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FFmpeg/libavcodec/mpegaudiodec.c

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  1. /*

  2.  * MPEG Audio decoder

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

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

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

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

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

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

  11.  *

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

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

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

  15.  * Lesser General Public License for more details.

  16.  *

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

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

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

  20.  */

  21. 

  22. /**

  23.  * @file

  24.  * MPEG Audio decoder

  25.  */

  26. 

  27. #define UNCHECKED_BITSTREAM_READER 1

  28. 

  29. #include "libavutil/audioconvert.h"

  30. #include "avcodec.h"

  31. #include "get_bits.h"

  32. #include "mathops.h"

  33. #include "mpegaudiodsp.h"

  34. 

  35. /*

  36.  * TODO:

  37.  *  - test lsf / mpeg25 extensively.

  38.  */

  39. 

  40. #include "mpegaudio.h"

  41. #include "mpegaudiodecheader.h"

  42. 

  43. #define BACKSTEP_SIZE 512

  44. #define EXTRABYTES 24

  45. 

  46. /* layer 3 "granule" */

  47. typedef struct GranuleDef {

  48.     uint8_t scfsi;

  49.     int part2_3_length;

  50.     int big_values;

  51.     int global_gain;

  52.     int scalefac_compress;

  53.     uint8_t block_type;

  54.     uint8_t switch_point;

  55.     int table_select[3];

  56.     int subblock_gain[3];

  57.     uint8_t scalefac_scale;

  58.     uint8_t count1table_select;

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

  60.     int preflag;

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

  62.     uint8_t scale_factors[40];

  63.     DECLARE_ALIGNED(16, INTFLOAT, sb_hybrid)[SBLIMIT * 18]; /* 576 samples */

  64. } GranuleDef;

  65. 

  66. typedef struct MPADecodeContext {

  67.     MPA_DECODE_HEADER

  68.     uint8_t last_buf[2 * BACKSTEP_SIZE + EXTRABYTES];

  69.     int last_buf_size;

  70.     /* next header (used in free format parsing) */

  71.     uint32_t free_format_next_header;

  72.     GetBitContext gb;

  73.     GetBitContext in_gb;

  74.     DECLARE_ALIGNED(32, MPA_INT, synth_buf)[MPA_MAX_CHANNELS][512 * 2];

  75.     int synth_buf_offset[MPA_MAX_CHANNELS];

  76.     DECLARE_ALIGNED(32, INTFLOAT, sb_samples)[MPA_MAX_CHANNELS][36][SBLIMIT];

  77.     INTFLOAT mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */

  78.     GranuleDef granules[2][2]; /* Used in Layer 3 */

  79.     int adu_mode; ///< 0 for standard mp3, 1 for adu formatted mp3

  80.     int dither_state;

  81.     int err_recognition;

  82.     AVCodecContext* avctx;

  83.     MPADSPContext mpadsp;

  84.     AVFrame frame;

  85. } MPADecodeContext;

  86. 

  87. #if CONFIG_FLOAT

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

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

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

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

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

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

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

  95. #   define OUT_FMT AV_SAMPLE_FMT_FLT

  96. #else

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

  98. /* WARNING: only correct for positive numbers */

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

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

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

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

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

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

  105. #   define OUT_FMT AV_SAMPLE_FMT_S16

  106. #endif

  107. 

  108. /****************/

  109. 

  110. #define HEADER_SIZE 4

  111. 

  112. #include "mpegaudiodata.h"

  113. #include "mpegaudiodectab.h"

  114. 

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

  116. static VLC huff_vlc[16];

  117. static VLC_TYPE huff_vlc_tables[

  118.     0 + 128 + 128 + 128 + 130 + 128 + 154 + 166 +

  119.   142 + 204 + 190 + 170 + 542 + 460 + 662 + 414

  120.   ][2];

  121. static const int huff_vlc_tables_sizes[16] = {

  122.     0,  128,  128,  128,  130,  128,  154,  166,

  123.   142,  204,  190,  170,  542,  460,  662,  414

  124. };

  125. static VLC huff_quad_vlc[2];

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

  127. static const int huff_quad_vlc_tables_sizes[2] = { 128, 16 };

  128. /* computed from band_size_long */

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

  130. #include "mpegaudio_tablegen.h"

  131. /* intensity stereo coef table */

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

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

  134. static INTFLOAT csa_table[8][4];

  135. 

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

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

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

  139. 

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

  141.     division_tab3, division_tab5, NULL, division_tab9

  142. };

  143. 

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

  145. static uint16_t scale_factor_modshift[64];

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

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

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

  149. 

  150. #define SCALE_GEN(v) \

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

  152. 

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

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

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

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

  157. };

  158. 

  159. /**

  160.  * Convert region offsets to region sizes and truncate

  161.  * size to big_values.

  162.  */

  163. static void ff_region_offset2size(GranuleDef *g)

  164. {

  165.     int i, k, j = 0;

  166.     g->region_size[2] = 576 / 2;

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

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

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

  170.         j = k;

  171.     }

  172. }

  173. 

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

  175. {

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

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

  178.     else {

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

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

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

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

  183.         else

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

  185.     }

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

  187. }

  188. 

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

  190. {

  191.     int l;

  192.     g->region_size[0] = band_index_long[s->sample_rate_index][ra1 + 1] >> 1;

  193.     /* should not overflow */

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

  195.     g->region_size[1] = band_index_long[s->sample_rate_index][      l] >> 1;

  196. }

  197. 

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

  199. {

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

  201.         if (g->switch_point) {

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

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

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

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

  206.                 g->long_end = 8;

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

  208.                 g->long_end = 6;

  209.             else

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

  211. 

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

  213.         } else {

  214.             g->long_end    = 0;

  215.             g->short_start = 0;

  216.         }

  217.     } else {

  218.         g->short_start = 13;

  219.         g->long_end    = 22;

  220.     }

  221. }

  222. 

  223. /* layer 1 unscaling */

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

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

  226. {

  227.     int shift, mod;

  228.     int64_t val;

  229. 

  230.     shift   = scale_factor_modshift[scale_factor];

  231.     mod     = shift & 3;

  232.     shift >>= 2;

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

  234.     shift  += n;

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

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

  237. }

  238. 

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

  240. {

  241.     int shift, mod, val;

  242. 

  243.     shift   = scale_factor_modshift[scale_factor];

  244.     mod     = shift & 3;

  245.     shift >>= 2;

  246. 

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

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

  249.     if (shift > 0)

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

  251.     return val;

  252. }

  253. 

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

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

  256. {

  257.     unsigned int m;

  258.     int e;

  259. 

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

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

  262.     e -= exponent >> 2;

  263.     assert(e >= 1);

  264.     if (e > 31)

  265.         return 0;

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

  267. 

  268.     return m;

  269. }

  270. 

  271. static av_cold void decode_init_static(void)

  272. {

  273.     int i, j, k;

  274.     int offset;

  275. 

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

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

  278.         int shift, mod;

  279.         /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  280.         shift = i / 3;

  281.         mod   = i % 3;

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

  283.     }

  284. 

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

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

  287.         int n, norm;

  288.         n = i + 2;

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

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

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

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

  293.         av_dlog(NULL, "%d: norm=%x s=%x %x %x\n", i, norm,

  294.                 scale_factor_mult[i][0],

  295.                 scale_factor_mult[i][1],

  296.                 scale_factor_mult[i][2]);

  297.     }

  298. 

  299.     RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));

  300. 

  301.     /* huffman decode tables */

  302.     offset = 0;

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

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

  305.         int xsize, x, y;

  306.         uint8_t  tmp_bits [512];

  307.         uint16_t tmp_codes[512];

  308. 

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

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

  311. 

  312.         xsize = h->xsize;

  313. 

  314.         j = 0;

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

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

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

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

  319.             }

  320.         }

  321. 

  322.         /* XXX: fail test */

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

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

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

  326.                  tmp_bits, 1, 1, tmp_codes, 2, 2,

  327.                  INIT_VLC_USE_NEW_STATIC);

  328.         offset += huff_vlc_tables_sizes[i];

  329.     }

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

  331. 

  332.     offset = 0;

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

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

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

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

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

  338.                  INIT_VLC_USE_NEW_STATIC);

  339.         offset += huff_quad_vlc_tables_sizes[i];

  340.     }

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

  342. 

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

  344.         k = 0;

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

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

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

  348.         }

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

  350.     }

  351. 

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

  353. 

  354.     mpegaudio_tableinit();

  355. 

  356.     for (i = 0; i < 4; i++) {

  357.         if (ff_mpa_quant_bits[i] < 0) {

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

  359.                 int val1, val2, val3, steps;

  360.                 int val = j;

  361.                 steps   = ff_mpa_quant_steps[i];

  362.                 val1    = val % steps;

  363.                 val    /= steps;

  364.                 val2    = val % steps;

  365.                 val3    = val / steps;

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

  367.             }

  368.         }

  369.     }

  370. 

  371. 

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

  373.         float f;

  374.         INTFLOAT v;

  375.         if (i != 6) {

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

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

  378.         } else {

  379.             v = FIXR(1.0);

  380.         }

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

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

  383.     }

  384.     /* invalid values */

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

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

  387. 

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

  389.         double f;

  390.         int e, k;

  391. 

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

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

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

  395.             k = i & 1;

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

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

  398.             av_dlog(NULL, "is_table_lsf %d %d: %f %f\n",

  399.                     i, j, (float) is_table_lsf[j][0][i],

  400.                     (float) is_table_lsf[j][1][i]);

  401.         }

  402.     }

  403. 

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

  405.         float ci, cs, ca;

  406.         ci = ci_table[i];

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

  408.         ca = cs * ci;

  409. #if !CONFIG_FLOAT

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

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

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

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

  414. #else

  415.         csa_table[i][0] = cs;

  416.         csa_table[i][1] = ca;

  417.         csa_table[i][2] = ca + cs;

  418.         csa_table[i][3] = ca - cs;

  419. #endif

  420.     }

  421. }

  422. 

  423. static av_cold int decode_init(AVCodecContext * avctx)

  424. {

  425.     static int initialized_tables = 0;

  426.     MPADecodeContext *s = avctx->priv_data;

  427. 

  428.     if (!initialized_tables) {

  429.         decode_init_static();

  430.         initialized_tables = 1;

  431.     }

  432. 

  433.     s->avctx = avctx;

  434. 

  435.     ff_mpadsp_init(&s->mpadsp);

  436. 

  437.     avctx->sample_fmt= OUT_FMT;

  438.     s->err_recognition = avctx->err_recognition;

  439. 

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

  441.         s->adu_mode = 1;

  442. 

  443.     avcodec_get_frame_defaults(&s->frame);

  444.     avctx->coded_frame = &s->frame;

  445. 

  446.     return 0;

  447. }

  448. 

  449. #define C3 FIXHR(0.86602540378443864676/2)

  450. #define C4 FIXHR(0.70710678118654752439/2) //0.5 / cos(pi*(9)/36)

  451. #define C5 FIXHR(0.51763809020504152469/2) //0.5 / cos(pi*(5)/36)

  452. #define C6 FIXHR(1.93185165257813657349/4) //0.5 / cos(pi*(15)/36)

  453. 

  454. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  455.    cases. */

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

  457. {

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

  459. 

  460.     in0  = in[0*3];

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

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

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

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

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

  466.     in5 += in3;

  467.     in3 += in1;

  468. 

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

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

  471. 

  472.     t1   = in0 - in4;

  473.     t2   = MULH3(in1 - in5, C4, 2);

  474. 

  475.     out[ 7] =

  476.     out[10] = t1 + t2;

  477.     out[ 1] =

  478.     out[ 4] = t1 - t2;

  479. 

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

  481.     in4     = in0 + in2;

  482.     in5    += 2*in1;

  483.     in1     = MULH3(in5 + in3, C5, 1);

  484.     out[ 8] =

  485.     out[ 9] = in4 + in1;

  486.     out[ 2] =

  487.     out[ 3] = in4 - in1;

  488. 

  489.     in0    -= in2;

  490.     in5     = MULH3(in5 - in3, C6, 2);

  491.     out[ 0] =

  492.     out[ 5] = in0 - in5;

  493.     out[ 6] =

  494.     out[11] = in0 + in5;

  495. }

  496. 

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

  498. static int mp_decode_layer1(MPADecodeContext *s)

  499. {

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

  501.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  502.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  503. 

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

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

  506.     else

  507.         bound = SBLIMIT;

  508. 

  509.     /* allocation bits */

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

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

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

  513.         }

  514.     }

  515.     for (i = bound; i < SBLIMIT; i++)

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

  517. 

  518.     /* scale factors */

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

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

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

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

  523.         }

  524.     }

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

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

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

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

  529.         }

  530.     }

  531. 

  532.     /* compute samples */

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

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

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

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

  537.                 if (n) {

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

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

  540.                 } else {

  541.                     v = 0;

  542.                 }

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

  544.             }

  545.         }

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

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

  548.             if (n) {

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

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

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

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

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

  554.             } else {

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

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

  557.             }

  558.         }

  559.     }

  560.     return 12;

  561. }

  562. 

  563. static int mp_decode_layer2(MPADecodeContext *s)

  564. {

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

  566.     const unsigned char *alloc_table;

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

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

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

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

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

  572. 

  573.     /* select decoding table */

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

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

  576.     sblimit     = ff_mpa_sblimit_table[table];

  577.     alloc_table = ff_mpa_alloc_tables[table];

  578. 

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

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

  581.     else

  582.         bound = sblimit;

  583. 

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

  585. 

  586.     /* sanity check */

  587.     if (bound > sblimit)

  588.         bound = sblimit;

  589. 

  590.     /* parse bit allocation */

  591.     j = 0;

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

  593.         bit_alloc_bits = alloc_table[j];

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

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

  596.         j += 1 << bit_alloc_bits;

  597.     }

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

  599.         bit_alloc_bits = alloc_table[j];

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

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

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

  603.         j += 1 << bit_alloc_bits;

  604.     }

  605. 

  606.     /* scale codes */

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

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

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

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

  611.         }

  612.     }

  613. 

  614.     /* scale factors */

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

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

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

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

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

  620.                 default:

  621.                 case 0:

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

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

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

  625.                     break;

  626.                 case 2:

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

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

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

  630.                     break;

  631.                 case 1:

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

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

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

  635.                     break;

  636.                 case 3:

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

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

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

  640.                     break;

  641.                 }

  642.             }

  643.         }

  644.     }

  645. 

  646.     /* samples */

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

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

  649.             j = 0;

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

  651.                 bit_alloc_bits = alloc_table[j];

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

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

  654.                     if (b) {

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

  656.                         qindex = alloc_table[j+b];

  657.                         bits = ff_mpa_quant_bits[qindex];

  658.                         if (bits < 0) {

  659.                             int v2;

  660.                             /* 3 values at the same time */

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

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

  663.                             steps  = ff_mpa_quant_steps[qindex];

  664. 

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

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

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

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

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

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

  671.                         } else {

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

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

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

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

  676.                             }

  677.                         }

  678.                     } else {

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

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

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

  682.                     }

  683.                 }

  684.                 /* next subband in alloc table */

  685.                 j += 1 << bit_alloc_bits;

  686.             }

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

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

  689.                 bit_alloc_bits = alloc_table[j];

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

  691.                 if (b) {

  692.                     int mant, scale0, scale1;

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

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

  695.                     qindex = alloc_table[j+b];

  696.                     bits = ff_mpa_quant_bits[qindex];

  697.                     if (bits < 0) {

  698.                         /* 3 values at the same time */

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

  700.                         steps = ff_mpa_quant_steps[qindex];

  701.                         mant = v % steps;

  702.                         v = v / steps;

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

  704.                             l2_unscale_group(steps, mant, scale0);

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

  706.                             l2_unscale_group(steps, mant, scale1);

  707.                         mant = v % steps;

  708.                         v = v / steps;

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

  710.                             l2_unscale_group(steps, mant, scale0);

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

  712.                             l2_unscale_group(steps, mant, scale1);

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

  714.                             l2_unscale_group(steps, v, scale0);

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

  716.                             l2_unscale_group(steps, v, scale1);

  717.                     } else {

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

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

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

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

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

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

  724.                         }

  725.                     }

  726.                 } else {

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

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

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

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

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

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

  733.                 }

  734.                 /* next subband in alloc table */

  735.                 j += 1 << bit_alloc_bits;

  736.             }

  737.             /* fill remaining samples to zero */

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

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

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

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

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

  743.                 }

  744.             }

  745.         }

  746.     }

  747.     return 3 * 12;

  748. }

  749. 

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

  751.     if (n == 3) {                   \

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

  753.         dst   = sf - 3 * m;         \

  754.         sf    = m;                  \

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

  756.         dst  = sf & 3;              \

  757.         sf >>= 2;                   \

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

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

  760.         dst   = sf - 5 * m;         \

  761.         sf    = m;                  \

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

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

  764.         dst   = sf - 6 * m;         \

  765.         sf    = m;                  \

  766.     } else {                        \

  767.         dst = 0;                    \

  768.     }

  769. 

  770. static av_always_inline void lsf_sf_expand(int *slen, int sf, int n1, int n2,

  771.                                            int n3)

  772. {

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

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

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

  776.     slen[0] = sf;

  777. }

  778. 

  779. static void exponents_from_scale_factors(MPADecodeContext *s, GranuleDef *g,

  780.                                          int16_t *exponents)

  781. {

  782.     const uint8_t *bstab, *pretab;

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

  784.     int16_t *exp_ptr;

  785. 

  786.     exp_ptr = exponents;

  787.     gain    = g->global_gain - 210;

  788.     shift   = g->scalefac_scale + 1;

  789. 

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

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

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

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

  794.         len = bstab[i];

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

  796.             *exp_ptr++ = v0;

  797.     }

  798. 

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

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

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

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

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

  804.         k        = g->long_end;

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

  806.             len = bstab[i];

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

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

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

  810.                     *exp_ptr++ = v0;

  811.             }

  812.         }

  813.     }

  814. }

  815. 

  816. /* handle n = 0 too */

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

  818. {

  819.     return n ? get_bits(s, n) : 0;

  820. }

  821. 

  822. 

  823. static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos,

  824.                           int *end_pos2)

  825. {

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

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

  828.         s->in_gb.buffer = NULL;

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

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

  831.         *end_pos2 =

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

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

  834.     }

  835. }

  836. 

  837. /* Following is a optimized code for

  838.             INTFLOAT v = *src

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

  840.                 v = -v;

  841.             *dst = v;

  842. */

  843. #if CONFIG_FLOAT

  844. #define READ_FLIP_SIGN(dst,src)                     \

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

  846.     AV_WN32A(dst, v);

  847. #else

  848. #define READ_FLIP_SIGN(dst,src)     \

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

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

  851. #endif

  852. 

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

  854.                           int16_t *exponents, int end_pos2)

  855. {

  856.     int s_index;

  857.     int i;

  858.     int last_pos, bits_left;

  859.     VLC *vlc;

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

  861. 

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

  863.     s_index = 0;

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

  865.         int j, k, l, linbits;

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

  867.         if (j == 0)

  868.             continue;

  869.         /* select vlc table */

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

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

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

  873.         vlc     = &huff_vlc[l];

  874. 

  875.         if (!l) {

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

  877.             s_index += 2 * j;

  878.             continue;

  879.         }

  880. 

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

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

  883.             int exponent, x, y;

  884.             int v;

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

  886. 

  887.             if (pos >= end_pos){

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

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

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

  891.                 if (pos >= end_pos)

  892.                     break;

  893.             }

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

  895. 

  896.             if (!y) {

  897.                 g->sb_hybrid[s_index  ] =

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

  899.                 s_index += 2;

  900.                 continue;

  901.             }

  902. 

  903.             exponent= exponents[s_index];

  904. 

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

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

  907.             if (y & 16) {

  908.                 x = y >> 5;

  909.                 y = y & 0x0f;

  910.                 if (x < 15) {

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

  912.                 } else {

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

  914.                     v  = l3_unscale(x, exponent);

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

  916.                         v = -v;

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

  918.                 }

  919.                 if (y < 15) {

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

  921.                 } else {

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

  923.                     v  = l3_unscale(y, exponent);

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

  925.                         v = -v;

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

  927.                 }

  928.             } else {

  929.                 x = y >> 5;

  930.                 y = y & 0x0f;

  931.                 x += y;

  932.                 if (x < 15) {

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

  934.                 } else {

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

  936.                     v  = l3_unscale(x, exponent);

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

  938.                         v = -v;

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

  940.                 }

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

  942.             }

  943.             s_index += 2;

  944.         }

  945.     }

  946. 

  947.     /* high frequencies */

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

  949.     last_pos = 0;

  950.     while (s_index <= 572) {

  951.         int pos, code;

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

  953.         if (pos >= end_pos) {

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

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

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

  957.                 s_index -= 4;

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

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

  960.                 if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))

  961.                     s_index=0;

  962.                 break;

  963.             }

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

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

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

  967.             if (pos >= end_pos)

  968.                 break;

  969.         }

  970.         last_pos = pos;

  971. 

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

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

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

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

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

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

  978.         while (code) {

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

  980.             int v;

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

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

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

  984.         }

  985.         s_index += 4;

  986.     }

  987.     /* skip extension bits */

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

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

  990.     if (bits_left < 0 && (s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))) {

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

  992.         s_index=0;

  993.     } else if (bits_left > 0 && (s->err_recognition & (AV_EF_BITSTREAM|AV_EF_AGGRESSIVE))) {

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

  995.         s_index = 0;

  996.     }

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

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

  999. 

  1000.     i = get_bits_count(&s->gb);

  1001.     switch_buffer(s, &i, &end_pos, &end_pos2);

  1002. 

  1003.     return 0;

  1004. }

  1005. 

  1006. /* Reorder short blocks from bitstream order to interleaved order. It

  1007.    would be faster to do it in parsing, but the code would be far more

  1008.    complicated */

  1009. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1010. {

  1011.     int i, j, len;

  1012.     INTFLOAT *ptr, *dst, *ptr1;

  1013.     INTFLOAT tmp[576];

  1014. 

  1015.     if (g->block_type != 2)

  1016.         return;

  1017. 

  1018.     if (g->switch_point) {

  1019.         if (s->sample_rate_index != 8)

  1020.             ptr = g->sb_hybrid + 36;

  1021.         else

  1022.             ptr = g->sb_hybrid + 48;

  1023.     } else {

  1024.         ptr = g->sb_hybrid;

  1025.     }

  1026. 

  1027.     for (i = g->short_start; i < 13; i++) {

  1028.         len  = band_size_short[s->sample_rate_index][i];

  1029.         ptr1 = ptr;

  1030.         dst  = tmp;

  1031.         for (j = len; j > 0; j--) {

  1032.             *dst++ = ptr[0*len];

  1033.             *dst++ = ptr[1*len];

  1034.             *dst++ = ptr[2*len];

  1035.             ptr++;

  1036.         }

  1037.         ptr += 2 * len;

  1038.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1039.     }

  1040. }

  1041. 

  1042. #define ISQRT2 FIXR(0.70710678118654752440)

  1043. 

  1044. static void compute_stereo(MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)

  1045. {

  1046.     int i, j, k, l;

  1047.     int sf_max, sf, len, non_zero_found;

  1048.     INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;

  1049.     int non_zero_found_short[3];

  1050. 

  1051.     /* intensity stereo */

  1052.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1053.         if (!s->lsf) {

  1054.             is_tab = is_table;

  1055.             sf_max = 7;

  1056.         } else {

  1057.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1058.             sf_max = 16;

  1059.         }

  1060. 

  1061.         tab0 = g0->sb_hybrid + 576;

  1062.         tab1 = g1->sb_hybrid + 576;

  1063. 

  1064.         non_zero_found_short[0] = 0;

  1065.         non_zero_found_short[1] = 0;

  1066.         non_zero_found_short[2] = 0;

  1067.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1068.         for (i = 12; i >= g1->short_start; i--) {

  1069.             /* for last band, use previous scale factor */

  1070.             if (i != 11)

  1071.                 k -= 3;

  1072.             len = band_size_short[s->sample_rate_index][i];

  1073.             for (l = 2; l >= 0; l--) {

  1074.                 tab0 -= len;

  1075.                 tab1 -= len;

  1076.                 if (!non_zero_found_short[l]) {

  1077.                     /* test if non zero band. if so, stop doing i-stereo */

  1078.                     for (j = 0; j < len; j++) {

  1079.                         if (tab1[j] != 0) {

  1080.                             non_zero_found_short[l] = 1;

  1081.                             goto found1;

  1082.                         }

  1083.                     }

  1084.                     sf = g1->scale_factors[k + l];

  1085.                     if (sf >= sf_max)

  1086.                         goto found1;

  1087. 

  1088.                     v1 = is_tab[0][sf];

  1089.                     v2 = is_tab[1][sf];

  1090.                     for (j = 0; j < len; j++) {

  1091.                         tmp0    = tab0[j];

  1092.                         tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1093.                         tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1094.                     }

  1095.                 } else {

  1096. found1:

  1097.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1098.                         /* lower part of the spectrum : do ms stereo

  1099.                            if enabled */

  1100.                         for (j = 0; j < len; j++) {

  1101.                             tmp0    = tab0[j];

  1102.                             tmp1    = tab1[j];

  1103.                             tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1104.                             tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1105.                         }

  1106.                     }

  1107.                 }

  1108.             }

  1109.         }

  1110. 

  1111.         non_zero_found = non_zero_found_short[0] |

  1112.                          non_zero_found_short[1] |

  1113.                          non_zero_found_short[2];

  1114. 

  1115.         for (i = g1->long_end - 1;i >= 0;i--) {

  1116.             len   = band_size_long[s->sample_rate_index][i];

  1117.             tab0 -= len;

  1118.             tab1 -= len;

  1119.             /* test if non zero band. if so, stop doing i-stereo */

  1120.             if (!non_zero_found) {

  1121.                 for (j = 0; j < len; j++) {

  1122.                     if (tab1[j] != 0) {

  1123.                         non_zero_found = 1;

  1124.                         goto found2;

  1125.                     }

  1126.                 }

  1127.                 /* for last band, use previous scale factor */

  1128.                 k  = (i == 21) ? 20 : i;

  1129.                 sf = g1->scale_factors[k];

  1130.                 if (sf >= sf_max)

  1131.                     goto found2;

  1132.                 v1 = is_tab[0][sf];

  1133.                 v2 = is_tab[1][sf];

  1134.                 for (j = 0; j < len; j++) {

  1135.                     tmp0    = tab0[j];

  1136.                     tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1137.                     tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1138.                 }

  1139.             } else {

  1140. found2:

  1141.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1142.                     /* lower part of the spectrum : do ms stereo

  1143.                        if enabled */

  1144.                     for (j = 0; j < len; j++) {

  1145.                         tmp0    = tab0[j];

  1146.                         tmp1    = tab1[j];

  1147.                         tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1148.                         tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1149.                     }

  1150.                 }

  1151.             }

  1152.         }

  1153.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1154.         /* ms stereo ONLY */

  1155.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1156.            global gain */

  1157.         tab0 = g0->sb_hybrid;

  1158.         tab1 = g1->sb_hybrid;

  1159.         for (i = 0; i < 576; i++) {

  1160.             tmp0    = tab0[i];

  1161.             tmp1    = tab1[i];

  1162.             tab0[i] = tmp0 + tmp1;

  1163.             tab1[i] = tmp0 - tmp1;

  1164.         }

  1165.     }

  1166. }

  1167. 

  1168. #if CONFIG_FLOAT

  1169. #define AA(j) do {                                                      \

  1170.         float tmp0 = ptr[-1-j];                                         \

  1171.         float tmp1 = ptr[   j];                                         \

  1172.         ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1];    \

  1173.         ptr[   j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0];    \

  1174.     } while (0)

  1175. #else

  1176. #define AA(j) do {                                              \

  1177.         int tmp0 = ptr[-1-j];                                   \

  1178.         int tmp1 = ptr[   j];                                   \

  1179.         int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]);          \

  1180.         ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2]));   \

  1181.         ptr[   j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3]));   \

  1182.     } while (0)

  1183. #endif

  1184. 

  1185. static void compute_antialias(MPADecodeContext *s, GranuleDef *g)

  1186. {

  1187.     INTFLOAT *ptr;

  1188.     int n, i;

  1189. 

  1190.     /* we antialias only "long" bands */

  1191.     if (g->block_type == 2) {

  1192.         if (!g->switch_point)

  1193.             return;

  1194.         /* XXX: check this for 8000Hz case */

  1195.         n = 1;

  1196.     } else {

  1197.         n = SBLIMIT - 1;

  1198.     }

  1199. 

  1200.     ptr = g->sb_hybrid + 18;

  1201.     for (i = n; i > 0; i--) {

  1202.         AA(0);

  1203.         AA(1);

  1204.         AA(2);

  1205.         AA(3);

  1206.         AA(4);

  1207.         AA(5);

  1208.         AA(6);

  1209.         AA(7);

  1210. 

  1211.         ptr += 18;

  1212.     }

  1213. }

  1214. 

  1215. static void compute_imdct(MPADecodeContext *s, GranuleDef *g,

  1216.                           INTFLOAT *sb_samples, INTFLOAT *mdct_buf)

  1217. {

  1218.     INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;

  1219.     INTFLOAT out2[12];

  1220.     int i, j, mdct_long_end, sblimit;

  1221. 

  1222.     /* find last non zero block */

  1223.     ptr  = g->sb_hybrid + 576;

  1224.     ptr1 = g->sb_hybrid + 2 * 18;

  1225.     while (ptr >= ptr1) {

  1226.         int32_t *p;

  1227.         ptr -= 6;

  1228.         p    = (int32_t*)ptr;

  1229.         if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])

  1230.             break;

  1231.     }

  1232.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  1233. 

  1234.     if (g->block_type == 2) {

  1235.         /* XXX: check for 8000 Hz */

  1236.         if (g->switch_point)

  1237.             mdct_long_end = 2;

  1238.         else

  1239.             mdct_long_end = 0;

  1240.     } else {

  1241.         mdct_long_end = sblimit;

  1242.     }

  1243. 

  1244.     s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,

  1245.                                      mdct_long_end, g->switch_point,

  1246.                                      g->block_type);

  1247. 

  1248.     buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);

  1249.     ptr = g->sb_hybrid + 18 * mdct_long_end;

  1250. 

  1251.     for (j = mdct_long_end; j < sblimit; j++) {

  1252.         /* select frequency inversion */

  1253.         win     = RENAME(ff_mdct_win)[2 + (4  & -(j & 1))];

  1254.         out_ptr = sb_samples + j;

  1255. 

  1256.         for (i = 0; i < 6; i++) {

  1257.             *out_ptr = buf[4*i];

  1258.             out_ptr += SBLIMIT;

  1259.         }

  1260.         imdct12(out2, ptr + 0);

  1261.         for (i = 0; i < 6; i++) {

  1262.             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*1)];

  1263.             buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);

  1264.             out_ptr += SBLIMIT;

  1265.         }

  1266.         imdct12(out2, ptr + 1);

  1267.         for (i = 0; i < 6; i++) {

  1268.             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*2)];

  1269.             buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);

  1270.             out_ptr += SBLIMIT;

  1271.         }

  1272.         imdct12(out2, ptr + 2);

  1273.         for (i = 0; i < 6; i++) {

  1274.             buf[4*(i + 6*0)] = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*0)];

  1275.             buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);

  1276.             buf[4*(i + 6*2)] = 0;

  1277.         }

  1278.         ptr += 18;

  1279.         buf += (j&3) != 3 ? 1 : (4*18-3);

  1280.     }

  1281.     /* zero bands */

  1282.     for (j = sblimit; j < SBLIMIT; j++) {

  1283.         /* overlap */

  1284.         out_ptr = sb_samples + j;

  1285.         for (i = 0; i < 18; i++) {

  1286.             *out_ptr = buf[4*i];

  1287.             buf[4*i]   = 0;

  1288.             out_ptr += SBLIMIT;

  1289.         }

  1290.         buf += (j&3) != 3 ? 1 : (4*18-3);

  1291.     }

  1292. }

  1293. 

  1294. /* main layer3 decoding function */

  1295. static int mp_decode_layer3(MPADecodeContext *s)

  1296. {

  1297.     int nb_granules, main_data_begin;

  1298.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  1299.     GranuleDef *g;

  1300.     int16_t exponents[576]; //FIXME try INTFLOAT

  1301. 

  1302.     /* read side info */

  1303.     if (s->lsf) {

  1304.         main_data_begin = get_bits(&s->gb, 8);

  1305.         skip_bits(&s->gb, s->nb_channels);

  1306.         nb_granules = 1;

  1307.     } else {

  1308.         main_data_begin = get_bits(&s->gb, 9);

  1309.         if (s->nb_channels == 2)

  1310.             skip_bits(&s->gb, 3);

  1311.         else

  1312.             skip_bits(&s->gb, 5);

  1313.         nb_granules = 2;

  1314.         for (ch = 0; ch < s->nb_channels; ch++) {

  1315.             s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */

  1316.             s->granules[ch][1].scfsi = get_bits(&s->gb, 4);

  1317.         }

  1318.     }

  1319. 

  1320.     for (gr = 0; gr < nb_granules; gr++) {

  1321.         for (ch = 0; ch < s->nb_channels; ch++) {

  1322.             av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);

  1323.             g = &s->granules[ch][gr];

  1324.             g->part2_3_length = get_bits(&s->gb, 12);

  1325.             g->big_values     = get_bits(&s->gb,  9);

  1326.             if (g->big_values > 288) {

  1327.                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");

  1328.                 return AVERROR_INVALIDDATA;

  1329.             }

  1330. 

  1331.             g->global_gain = get_bits(&s->gb, 8);

  1332.             /* if MS stereo only is selected, we precompute the

  1333.                1/sqrt(2) renormalization factor */

  1334.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  1335.                 MODE_EXT_MS_STEREO)

  1336.                 g->global_gain -= 2;

  1337.             if (s->lsf)

  1338.                 g->scalefac_compress = get_bits(&s->gb, 9);

  1339.             else

  1340.                 g->scalefac_compress = get_bits(&s->gb, 4);

  1341.             blocksplit_flag = get_bits1(&s->gb);

  1342.             if (blocksplit_flag) {

  1343.                 g->block_type = get_bits(&s->gb, 2);

  1344.                 if (g->block_type == 0) {

  1345.                     av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");

  1346.                     return AVERROR_INVALIDDATA;

  1347.                 }

  1348.                 g->switch_point = get_bits1(&s->gb);

  1349.                 for (i = 0; i < 2; i++)

  1350.                     g->table_select[i] = get_bits(&s->gb, 5);

  1351.                 for (i = 0; i < 3; i++)

  1352.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  1353.                 ff_init_short_region(s, g);

  1354.             } else {

  1355.                 int region_address1, region_address2;

  1356.                 g->block_type = 0;

  1357.                 g->switch_point = 0;

  1358.                 for (i = 0; i < 3; i++)

  1359.                     g->table_select[i] = get_bits(&s->gb, 5);

  1360.                 /* compute huffman coded region sizes */

  1361.                 region_address1 = get_bits(&s->gb, 4);

  1362.                 region_address2 = get_bits(&s->gb, 3);

  1363.                 av_dlog(s->avctx, "region1=%d region2=%d\n",

  1364.                         region_address1, region_address2);

  1365.                 ff_init_long_region(s, g, region_address1, region_address2);

  1366.             }

  1367.             ff_region_offset2size(g);

  1368.             ff_compute_band_indexes(s, g);

  1369. 

  1370.             g->preflag = 0;

  1371.             if (!s->lsf)

  1372.                 g->preflag = get_bits1(&s->gb);

  1373.             g->scalefac_scale     = get_bits1(&s->gb);

  1374.             g->count1table_select = get_bits1(&s->gb);

  1375.             av_dlog(s->avctx, "block_type=%d switch_point=%d\n",

  1376.                     g->block_type, g->switch_point);

  1377.         }

  1378.     }

  1379. 

  1380.     if (!s->adu_mode) {

  1381.         int skip;

  1382.         const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  1383.         assert((get_bits_count(&s->gb) & 7) == 0);

  1384.         /* now we get bits from the main_data_begin offset */

  1385.         av_dlog(s->avctx, "seekback: %d\n", main_data_begin);

  1386.     //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);

  1387. 

  1388.         memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);

  1389.         s->in_gb = s->gb;

  1390.         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);

  1391. #if !UNCHECKED_BITSTREAM_READER

  1392.         s->gb.size_in_bits_plus8 += EXTRABYTES * 8;

  1393. #endif

  1394.         skip_bits_long(&s->gb, 8*(s->last_buf_size - main_data_begin));

  1395.     }

  1396. 

  1397.     for (gr = 0; gr < nb_granules; gr++) {

  1398.         for (ch = 0; ch < s->nb_channels; ch++) {

  1399.             g = &s->granules[ch][gr];

  1400.             if (get_bits_count(&s->gb) < 0) {

  1401.                 av_log(s->avctx, AV_LOG_DEBUG, "mdb:%d, lastbuf:%d skipping granule %d\n",

  1402.                        main_data_begin, s->last_buf_size, gr);

  1403.                 skip_bits_long(&s->gb, g->part2_3_length);

  1404.                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));

  1405.                 if (get_bits_count(&s->gb) >= s->gb.size_in_bits && s->in_gb.buffer) {

  1406.                     skip_bits_long(&s->in_gb, get_bits_count(&s->gb) - s->gb.size_in_bits);

  1407.                     s->gb           = s->in_gb;

  1408.                     s->in_gb.buffer = NULL;

  1409.                 }

  1410.                 continue;

  1411.             }

  1412. 

  1413.             bits_pos = get_bits_count(&s->gb);

  1414. 

  1415.             if (!s->lsf) {

  1416.                 uint8_t *sc;

  1417.                 int slen, slen1, slen2;

  1418. 

  1419.                 /* MPEG1 scale factors */

  1420.                 slen1 = slen_table[0][g->scalefac_compress];

  1421.                 slen2 = slen_table[1][g->scalefac_compress];

  1422.                 av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);

  1423.                 if (g->block_type == 2) {

  1424.                     n = g->switch_point ? 17 : 18;

  1425.                     j = 0;

  1426.                     if (slen1) {

  1427.                         for (i = 0; i < n; i++)

  1428.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  1429.                     } else {

  1430.                         for (i = 0; i < n; i++)

  1431.                             g->scale_factors[j++] = 0;

  1432.                     }

  1433.                     if (slen2) {

  1434.                         for (i = 0; i < 18; i++)

  1435.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  1436.                         for (i = 0; i < 3; i++)

  1437.                             g->scale_factors[j++] = 0;

  1438.                     } else {

  1439.                         for (i = 0; i < 21; i++)

  1440.                             g->scale_factors[j++] = 0;

  1441.                     }

  1442.                 } else {

  1443.                     sc = s->granules[ch][0].scale_factors;

  1444.                     j = 0;

  1445.                     for (k = 0; k < 4; k++) {

  1446.                         n = k == 0 ? 6 : 5;

  1447.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  1448.                             slen = (k < 2) ? slen1 : slen2;

  1449.                             if (slen) {

  1450.                                 for (i = 0; i < n; i++)

  1451.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  1452.                             } else {

  1453.                                 for (i = 0; i < n; i++)

  1454.                                     g->scale_factors[j++] = 0;

  1455.                             }

  1456.                         } else {

  1457.                             /* simply copy from last granule */

  1458.                             for (i = 0; i < n; i++) {

  1459.                                 g->scale_factors[j] = sc[j];

  1460.                                 j++;

  1461.                             }

  1462.                         }

  1463.                     }

  1464.                     g->scale_factors[j++] = 0;

  1465.                 }

  1466.             } else {

  1467.                 int tindex, tindex2, slen[4], sl, sf;

  1468. 

  1469.                 /* LSF scale factors */

  1470.                 if (g->block_type == 2)

  1471.                     tindex = g->switch_point ? 2 : 1;

  1472.                 else

  1473.                     tindex = 0;

  1474. 

  1475.                 sf = g->scalefac_compress;

  1476.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  1477.                     /* intensity stereo case */

  1478.                     sf >>= 1;

  1479.                     if (sf < 180) {

  1480.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  1481.                         tindex2 = 3;

  1482.                     } else if (sf < 244) {

  1483.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  1484.                         tindex2 = 4;

  1485.                     } else {

  1486.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  1487.                         tindex2 = 5;

  1488.                     }

  1489.                 } else {

  1490.                     /* normal case */

  1491.                     if (sf < 400) {

  1492.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  1493.                         tindex2 = 0;

  1494.                     } else if (sf < 500) {

  1495.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  1496.                         tindex2 = 1;

  1497.                     } else {

  1498.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  1499.                         tindex2 = 2;

  1500.                         g->preflag = 1;

  1501.                     }

  1502.                 }

  1503. 

  1504.                 j = 0;

  1505.                 for (k = 0; k < 4; k++) {

  1506.                     n  = lsf_nsf_table[tindex2][tindex][k];

  1507.                     sl = slen[k];

  1508.                     if (sl) {

  1509.                         for (i = 0; i < n; i++)

  1510.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  1511.                     } else {

  1512.                         for (i = 0; i < n; i++)

  1513.                             g->scale_factors[j++] = 0;

  1514.                     }

  1515.                 }

  1516.                 /* XXX: should compute exact size */

  1517.                 for (; j < 40; j++)

  1518.                     g->scale_factors[j] = 0;

  1519.             }

  1520. 

  1521.             exponents_from_scale_factors(s, g, exponents);

  1522. 

  1523.             /* read Huffman coded residue */

  1524.             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);

  1525.         } /* ch */

  1526. 

  1527.         if (s->nb_channels == 2)

  1528.             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);

  1529. 

  1530.         for (ch = 0; ch < s->nb_channels; ch++) {

  1531.             g = &s->granules[ch][gr];

  1532. 

  1533.             reorder_block(s, g);

  1534.             compute_antialias(s, g);

  1535.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  1536.         }

  1537.     } /* gr */

  1538.     if (get_bits_count(&s->gb) < 0)

  1539.         skip_bits_long(&s->gb, -get_bits_count(&s->gb));

  1540.     return nb_granules * 18;

  1541. }

  1542. 

  1543. static int mp_decode_frame(MPADecodeContext *s, OUT_INT *samples,

  1544.                            const uint8_t *buf, int buf_size)

  1545. {

  1546.     int i, nb_frames, ch, ret;

  1547.     OUT_INT *samples_ptr;

  1548. 

  1549.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);

  1550. 

  1551.     /* skip error protection field */

  1552.     if (s->error_protection)

  1553.         skip_bits(&s->gb, 16);

  1554. 

  1555.     switch(s->layer) {

  1556.     case 1:

  1557.         s->avctx->frame_size = 384;

  1558.         nb_frames = mp_decode_layer1(s);

  1559.         break;

  1560.     case 2:

  1561.         s->avctx->frame_size = 1152;

  1562.         nb_frames = mp_decode_layer2(s);

  1563.         break;

  1564.     case 3:

  1565.         s->avctx->frame_size = s->lsf ? 576 : 1152;

  1566.     default:

  1567.         nb_frames = mp_decode_layer3(s);

  1568. 

  1569.         s->last_buf_size=0;

  1570.         if (s->in_gb.buffer) {

  1571.             align_get_bits(&s->gb);

  1572.             i = get_bits_left(&s->gb)>>3;

  1573.             if (i >= 0 && i <= BACKSTEP_SIZE) {

  1574.                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);

  1575.                 s->last_buf_size=i;

  1576.             } else

  1577.                 av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);

  1578.             s->gb           = s->in_gb;

  1579.             s->in_gb.buffer = NULL;

  1580.         }

  1581. 

  1582.         align_get_bits(&s->gb);

  1583.         assert((get_bits_count(&s->gb) & 7) == 0);

  1584.         i = get_bits_left(&s->gb) >> 3;

  1585. 

  1586.         if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {

  1587.             if (i < 0)

  1588.                 av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);

  1589.             i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);

  1590.         }

  1591.         assert(i <= buf_size - HEADER_SIZE && i >= 0);

  1592.         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);

  1593.         s->last_buf_size += i;

  1594.     }

  1595. 

  1596.     /* get output buffer */

  1597.     if (!samples) {

  1598.         s->frame.nb_samples = s->avctx->frame_size;

  1599.         if ((ret = s->avctx->get_buffer(s->avctx, &s->frame)) < 0) {

  1600.             av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  1601.             return ret;

  1602.         }

  1603.         samples = (OUT_INT *)s->frame.data[0];

  1604.     }

  1605. 

  1606.     /* apply the synthesis filter */

  1607.     for (ch = 0; ch < s->nb_channels; ch++) {

  1608.         samples_ptr = samples + ch;

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

  1610.             RENAME(ff_mpa_synth_filter)(

  1611.                          &s->mpadsp,

  1612.                          s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  1613.                          RENAME(ff_mpa_synth_window), &s->dither_state,

  1614.                          samples_ptr, s->nb_channels,

  1615.                          s->sb_samples[ch][i]);

  1616.             samples_ptr += 32 * s->nb_channels;

  1617.         }

  1618.     }

  1619. 

  1620.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  1621. }

  1622. 

  1623. static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,

  1624.                         AVPacket *avpkt)

  1625. {

  1626.     const uint8_t *buf  = avpkt->data;

  1627.     int buf_size        = avpkt->size;

  1628.     MPADecodeContext *s = avctx->priv_data;

  1629.     uint32_t header;

  1630.     int out_size;

  1631. 

  1632.     if (buf_size < HEADER_SIZE)

  1633.         return AVERROR_INVALIDDATA;

  1634. 

  1635.     header = AV_RB32(buf);

  1636.     if (ff_mpa_check_header(header) < 0) {

  1637.         av_log(avctx, AV_LOG_ERROR, "Header missing\n");

  1638.         return AVERROR_INVALIDDATA;

  1639.     }

  1640. 

  1641.     if (avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {

  1642.         /* free format: prepare to compute frame size */

  1643.         s->frame_size = -1;

  1644.         return AVERROR_INVALIDDATA;

  1645.     }

  1646.     /* update codec info */

  1647.     avctx->channels       = s->nb_channels;

  1648.     avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;

  1649.     if (!avctx->bit_rate)

  1650.         avctx->bit_rate = s->bit_rate;

  1651.     avctx->sub_id = s->layer;

  1652. 

  1653.     if (s->frame_size <= 0 || s->frame_size > buf_size) {

  1654.         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

  1655.         return AVERROR_INVALIDDATA;

  1656.     }else if(s->frame_size < buf_size){

  1657.         av_log(avctx, AV_LOG_DEBUG, "incorrect frame size - multiple frames in buffer?\n");

  1658.         buf_size= s->frame_size;

  1659.     }

  1660. 

  1661.     out_size = mp_decode_frame(s, NULL, buf, buf_size);

  1662.     if (out_size >= 0) {

  1663.         *got_frame_ptr   = 1;

  1664.         *(AVFrame *)data = s->frame;

  1665.         avctx->sample_rate = s->sample_rate;

  1666.         //FIXME maybe move the other codec info stuff from above here too

  1667.     } else {

  1668.         av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");

  1669.         /* Only return an error if the bad frame makes up the whole packet.

  1670.            If there is more data in the packet, just consume the bad frame

  1671.            instead of returning an error, which would discard the whole

  1672.            packet. */

  1673.         *got_frame_ptr = 0;

  1674.         if (buf_size == avpkt->size)

  1675.             return out_size;

  1676.     }

  1677.     s->frame_size = 0;

  1678.     return buf_size;

  1679. }

  1680. 

  1681. static void flush(AVCodecContext *avctx)

  1682. {

  1683.     MPADecodeContext *s = avctx->priv_data;

  1684.     memset(s->synth_buf, 0, sizeof(s->synth_buf));

  1685.     s->last_buf_size = 0;

  1686. }

  1687. 

  1688. #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER

  1689. static int decode_frame_adu(AVCodecContext *avctx, void *data,

  1690.                             int *got_frame_ptr, AVPacket *avpkt)

  1691. {

  1692.     const uint8_t *buf  = avpkt->data;

  1693.     int buf_size        = avpkt->size;

  1694.     MPADecodeContext *s = avctx->priv_data;

  1695.     uint32_t header;

  1696.     int len, out_size;

  1697. 

  1698.     len = buf_size;

  1699. 

  1700.     // Discard too short frames

  1701.     if (buf_size < HEADER_SIZE) {

  1702.         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");

  1703.         return AVERROR_INVALIDDATA;

  1704.     }

  1705. 

  1706. 

  1707.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  1708.         len = MPA_MAX_CODED_FRAME_SIZE;

  1709. 

  1710.     // Get header and restore sync word

  1711.     header = AV_RB32(buf) | 0xffe00000;

  1712. 

  1713.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  1714.         av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");

  1715.         return AVERROR_INVALIDDATA;

  1716.     }

  1717. 

  1718.     avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);

  1719.     /* update codec info */

  1720.     avctx->sample_rate = s->sample_rate;

  1721.     avctx->channels    = s->nb_channels;

  1722.     if (!avctx->bit_rate)

  1723.         avctx->bit_rate = s->bit_rate;

  1724.     avctx->sub_id = s->layer;

  1725. 

  1726.     s->frame_size = len;

  1727. 

  1728. #if FF_API_PARSE_FRAME

  1729.     if (avctx->parse_only)

  1730.         out_size = buf_size;

  1731.     else

  1732. #endif

  1733.     out_size = mp_decode_frame(s, NULL, buf, buf_size);

  1734. 

  1735.     *got_frame_ptr   = 1;

  1736.     *(AVFrame *)data = s->frame;

  1737. 

  1738.     return buf_size;

  1739. }

  1740. #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */

  1741. 

  1742. #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER

  1743. 

  1744. /**

  1745.  * Context for MP3On4 decoder

  1746.  */

  1747. typedef struct MP3On4DecodeContext {

  1748.     AVFrame *frame;

  1749.     int frames;                     ///< number of mp3 frames per block (number of mp3 decoder instances)

  1750.     int syncword;                   ///< syncword patch

  1751.     const uint8_t *coff;            ///< channel offsets in output buffer

  1752.     MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance

  1753.     OUT_INT *decoded_buf;           ///< output buffer for decoded samples

  1754. } MP3On4DecodeContext;

  1755. 

  1756. #include "mpeg4audio.h"

  1757. 

  1758. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  1759. 

  1760. /* number of mp3 decoder instances */

  1761. static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };

  1762. 

  1763. /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */

  1764. static const uint8_t chan_offset[8][5] = {

  1765.     { 0             },

  1766.     { 0             },  // C

  1767.     { 0             },  // FLR

  1768.     { 2, 0          },  // C FLR

  1769.     { 2, 0, 3       },  // C FLR BS

  1770.     { 2, 0, 3       },  // C FLR BLRS

  1771.     { 2, 0, 4, 3    },  // C FLR BLRS LFE

  1772.     { 2, 0, 6, 4, 3 },  // C FLR BLRS BLR LFE

  1773. };

  1774. 

  1775. /* mp3on4 channel layouts */

  1776. static const int16_t chan_layout[8] = {

  1777.     0,

  1778.     AV_CH_LAYOUT_MONO,

  1779.     AV_CH_LAYOUT_STEREO,

  1780.     AV_CH_LAYOUT_SURROUND,

  1781.     AV_CH_LAYOUT_4POINT0,

  1782.     AV_CH_LAYOUT_5POINT0,

  1783.     AV_CH_LAYOUT_5POINT1,

  1784.     AV_CH_LAYOUT_7POINT1

  1785. };

  1786. 

  1787. static av_cold int decode_close_mp3on4(AVCodecContext * avctx)

  1788. {

  1789.     MP3On4DecodeContext *s = avctx->priv_data;

  1790.     int i;

  1791. 

  1792.     for (i = 0; i < s->frames; i++)

  1793.         av_free(s->mp3decctx[i]);

  1794. 

  1795.     av_freep(&s->decoded_buf);

  1796. 

  1797.     return 0;

  1798. }

  1799. 

  1800. 

  1801. static int decode_init_mp3on4(AVCodecContext * avctx)

  1802. {

  1803.     MP3On4DecodeContext *s = avctx->priv_data;

  1804.     MPEG4AudioConfig cfg;

  1805.     int i;

  1806. 

  1807.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  1808.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  1809.         return AVERROR_INVALIDDATA;

  1810.     }

  1811. 

  1812.     avpriv_mpeg4audio_get_config(&cfg, avctx->extradata,

  1813.                                  avctx->extradata_size * 8, 1);

  1814.     if (!cfg.chan_config || cfg.chan_config > 7) {

  1815.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  1816.         return AVERROR_INVALIDDATA;

  1817.     }

  1818.     s->frames             = mp3Frames[cfg.chan_config];

  1819.     s->coff               = chan_offset[cfg.chan_config];

  1820.     avctx->channels       = ff_mpeg4audio_channels[cfg.chan_config];

  1821.     avctx->channel_layout = chan_layout[cfg.chan_config];

  1822. 

  1823.     if (cfg.sample_rate < 16000)

  1824.         s->syncword = 0xffe00000;

  1825.     else

  1826.         s->syncword = 0xfff00000;

  1827. 

  1828.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  1829.      * We replace avctx->priv_data with the context of the first decoder so that

  1830.      * decode_init() does not have to be changed.

  1831.      * Other decoders will be initialized here copying data from the first context

  1832.      */

  1833.     // Allocate zeroed memory for the first decoder context

  1834.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  1835.     if (!s->mp3decctx[0])

  1836.         goto alloc_fail;

  1837.     // Put decoder context in place to make init_decode() happy

  1838.     avctx->priv_data = s->mp3decctx[0];

  1839.     decode_init(avctx);

  1840.     s->frame = avctx->coded_frame;

  1841.     // Restore mp3on4 context pointer

  1842.     avctx->priv_data = s;

  1843.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  1844. 

  1845.     /* Create a separate codec/context for each frame (first is already ok).

  1846.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  1847.      */

  1848.     for (i = 1; i < s->frames; i++) {

  1849.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  1850.         if (!s->mp3decctx[i])

  1851.             goto alloc_fail;

  1852.         s->mp3decctx[i]->adu_mode = 1;

  1853.         s->mp3decctx[i]->avctx = avctx;

  1854.         s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;

  1855.     }

  1856. 

  1857.     /* Allocate buffer for multi-channel output if needed */

  1858.     if (s->frames > 1) {

  1859.         s->decoded_buf = av_malloc(MPA_FRAME_SIZE * MPA_MAX_CHANNELS *

  1860.                                    sizeof(*s->decoded_buf));

  1861.         if (!s->decoded_buf)

  1862.             goto alloc_fail;

  1863.     }

  1864. 

  1865.     return 0;

  1866. alloc_fail:

  1867.     decode_close_mp3on4(avctx);

  1868.     return AVERROR(ENOMEM);

  1869. }

  1870. 

  1871. 

  1872. static void flush_mp3on4(AVCodecContext *avctx)

  1873. {

  1874.     int i;

  1875.     MP3On4DecodeContext *s = avctx->priv_data;

  1876. 

  1877.     for (i = 0; i < s->frames; i++) {

  1878.         MPADecodeContext *m = s->mp3decctx[i];

  1879.         memset(m->synth_buf, 0, sizeof(m->synth_buf));

  1880.         m->last_buf_size = 0;

  1881.     }

  1882. }

  1883. 

  1884. 

  1885. static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,

  1886.                                int *got_frame_ptr, AVPacket *avpkt)

  1887. {

  1888.     const uint8_t *buf     = avpkt->data;

  1889.     int buf_size           = avpkt->size;

  1890.     MP3On4DecodeContext *s = avctx->priv_data;

  1891.     MPADecodeContext *m;

  1892.     int fsize, len = buf_size, out_size = 0;

  1893.     uint32_t header;

  1894.     OUT_INT *out_samples;

  1895.     OUT_INT *outptr, *bp;

  1896.     int fr, j, n, ch, ret;

  1897. 

  1898.     /* get output buffer */

  1899.     s->frame->nb_samples = MPA_FRAME_SIZE;

  1900.     if ((ret = avctx->get_buffer(avctx, s->frame)) < 0) {

  1901.         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  1902.         return ret;

  1903.     }

  1904.     out_samples = (OUT_INT *)s->frame->data[0];

  1905. 

  1906.     // Discard too short frames

  1907.     if (buf_size < HEADER_SIZE)

  1908.         return AVERROR_INVALIDDATA;

  1909. 

  1910.     // If only one decoder interleave is not needed

  1911.     outptr = s->frames == 1 ? out_samples : s->decoded_buf;

  1912. 

  1913.     avctx->bit_rate = 0;

  1914. 

  1915.     ch = 0;

  1916.     for (fr = 0; fr < s->frames; fr++) {

  1917.         fsize = AV_RB16(buf) >> 4;

  1918.         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);

  1919.         m     = s->mp3decctx[fr];

  1920.         assert(m != NULL);

  1921. 

  1922.         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header

  1923. 

  1924.         if (ff_mpa_check_header(header) < 0) // Bad header, discard block

  1925.             break;

  1926. 

  1927.         avpriv_mpegaudio_decode_header((MPADecodeHeader *)m, header);

  1928. 

  1929.         if (ch + m->nb_channels > avctx->channels) {

  1930.             av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "

  1931.                                         "channel count\n");

  1932.             return AVERROR_INVALIDDATA;

  1933.         }

  1934.         ch += m->nb_channels;

  1935. 

  1936.         out_size += mp_decode_frame(m, outptr, buf, fsize);

  1937.         buf      += fsize;

  1938.         len      -= fsize;

  1939. 

  1940.         if (s->frames > 1) {

  1941.             n = m->avctx->frame_size*m->nb_channels;

  1942.             /* interleave output data */

  1943.             bp = out_samples + s->coff[fr];

  1944.             if (m->nb_channels == 1) {

  1945.                 for (j = 0; j < n; j++) {

  1946.                     *bp = s->decoded_buf[j];

  1947.                     bp += avctx->channels;

  1948.                 }

  1949.             } else {

  1950.                 for (j = 0; j < n; j++) {

  1951.                     bp[0] = s->decoded_buf[j++];

  1952.                     bp[1] = s->decoded_buf[j];

  1953.                     bp   += avctx->channels;

  1954.                 }

  1955.             }

  1956.         }

  1957.         avctx->bit_rate += m->bit_rate;

  1958.     }

  1959. 

  1960.     /* update codec info */

  1961.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  1962. 

  1963.     s->frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));

  1964.     *got_frame_ptr   = 1;

  1965.     *(AVFrame *)data = *s->frame;

  1966. 

  1967.     return buf_size;

  1968. }

  1969. #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */

  1970. 

  1971. #if !CONFIG_FLOAT

  1972. #if CONFIG_MP1_DECODER

  1973. AVCodec ff_mp1_decoder = {

  1974.     .name           = "mp1",

  1975.     .type           = AVMEDIA_TYPE_AUDIO,

  1976.     .id             = CODEC_ID_MP1,

  1977.     .priv_data_size = sizeof(MPADecodeContext),

  1978.     .init           = decode_init,

  1979.     .decode         = decode_frame,

  1980. #if FF_API_PARSE_FRAME

  1981.     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,

  1982. #else

  1983.     .capabilities   = CODEC_CAP_DR1,

  1984. #endif

  1985.     .flush          = flush,

  1986.     .long_name      = NULL_IF_CONFIG_SMALL("MP1 (MPEG audio layer 1)"),

  1987. };

  1988. #endif

  1989. #if CONFIG_MP2_DECODER

  1990. AVCodec ff_mp2_decoder = {

  1991.     .name           = "mp2",

  1992.     .type           = AVMEDIA_TYPE_AUDIO,

  1993.     .id             = CODEC_ID_MP2,

  1994.     .priv_data_size = sizeof(MPADecodeContext),

  1995.     .init           = decode_init,

  1996.     .decode         = decode_frame,

  1997. #if FF_API_PARSE_FRAME

  1998.     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,

  1999. #else

  2000.     .capabilities   = CODEC_CAP_DR1,

  2001. #endif

  2002.     .flush          = flush,

  2003.     .long_name      = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),

  2004. };

  2005. #endif

  2006. #if CONFIG_MP3_DECODER

  2007. AVCodec ff_mp3_decoder = {

  2008.     .name           = "mp3",

  2009.     .type           = AVMEDIA_TYPE_AUDIO,

  2010.     .id             = CODEC_ID_MP3,

  2011.     .priv_data_size = sizeof(MPADecodeContext),

  2012.     .init           = decode_init,

  2013.     .decode         = decode_frame,

  2014. #if FF_API_PARSE_FRAME

  2015.     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,

  2016. #else

  2017.     .capabilities   = CODEC_CAP_DR1,

  2018. #endif

  2019.     .flush          = flush,

  2020.     .long_name      = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),

  2021. };

  2022. #endif

  2023. #if CONFIG_MP3ADU_DECODER

  2024. AVCodec ff_mp3adu_decoder = {

  2025.     .name           = "mp3adu",

  2026.     .type           = AVMEDIA_TYPE_AUDIO,

  2027.     .id             = CODEC_ID_MP3ADU,

  2028.     .priv_data_size = sizeof(MPADecodeContext),

  2029.     .init           = decode_init,

  2030.     .decode         = decode_frame_adu,

  2031. #if FF_API_PARSE_FRAME

  2032.     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,

  2033. #else

  2034.     .capabilities   = CODEC_CAP_DR1,

  2035. #endif

  2036.     .flush          = flush,

  2037.     .long_name      = NULL_IF_CONFIG_SMALL("ADU (Application Data Unit) MP3 (MPEG audio layer 3)"),

  2038. };

  2039. #endif

  2040. #if CONFIG_MP3ON4_DECODER

  2041. AVCodec ff_mp3on4_decoder = {

  2042.     .name           = "mp3on4",

  2043.     .type           = AVMEDIA_TYPE_AUDIO,

  2044.     .id             = CODEC_ID_MP3ON4,

  2045.     .priv_data_size = sizeof(MP3On4DecodeContext),

  2046.     .init           = decode_init_mp3on4,

  2047.     .close          = decode_close_mp3on4,

  2048.     .decode         = decode_frame_mp3on4,

  2049.     .capabilities   = CODEC_CAP_DR1,

  2050.     .flush          = flush_mp3on4,

  2051.     .long_name      = NULL_IF_CONFIG_SMALL("MP3onMP4"),

  2052. };

  2053. #endif

  2054. #endif