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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 Libav.

  6.  *

  7.  * Libav 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.  * Libav 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 Libav; 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. 

  33. /*

  34.  * TODO:

  35.  *  - test lsf / mpeg25 extensively.

  36.  */

  37. 

  38. #include "mpegaudio.h"

  39. #include "mpegaudiodecheader.h"

  40. 

  41. #if CONFIG_FLOAT

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

  43. #   define compute_antialias compute_antialias_float

  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. #else

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

  52. #   define compute_antialias compute_antialias_integer

  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

  60. #endif

  61. 

  62. /****************/

  63. 

  64. #define HEADER_SIZE 4

  65. 

  66. #include "mpegaudiodata.h"

  67. #include "mpegaudiodectab.h"

  68. 

  69. #if CONFIG_FLOAT

  70. #    include "fft.h"

  71. #else

  72. #    include "dct32.c"

  73. #endif

  74. 

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

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

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

  78. 

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

  80. static VLC huff_vlc[16];

  81. static VLC_TYPE huff_vlc_tables[

  82.   0+128+128+128+130+128+154+166+

  83.   142+204+190+170+542+460+662+414

  84.   ][2];

  85. static const int huff_vlc_tables_sizes[16] = {

  86.   0, 128, 128, 128, 130, 128, 154, 166,

  87.   142, 204, 190, 170, 542, 460, 662, 414

  88. };

  89. static VLC huff_quad_vlc[2];

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

  91. static const int huff_quad_vlc_tables_sizes[2] = {

  92.   128, 16

  93. };

  94. /* computed from band_size_long */

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

  96. #include "mpegaudio_tablegen.h"

  97. /* intensity stereo coef table */

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

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

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

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

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

  103. 

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

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

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

  107. 

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

  109.     division_tab3, division_tab5, NULL, division_tab9

  110. };

  111. 

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

  113. static uint16_t scale_factor_modshift[64];

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

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

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

  117. 

  118. #define SCALE_GEN(v) \

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

  120. 

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

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

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

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

  125. };

  126. 

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

  128. 

  129. /**

  130.  * Convert region offsets to region sizes and truncate

  131.  * size to big_values.

  132.  */

  133. static void ff_region_offset2size(GranuleDef *g){

  134.     int i, k, j=0;

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

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

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

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

  139.         j = k;

  140.     }

  141. }

  142. 

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

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

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

  146.     else {

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

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

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

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

  151.         else

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

  153.     }

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

  155. }

  156. 

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

  158.     int l;

  159.     g->region_size[0] =

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

  161.     /* should not overflow */

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

  163.     g->region_size[1] =

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

  165. }

  166. 

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

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

  169.         if (g->switch_point) {

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

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

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

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

  174.                 g->long_end = 8;

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

  176.                 g->long_end = 6;

  177.             else

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

  179. 

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

  181.         } else {

  182.             g->long_end = 0;

  183.             g->short_start = 0;

  184.         }

  185.     } else {

  186.         g->short_start = 13;

  187.         g->long_end = 22;

  188.     }

  189. }

  190. 

  191. /* layer 1 unscaling */

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

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

  194. {

  195.     int shift, mod;

  196.     int64_t val;

  197. 

  198.     shift = scale_factor_modshift[scale_factor];

  199.     mod = shift & 3;

  200.     shift >>= 2;

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

  202.     shift += n;

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

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

  205. }

  206. 

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

  208. {

  209.     int shift, mod, val;

  210. 

  211.     shift = scale_factor_modshift[scale_factor];

  212.     mod = shift & 3;

  213.     shift >>= 2;

  214. 

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

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

  217.     if (shift > 0)

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

  219.     return val;

  220. }

  221. 

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

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

  224. {

  225.     unsigned int m;

  226.     int e;

  227. 

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

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

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

  231.     assert(e>=1);

  232.     if (e > 31)

  233.         return 0;

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

  235. 

  236.     return m;

  237. }

  238. 

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

  240. #define DEV_ORDER 13

  241. 

  242. #define POW_FRAC_BITS 24

  243. #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)

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

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

  246. 

  247. static int dev_4_3_coefs[DEV_ORDER];

  248. 

  249. static av_cold void int_pow_init(void)

  250. {

  251.     int i, a;

  252. 

  253.     a = POW_FIX(1.0);

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

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

  256.         dev_4_3_coefs[i] = a;

  257.     }

  258. }

  259. 

  260. static av_cold int decode_init(AVCodecContext * avctx)

  261. {

  262.     MPADecodeContext *s = avctx->priv_data;

  263.     static int init=0;

  264.     int i, j, k;

  265. 

  266.     s->avctx = avctx;

  267.     s->apply_window_mp3 = apply_window_mp3_c;

  268. #if HAVE_MMX && CONFIG_FLOAT

  269.     ff_mpegaudiodec_init_mmx(s);

  270. #endif

  271. #if CONFIG_FLOAT

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

  273. #endif

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

  275. 

  276.     avctx->sample_fmt= OUT_FMT;

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

  278. 

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

  280.         int offset;

  281. 

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

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

  284.             int shift, mod;

  285.             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  286.             shift = (i / 3);

  287.             mod = i % 3;

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

  289.         }

  290. 

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

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

  293.             int n, norm;

  294.             n = i + 2;

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

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

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

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

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

  300.                     i, norm,

  301.                     scale_factor_mult[i][0],

  302.                     scale_factor_mult[i][1],

  303.                     scale_factor_mult[i][2]);

  304.         }

  305. 

  306.         RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));

  307. 

  308.         /* huffman decode tables */

  309.         offset = 0;

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

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

  312.             int xsize, x, y;

  313.             uint8_t  tmp_bits [512];

  314.             uint16_t tmp_codes[512];

  315. 

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

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

  318. 

  319.             xsize = h->xsize;

  320. 

  321.             j = 0;

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

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

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

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

  326.                 }

  327.             }

  328. 

  329.             /* XXX: fail test */

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

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

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

  333.                      tmp_bits, 1, 1, tmp_codes, 2, 2,

  334.                      INIT_VLC_USE_NEW_STATIC);

  335.             offset += huff_vlc_tables_sizes[i];

  336.         }

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

  338. 

  339.         offset = 0;

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

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

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

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

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

  345.                      INIT_VLC_USE_NEW_STATIC);

  346.             offset += huff_quad_vlc_tables_sizes[i];

  347.         }

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

  349. 

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

  351.             k = 0;

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

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

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

  355.             }

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

  357.         }

  358. 

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

  360. 

  361.         int_pow_init();

  362.         mpegaudio_tableinit();

  363. 

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

  365.             if (ff_mpa_quant_bits[i] < 0)

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

  367.                     int val1, val2, val3, steps;

  368.                     int val = j;

  369.                     steps  = ff_mpa_quant_steps[i];

  370.                     val1 = val % steps;

  371.                     val /= steps;

  372.                     val2 = val % steps;

  373.                     val3 = val / steps;

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

  375.                 }

  376. 

  377. 

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

  379.             float f;

  380.             INTFLOAT v;

  381.             if (i != 6) {

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

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

  384.             } else {

  385.                 v = FIXR(1.0);

  386.             }

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

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

  389.         }

  390.         /* invalid values */

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

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

  393. 

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

  395.             double f;

  396.             int e, k;

  397. 

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

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

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

  401.                 k = i & 1;

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

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

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

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

  406.             }

  407.         }

  408. 

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

  410.             float ci, cs, ca;

  411.             ci = ci_table[i];

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

  413.             ca = cs * ci;

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

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

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

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

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

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

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

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

  422.         }

  423. 

  424.         /* compute mdct windows */

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

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

  427.                 double d;

  428. 

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

  430.                     continue;

  431. 

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

  433.                 if(j==1){

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

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

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

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

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

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

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

  441.                 }

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

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

  444. 

  445.                 if(j==2)

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

  447.                 else

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

  449.             }

  450.         }

  451. 

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

  453.            the sign of the right window coefs */

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

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

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

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

  458.             }

  459.         }

  460. 

  461.         init = 1;

  462.     }

  463. 

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

  465.         s->adu_mode = 1;

  466.     return 0;

  467. }

  468. 

  469. 

  470. #if CONFIG_FLOAT

  471. static inline float round_sample(float *sum)

  472. {

  473.     float sum1=*sum;

  474.     *sum = 0;

  475.     return sum1;

  476. }

  477. 

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

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

  480. 

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

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

  483. 

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

  485. 

  486. #else

  487. 

  488. static inline int round_sample(int64_t *sum)

  489. {

  490.     int sum1;

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

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

  493.     return av_clip(sum1, OUT_MIN, OUT_MAX);

  494. }

  495. 

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

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

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

  499. #endif

  500. 

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

  502. {                                         \

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

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

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

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

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

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

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

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

  511. }

  512. 

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

  514. {                                               \

  515.     INTFLOAT tmp;\

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  540. }

  541. 

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

  543. {

  544.     int i, j;

  545. 

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

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

  548.         INTFLOAT v;

  549.         v = ff_mpa_enwindow[i];

  550. #if CONFIG_FLOAT

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

  552. #endif

  553.         window[i] = v;

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

  555.             v = -v;

  556.         if (i != 0)

  557.             window[512 - i] = v;

  558.     }

  559. 

  560.     // Needed for avoiding shuffles in ASM implementations

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

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

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

  564. 

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

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

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

  568. }

  569. 

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

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

  572. {

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

  574.     int j;

  575.     OUT_INT *samples2;

  576. #if CONFIG_FLOAT

  577.     float sum, sum2;

  578. #else

  579.     int64_t sum, sum2;

  580. #endif

  581. 

  582.     /* copy to avoid wrap */

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

  584. 

  585.     samples2 = samples + 31 * incr;

  586.     w = window;

  587.     w2 = window + 31;

  588. 

  589.     sum = *dither_state;

  590.     p = synth_buf + 16;

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

  592.     p = synth_buf + 48;

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

  594.     *samples = round_sample(&sum);

  595.     samples += incr;

  596.     w++;

  597. 

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

  599.        access per two sample */

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

  601.         sum2 = 0;

  602.         p = synth_buf + 16 + j;

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

  604.         p = synth_buf + 48 - j;

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

  606. 

  607.         *samples = round_sample(&sum);

  608.         samples += incr;

  609.         sum += sum2;

  610.         *samples2 = round_sample(&sum);

  611.         samples2 -= incr;

  612.         w++;

  613.         w2--;

  614.     }

  615. 

  616.     p = synth_buf + 32;

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

  618.     *samples = round_sample(&sum);

  619.     *dither_state= sum;

  620. }

  621. 

  622. 

  623. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

  624.    32 samples. */

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

  626. #if !CONFIG_FLOAT

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

  628.                          MPA_INT *window, int *dither_state,

  629.                          OUT_INT *samples, int incr,

  630.                          INTFLOAT sb_samples[SBLIMIT])

  631. {

  632.     register MPA_INT *synth_buf;

  633.     int offset;

  634. 

  635.     offset = *synth_buf_offset;

  636.     synth_buf = synth_buf_ptr + offset;

  637. 

  638.     dct32(synth_buf, sb_samples);

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

  640. 

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

  642.     *synth_buf_offset = offset;

  643. }

  644. #endif

  645. 

  646. #define C3 FIXHR(0.86602540378443864676/2)

  647. 

  648. /* 0.5 / cos(pi*(2*i+1)/36) */

  649. static const INTFLOAT icos36[9] = {

  650.     FIXR(0.50190991877167369479),

  651.     FIXR(0.51763809020504152469), //0

  652.     FIXR(0.55168895948124587824),

  653.     FIXR(0.61038729438072803416),

  654.     FIXR(0.70710678118654752439), //1

  655.     FIXR(0.87172339781054900991),

  656.     FIXR(1.18310079157624925896),

  657.     FIXR(1.93185165257813657349), //2

  658.     FIXR(5.73685662283492756461),

  659. };

  660. 

  661. /* 0.5 / cos(pi*(2*i+1)/36) */

  662. static const INTFLOAT icos36h[9] = {

  663.     FIXHR(0.50190991877167369479/2),

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

  665.     FIXHR(0.55168895948124587824/2),

  666.     FIXHR(0.61038729438072803416/2),

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

  668.     FIXHR(0.87172339781054900991/2),

  669.     FIXHR(1.18310079157624925896/4),

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

  671. //    FIXHR(5.73685662283492756461),

  672. };

  673. 

  674. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  675.    cases. */

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

  677. {

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

  679. 

  680.     in0= in[0*3];

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

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

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

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

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

  686.     in5 += in3;

  687.     in3 += in1;

  688. 

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

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

  691. 

  692.     t1 = in0 - in4;

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

  694. 

  695.     out[ 7]=

  696.     out[10]= t1 + t2;

  697.     out[ 1]=

  698.     out[ 4]= t1 - t2;

  699. 

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

  701.     in4 = in0 + in2;

  702.     in5 += 2*in1;

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

  704.     out[ 8]=

  705.     out[ 9]= in4 + in1;

  706.     out[ 2]=

  707.     out[ 3]= in4 - in1;

  708. 

  709.     in0 -= in2;

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

  711.     out[ 0]=

  712.     out[ 5]= in0 - in5;

  713.     out[ 6]=

  714.     out[11]= in0 + in5;

  715. }

  716. 

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

  718. #define C1 FIXHR(0.98480775301220805936/2)

  719. #define C2 FIXHR(0.93969262078590838405/2)

  720. #define C3 FIXHR(0.86602540378443864676/2)

  721. #define C4 FIXHR(0.76604444311897803520/2)

  722. #define C5 FIXHR(0.64278760968653932632/2)

  723. #define C6 FIXHR(0.5/2)

  724. #define C7 FIXHR(0.34202014332566873304/2)

  725. #define C8 FIXHR(0.17364817766693034885/2)

  726. 

  727. 

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

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

  730. {

  731.     int i, j;

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

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

  734. 

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

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

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

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

  739. 

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

  741.         tmp1 = tmp + j;

  742.         in1 = in + j;

  743. 

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

  745. 

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

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

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

  749.         tmp1[16] = t1 + t2;

  750. 

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

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

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

  754. 

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

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

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

  758. 

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

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

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

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

  763. 

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

  765. 

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

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

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

  769.     }

  770. 

  771.     i = 0;

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

  773.         t0 = tmp[i];

  774.         t1 = tmp[i + 2];

  775.         s0 = t1 + t0;

  776.         s2 = t1 - t0;

  777. 

  778.         t2 = tmp[i + 1];

  779.         t3 = tmp[i + 3];

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

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

  782. 

  783.         t0 = s0 + s1;

  784.         t1 = s0 - s1;

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

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

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

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

  789. 

  790.         t0 = s2 + s3;

  791.         t1 = s2 - s3;

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

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

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

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

  796.         i += 4;

  797.     }

  798. 

  799.     s0 = tmp[16];

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

  801.     t0 = s0 + s1;

  802.     t1 = s0 - s1;

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

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

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

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

  807. }

  808. 

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

  810. static int mp_decode_layer1(MPADecodeContext *s)

  811. {

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

  813.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  814.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  815. 

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

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

  818.     else

  819.         bound = SBLIMIT;

  820. 

  821.     /* allocation bits */

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

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

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

  825.         }

  826.     }

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

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

  829.     }

  830. 

  831.     /* scale factors */

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

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

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

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

  836.         }

  837.     }

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

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

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

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

  842.         }

  843.     }

  844. 

  845.     /* compute samples */

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

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

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

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

  850.                 if (n) {

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

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

  853.                 } else {

  854.                     v = 0;

  855.                 }

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

  857.             }

  858.         }

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

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

  861.             if (n) {

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

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

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

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

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

  867.             } else {

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

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

  870.             }

  871.         }

  872.     }

  873.     return 12;

  874. }

  875. 

  876. static int mp_decode_layer2(MPADecodeContext *s)

  877. {

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

  879.     const unsigned char *alloc_table;

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

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

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

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

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

  885. 

  886.     /* select decoding table */

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

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

  889.     sblimit = ff_mpa_sblimit_table[table];

  890.     alloc_table = ff_mpa_alloc_tables[table];

  891. 

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

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

  894.     else

  895.         bound = sblimit;

  896. 

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

  898. 

  899.     /* sanity check */

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

  901. 

  902.     /* parse bit allocation */

  903.     j = 0;

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

  905.         bit_alloc_bits = alloc_table[j];

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

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

  908.         }

  909.         j += 1 << bit_alloc_bits;

  910.     }

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

  912.         bit_alloc_bits = alloc_table[j];

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

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

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

  916.         j += 1 << bit_alloc_bits;

  917.     }

  918. 

  919.     /* scale codes */

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

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

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

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

  924.         }

  925.     }

  926. 

  927.     /* scale factors */

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

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

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

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

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

  933.                 default:

  934.                 case 0:

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

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

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

  938.                     break;

  939.                 case 2:

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

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

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

  943.                     break;

  944.                 case 1:

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

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

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

  948.                     break;

  949.                 case 3:

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

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

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

  953.                     break;

  954.                 }

  955.             }

  956.         }

  957.     }

  958. 

  959.     /* samples */

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

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

  962.             j = 0;

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

  964.                 bit_alloc_bits = alloc_table[j];

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

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

  967.                     if (b) {

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

  969.                         qindex = alloc_table[j+b];

  970.                         bits = ff_mpa_quant_bits[qindex];

  971.                         if (bits < 0) {

  972.                             int v2;

  973.                             /* 3 values at the same time */

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

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

  976.                             steps  = ff_mpa_quant_steps[qindex];

  977. 

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

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

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

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

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

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

  984.                         } else {

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

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

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

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

  989.                             }

  990.                         }

  991.                     } else {

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

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

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

  995.                     }

  996.                 }

  997.                 /* next subband in alloc table */

  998.                 j += 1 << bit_alloc_bits;

  999.             }

  1000.             /* XXX: find a way to avoid this duplication of code */

  1001.             for(i=bound;i<sblimit;i++) {

  1002.                 bit_alloc_bits = alloc_table[j];

  1003.                 b = bit_alloc[0][i];

  1004.                 if (b) {

  1005.                     int mant, scale0, scale1;

  1006.                     scale0 = scale_factors[0][i][k];

  1007.                     scale1 = scale_factors[1][i][k];

  1008.                     qindex = alloc_table[j+b];

  1009.                     bits = ff_mpa_quant_bits[qindex];

  1010.                     if (bits < 0) {

  1011.                         /* 3 values at the same time */

  1012.                         v = get_bits(&s->gb, -bits);

  1013.                         steps = ff_mpa_quant_steps[qindex];

  1014.                         mant = v % steps;

  1015.                         v = v / steps;

  1016.                         s->sb_samples[0][k * 12 + l + 0][i] =

  1017.                             l2_unscale_group(steps, mant, scale0);

  1018.                         s->sb_samples[1][k * 12 + l + 0][i] =

  1019.                             l2_unscale_group(steps, mant, scale1);

  1020.                         mant = v % steps;

  1021.                         v = v / steps;

  1022.                         s->sb_samples[0][k * 12 + l + 1][i] =

  1023.                             l2_unscale_group(steps, mant, scale0);

  1024.                         s->sb_samples[1][k * 12 + l + 1][i] =

  1025.                             l2_unscale_group(steps, mant, scale1);

  1026.                         s->sb_samples[0][k * 12 + l + 2][i] =

  1027.                             l2_unscale_group(steps, v, scale0);

  1028.                         s->sb_samples[1][k * 12 + l + 2][i] =

  1029.                             l2_unscale_group(steps, v, scale1);

  1030.                     } else {

  1031.                         for(m=0;m<3;m++) {

  1032.                             mant = get_bits(&s->gb, bits);

  1033.                             s->sb_samples[0][k * 12 + l + m][i] =

  1034.                                 l1_unscale(bits - 1, mant, scale0);

  1035.                             s->sb_samples[1][k * 12 + l + m][i] =

  1036.                                 l1_unscale(bits - 1, mant, scale1);

  1037.                         }

  1038.                     }

  1039.                 } else {

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

  1041.                     s->sb_samples[0][k * 12 + l + 1][i] = 0;

  1042.                     s->sb_samples[0][k * 12 + l + 2][i] = 0;

  1043.                     s->sb_samples[1][k * 12 + l + 0][i] = 0;

  1044.                     s->sb_samples[1][k * 12 + l + 1][i] = 0;

  1045.                     s->sb_samples[1][k * 12 + l + 2][i] = 0;

  1046.                 }

  1047.                 /* next subband in alloc table */

  1048.                 j += 1 << bit_alloc_bits;

  1049.             }

  1050.             /* fill remaining samples to zero */

  1051.             for(i=sblimit;i<SBLIMIT;i++) {

  1052.                 for(ch=0;ch<s->nb_channels;ch++) {

  1053.                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1054.                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1055.                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1056.                 }

  1057.             }

  1058.         }

  1059.     }

  1060.     return 3 * 12;

  1061. }

  1062. 

  1063. #define SPLIT(dst,sf,n)\

  1064.     if(n==3){\

  1065.         int m= (sf*171)>>9;\

  1066.         dst= sf - 3*m;\

  1067.         sf=m;\

  1068.     }else if(n==4){\

  1069.         dst= sf&3;\

  1070.         sf>>=2;\

  1071.     }else if(n==5){\

  1072.         int m= (sf*205)>>10;\

  1073.         dst= sf - 5*m;\

  1074.         sf=m;\

  1075.     }else if(n==6){\

  1076.         int m= (sf*171)>>10;\

  1077.         dst= sf - 6*m;\

  1078.         sf=m;\

  1079.     }else{\

  1080.         dst=0;\

  1081.     }

  1082. 

  1083. static av_always_inline void lsf_sf_expand(int *slen,

  1084.                                  int sf, int n1, int n2, int n3)

  1085. {

  1086.     SPLIT(slen[3], sf, n3)

  1087.     SPLIT(slen[2], sf, n2)

  1088.     SPLIT(slen[1], sf, n1)

  1089.     slen[0] = sf;

  1090. }

  1091. 

  1092. static void exponents_from_scale_factors(MPADecodeContext *s,

  1093.                                          GranuleDef *g,

  1094.                                          int16_t *exponents)

  1095. {

  1096.     const uint8_t *bstab, *pretab;

  1097.     int len, i, j, k, l, v0, shift, gain, gains[3];

  1098.     int16_t *exp_ptr;

  1099. 

  1100.     exp_ptr = exponents;

  1101.     gain = g->global_gain - 210;

  1102.     shift = g->scalefac_scale + 1;

  1103. 

  1104.     bstab = band_size_long[s->sample_rate_index];

  1105.     pretab = mpa_pretab[g->preflag];

  1106.     for(i=0;i<g->long_end;i++) {

  1107.         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;

  1108.         len = bstab[i];

  1109.         for(j=len;j>0;j--)

  1110.             *exp_ptr++ = v0;

  1111.     }

  1112. 

  1113.     if (g->short_start < 13) {

  1114.         bstab = band_size_short[s->sample_rate_index];

  1115.         gains[0] = gain - (g->subblock_gain[0] << 3);

  1116.         gains[1] = gain - (g->subblock_gain[1] << 3);

  1117.         gains[2] = gain - (g->subblock_gain[2] << 3);

  1118.         k = g->long_end;

  1119.         for(i=g->short_start;i<13;i++) {

  1120.             len = bstab[i];

  1121.             for(l=0;l<3;l++) {

  1122.                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;

  1123.                 for(j=len;j>0;j--)

  1124.                 *exp_ptr++ = v0;

  1125.             }

  1126.         }

  1127.     }

  1128. }

  1129. 

  1130. /* handle n = 0 too */

  1131. static inline int get_bitsz(GetBitContext *s, int n)

  1132. {

  1133.     if (n == 0)

  1134.         return 0;

  1135.     else

  1136.         return get_bits(s, n);

  1137. }

  1138. 

  1139. 

  1140. static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos, int *end_pos2){

  1141.     if(s->in_gb.buffer && *pos >= s->gb.size_in_bits){

  1142.         s->gb= s->in_gb;

  1143.         s->in_gb.buffer=NULL;

  1144.         assert((get_bits_count(&s->gb) & 7) == 0);

  1145.         skip_bits_long(&s->gb, *pos - *end_pos);

  1146.         *end_pos2=

  1147.         *end_pos= *end_pos2 + get_bits_count(&s->gb) - *pos;

  1148.         *pos= get_bits_count(&s->gb);

  1149.     }

  1150. }

  1151. 

  1152. /* Following is a optimized code for

  1153.             INTFLOAT v = *src

  1154.             if(get_bits1(&s->gb))

  1155.                 v = -v;

  1156.             *dst = v;

  1157. */

  1158. #if CONFIG_FLOAT

  1159. #define READ_FLIP_SIGN(dst,src)\

  1160.             v = AV_RN32A(src) ^ (get_bits1(&s->gb)<<31);\

  1161.             AV_WN32A(dst, v);

  1162. #else

  1163. #define READ_FLIP_SIGN(dst,src)\

  1164.             v= -get_bits1(&s->gb);\

  1165.             *(dst) = (*(src) ^ v) - v;

  1166. #endif

  1167. 

  1168. static int huffman_decode(MPADecodeContext *s, GranuleDef *g,

  1169.                           int16_t *exponents, int end_pos2)

  1170. {

  1171.     int s_index;

  1172.     int i;

  1173.     int last_pos, bits_left;

  1174.     VLC *vlc;

  1175.     int end_pos= FFMIN(end_pos2, s->gb.size_in_bits);

  1176. 

  1177.     /* low frequencies (called big values) */

  1178.     s_index = 0;

  1179.     for(i=0;i<3;i++) {

  1180.         int j, k, l, linbits;

  1181.         j = g->region_size[i];

  1182.         if (j == 0)

  1183.             continue;

  1184.         /* select vlc table */

  1185.         k = g->table_select[i];

  1186.         l = mpa_huff_data[k][0];

  1187.         linbits = mpa_huff_data[k][1];

  1188.         vlc = &huff_vlc[l];

  1189. 

  1190.         if(!l){

  1191.             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*2*j);

  1192.             s_index += 2*j;

  1193.             continue;

  1194.         }

  1195. 

  1196.         /* read huffcode and compute each couple */

  1197.         for(;j>0;j--) {

  1198.             int exponent, x, y;

  1199.             int v;

  1200.             int pos= get_bits_count(&s->gb);

  1201. 

  1202.             if (pos >= end_pos){

  1203. //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1204.                 switch_buffer(s, &pos, &end_pos, &end_pos2);

  1205. //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);

  1206.                 if(pos >= end_pos)

  1207.                     break;

  1208.             }

  1209.             y = get_vlc2(&s->gb, vlc->table, 7, 3);

  1210. 

  1211.             if(!y){

  1212.                 g->sb_hybrid[s_index  ] =

  1213.                 g->sb_hybrid[s_index+1] = 0;

  1214.                 s_index += 2;

  1215.                 continue;

  1216.             }

  1217. 

  1218.             exponent= exponents[s_index];

  1219. 

  1220.             av_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",

  1221.                     i, g->region_size[i] - j, x, y, exponent);

  1222.             if(y&16){

  1223.                 x = y >> 5;

  1224.                 y = y & 0x0f;

  1225.                 if (x < 15){

  1226.                     READ_FLIP_SIGN(g->sb_hybrid+s_index, RENAME(expval_table)[ exponent ]+x)

  1227.                 }else{

  1228.                     x += get_bitsz(&s->gb, linbits);

  1229.                     v = l3_unscale(x, exponent);

  1230.                     if (get_bits1(&s->gb))

  1231.                         v = -v;

  1232.                     g->sb_hybrid[s_index] = v;

  1233.                 }

  1234.                 if (y < 15){

  1235.                     READ_FLIP_SIGN(g->sb_hybrid+s_index+1, RENAME(expval_table)[ exponent ]+y)

  1236.                 }else{

  1237.                     y += get_bitsz(&s->gb, linbits);

  1238.                     v = l3_unscale(y, exponent);

  1239.                     if (get_bits1(&s->gb))

  1240.                         v = -v;

  1241.                     g->sb_hybrid[s_index+1] = v;

  1242.                 }

  1243.             }else{

  1244.                 x = y >> 5;

  1245.                 y = y & 0x0f;

  1246.                 x += y;

  1247.                 if (x < 15){

  1248.                     READ_FLIP_SIGN(g->sb_hybrid+s_index+!!y, RENAME(expval_table)[ exponent ]+x)

  1249.                 }else{

  1250.                     x += get_bitsz(&s->gb, linbits);

  1251.                     v = l3_unscale(x, exponent);

  1252.                     if (get_bits1(&s->gb))

  1253.                         v = -v;

  1254.                     g->sb_hybrid[s_index+!!y] = v;

  1255.                 }

  1256.                 g->sb_hybrid[s_index+ !y] = 0;

  1257.             }

  1258.             s_index+=2;

  1259.         }

  1260.     }

  1261. 

  1262.     /* high frequencies */

  1263.     vlc = &huff_quad_vlc[g->count1table_select];

  1264.     last_pos=0;

  1265.     while (s_index <= 572) {

  1266.         int pos, code;

  1267.         pos = get_bits_count(&s->gb);

  1268.         if (pos >= end_pos) {

  1269.             if (pos > end_pos2 && last_pos){

  1270.                 /* some encoders generate an incorrect size for this

  1271.                    part. We must go back into the data */

  1272.                 s_index -= 4;

  1273.                 skip_bits_long(&s->gb, last_pos - pos);

  1274.                 av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);

  1275.                 if(s->error_recognition >= FF_ER_COMPLIANT)

  1276.                     s_index=0;

  1277.                 break;

  1278.             }

  1279. //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1280.             switch_buffer(s, &pos, &end_pos, &end_pos2);

  1281. //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);

  1282.             if(pos >= end_pos)

  1283.                 break;

  1284.         }

  1285.         last_pos= pos;

  1286. 

  1287.         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);

  1288.         av_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);

  1289.         g->sb_hybrid[s_index+0]=

  1290.         g->sb_hybrid[s_index+1]=

  1291.         g->sb_hybrid[s_index+2]=

  1292.         g->sb_hybrid[s_index+3]= 0;

  1293.         while(code){

  1294.             static const int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};

  1295.             int v;

  1296.             int pos= s_index+idxtab[code];

  1297.             code ^= 8>>idxtab[code];

  1298.             READ_FLIP_SIGN(g->sb_hybrid+pos, RENAME(exp_table)+exponents[pos])

  1299.         }

  1300.         s_index+=4;

  1301.     }

  1302.     /* skip extension bits */

  1303.     bits_left = end_pos2 - get_bits_count(&s->gb);

  1304. //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);

  1305.     if (bits_left < 0 && s->error_recognition >= FF_ER_COMPLIANT) {

  1306.         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1307.         s_index=0;

  1308.     }else if(bits_left > 0 && s->error_recognition >= FF_ER_AGGRESSIVE){

  1309.         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1310.         s_index=0;

  1311.     }

  1312.     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*(576 - s_index));

  1313.     skip_bits_long(&s->gb, bits_left);

  1314. 

  1315.     i= get_bits_count(&s->gb);

  1316.     switch_buffer(s, &i, &end_pos, &end_pos2);

  1317. 

  1318.     return 0;

  1319. }

  1320. 

  1321. /* Reorder short blocks from bitstream order to interleaved order. It

  1322.    would be faster to do it in parsing, but the code would be far more

  1323.    complicated */

  1324. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1325. {

  1326.     int i, j, len;

  1327.     INTFLOAT *ptr, *dst, *ptr1;

  1328.     INTFLOAT tmp[576];

  1329. 

  1330.     if (g->block_type != 2)

  1331.         return;

  1332. 

  1333.     if (g->switch_point) {

  1334.         if (s->sample_rate_index != 8) {

  1335.             ptr = g->sb_hybrid + 36;

  1336.         } else {

  1337.             ptr = g->sb_hybrid + 48;

  1338.         }

  1339.     } else {

  1340.         ptr = g->sb_hybrid;

  1341.     }

  1342. 

  1343.     for(i=g->short_start;i<13;i++) {

  1344.         len = band_size_short[s->sample_rate_index][i];

  1345.         ptr1 = ptr;

  1346.         dst = tmp;

  1347.         for(j=len;j>0;j--) {

  1348.             *dst++ = ptr[0*len];

  1349.             *dst++ = ptr[1*len];

  1350.             *dst++ = ptr[2*len];

  1351.             ptr++;

  1352.         }

  1353.         ptr+=2*len;

  1354.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1355.     }

  1356. }

  1357. 

  1358. #define ISQRT2 FIXR(0.70710678118654752440)

  1359. 

  1360. static void compute_stereo(MPADecodeContext *s,

  1361.                            GranuleDef *g0, GranuleDef *g1)

  1362. {

  1363.     int i, j, k, l;

  1364.     int sf_max, sf, len, non_zero_found;

  1365.     INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;

  1366.     int non_zero_found_short[3];

  1367. 

  1368.     /* intensity stereo */

  1369.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1370.         if (!s->lsf) {

  1371.             is_tab = is_table;

  1372.             sf_max = 7;

  1373.         } else {

  1374.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1375.             sf_max = 16;

  1376.         }

  1377. 

  1378.         tab0 = g0->sb_hybrid + 576;

  1379.         tab1 = g1->sb_hybrid + 576;

  1380. 

  1381.         non_zero_found_short[0] = 0;

  1382.         non_zero_found_short[1] = 0;

  1383.         non_zero_found_short[2] = 0;

  1384.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1385.         for(i = 12;i >= g1->short_start;i--) {

  1386.             /* for last band, use previous scale factor */

  1387.             if (i != 11)

  1388.                 k -= 3;

  1389.             len = band_size_short[s->sample_rate_index][i];

  1390.             for(l=2;l>=0;l--) {

  1391.                 tab0 -= len;

  1392.                 tab1 -= len;

  1393.                 if (!non_zero_found_short[l]) {

  1394.                     /* test if non zero band. if so, stop doing i-stereo */

  1395.                     for(j=0;j<len;j++) {

  1396.                         if (tab1[j] != 0) {

  1397.                             non_zero_found_short[l] = 1;

  1398.                             goto found1;

  1399.                         }

  1400.                     }

  1401.                     sf = g1->scale_factors[k + l];

  1402.                     if (sf >= sf_max)

  1403.                         goto found1;

  1404. 

  1405.                     v1 = is_tab[0][sf];

  1406.                     v2 = is_tab[1][sf];

  1407.                     for(j=0;j<len;j++) {

  1408.                         tmp0 = tab0[j];

  1409.                         tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1410.                         tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1411.                     }

  1412.                 } else {

  1413.                 found1:

  1414.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1415.                         /* lower part of the spectrum : do ms stereo

  1416.                            if enabled */

  1417.                         for(j=0;j<len;j++) {

  1418.                             tmp0 = tab0[j];

  1419.                             tmp1 = tab1[j];

  1420.                             tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1421.                             tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1422.                         }

  1423.                     }

  1424.                 }

  1425.             }

  1426.         }

  1427. 

  1428.         non_zero_found = non_zero_found_short[0] |

  1429.             non_zero_found_short[1] |

  1430.             non_zero_found_short[2];

  1431. 

  1432.         for(i = g1->long_end - 1;i >= 0;i--) {

  1433.             len = band_size_long[s->sample_rate_index][i];

  1434.             tab0 -= len;

  1435.             tab1 -= len;

  1436.             /* test if non zero band. if so, stop doing i-stereo */

  1437.             if (!non_zero_found) {

  1438.                 for(j=0;j<len;j++) {

  1439.                     if (tab1[j] != 0) {

  1440.                         non_zero_found = 1;

  1441.                         goto found2;

  1442.                     }

  1443.                 }

  1444.                 /* for last band, use previous scale factor */

  1445.                 k = (i == 21) ? 20 : i;

  1446.                 sf = g1->scale_factors[k];

  1447.                 if (sf >= sf_max)

  1448.                     goto found2;

  1449.                 v1 = is_tab[0][sf];

  1450.                 v2 = is_tab[1][sf];

  1451.                 for(j=0;j<len;j++) {

  1452.                     tmp0 = tab0[j];

  1453.                     tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1454.                     tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1455.                 }

  1456.             } else {

  1457.             found2:

  1458.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1459.                     /* lower part of the spectrum : do ms stereo

  1460.                        if enabled */

  1461.                     for(j=0;j<len;j++) {

  1462.                         tmp0 = tab0[j];

  1463.                         tmp1 = tab1[j];

  1464.                         tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1465.                         tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1466.                     }

  1467.                 }

  1468.             }

  1469.         }

  1470.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1471.         /* ms stereo ONLY */

  1472.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1473.            global gain */

  1474.         tab0 = g0->sb_hybrid;

  1475.         tab1 = g1->sb_hybrid;

  1476.         for(i=0;i<576;i++) {

  1477.             tmp0 = tab0[i];

  1478.             tmp1 = tab1[i];

  1479.             tab0[i] = tmp0 + tmp1;

  1480.             tab1[i] = tmp0 - tmp1;

  1481.         }

  1482.     }

  1483. }

  1484. 

  1485. #if !CONFIG_FLOAT

  1486. static void compute_antialias_integer(MPADecodeContext *s,

  1487.                               GranuleDef *g)

  1488. {

  1489.     int32_t *ptr, *csa;

  1490.     int n, i;

  1491. 

  1492.     /* we antialias only "long" bands */

  1493.     if (g->block_type == 2) {

  1494.         if (!g->switch_point)

  1495.             return;

  1496.         /* XXX: check this for 8000Hz case */

  1497.         n = 1;

  1498.     } else {

  1499.         n = SBLIMIT - 1;

  1500.     }

  1501. 

  1502.     ptr = g->sb_hybrid + 18;

  1503.     for(i = n;i > 0;i--) {

  1504.         int tmp0, tmp1, tmp2;

  1505.         csa = &csa_table[0][0];

  1506. #define INT_AA(j) \

  1507.             tmp0 = ptr[-1-j];\

  1508.             tmp1 = ptr[   j];\

  1509.             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\

  1510.             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\

  1511.             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));

  1512. 

  1513.         INT_AA(0)

  1514.         INT_AA(1)

  1515.         INT_AA(2)

  1516.         INT_AA(3)

  1517.         INT_AA(4)

  1518.         INT_AA(5)

  1519.         INT_AA(6)

  1520.         INT_AA(7)

  1521. 

  1522.         ptr += 18;

  1523.     }

  1524. }

  1525. #endif

  1526. 

  1527. static void compute_imdct(MPADecodeContext *s,

  1528.                           GranuleDef *g,

  1529.                           INTFLOAT *sb_samples,

  1530.                           INTFLOAT *mdct_buf)

  1531. {

  1532.     INTFLOAT *win, *win1, *out_ptr, *ptr, *buf, *ptr1;

  1533.     INTFLOAT out2[12];

  1534.     int i, j, mdct_long_end, sblimit;

  1535. 

  1536.     /* find last non zero block */

  1537.     ptr = g->sb_hybrid + 576;

  1538.     ptr1 = g->sb_hybrid + 2 * 18;

  1539.     while (ptr >= ptr1) {

  1540.         int32_t *p;

  1541.         ptr -= 6;

  1542.         p= (int32_t*)ptr;

  1543.         if(p[0] | p[1] | p[2] | p[3] | p[4] | p[5])

  1544.             break;

  1545.     }

  1546.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  1547. 

  1548.     if (g->block_type == 2) {

  1549.         /* XXX: check for 8000 Hz */

  1550.         if (g->switch_point)

  1551.             mdct_long_end = 2;

  1552.         else

  1553.             mdct_long_end = 0;

  1554.     } else {

  1555.         mdct_long_end = sblimit;

  1556.     }

  1557. 

  1558.     buf = mdct_buf;

  1559.     ptr = g->sb_hybrid;

  1560.     for(j=0;j<mdct_long_end;j++) {

  1561.         /* apply window & overlap with previous buffer */

  1562.         out_ptr = sb_samples + j;

  1563.         /* select window */

  1564.         if (g->switch_point && j < 2)

  1565.             win1 = mdct_win[0];

  1566.         else

  1567.             win1 = mdct_win[g->block_type];

  1568.         /* select frequency inversion */

  1569.         win = win1 + ((4 * 36) & -(j & 1));

  1570.         imdct36(out_ptr, buf, ptr, win);

  1571.         out_ptr += 18*SBLIMIT;

  1572.         ptr += 18;

  1573.         buf += 18;

  1574.     }

  1575.     for(j=mdct_long_end;j<sblimit;j++) {

  1576.         /* select frequency inversion */

  1577.         win = mdct_win[2] + ((4 * 36) & -(j & 1));

  1578.         out_ptr = sb_samples + j;

  1579. 

  1580.         for(i=0; i<6; i++){

  1581.             *out_ptr = buf[i];

  1582.             out_ptr += SBLIMIT;

  1583.         }

  1584.         imdct12(out2, ptr + 0);

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

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

  1587.             buf[i + 6*2] = MULH3(out2[i + 6], win[i + 6], 1);

  1588.             out_ptr += SBLIMIT;

  1589.         }

  1590.         imdct12(out2, ptr + 1);

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

  1592.             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[i + 6*2];

  1593.             buf[i + 6*0] = MULH3(out2[i + 6], win[i + 6], 1);

  1594.             out_ptr += SBLIMIT;

  1595.         }

  1596.         imdct12(out2, ptr + 2);

  1597.         for(i=0;i<6;i++) {

  1598.             buf[i + 6*0] = MULH3(out2[i    ], win[i    ], 1) + buf[i + 6*0];

  1599.             buf[i + 6*1] = MULH3(out2[i + 6], win[i + 6], 1);

  1600.             buf[i + 6*2] = 0;

  1601.         }

  1602.         ptr += 18;

  1603.         buf += 18;

  1604.     }

  1605.     /* zero bands */

  1606.     for(j=sblimit;j<SBLIMIT;j++) {

  1607.         /* overlap */

  1608.         out_ptr = sb_samples + j;

  1609.         for(i=0;i<18;i++) {

  1610.             *out_ptr = buf[i];

  1611.             buf[i] = 0;

  1612.             out_ptr += SBLIMIT;

  1613.         }

  1614.         buf += 18;

  1615.     }

  1616. }

  1617. 

  1618. /* main layer3 decoding function */

  1619. static int mp_decode_layer3(MPADecodeContext *s)

  1620. {

  1621.     int nb_granules, main_data_begin, private_bits;

  1622.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  1623.     GranuleDef *g;

  1624.     int16_t exponents[576]; //FIXME try INTFLOAT

  1625. 

  1626.     /* read side info */

  1627.     if (s->lsf) {

  1628.         main_data_begin = get_bits(&s->gb, 8);

  1629.         private_bits = get_bits(&s->gb, s->nb_channels);

  1630.         nb_granules = 1;

  1631.     } else {

  1632.         main_data_begin = get_bits(&s->gb, 9);

  1633.         if (s->nb_channels == 2)

  1634.             private_bits = get_bits(&s->gb, 3);

  1635.         else

  1636.             private_bits = get_bits(&s->gb, 5);

  1637.         nb_granules = 2;

  1638.         for(ch=0;ch<s->nb_channels;ch++) {

  1639.             s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */

  1640.             s->granules[ch][1].scfsi = get_bits(&s->gb, 4);

  1641.         }

  1642.     }

  1643. 

  1644.     for(gr=0;gr<nb_granules;gr++) {

  1645.         for(ch=0;ch<s->nb_channels;ch++) {

  1646.             av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);

  1647.             g = &s->granules[ch][gr];

  1648.             g->part2_3_length = get_bits(&s->gb, 12);

  1649.             g->big_values = get_bits(&s->gb, 9);

  1650.             if(g->big_values > 288){

  1651.                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");

  1652.                 return -1;

  1653.             }

  1654. 

  1655.             g->global_gain = get_bits(&s->gb, 8);

  1656.             /* if MS stereo only is selected, we precompute the

  1657.                1/sqrt(2) renormalization factor */

  1658.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  1659.                 MODE_EXT_MS_STEREO)

  1660.                 g->global_gain -= 2;

  1661.             if (s->lsf)

  1662.                 g->scalefac_compress = get_bits(&s->gb, 9);

  1663.             else

  1664.                 g->scalefac_compress = get_bits(&s->gb, 4);

  1665.             blocksplit_flag = get_bits1(&s->gb);

  1666.             if (blocksplit_flag) {

  1667.                 g->block_type = get_bits(&s->gb, 2);

  1668.                 if (g->block_type == 0){

  1669.                     av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");

  1670.                     return -1;

  1671.                 }

  1672.                 g->switch_point = get_bits1(&s->gb);

  1673.                 for(i=0;i<2;i++)

  1674.                     g->table_select[i] = get_bits(&s->gb, 5);

  1675.                 for(i=0;i<3;i++)

  1676.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  1677.                 ff_init_short_region(s, g);

  1678.             } else {

  1679.                 int region_address1, region_address2;

  1680.                 g->block_type = 0;

  1681.                 g->switch_point = 0;

  1682.                 for(i=0;i<3;i++)

  1683.                     g->table_select[i] = get_bits(&s->gb, 5);

  1684.                 /* compute huffman coded region sizes */

  1685.                 region_address1 = get_bits(&s->gb, 4);

  1686.                 region_address2 = get_bits(&s->gb, 3);

  1687.                 av_dlog(s->avctx, "region1=%d region2=%d\n",

  1688.                         region_address1, region_address2);

  1689.                 ff_init_long_region(s, g, region_address1, region_address2);

  1690.             }

  1691.             ff_region_offset2size(g);

  1692.             ff_compute_band_indexes(s, g);

  1693. 

  1694.             g->preflag = 0;

  1695.             if (!s->lsf)

  1696.                 g->preflag = get_bits1(&s->gb);

  1697.             g->scalefac_scale = get_bits1(&s->gb);

  1698.             g->count1table_select = get_bits1(&s->gb);

  1699.             av_dlog(s->avctx, "block_type=%d switch_point=%d\n",

  1700.                     g->block_type, g->switch_point);

  1701.         }

  1702.     }

  1703. 

  1704.   if (!s->adu_mode) {

  1705.     const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  1706.     assert((get_bits_count(&s->gb) & 7) == 0);

  1707.     /* now we get bits from the main_data_begin offset */

  1708.     av_dlog(s->avctx, "seekback: %d\n", main_data_begin);

  1709. //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);

  1710. 

  1711.     memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);

  1712.     s->in_gb= s->gb;

  1713.         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);

  1714.         skip_bits_long(&s->gb, 8*(s->last_buf_size - main_data_begin));

  1715.   }

  1716. 

  1717.     for(gr=0;gr<nb_granules;gr++) {

  1718.         for(ch=0;ch<s->nb_channels;ch++) {

  1719.             g = &s->granules[ch][gr];

  1720.             if(get_bits_count(&s->gb)<0){

  1721.                 av_log(s->avctx, AV_LOG_DEBUG, "mdb:%d, lastbuf:%d skipping granule %d\n",

  1722.                                             main_data_begin, s->last_buf_size, gr);

  1723.                 skip_bits_long(&s->gb, g->part2_3_length);

  1724.                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));

  1725.                 if(get_bits_count(&s->gb) >= s->gb.size_in_bits && s->in_gb.buffer){

  1726.                     skip_bits_long(&s->in_gb, get_bits_count(&s->gb) - s->gb.size_in_bits);

  1727.                     s->gb= s->in_gb;

  1728.                     s->in_gb.buffer=NULL;

  1729.                 }

  1730.                 continue;

  1731.             }

  1732. 

  1733.             bits_pos = get_bits_count(&s->gb);

  1734. 

  1735.             if (!s->lsf) {

  1736.                 uint8_t *sc;

  1737.                 int slen, slen1, slen2;

  1738. 

  1739.                 /* MPEG1 scale factors */

  1740.                 slen1 = slen_table[0][g->scalefac_compress];

  1741.                 slen2 = slen_table[1][g->scalefac_compress];

  1742.                 av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);

  1743.                 if (g->block_type == 2) {

  1744.                     n = g->switch_point ? 17 : 18;

  1745.                     j = 0;

  1746.                     if(slen1){

  1747.                         for(i=0;i<n;i++)

  1748.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  1749.                     }else{

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

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

  1752.                     }

  1753.                     if(slen2){

  1754.                         for(i=0;i<18;i++)

  1755.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  1756.                         for(i=0;i<3;i++)

  1757.                             g->scale_factors[j++] = 0;

  1758.                     }else{

  1759.                         for(i=0;i<21;i++)

  1760.                             g->scale_factors[j++] = 0;

  1761.                     }

  1762.                 } else {

  1763.                     sc = s->granules[ch][0].scale_factors;

  1764.                     j = 0;

  1765.                     for(k=0;k<4;k++) {

  1766.                         n = (k == 0 ? 6 : 5);

  1767.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  1768.                             slen = (k < 2) ? slen1 : slen2;

  1769.                             if(slen){

  1770.                                 for(i=0;i<n;i++)

  1771.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  1772.                             }else{

  1773.                                 for(i=0;i<n;i++)

  1774.                                     g->scale_factors[j++] = 0;

  1775.                             }

  1776.                         } else {

  1777.                             /* simply copy from last granule */

  1778.                             for(i=0;i<n;i++) {

  1779.                                 g->scale_factors[j] = sc[j];

  1780.                                 j++;

  1781.                             }

  1782.                         }

  1783.                     }

  1784.                     g->scale_factors[j++] = 0;

  1785.                 }

  1786.             } else {

  1787.                 int tindex, tindex2, slen[4], sl, sf;

  1788. 

  1789.                 /* LSF scale factors */

  1790.                 if (g->block_type == 2) {

  1791.                     tindex = g->switch_point ? 2 : 1;

  1792.                 } else {

  1793.                     tindex = 0;

  1794.                 }

  1795.                 sf = g->scalefac_compress;

  1796.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  1797.                     /* intensity stereo case */

  1798.                     sf >>= 1;

  1799.                     if (sf < 180) {

  1800.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  1801.                         tindex2 = 3;

  1802.                     } else if (sf < 244) {

  1803.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  1804.                         tindex2 = 4;

  1805.                     } else {

  1806.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  1807.                         tindex2 = 5;

  1808.                     }

  1809.                 } else {

  1810.                     /* normal case */

  1811.                     if (sf < 400) {

  1812.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  1813.                         tindex2 = 0;

  1814.                     } else if (sf < 500) {

  1815.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  1816.                         tindex2 = 1;

  1817.                     } else {

  1818.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  1819.                         tindex2 = 2;

  1820.                         g->preflag = 1;

  1821.                     }

  1822.                 }

  1823. 

  1824.                 j = 0;

  1825.                 for(k=0;k<4;k++) {

  1826.                     n = lsf_nsf_table[tindex2][tindex][k];

  1827.                     sl = slen[k];

  1828.                     if(sl){

  1829.                         for(i=0;i<n;i++)

  1830.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  1831.                     }else{

  1832.                         for(i=0;i<n;i++)

  1833.                             g->scale_factors[j++] = 0;

  1834.                     }

  1835.                 }

  1836.                 /* XXX: should compute exact size */

  1837.                 for(;j<40;j++)

  1838.                     g->scale_factors[j] = 0;

  1839.             }

  1840. 

  1841.             exponents_from_scale_factors(s, g, exponents);

  1842. 

  1843.             /* read Huffman coded residue */

  1844.             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);

  1845.         } /* ch */

  1846. 

  1847.         if (s->nb_channels == 2)

  1848.             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);

  1849. 

  1850.         for(ch=0;ch<s->nb_channels;ch++) {

  1851.             g = &s->granules[ch][gr];

  1852. 

  1853.             reorder_block(s, g);

  1854.             compute_antialias(s, g);

  1855.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  1856.         }

  1857.     } /* gr */

  1858.     if(get_bits_count(&s->gb)<0)

  1859.         skip_bits_long(&s->gb, -get_bits_count(&s->gb));

  1860.     return nb_granules * 18;

  1861. }

  1862. 

  1863. static int mp_decode_frame(MPADecodeContext *s,

  1864.                            OUT_INT *samples, const uint8_t *buf, int buf_size)

  1865. {

  1866.     int i, nb_frames, ch;

  1867.     OUT_INT *samples_ptr;

  1868. 

  1869.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)*8);

  1870. 

  1871.     /* skip error protection field */

  1872.     if (s->error_protection)

  1873.         skip_bits(&s->gb, 16);

  1874. 

  1875.     av_dlog(s->avctx, "frame %d:\n", s->frame_count);

  1876.     switch(s->layer) {

  1877.     case 1:

  1878.         s->avctx->frame_size = 384;

  1879.         nb_frames = mp_decode_layer1(s);

  1880.         break;

  1881.     case 2:

  1882.         s->avctx->frame_size = 1152;

  1883.         nb_frames = mp_decode_layer2(s);

  1884.         break;

  1885.     case 3:

  1886.         s->avctx->frame_size = s->lsf ? 576 : 1152;

  1887.     default:

  1888.         nb_frames = mp_decode_layer3(s);

  1889. 

  1890.         s->last_buf_size=0;

  1891.         if(s->in_gb.buffer){

  1892.             align_get_bits(&s->gb);

  1893.             i= get_bits_left(&s->gb)>>3;

  1894.             if(i >= 0 && i <= BACKSTEP_SIZE){

  1895.                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);

  1896.                 s->last_buf_size=i;

  1897.             }else

  1898.                 av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);

  1899.             s->gb= s->in_gb;

  1900.             s->in_gb.buffer= NULL;

  1901.         }

  1902. 

  1903.         align_get_bits(&s->gb);

  1904.         assert((get_bits_count(&s->gb) & 7) == 0);

  1905.         i= get_bits_left(&s->gb)>>3;

  1906. 

  1907.         if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){

  1908.             if(i<0)

  1909.                 av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);

  1910.             i= FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);

  1911.         }

  1912.         assert(i <= buf_size - HEADER_SIZE && i>= 0);

  1913.         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);

  1914.         s->last_buf_size += i;

  1915. 

  1916.         break;

  1917.     }

  1918. 

  1919.     /* apply the synthesis filter */

  1920.     for(ch=0;ch<s->nb_channels;ch++) {

  1921.         samples_ptr = samples + ch;

  1922.         for(i=0;i<nb_frames;i++) {

  1923.             RENAME(ff_mpa_synth_filter)(

  1924. #if CONFIG_FLOAT

  1925.                          s,

  1926. #endif

  1927.                          s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  1928.                          RENAME(ff_mpa_synth_window), &s->dither_state,

  1929.                          samples_ptr, s->nb_channels,

  1930.                          s->sb_samples[ch][i]);

  1931.             samples_ptr += 32 * s->nb_channels;

  1932.         }

  1933.     }

  1934. 

  1935.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  1936. }

  1937. 

  1938. static int decode_frame(AVCodecContext * avctx,

  1939.                         void *data, int *data_size,

  1940.                         AVPacket *avpkt)

  1941. {

  1942.     const uint8_t *buf = avpkt->data;

  1943.     int buf_size = avpkt->size;

  1944.     MPADecodeContext *s = avctx->priv_data;

  1945.     uint32_t header;

  1946.     int out_size;

  1947.     OUT_INT *out_samples = data;

  1948. 

  1949.     if(buf_size < HEADER_SIZE)

  1950.         return -1;

  1951. 

  1952.     header = AV_RB32(buf);

  1953.     if(ff_mpa_check_header(header) < 0){

  1954.         av_log(avctx, AV_LOG_ERROR, "Header missing\n");

  1955.         return -1;

  1956.     }

  1957. 

  1958.     if (ff_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {

  1959.         /* free format: prepare to compute frame size */

  1960.         s->frame_size = -1;

  1961.         return -1;

  1962.     }

  1963.     /* update codec info */

  1964.     avctx->channels = s->nb_channels;

  1965.     avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;

  1966.     if (!avctx->bit_rate)

  1967.         avctx->bit_rate = s->bit_rate;

  1968.     avctx->sub_id = s->layer;

  1969. 

  1970.     if(*data_size < 1152*avctx->channels*sizeof(OUT_INT))

  1971.         return -1;

  1972.     *data_size = 0;

  1973. 

  1974.     if(s->frame_size<=0 || s->frame_size > buf_size){

  1975.         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

  1976.         return -1;

  1977.     }else if(s->frame_size < buf_size){

  1978.         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");

  1979.         buf_size= s->frame_size;

  1980.     }

  1981. 

  1982.     out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  1983.     if(out_size>=0){

  1984.         *data_size = out_size;

  1985.         avctx->sample_rate = s->sample_rate;

  1986.         //FIXME maybe move the other codec info stuff from above here too

  1987.     }else

  1988.         av_log(avctx, AV_LOG_DEBUG, "Error while decoding MPEG audio frame.\n"); //FIXME return -1 / but also return the number of bytes consumed

  1989.     s->frame_size = 0;

  1990.     return buf_size;

  1991. }

  1992. 

  1993. static void flush(AVCodecContext *avctx){

  1994.     MPADecodeContext *s = avctx->priv_data;

  1995.     memset(s->synth_buf, 0, sizeof(s->synth_buf));

  1996.     s->last_buf_size= 0;

  1997. }

  1998. 

  1999. #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER

  2000. static int decode_frame_adu(AVCodecContext * avctx,

  2001.                         void *data, int *data_size,

  2002.                         AVPacket *avpkt)

  2003. {

  2004.     const uint8_t *buf = avpkt->data;

  2005.     int buf_size = avpkt->size;

  2006.     MPADecodeContext *s = avctx->priv_data;

  2007.     uint32_t header;

  2008.     int len, out_size;

  2009.     OUT_INT *out_samples = data;

  2010. 

  2011.     len = buf_size;

  2012. 

  2013.     // Discard too short frames

  2014.     if (buf_size < HEADER_SIZE) {

  2015.         *data_size = 0;

  2016.         return buf_size;

  2017.     }

  2018. 

  2019. 

  2020.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  2021.         len = MPA_MAX_CODED_FRAME_SIZE;

  2022. 

  2023.     // Get header and restore sync word

  2024.     header = AV_RB32(buf) | 0xffe00000;

  2025. 

  2026.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  2027.         *data_size = 0;

  2028.         return buf_size;

  2029.     }

  2030. 

  2031.     ff_mpegaudio_decode_header((MPADecodeHeader *)s, header);

  2032.     /* update codec info */

  2033.     avctx->sample_rate = s->sample_rate;

  2034.     avctx->channels = s->nb_channels;

  2035.     if (!avctx->bit_rate)

  2036.         avctx->bit_rate = s->bit_rate;

  2037.     avctx->sub_id = s->layer;

  2038. 

  2039.     s->frame_size = len;

  2040. 

  2041.     if (avctx->parse_only) {

  2042.         out_size = buf_size;

  2043.     } else {

  2044.         out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2045.     }

  2046. 

  2047.     *data_size = out_size;

  2048.     return buf_size;

  2049. }

  2050. #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */

  2051. 

  2052. #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER

  2053. 

  2054. /**

  2055.  * Context for MP3On4 decoder

  2056.  */

  2057. typedef struct MP3On4DecodeContext {

  2058.     int frames;   ///< number of mp3 frames per block (number of mp3 decoder instances)

  2059.     int syncword; ///< syncword patch

  2060.     const uint8_t *coff; ///< channels offsets in output buffer

  2061.     MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance

  2062. } MP3On4DecodeContext;

  2063. 

  2064. #include "mpeg4audio.h"

  2065. 

  2066. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  2067. static const uint8_t mp3Frames[8] = {0,1,1,2,3,3,4,5};   /* number of mp3 decoder instances */

  2068. /* offsets into output buffer, assume output order is FL FR BL BR C LFE */

  2069. static const uint8_t chan_offset[8][5] = {

  2070.     {0},

  2071.     {0},            // C

  2072.     {0},            // FLR

  2073.     {2,0},          // C FLR

  2074.     {2,0,3},        // C FLR BS

  2075.     {4,0,2},        // C FLR BLRS

  2076.     {4,0,2,5},      // C FLR BLRS LFE

  2077.     {4,0,2,6,5},    // C FLR BLRS BLR LFE

  2078. };

  2079. 

  2080. 

  2081. static int decode_init_mp3on4(AVCodecContext * avctx)

  2082. {

  2083.     MP3On4DecodeContext *s = avctx->priv_data;

  2084.     MPEG4AudioConfig cfg;

  2085.     int i;

  2086. 

  2087.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  2088.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  2089.         return -1;

  2090.     }

  2091. 

  2092.     ff_mpeg4audio_get_config(&cfg, avctx->extradata, avctx->extradata_size);

  2093.     if (!cfg.chan_config || cfg.chan_config > 7) {

  2094.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  2095.         return -1;

  2096.     }

  2097.     s->frames = mp3Frames[cfg.chan_config];

  2098.     s->coff = chan_offset[cfg.chan_config];

  2099.     avctx->channels = ff_mpeg4audio_channels[cfg.chan_config];

  2100. 

  2101.     if (cfg.sample_rate < 16000)

  2102.         s->syncword = 0xffe00000;

  2103.     else

  2104.         s->syncword = 0xfff00000;

  2105. 

  2106.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  2107.      * We replace avctx->priv_data with the context of the first decoder so that

  2108.      * decode_init() does not have to be changed.

  2109.      * Other decoders will be initialized here copying data from the first context

  2110.      */

  2111.     // Allocate zeroed memory for the first decoder context

  2112.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  2113.     // Put decoder context in place to make init_decode() happy

  2114.     avctx->priv_data = s->mp3decctx[0];

  2115.     decode_init(avctx);

  2116.     // Restore mp3on4 context pointer

  2117.     avctx->priv_data = s;

  2118.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  2119. 

  2120.     /* Create a separate codec/context for each frame (first is already ok).

  2121.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  2122.      */

  2123.     for (i = 1; i < s->frames; i++) {

  2124.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  2125.         s->mp3decctx[i]->adu_mode = 1;

  2126.         s->mp3decctx[i]->avctx = avctx;

  2127.     }

  2128. 

  2129.     return 0;

  2130. }

  2131. 

  2132. 

  2133. static av_cold int decode_close_mp3on4(AVCodecContext * avctx)

  2134. {

  2135.     MP3On4DecodeContext *s = avctx->priv_data;

  2136.     int i;

  2137. 

  2138.     for (i = 0; i < s->frames; i++)

  2139.         av_free(s->mp3decctx[i]);

  2140. 

  2141.     return 0;

  2142. }

  2143. 

  2144. 

  2145. static int decode_frame_mp3on4(AVCodecContext * avctx,

  2146.                         void *data, int *data_size,

  2147.                         AVPacket *avpkt)

  2148. {

  2149.     const uint8_t *buf = avpkt->data;

  2150.     int buf_size = avpkt->size;

  2151.     MP3On4DecodeContext *s = avctx->priv_data;

  2152.     MPADecodeContext *m;

  2153.     int fsize, len = buf_size, out_size = 0;

  2154.     uint32_t header;

  2155.     OUT_INT *out_samples = data;

  2156.     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];

  2157.     OUT_INT *outptr, *bp;

  2158.     int fr, j, n;

  2159. 

  2160.     if(*data_size < MPA_FRAME_SIZE * MPA_MAX_CHANNELS * s->frames * sizeof(OUT_INT))

  2161.         return -1;

  2162. 

  2163.     *data_size = 0;

  2164.     // Discard too short frames

  2165.     if (buf_size < HEADER_SIZE)

  2166.         return -1;

  2167. 

  2168.     // If only one decoder interleave is not needed

  2169.     outptr = s->frames == 1 ? out_samples : decoded_buf;

  2170. 

  2171.     avctx->bit_rate = 0;

  2172. 

  2173.     for (fr = 0; fr < s->frames; fr++) {

  2174.         fsize = AV_RB16(buf) >> 4;

  2175.         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);

  2176.         m = s->mp3decctx[fr];

  2177.         assert (m != NULL);

  2178. 

  2179.         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header

  2180. 

  2181.         if (ff_mpa_check_header(header) < 0) // Bad header, discard block

  2182.             break;

  2183. 

  2184.         ff_mpegaudio_decode_header((MPADecodeHeader *)m, header);

  2185.         out_size += mp_decode_frame(m, outptr, buf, fsize);

  2186.         buf += fsize;

  2187.         len -= fsize;

  2188. 

  2189.         if(s->frames > 1) {

  2190.             n = m->avctx->frame_size*m->nb_channels;

  2191.             /* interleave output data */

  2192.             bp = out_samples + s->coff[fr];

  2193.             if(m->nb_channels == 1) {

  2194.                 for(j = 0; j < n; j++) {

  2195.                     *bp = decoded_buf[j];

  2196.                     bp += avctx->channels;

  2197.                 }

  2198.             } else {

  2199.                 for(j = 0; j < n; j++) {

  2200.                     bp[0] = decoded_buf[j++];

  2201.                     bp[1] = decoded_buf[j];

  2202.                     bp += avctx->channels;

  2203.                 }

  2204.             }

  2205.         }

  2206.         avctx->bit_rate += m->bit_rate;

  2207.     }

  2208. 

  2209.     /* update codec info */

  2210.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  2211. 

  2212.     *data_size = out_size;

  2213.     return buf_size;

  2214. }

  2215. #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */

  2216. 

  2217. #if !CONFIG_FLOAT

  2218. #if CONFIG_MP1_DECODER

  2219. AVCodec ff_mp1_decoder =

  2220. {

  2221.     "mp1",

  2222.     AVMEDIA_TYPE_AUDIO,

  2223.     CODEC_ID_MP1,

  2224.     sizeof(MPADecodeContext),

  2225.     decode_init,

  2226.     NULL,

  2227.     NULL,

  2228.     decode_frame,

  2229.     CODEC_CAP_PARSE_ONLY,

  2230.     .flush= flush,

  2231.     .long_name= NULL_IF_CONFIG_SMALL("MP1 (MPEG audio layer 1)"),

  2232. };

  2233. #endif

  2234. #if CONFIG_MP2_DECODER

  2235. AVCodec ff_mp2_decoder =

  2236. {

  2237.     "mp2",

  2238.     AVMEDIA_TYPE_AUDIO,

  2239.     CODEC_ID_MP2,

  2240.     sizeof(MPADecodeContext),

  2241.     decode_init,

  2242.     NULL,

  2243.     NULL,

  2244.     decode_frame,

  2245.     CODEC_CAP_PARSE_ONLY,

  2246.     .flush= flush,

  2247.     .long_name= NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),

  2248. };

  2249. #endif

  2250. #if CONFIG_MP3_DECODER

  2251. AVCodec ff_mp3_decoder =

  2252. {

  2253.     "mp3",

  2254.     AVMEDIA_TYPE_AUDIO,

  2255.     CODEC_ID_MP3,

  2256.     sizeof(MPADecodeContext),

  2257.     decode_init,

  2258.     NULL,

  2259.     NULL,

  2260.     decode_frame,

  2261.     CODEC_CAP_PARSE_ONLY,

  2262.     .flush= flush,

  2263.     .long_name= NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),

  2264. };

  2265. #endif

  2266. #if CONFIG_MP3ADU_DECODER

  2267. AVCodec ff_mp3adu_decoder =

  2268. {

  2269.     "mp3adu",

  2270.     AVMEDIA_TYPE_AUDIO,

  2271.     CODEC_ID_MP3ADU,

  2272.     sizeof(MPADecodeContext),

  2273.     decode_init,

  2274.     NULL,

  2275.     NULL,

  2276.     decode_frame_adu,

  2277.     CODEC_CAP_PARSE_ONLY,

  2278.     .flush= flush,

  2279.     .long_name= NULL_IF_CONFIG_SMALL("ADU (Application Data Unit) MP3 (MPEG audio layer 3)"),

  2280. };

  2281. #endif

  2282. #if CONFIG_MP3ON4_DECODER

  2283. AVCodec ff_mp3on4_decoder =

  2284. {

  2285.     "mp3on4",

  2286.     AVMEDIA_TYPE_AUDIO,

  2287.     CODEC_ID_MP3ON4,

  2288.     sizeof(MP3On4DecodeContext),

  2289.     decode_init_mp3on4,

  2290.     NULL,

  2291.     decode_close_mp3on4,

  2292.     decode_frame_mp3on4,

  2293.     .flush= flush,

  2294.     .long_name= NULL_IF_CONFIG_SMALL("MP3onMP4"),

  2295. };

  2296. #endif

  2297. #endif