;

  1331.         } else {

  1332.             ptr = g->sb_hybrid + 48;

  1333.         }

  1334.     } else {

  1335.         ptr = g->sb_hybrid;

  1336.     }

  1337. 

  1338.     for(i=g->short_start;i<13;i++) {

  1339.         len = band_size_short[s->sample_rate_index][i];

  1340.         ptr1 = ptr;

  1341.         dst = tmp;

  1342.         for(j=len;j>0;j--) {

  1343.             *dst++ = ptr[0*len];

  1344.             *dst++ = ptr[1*len];

  1345.             *dst++ = ptr[2*len];

  1346.             ptr++;

  1347.         }

  1348.         ptr+=2*len;

  1349.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1350.     }

  1351. }

  1352. 

  1353. #define ISQRT2 FIXR(0.70710678118654752440)

  1354. 

  1355. static void compute_stereo(MPADecodeContext *s,

  1356.                            GranuleDef *g0, GranuleDef *g1)

  1357. {

  1358.     int i, j, k, l;

  1359.     int sf_max, sf, len, non_zero_found;

  1360.     INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;

  1361.     int non_zero_found_short[3];

  1362. 

  1363.     /* intensity stereo */

  1364.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1365.         if (!s->lsf) {

  1366.             is_tab = is_table;

  1367.             sf_max = 7;

  1368.         } else {

  1369.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1370.             sf_max = 16;

  1371.         }

  1372. 

  1373.         tab0 = g0->sb_hybrid + 576;

  1374.         tab1 = g1->sb_hybrid + 576;

  1375. 

  1376.         non_zero_found_short[0] = 0;

  1377.         non_zero_found_short[1] = 0;

  1378.         non_zero_found_short[2] = 0;

  1379.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1380.         for(i = 12;i >= g1->short_start;i--) {

  1381.             /* for last band, use previous scale factor */

  1382.             if (i != 11)

  1383.                 k -= 3;

  1384.             len = band_size_short[s->sample_rate_index][i];

  1385.             for(l=2;l>=0;l--) {

  1386.                 tab0 -= len;

  1387.                 tab1 -= len;

  1388.                 if (!non_zero_found_short[l]) {

  1389.                     /* test if non zero band. if so, stop doing i-stereo */

  1390.                     for(j=0;j<len;j++) {

  1391.                         if (tab1[j] != 0) {

  1392.                             non_zero_found_short[l] = 1;

  1393.                             goto found1;

  1394.                         }

  1395.                     }

  1396.                     sf = g1->scale_factors[k + l];

  1397.                     if (sf >= sf_max)

  1398.                         goto found1;

  1399. 

  1400.                     v1 = is_tab[0][sf];

  1401.                     v2 = is_tab[1][sf];

  1402.                     for(j=0;j<len;j++) {

  1403.                         tmp0 = tab0[j];

  1404.                         tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1405.                         tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1406.                     }

  1407.                 } else {

  1408.                 found1:

  1409.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1410.                         /* lower part of the spectrum : do ms stereo

  1411.                            if enabled */

  1412.                         for(j=0;j<len;j++) {

  1413.                             tmp0 = tab0[j];

  1414.                             tmp1 = tab1[j];

  1415.                             tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1416.                             tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1417.                         }

  1418.                     }

  1419.                 }

  1420.             }

  1421.         }

  1422. 

  1423.         non_zero_found = non_zero_found_short[0] |

  1424.             non_zero_found_short[1] |

  1425.             non_zero_found_short[2];

  1426. 

  1427.         for(i = g1->long_end - 1;i >= 0;i--) {

  1428.             len = band_size_long[s->sample_rate_index][i];

  1429.             tab0 -= len;

  1430.             tab1 -= len;

  1431.             /* test if non zero band. if so, stop doing i-stereo */

  1432.             if (!non_zero_found) {

  1433.                 for(j=0;j<len;j++) {

  1434.                     if (tab1[j] != 0) {

  1435.                         non_zero_found = 1;

  1436.                         goto found2;

  1437.                     }

  1438.                 }

  1439.                 /* for last band, use previous scale factor */

  1440.                 k = (i == 21) ? 20 : i;

  1441.                 sf = g1->scale_factors[k];

  1442.                 if (sf >= sf_max)

  1443.                     goto found2;

  1444.                 v1 = is_tab[0][sf];

  1445.                 v2 = is_tab[1][sf];

  1446.                 for(j=0;j<len;j++) {

  1447.                     tmp0 = tab0[j];

  1448.                     tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1449.                     tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1450.                 }

  1451.             } else {

  1452.             found2:

  1453.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1454.                     /* lower part of the spectrum : do ms stereo

  1455.                        if enabled */

  1456.                     for(j=0;j<len;j++) {

  1457.                         tmp0 = tab0[j];

  1458.                         tmp1 = tab1[j];

  1459.                         tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1460.                         tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1461.                     }

  1462.                 }

  1463.             }

  1464.         }

  1465.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1466.         /* ms stereo ONLY */

  1467.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1468.            global gain */

  1469.         tab0 = g0->sb_hybrid;

  1470.         tab1 = g1->sb_hybrid;

  1471.         for(i=0;i<576;i++) {

  1472.             tmp0 = tab0[i];

  1473.             tmp1 = tab1[i];

  1474.             tab0[i] = tmp0 + tmp1;

  1475.             tab1[i] = tmp0 - tmp1;

  1476.         }

  1477.     }

  1478. }

  1479. 

  1480. #if !CONFIG_FLOAT

  1481. static void compute_antialias_fixed(MPADecodeContext *s, GranuleDef *g)

  1482. {

  1483.     int32_t *ptr, *csa;

  1484.     int n, i;

  1485. 

  1486.     /* we antialias only "long" bands */

  1487.     if (g->block_type == 2) {

  1488.         if (!g->switch_point)

  1489.             return;

  1490.         /* XXX: check this for 8000Hz case */

  1491.         n = 1;

  1492.     } else {

  1493.         n = SBLIMIT - 1;

  1494.     }

  1495. 

  1496.     ptr = g->sb_hybrid + 18;

  1497.     for(i = n;i > 0;i--) {

  1498.         int tmp0, tmp1, tmp2;

  1499.         csa = &csa_table[0][0];

  1500. #define INT_AA(j) \

  1501.             tmp0 = ptr[-1-j];\

  1502.             tmp1 = ptr[   j];\

  1503.             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\

  1504.             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\

  1505.             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));

  1506. 

  1507.         INT_AA(0)

  1508.         INT_AA(1)

  1509.         INT_AA(2)

  1510.         INT_AA(3)

  1511.         INT_AA(4)

  1512.         INT_AA(5)

  1513.         INT_AA(6)

  1514.         INT_AA(7)

  1515. 

  1516.         ptr += 18;

  1517.     }

  1518. }

  1519. #endif

  1520. 

  1521. static void compute_imdct(MPADecodeContext *s,

  1522.                           GranuleDef *g,

  1523.                           INTFLOAT *sb_samples,

  1524.                           INTFLOAT *mdct_buf)

  1525. {

  1526.     INTFLOAT *win, *win1, *out_ptr, *ptr, *buf, *ptr1;

  1527.     INTFLOAT out2[12];

  1528.     int i, j, mdct_long_end, sblimit;

  1529. 

  1530.     /* find last non zero block */

  1531.     ptr = g->sb_hybrid + 576;

  1532.     ptr1 = g->sb_hybrid + 2 * 18;

  1533.     while (ptr >= ptr1) {

  1534.         int32_t *p;

  1535.         ptr -= 6;

  1536.         p= (int32_t*)ptr;

  1537.         if(p[0] | p[1] | p[2] | p[3] | p[4] | p[5])

  1538.             break;

  1539.     }

  1540.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  1541. 

  1542.     if (g->block_type == 2) {

  1543.         /* XXX: check for 8000 Hz */

  1544.         if (g->switch_point)

  1545.             mdct_long_end = 2;

  1546.         else

  1547.             mdct_long_end = 0;

  1548.     } else {

  1549.         mdct_long_end = sblimit;

  1550.     }

  1551. 

  1552.     buf = mdct_buf;

  1553.     ptr = g->sb_hybrid;

  1554.     for(j=0;j<mdct_long_end;j++) {

  1555.         /* apply window & overlap with previous buffer */

  1556.         out_ptr = sb_samples + j;

  1557.         /* select window */

  1558.         if (g->switch_point && j < 2)

  1559.             win1 = mdct_win[0];

  1560.         else

  1561.             win1 = mdct_win[g->block_type];

  1562.         /* select frequency inversion */

  1563.         win = win1 + ((4 * 36) & -(j & 1));

  1564.         imdct36(out_ptr, buf, ptr, win);

  1565.         out_ptr += 18*SBLIMIT;

  1566.         ptr += 18;

  1567.         buf += 18;

  1568.     }

  1569.     for(j=mdct_long_end;j<sblimit;j++) {

  1570.         /* select frequency inversion */

  1571.         win = mdct_win[2] + ((4 * 36) & -(j & 1));

  1572.         out_ptr = sb_samples + j;

  1573. 

  1574.         for(i=0; i<6; i++){

  1575.             *out_ptr = buf[i];

  1576.             out_ptr += SBLIMIT;

  1577.         }

  1578.         imdct12(out2, ptr + 0);

  1579.         for(i=0;i<6;i++) {

  1580.             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[i + 6*1];

  1581.             buf[i + 6*2] = MULH3(out2[i + 6], win[i + 6], 1);

  1582.             out_ptr += SBLIMIT;

  1583.         }

  1584.         imdct12(out2, ptr + 1);

  1585.         for(i=0;i<6;i++) {

  1586.             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[i + 6*2];

  1587.             buf[i + 6*0] = MULH3(out2[i + 6], win[i + 6], 1);

  1588.             out_ptr += SBLIMIT;

  1589.         }

  1590.         imdct12(out2, ptr + 2);

  1591.         for(i=0;i<6;i++) {

  1592.             buf[i + 6*0] = MULH3(out2[i    ], win[i    ], 1) + buf[i + 6*0];

  1593.             buf[i + 6*1] = MULH3(out2[i + 6], win[i + 6], 1);

  1594.             buf[i + 6*2] = 0;

  1595.         }

  1596.         ptr += 18;

  1597.         buf += 18;

  1598.     }

  1599.     /* zero bands */

  1600.     for(j=sblimit;j<SBLIMIT;j++) {

  1601.         /* overlap */

  1602.         out_ptr = sb_samples + j;

  1603.         for(i=0;i<18;i++) {

  1604.             *out_ptr = buf[i];

  1605.             buf[i] = 0;

  1606.             out_ptr += SBLIMIT;

  1607.         }

  1608.         buf += 18;

  1609.     }

  1610. }

  1611. 

  1612. /* main layer3 decoding function */

  1613. static int mp_decode_layer3(MPADecodeContext *s)

  1614. {

  1615.     int nb_granules, main_data_begin, private_bits;

  1616.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  1617.     GranuleDef *g;

  1618.     int16_t exponents[576]; //FIXME try INTFLOAT

  1619. 

  1620.     /* read side info */

  1621.     if (s->lsf) {

  1622.         main_data_begin = get_bits(&s->gb, 8);

  1623.         private_bits = get_bits(&s->gb, s->nb_channels);

  1624.         nb_granules = 1;

  1625.     } else {

  1626.         main_data_begin = get_bits(&s->gb, 9);

  1627.         if (s->nb_channels == 2)

  1628.             private_bits = get_bits(&s->gb, 3);

  1629.         else

  1630.             private_bits = get_bits(&s->gb, 5);

  1631.         nb_granules = 2;

  1632.         for(ch=0;ch<s->nb_channels;ch++) {

  1633.             s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */

  1634.             s->granules[ch][1].scfsi = get_bits(&s->gb, 4);

  1635.         }

  1636.     }

  1637. 

  1638.     for(gr=0;gr<nb_granules;gr++) {

  1639.         for(ch=0;ch<s->nb_channels;ch++) {

  1640.             av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);

  1641.             g = &s->granules[ch][gr];

  1642.             g->part2_3_length = get_bits(&s->gb, 12);

  1643.             g->big_values = get_bits(&s->gb, 9);

  1644.             if(g->big_values > 288){

  1645.                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");

  1646.                 return -1;

  1647.             }

  1648. 

  1649.             g->global_gain = get_bits(&s->gb, 8);

  1650.             /* if MS stereo only is selected, we precompute the

  1651.                1/sqrt(2) renormalization factor */

  1652.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  1653.                 MODE_EXT_MS_STEREO)

  1654.                 g->global_gain -= 2;

  1655.             if (s->lsf)

  1656.                 g->scalefac_compress = get_bits(&s->gb, 9);

  1657.             else

  1658.                 g->scalefac_compress = get_bits(&s->gb, 4);

  1659.             blocksplit_flag = get_bits1(&s->gb);

  1660.             if (blocksplit_flag) {

  1661.                 g->block_type = get_bits(&s->gb, 2);

  1662.                 if (g->block_type == 0){

  1663.                     av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");

  1664.                     return -1;

  1665.                 }

  1666.                 g->switch_point = get_bits1(&s->gb);

  1667.                 for(i=0;i<2;i++)

  1668.                     g->table_select[i] = get_bits(&s->gb, 5);

  1669.                 for(i=0;i<3;i++)

  1670.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  1671.                 ff_init_short_region(s, g);

  1672.             } else {

  1673.                 int region_address1, region_address2;

  1674.                 g->block_type = 0;

  1675.                 g->switch_point = 0;

  1676.                 for(i=0;i<3;i++)

  1677.                     g->table_select[i] = get_bits(&s->gb, 5);

  1678.                 /* compute huffman coded region sizes */

  1679.                 region_address1 = get_bits(&s->gb, 4);

  1680.                 region_address2 = get_bits(&s->gb, 3);

  1681.                 av_dlog(s->avctx, "region1=%d region2=%d\n",

  1682.                         region_address1, region_address2);

  1683.                 ff_init_long_region(s, g, region_address1, region_address2);

  1684.             }

  1685.             ff_region_offset2size(g);

  1686.             ff_compute_band_indexes(s, g);

  1687. 

  1688.             g->preflag = 0;

  1689.             if (!s->lsf)

  1690.                 g->preflag = get_bits1(&s->gb);

  1691.             g->scalefac_scale = get_bits1(&s->gb);

  1692.             g->count1table_select = get_bits1(&s->gb);

  1693.             av_dlog(s->avctx, "block_type=%d switch_point=%d\n",

  1694.                     g->block_type, g->switch_point);

  1695.         }

  1696.     }

  1697. 

  1698.   if (!s->adu_mode) {

  1699.     const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  1700.     assert((get_bits_count(&s->gb) & 7) == 0);

  1701.     /* now we get bits from the main_data_begin offset */

  1702.     av_dlog(s->avctx, "seekback: %d\n", main_data_begin);

  1703. //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);

  1704. 

  1705.     memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);

  1706.     s->in_gb= s->gb;

  1707.         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);

  1708.         skip_bits_long(&s->gb, 8*(s->last_buf_size - main_data_begin));

  1709.   }

  1710. 

  1711.     for(gr=0;gr<nb_granules;gr++) {

  1712.         for(ch=0;ch<s->nb_channels;ch++) {

  1713.             g = &s->granules[ch][gr];

  1714.             if(get_bits_count(&s->gb)<0){

  1715.                 av_log(s->avctx, AV_LOG_DEBUG, "mdb:%d, lastbuf:%d skipping granule %d\n",

  1716.                                             main_data_begin, s->last_buf_size, gr);

  1717.                 skip_bits_long(&s->gb, g->part2_3_length);

  1718.                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));

  1719.                 if(get_bits_count(&s->gb) >= s->gb.size_in_bits && s->in_gb.buffer){

  1720.                     skip_bits_long(&s->in_gb, get_bits_count(&s->gb) - s->gb.size_in_bits);

  1721.                     s->gb= s->in_gb;

  1722.                     s->in_gb.buffer=NULL;

  1723.                 }

  1724.                 continue;

  1725.             }

  1726. 

  1727.             bits_pos = get_bits_count(&s->gb);

  1728. 

  1729.             if (!s->lsf) {

  1730.                 uint8_t *sc;

  1731.                 int slen, slen1, slen2;

  1732. 

  1733.                 /* MPEG1 scale factors */

  1734.                 slen1 = slen_table[0][g->scalefac_compress];

  1735.                 slen2 = slen_table[1][g->scalefac_compress];

  1736.                 av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);

  1737.                 if (g->block_type == 2) {

  1738.                     n = g->switch_point ? 17 : 18;

  1739.                     j = 0;

  1740.                     if(slen1){

  1741.                         for(i=0;i<n;i++)

  1742.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  1743.                     }else{

  1744.                         for(i=0;i<n;i++)

  1745.                             g->scale_factors[j++] = 0;

  1746.                     }

  1747.                     if(slen2){

  1748.                         for(i=0;i<18;i++)

  1749.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  1750.                         for(i=0;i<3;i++)

  1751.                             g->scale_factors[j++] = 0;

  1752.                     }else{

  1753.                         for(i=0;i<21;i++)

  1754.                             g->scale_factors[j++] = 0;

  1755.                     }

  1756.                 } else {

  1757.                     sc = s->granules[ch][0].scale_factors;

  1758.                     j = 0;

  1759.                     for(k=0;k<4;k++) {

  1760.                         n = (k == 0 ? 6 : 5);

  1761.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  1762.                             slen = (k < 2) ? slen1 : slen2;

  1763.                             if(slen){

  1764.                                 for(i=0;i<n;i++)

  1765.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  1766.                             }else{

  1767.                                 for(i=0;i<n;i++)

  1768.                                     g->scale_factors[j++] = 0;

  1769.                             }

  1770.                         } else {

  1771.                             /* simply copy from last granule */

  1772.                             for(i=0;i<n;i++) {

  1773.                                 g->scale_factors[j] = sc[j];

  1774.                                 j++;

  1775.                             }

  1776.                         }

  1777.                     }

  1778.                     g->scale_factors[j++] = 0;

  1779.                 }

  1780.             } else {

  1781.                 int tindex, tindex2, slen[4], sl, sf;

  1782. 

  1783.                 /* LSF scale factors */

  1784.                 if (g->block_type == 2) {

  1785.                     tindex = g->switch_point ? 2 : 1;

  1786.                 } else {

  1787.                     tindex = 0;

  1788.                 }

  1789.                 sf = g->scalefac_compress;

  1790.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  1791.                     /* intensity stereo case */

  1792.                     sf >>= 1;

  1793.                     if (sf < 180) {

  1794.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  1795.                         tindex2 = 3;

  1796.                     } else if (sf < 244) {

  1797.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  1798.                         tindex2 = 4;

  1799.                     } else {

  1800.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  1801.                         tindex2 = 5;

  1802.                     }

  1803.                 } else {

  1804.                     /* normal case */

  1805.                     if (sf < 400) {

  1806.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  1807.                         tindex2 = 0;

  1808.                     } else if (sf < 500) {

  1809.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  1810.                         tindex2 = 1;

  1811.                     } else {

  1812.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  1813.                         tindex2 = 2;

  1814.                         g->preflag = 1;

  1815.                     }

  1816.                 }

  1817. 

  1818.                 j = 0;

  1819.                 for(k=0;k<4;k++) {

  1820.                     n = lsf_nsf_table[tindex2][tindex][k];

  1821.                     sl = slen[k];

  1822.                     if(sl){

  1823.                         for(i=0;i<n;i++)

  1824.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  1825.                     }else{

  1826.                         for(i=0;i<n;i++)

  1827.                             g->scale_factors[j++] = 0;

  1828.                     }

  1829.                 }

  1830.                 /* XXX: should compute exact size */

  1831.                 for(;j<40;j++)

  1832.                     g->scale_factors[j] = 0;

  1833.             }

  1834. 

  1835.             exponents_from_scale_factors(s, g, exponents);

  1836. 

  1837.             /* read Huffman coded residue */

  1838.             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);

  1839.         } /* ch */

  1840. 

  1841.         if (s->nb_channels == 2)

  1842.             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);

  1843. 

  1844.         for(ch=0;ch<s->nb_channels;ch++) {

  1845.             g = &s->granules[ch][gr];

  1846. 

  1847.             reorder_block(s, g);

  1848.             RENAME(compute_antialias)(s, g);

  1849.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  1850.         }

  1851.     } /* gr */

  1852.     if(get_bits_count(&s->gb)<0)

  1853.         skip_bits_long(&s->gb, -get_bits_count(&s->gb));

  1854.     return nb_granules * 18;

  1855. }

  1856. 

  1857. static int mp_decode_frame(MPADecodeContext *s,

  1858.                            OUT_INT *samples, const uint8_t *buf, int buf_size)

  1859. {

  1860.     int i, nb_frames, ch;

  1861.     OUT_INT *samples_ptr;

  1862. 

  1863.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)*8);

  1864. 

  1865.     /* skip error protection field */

  1866.     if (s->error_protection)

  1867.         skip_bits(&s->gb, 16);

  1868. 

  1869.     switch(s->layer) {

  1870.     case 1:

  1871.         s->avctx->frame_size = 384;

  1872.         nb_frames = mp_decode_layer1(s);

  1873.         break;

  1874.     case 2:

  1875.         s->avctx->frame_size = 1152;

  1876.         nb_frames = mp_decode_layer2(s);

  1877.         break;

  1878.     case 3:

  1879.         s->avctx->frame_size = s->lsf ? 576 : 1152;

  1880.     default:

  1881.         nb_frames = mp_decode_layer3(s);

  1882. 

  1883.         s->last_buf_size=0;

  1884.         if(s->in_gb.buffer){

  1885.             align_get_bits(&s->gb);

  1886.             i= get_bits_left(&s->gb)>>3;

  1887.             if(i >= 0 && i <= BACKSTEP_SIZE){

  1888.                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);

  1889.                 s->last_buf_size=i;

  1890.             }else

  1891.                 av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);

  1892.             s->gb= s->in_gb;

  1893.             s->in_gb.buffer= NULL;

  1894.         }

  1895. 

  1896.         align_get_bits(&s->gb);

  1897.         assert((get_bits_count(&s->gb) & 7) == 0);

  1898.         i= get_bits_left(&s->gb)>>3;

  1899. 

  1900.         if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){

  1901.             if(i<0)

  1902.                 av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);

  1903.             i= FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);

  1904.         }

  1905.         assert(i <= buf_size - HEADER_SIZE && i>= 0);

  1906.         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);

  1907.         s->last_buf_size += i;

  1908. 

  1909.         break;

  1910.     }

  1911. 

  1912.     /* apply the synthesis filter */

  1913.     for(ch=0;ch<s->nb_channels;ch++) {

  1914.         samples_ptr = samples + ch;

  1915.         for(i=0;i<nb_frames;i++) {

  1916.             RENAME(ff_mpa_synth_filter)(

  1917. #if CONFIG_FLOAT

  1918.                          s,

  1919. #endif

  1920.                          s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  1921.                          RENAME(ff_mpa_synth_window), &s->dither_state,

  1922.                          samples_ptr, s->nb_channels,

  1923.                          s->sb_samples[ch][i]);

  1924.             samples_ptr += 32 * s->nb_channels;

  1925.         }

  1926.     }

  1927. 

  1928.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  1929. }

  1930. 

  1931. static int decode_frame(AVCodecContext * avctx,

  1932.                         void *data, int *data_size,

  1933.                         AVPacket *avpkt)

  1934. {

  1935.     const uint8_t *buf = avpkt->data;

  1936.     int buf_size = avpkt->size;

  1937.     MPADecodeContext *s = avctx->priv_data;

  1938.     uint32_t header;

  1939.     int out_size;

  1940.     OUT_INT *out_samples = data;

  1941. 

  1942.     if(buf_size < HEADER_SIZE)

  1943.         return -1;

  1944. 

  1945.     header = AV_RB32(buf);

  1946.     if(ff_mpa_check_header(header) < 0){

  1947.         av_log(avctx, AV_LOG_ERROR, "Header missing\n");

  1948.         return -1;

  1949.     }

  1950. 

  1951.     if (ff_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {

  1952.         /* free format: prepare to compute frame size */

  1953.         s->frame_size = -1;

  1954.         return -1;

  1955.     }

  1956.     /* update codec info */

  1957.     avctx->channels = s->nb_channels;

  1958.     avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;

  1959.     if (!avctx->bit_rate)

  1960.         avctx->bit_rate = s->bit_rate;

  1961.     avctx->sub_id = s->layer;

  1962. 

  1963.     if(*data_size < 1152*avctx->channels*sizeof(OUT_INT))

  1964.         return -1;

  1965.     *data_size = 0;

  1966. 

  1967.     if(s->frame_size<=0 || s->frame_size > buf_size){

  1968.         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

  1969.         return -1;

  1970.     }else if(s->frame_size < buf_size){

  1971.         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");

  1972.         buf_size= s->frame_size;

  1973.     }

  1974. 

  1975.     out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  1976.     if(out_size>=0){

  1977.         *data_size = out_size;

  1978.         avctx->sample_rate = s->sample_rate;

  1979.         //FIXME maybe move the other codec info stuff from above here too

  1980.     }else

  1981.         av_log(avctx, AV_LOG_DEBUG, "Error while decoding MPEG audio frame.\n"); //FIXME return -1 / but also return the number of bytes consumed

  1982.     s->frame_size = 0;

  1983.     return buf_size;

  1984. }

  1985. 

  1986. static void flush(AVCodecContext *avctx){

  1987.     MPADecodeContext *s = avctx->priv_data;

  1988.     memset(s->synth_buf, 0, sizeof(s->synth_buf));

  1989.     s->last_buf_size= 0;

  1990. }

  1991. 

  1992. #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER

  1993. static int decode_frame_adu(AVCodecContext * avctx,

  1994.                         void *data, int *data_size,

  1995.                         AVPacket *avpkt)

  1996. {

  1997.     const uint8_t *buf = avpkt->data;

  1998.     int buf_size = avpkt->size;

  1999.     MPADecodeContext *s = avctx->priv_data;

  2000.     uint32_t header;

  2001.     int len, out_size;

  2002.     OUT_INT *out_samples = data;

  2003. 

  2004.     len = buf_size;

  2005. 

  2006.     // Discard too short frames

  2007.     if (buf_size < HEADER_SIZE) {

  2008.         *data_size = 0;

  2009.         return buf_size;

  2010.     }

  2011. 

  2012. 

  2013.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  2014.         len = MPA_MAX_CODED_FRAME_SIZE;

  2015. 

  2016.     // Get header and restore sync word

  2017.     header = AV_RB32(buf) | 0xffe00000;

  2018. 

  2019.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  2020.         *data_size = 0;

  2021.         return buf_size;

  2022.     }

  2023. 

  2024.     ff_mpegaudio_decode_header((MPADecodeHeader *)s, header);

  2025.     /* update codec info */

  2026.     avctx->sample_rate = s->sample_rate;

  2027.     avctx->channels = s->nb_channels;

  2028.     if (!avctx->bit_rate)

  2029.         avctx->bit_rate = s->bit_rate;

  2030.     avctx->sub_id = s->layer;

  2031. 

  2032.     s->frame_size = len;

  2033. 

  2034.     if (avctx->parse_only) {

  2035.         out_size = buf_size;

  2036.     } else {

  2037.         out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2038.     }

  2039. 

  2040.     *data_size = out_size;

  2041.     return buf_size;

  2042. }

  2043. #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */

  2044. 

  2045. #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER

  2046. 

  2047. /**

  2048.  * Context for MP3On4 decoder

  2049.  */

  2050. typedef struct MP3On4DecodeContext {

  2051.     int frames;   ///< number of mp3 frames per block (number of mp3 decoder instances)

  2052.     int syncword; ///< syncword patch

  2053.     const uint8_t *coff; ///< channels offsets in output buffer

  2054.     MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance

  2055. } MP3On4DecodeContext;

  2056. 

  2057. #include "mpeg4audio.h"

  2058. 

  2059. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  2060. static const uint8_t mp3Frames[8] = {0,1,1,2,3,3,4,5};   /* number of mp3 decoder instances */

  2061. /* offsets into output buffer, assume output order is FL FR BL BR C LFE */

  2062. static const uint8_t chan_offset[8][5] = {

  2063.     {0},

  2064.     {0},            // C

  2065.     {0},            // FLR

  2066.     {2,0},          // C FLR

  2067.     {2,0,3},        // C FLR BS

  2068.     {4,0,2},        // C FLR BLRS

  2069.     {4,0,2,5},      // C FLR BLRS LFE

  2070.     {4,0,2,6,5},    // C FLR BLRS BLR LFE

  2071. };

  2072. 

  2073. 

  2074. static int decode_init_mp3on4(AVCodecContext * avctx)

  2075. {

  2076.     MP3On4DecodeContext *s = avctx->priv_data;

  2077.     MPEG4AudioConfig cfg;

  2078.     int i;

  2079. 

  2080.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  2081.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  2082.         return -1;

  2083.     }

  2084. 

  2085.     ff_mpeg4audio_get_config(&cfg, avctx->extradata, avctx->extradata_size);

  2086.     if (!cfg.chan_config || cfg.chan_config > 7) {

  2087.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  2088.         return -1;

  2089.     }

  2090.     s->frames = mp3Frames[cfg.chan_config];

  2091.     s->coff = chan_offset[cfg.chan_config];

  2092.     avctx->channels = ff_mpeg4audio_channels[cfg.chan_config];

  2093. 

  2094.     if (cfg.sample_rate < 16000)

  2095.         s->syncword = 0xffe00000;

  2096.     else

  2097.         s->syncword = 0xfff00000;

  2098. 

  2099.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  2100.      * We replace avctx->priv_data with the context of the first decoder so that

  2101.      * decode_init() does not have to be changed.

  2102.      * Other decoders will be initialized here copying data from the first context

  2103.      */

  2104.     // Allocate zeroed memory for the first decoder context

  2105.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  2106.     // Put decoder context in place to make init_decode() happy

  2107.     avctx->priv_data = s->mp3decctx[0];

  2108.     decode_init(avctx);

  2109.     // Restore mp3on4 context pointer

  2110.     avctx->priv_data = s;

  2111.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  2112. 

  2113.     /* Create a separate codec/context for each frame (first is already ok).

  2114.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  2115.      */

  2116.     for (i = 1; i < s->frames; i++) {

  2117.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  2118.         s->mp3decctx[i]->adu_mode = 1;

  2119.         s->mp3decctx[i]->avctx = avctx;

  2120.     }

  2121. 

  2122.     return 0;

  2123. }

  2124. 

  2125. 

  2126. static av_cold int decode_close_mp3on4(AVCodecContext * avctx)

  2127. {

  2128.     MP3On4DecodeContext *s = avctx->priv_data;

  2129.     int i;

  2130. 

  2131.     for (i = 0; i < s->frames; i++)

  2132.         av_free(s->mp3decctx[i]);

  2133. 

  2134.     return 0;

  2135. }

  2136. 

  2137. 

  2138. static int decode_frame_mp3on4(AVCodecContext * avctx,

  2139.                         void *data, int *data_size,

  2140.                         AVPacket *avpkt)

  2141. {

  2142.     const uint8_t *buf = avpkt->data;

  2143.     int buf_size = avpkt->size;

  2144.     MP3On4DecodeContext *s = avctx->priv_data;

  2145.     MPADecodeContext *m;

  2146.     int fsize, len = buf_size, out_size = 0;

  2147.     uint32_t header;

  2148.     OUT_INT *out_samples = data;

  2149.     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];

  2150.     OUT_INT *outptr, *bp;

  2151.     int fr, j, n;

  2152. 

  2153.     if(*data_size < MPA_FRAME_SIZE * MPA_MAX_CHANNELS * s->frames * sizeof(OUT_INT))

  2154.         return -1;

  2155. 

  2156.     *data_size = 0;

  2157.     // Discard too short frames

  2158.     if (buf_size < HEADER_SIZE)

  2159.         return -1;

  2160. 

  2161.     // If only one decoder interleave is not needed

  2162.     outptr = s->frames == 1 ? out_samples : decoded_buf;

  2163. 

  2164.     avctx->bit_rate = 0;

  2165. 

  2166.     for (fr = 0; fr < s->frames; fr++) {

  2167.         fsize = AV_RB16(buf) >> 4;

  2168.         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);

  2169.         m = s->mp3decctx[fr];

  2170.         assert (m != NULL);

  2171. 

  2172.         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header

  2173. 

  2174.         if (ff_mpa_check_header(header) < 0) // Bad header, discard block

  2175.             break;

  2176. 

  2177.         ff_mpegaudio_decode_header((MPADecodeHeader *)m, header);

  2178.         out_size += mp_decode_frame(m, outptr, buf, fsize);

  2179.         buf += fsize;

  2180.         len -= fsize;

  2181. 

  2182.         if(s->frames > 1) {

  2183.             n = m->avctx->frame_size*m->nb_channels;

  2184.             /* interleave output data */

  2185.             bp = out_samples + s->coff[fr];

  2186.             if(m->nb_channels == 1) {

  2187.                 for(j = 0; j < n; j++) {

  2188.                     *bp = decoded_buf[j];

  2189.                     bp += avctx->channels;

  2190.                 }

  2191.             } else {

  2192.                 for(j = 0; j < n; j++) {

  2193.                     bp[0] = decoded_buf[j++];

  2194.                     bp[1] = decoded_buf[j];

  2195.                     bp += avctx->channels;

  2196.                 }

  2197.             }

  2198.         }

  2199.         avctx->bit_rate += m->bit_rate;

  2200.     }

  2201. 

  2202.     /* update codec info */

  2203.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  2204. 

  2205.     *data_size = out_size;

  2206.     return buf_size;

  2207. }

  2208. #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */

  2209. 

  2210. #if !CONFIG_FLOAT

  2211. #if CONFIG_MP1_DECODER

  2212. AVCodec ff_mp1_decoder =

  2213. {

  2214.     "mp1",

  2215.     AVMEDIA_TYPE_AUDIO,

  2216.     CODEC_ID_MP1,

  2217.     sizeof(MPADecodeContext),

  2218.     decode_init,

  2219.     NULL,

  2220.     NULL,

  2221.     decode_frame,

  2222.     CODEC_CAP_PARSE_ONLY,

  2223.     .flush= flush,

  2224.     .long_name= NULL_IF_CONFIG_SMALL("MP1 (MPEG audio layer 1)"),

  2225. };

  2226. #endif

  2227. #if CONFIG_MP2_DECODER

  2228. AVCodec ff_mp2_decoder =

  2229. {

  2230.     "mp2",

  2231.     AVMEDIA_TYPE_AUDIO,

  2232.     CODEC_ID_MP2,

  2233.     sizeof(MPADecodeContext),

  2234.     decode_init,

  2235.     NULL,

  2236.     NULL,

  2237.     decode_frame,

  2238.     CODEC_CAP_PARSE_ONLY,

  2239.     .flush= flush,

  2240.     .long_name= NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),

  2241. };

  2242. #endif

  2243. #if CONFIG_MP3_DECODER

  2244. AVCodec ff_mp3_decoder =

  2245. {

  2246.     "mp3",

  2247.     AVMEDIA_TYPE_AUDIO,

  2248.     CODEC_ID_MP3,

  2249.     sizeof(MPADecodeContext),

  2250.     decode_init,

  2251.     NULL,

  2252.     NULL,

  2253.     decode_frame,

  2254.     CODEC_CAP_PARSE_ONLY,

  2255.     .flush= flush,

  2256.     .long_name= NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),

  2257. };

  2258. #endif

  2259. #if CONFIG_MP3ADU_DECODER

  2260. AVCodec ff_mp3adu_decoder =

  2261. {

  2262.     "mp3adu",

  2263.     AVMEDIA_TYPE_AUDIO,

  2264.     CODEC_ID_MP3ADU,

  2265.     sizeof(MPADecodeContext),

  2266.     decode_init,

  2267.     NULL,

  2268.     NULL,

  2269.     decode_frame_adu,

  2270.     CODEC_CAP_PARSE_ONLY,

  2271.     .flush= flush,

  2272.     .long_name= NULL_IF_CONFIG_SMALL("ADU (Application Data Unit) MP3 (MPEG audio layer 3)"),

  2273. };

  2274. #endif

  2275. #if CONFIG_MP3ON4_DECODER

  2276. AVCodec ff_mp3on4_decoder =

  2277. {

  2278.     "mp3on4",

  2279.     AVMEDIA_TYPE_AUDIO,

  2280.     CODEC_ID_MP3ON4,

  2281.     sizeof(MP3On4DecodeContext),

  2282.     decode_init_mp3on4,

  2283.     NULL,

  2284.     decode_close_mp3on4,

  2285.     decode_frame_mp3on4,

  2286.     .flush= flush,

  2287.     .long_name= NULL_IF_CONFIG_SMALL("MP3onMP4"),

  2288. };

  2289. #endif

  2290. #endif