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FFmpeg/libavcodec/mpegaudiodec_template.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/attributes.h"

  28. #include "libavutil/avassert.h"

  29. #include "libavutil/channel_layout.h"

  30. #include "libavutil/float_dsp.h"

  31. #include "avcodec.h"

  32. #include "get_bits.h"

  33. #include "internal.h"

  34. #include "mathops.h"

  35. #include "mpegaudiodsp.h"

  36. 

  37. /*

  38.  * TODO:

  39.  *  - test lsf / mpeg25 extensively.

  40.  */

  41. 

  42. #include "mpegaudio.h"

  43. #include "mpegaudiodecheader.h"

  44. 

  45. #define BACKSTEP_SIZE 512

  46. #define EXTRABYTES 24

  47. #define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES

  48. 

  49. /* layer 3 "granule" */

  50. typedef struct GranuleDef {

  51.     uint8_t scfsi;

  52.     int part2_3_length;

  53.     int big_values;

  54.     int global_gain;

  55.     int scalefac_compress;

  56.     uint8_t block_type;

  57.     uint8_t switch_point;

  58.     int table_select[3];

  59.     int subblock_gain[3];

  60.     uint8_t scalefac_scale;

  61.     uint8_t count1table_select;

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

  63.     int preflag;

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

  65.     uint8_t scale_factors[40];

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

  67. } GranuleDef;

  68. 

  69. typedef struct MPADecodeContext {

  70.     MPA_DECODE_HEADER

  71.     uint8_t last_buf[LAST_BUF_SIZE];

  72.     int last_buf_size;

  73.     int extrasize;

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

  75.     uint32_t free_format_next_header;

  76.     GetBitContext gb;

  77.     GetBitContext in_gb;

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

  79.     int synth_buf_offset[MPA_MAX_CHANNELS];

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

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

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

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

  84.     int dither_state;

  85.     int err_recognition;

  86.     AVCodecContext* avctx;

  87.     MPADSPContext mpadsp;

  88.     AVFloatDSPContext fdsp;

  89.     AVFrame *frame;

  90. } MPADecodeContext;

  91. 

  92. #define HEADER_SIZE 4

  93. 

  94. #include "mpegaudiodata.h"

  95. #include "mpegaudiodectab.h"

  96. 

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

  98. static VLC huff_vlc[16];

  99. static VLC_TYPE huff_vlc_tables[

  100.     0 + 128 + 128 + 128 + 130 + 128 + 154 + 166 +

  101.   142 + 204 + 190 + 170 + 542 + 460 + 662 + 414

  102.   ][2];

  103. static const int huff_vlc_tables_sizes[16] = {

  104.     0,  128,  128,  128,  130,  128,  154,  166,

  105.   142,  204,  190,  170,  542,  460,  662,  414

  106. };

  107. static VLC huff_quad_vlc[2];

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

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

  110. /* computed from band_size_long */

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

  112. #include "mpegaudio_tablegen.h"

  113. /* intensity stereo coef table */

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

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

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

  117. 

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

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

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

  121. 

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

  123.     division_tab3, division_tab5, NULL, division_tab9

  124. };

  125. 

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

  127. static uint16_t scale_factor_modshift[64];

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

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

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

  131. 

  132. #define SCALE_GEN(v) \

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

  134. 

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

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

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

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

  139. };

  140. 

  141. /**

  142.  * Convert region offsets to region sizes and truncate

  143.  * size to big_values.

  144.  */

  145. static void region_offset2size(GranuleDef *g)

  146. {

  147.     int i, k, j = 0;

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

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

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

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

  152.         j = k;

  153.     }

  154. }

  155. 

  156. static void init_short_region(MPADecodeContext *s, GranuleDef *g)

  157. {

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

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

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

  161.         else

  162.             g->region_size[0] = (72 / 2);

  163.     } else {

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

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

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

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

  168.         else

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

  170.     }

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

  172. }

  173. 

  174. static void init_long_region(MPADecodeContext *s, GranuleDef *g,

  175.                              int ra1, int ra2)

  176. {

  177.     int l;

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

  179.     /* should not overflow */

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

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

  182. }

  183. 

  184. static void compute_band_indexes(MPADecodeContext *s, GranuleDef *g)

  185. {

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

  187.         if (g->switch_point) {

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

  189.                 long blocks.  For 8000Hz, we handle the 72 first

  190.                 exponents as long blocks */

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

  192.                 g->long_end = 8;

  193.             else

  194.                 g->long_end = 6;

  195. 

  196.             g->short_start = 3;

  197.         } else {

  198.             g->long_end    = 0;

  199.             g->short_start = 0;

  200.         }

  201.     } else {

  202.         g->short_start = 13;

  203.         g->long_end    = 22;

  204.     }

  205. }

  206. 

  207. /* layer 1 unscaling */

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

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

  210. {

  211.     int shift, mod;

  212.     int64_t val;

  213. 

  214.     shift   = scale_factor_modshift[scale_factor];

  215.     mod     = shift & 3;

  216.     shift >>= 2;

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

  218.     shift  += n;

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

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

  221. }

  222. 

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

  224. {

  225.     int shift, mod, val;

  226. 

  227.     shift   = scale_factor_modshift[scale_factor];

  228.     mod     = shift & 3;

  229.     shift >>= 2;

  230. 

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

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

  233.     if (shift > 0)

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

  235.     return val;

  236. }

  237. 

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

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

  240. {

  241.     unsigned int m;

  242.     int e;

  243. 

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

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

  246.     e -= exponent >> 2;

  247.     assert(e >= 1);

  248.     if (e > 31)

  249.         return 0;

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

  251. 

  252.     return m;

  253. }

  254. 

  255. static av_cold void decode_init_static(void)

  256. {

  257.     int i, j, k;

  258.     int offset;

  259. 

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

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

  262.         int shift, mod;

  263.         /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  264.         shift = i / 3;

  265.         mod   = i % 3;

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

  267.     }

  268. 

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

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

  271.         int n, norm;

  272.         n = i + 2;

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

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

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

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

  277.         ff_dlog(NULL, "%d: norm=%x s=%x %x %x\n", i, norm,

  278.                 scale_factor_mult[i][0],

  279.                 scale_factor_mult[i][1],

  280.                 scale_factor_mult[i][2]);

  281.     }

  282. 

  283.     RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));

  284. 

  285.     /* huffman decode tables */

  286.     offset = 0;

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

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

  289.         int xsize, x, y;

  290.         uint8_t  tmp_bits [512] = { 0 };

  291.         uint16_t tmp_codes[512] = { 0 };

  292. 

  293.         xsize = h->xsize;

  294. 

  295.         j = 0;

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

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

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

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

  300.             }

  301.         }

  302. 

  303.         /* XXX: fail test */

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

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

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

  307.                  tmp_bits, 1, 1, tmp_codes, 2, 2,

  308.                  INIT_VLC_USE_NEW_STATIC);

  309.         offset += huff_vlc_tables_sizes[i];

  310.     }

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

  312. 

  313.     offset = 0;

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

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

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

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

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

  319.                  INIT_VLC_USE_NEW_STATIC);

  320.         offset += huff_quad_vlc_tables_sizes[i];

  321.     }

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

  323. 

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

  325.         k = 0;

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

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

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

  329.         }

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

  331.     }

  332. 

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

  334. 

  335.     mpegaudio_tableinit();

  336. 

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

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

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

  340.                 int val1, val2, val3, steps;

  341.                 int val = j;

  342.                 steps   = ff_mpa_quant_steps[i];

  343.                 val1    = val % steps;

  344.                 val    /= steps;

  345.                 val2    = val % steps;

  346.                 val3    = val / steps;

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

  348.             }

  349.         }

  350.     }

  351. 

  352. 

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

  354.         float f;

  355.         INTFLOAT v;

  356.         if (i != 6) {

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

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

  359.         } else {

  360.             v = FIXR(1.0);

  361.         }

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

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

  364.     }

  365.     /* invalid values */

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

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

  368. 

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

  370.         double f;

  371.         int e, k;

  372. 

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

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

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

  376.             k = i & 1;

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

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

  379.             ff_dlog(NULL, "is_table_lsf %d %d: %f %f\n",

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

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

  382.         }

  383.     }

  384. 

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

  386.         float ci, cs, ca;

  387.         ci = ci_table[i];

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

  389.         ca = cs * ci;

  390. #if !CONFIG_FLOAT

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

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

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

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

  395. #else

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

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

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

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

  400. #endif

  401.     }

  402. }

  403. 

  404. static av_cold int decode_init(AVCodecContext * avctx)

  405. {

  406.     static int initialized_tables = 0;

  407.     MPADecodeContext *s = avctx->priv_data;

  408. 

  409.     if (!initialized_tables) {

  410.         decode_init_static();

  411.         initialized_tables = 1;

  412.     }

  413. 

  414.     s->avctx = avctx;

  415. 

  416.     avpriv_float_dsp_init(&s->fdsp, avctx->flags & AV_CODEC_FLAG_BITEXACT);

  417.     ff_mpadsp_init(&s->mpadsp);

  418. 

  419.     if (avctx->request_sample_fmt == OUT_FMT &&

  420.         avctx->codec_id != AV_CODEC_ID_MP3ON4)

  421.         avctx->sample_fmt = OUT_FMT;

  422.     else

  423.         avctx->sample_fmt = OUT_FMT_P;

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

  425. 

  426.     if (avctx->codec_id == AV_CODEC_ID_MP3ADU)

  427.         s->adu_mode = 1;

  428. 

  429.     return 0;

  430. }

  431. 

  432. #define C3 FIXHR(0.86602540378443864676/2)

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

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

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

  436. 

  437. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  438.    cases. */

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

  440. {

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

  442. 

  443.     in0  = in[0*3];

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

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

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

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

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

  449.     in5 += in3;

  450.     in3 += in1;

  451. 

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

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

  454. 

  455.     t1   = in0 - in4;

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

  457. 

  458.     out[ 7] =

  459.     out[10] = t1 + t2;

  460.     out[ 1] =

  461.     out[ 4] = t1 - t2;

  462. 

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

  464.     in4     = in0 + in2;

  465.     in5    += 2*in1;

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

  467.     out[ 8] =

  468.     out[ 9] = in4 + in1;

  469.     out[ 2] =

  470.     out[ 3] = in4 - in1;

  471. 

  472.     in0    -= in2;

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

  474.     out[ 0] =

  475.     out[ 5] = in0 - in5;

  476.     out[ 6] =

  477.     out[11] = in0 + in5;

  478. }

  479. 

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

  481. static int mp_decode_layer1(MPADecodeContext *s)

  482. {

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

  484.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  485.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  486. 

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

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

  489.     else

  490.         bound = SBLIMIT;

  491. 

  492.     /* allocation bits */

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

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

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

  496.         }

  497.     }

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

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

  500. 

  501.     /* scale factors */

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

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

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

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

  506.         }

  507.     }

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

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

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

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

  512.         }

  513.     }

  514. 

  515.     /* compute samples */

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

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

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

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

  520.                 if (n) {

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

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

  523.                 } else {

  524.                     v = 0;

  525.                 }

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

  527.             }

  528.         }

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

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

  531.             if (n) {

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

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

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

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

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

  537.             } else {

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

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

  540.             }

  541.         }

  542.     }

  543.     return 12;

  544. }

  545. 

  546. static int mp_decode_layer2(MPADecodeContext *s)

  547. {

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

  549.     const unsigned char *alloc_table;

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

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

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

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

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

  555. 

  556.     /* select decoding table */

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

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

  559.     sblimit     = ff_mpa_sblimit_table[table];

  560.     alloc_table = ff_mpa_alloc_tables[table];

  561. 

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

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

  564.     else

  565.         bound = sblimit;

  566. 

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

  568. 

  569.     /* sanity check */

  570.     if (bound > sblimit)

  571.         bound = sblimit;

  572. 

  573.     /* parse bit allocation */

  574.     j = 0;

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

  576.         bit_alloc_bits = alloc_table[j];

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

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

  579.         j += 1 << bit_alloc_bits;

  580.     }

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

  582.         bit_alloc_bits = alloc_table[j];

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

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

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

  586.         j += 1 << bit_alloc_bits;

  587.     }

  588. 

  589.     /* scale codes */

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

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

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

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

  594.         }

  595.     }

  596. 

  597.     /* scale factors */

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

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

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

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

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

  603.                 default:

  604.                 case 0:

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

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

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

  608.                     break;

  609.                 case 2:

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

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

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

  613.                     break;

  614.                 case 1:

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

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

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

  618.                     break;

  619.                 case 3:

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

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

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

  623.                     break;

  624.                 }

  625.             }

  626.         }

  627.     }

  628. 

  629.     /* samples */

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

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

  632.             j = 0;

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

  634.                 bit_alloc_bits = alloc_table[j];

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

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

  637.                     if (b) {

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

  639.                         qindex = alloc_table[j+b];

  640.                         bits = ff_mpa_quant_bits[qindex];

  641.                         if (bits < 0) {

  642.                             int v2;

  643.                             /* 3 values at the same time */

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

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

  646.                             steps  = ff_mpa_quant_steps[qindex];

  647. 

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

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

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

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

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

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

  654.                         } else {

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

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

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

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

  659.                             }

  660.                         }

  661.                     } else {

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

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

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

  665.                     }

  666.                 }

  667.                 /* next subband in alloc table */

  668.                 j += 1 << bit_alloc_bits;

  669.             }

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

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

  672.                 bit_alloc_bits = alloc_table[j];

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

  674.                 if (b) {

  675.                     int mant, scale0, scale1;

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

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

  678.                     qindex = alloc_table[j+b];

  679.                     bits = ff_mpa_quant_bits[qindex];

  680.                     if (bits < 0) {

  681.                         /* 3 values at the same time */

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

  683.                         steps = ff_mpa_quant_steps[qindex];

  684.                         mant = v % steps;

  685.                         v = v / steps;

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

  687.                             l2_unscale_group(steps, mant, scale0);

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

  689.                             l2_unscale_group(steps, mant, scale1);

  690.                         mant = v % steps;

  691.                         v = v / steps;

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

  693.                             l2_unscale_group(steps, mant, scale0);

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

  695.                             l2_unscale_group(steps, mant, scale1);

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

  697.                             l2_unscale_group(steps, v, scale0);

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

  699.                             l2_unscale_group(steps, v, scale1);

  700.                     } else {

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

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

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

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

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

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

  707.                         }

  708.                     }

  709.                 } else {

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

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

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

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

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

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

  716.                 }

  717.                 /* next subband in alloc table */

  718.                 j += 1 << bit_alloc_bits;

  719.             }

  720.             /* fill remaining samples to zero */

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

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

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

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

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

  726.                 }

  727.             }

  728.         }

  729.     }

  730.     return 3 * 12;

  731. }

  732. 

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

  734.     if (n == 3) {                   \

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

  736.         dst   = sf - 3 * m;         \

  737.         sf    = m;                  \

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

  739.         dst  = sf & 3;              \

  740.         sf >>= 2;                   \

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

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

  743.         dst   = sf - 5 * m;         \

  744.         sf    = m;                  \

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

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

  747.         dst   = sf - 6 * m;         \

  748.         sf    = m;                  \

  749.     } else {                        \

  750.         dst = 0;                    \

  751.     }

  752. 

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

  754.                                            int n3)

  755. {

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

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

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

  759.     slen[0] = sf;

  760. }

  761. 

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

  763.                                          int16_t *exponents)

  764. {

  765.     const uint8_t *bstab, *pretab;

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

  767.     int16_t *exp_ptr;

  768. 

  769.     exp_ptr = exponents;

  770.     gain    = g->global_gain - 210;

  771.     shift   = g->scalefac_scale + 1;

  772. 

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

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

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

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

  777.         len = bstab[i];

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

  779.             *exp_ptr++ = v0;

  780.     }

  781. 

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

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

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

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

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

  787.         k        = g->long_end;

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

  789.             len = bstab[i];

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

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

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

  793.                     *exp_ptr++ = v0;

  794.             }

  795.         }

  796.     }

  797. }

  798. 

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

  800.                           int *end_pos2)

  801. {

  802.     if (s->in_gb.buffer && *pos >= s->gb.size_in_bits - s->extrasize * 8) {

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

  804.         s->in_gb.buffer = NULL;

  805.         s->extrasize    = 0;

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

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

  808.         *end_pos2 =

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

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

  811.     }

  812. }

  813. 

  814. /* Following is a optimized code for

  815.             INTFLOAT v = *src

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

  817.                 v = -v;

  818.             *dst = v;

  819. */

  820. #if CONFIG_FLOAT

  821. #define READ_FLIP_SIGN(dst,src)                     \

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

  823.     AV_WN32A(dst, v);

  824. #else

  825. #define READ_FLIP_SIGN(dst,src)     \

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

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

  828. #endif

  829. 

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

  831.                           int16_t *exponents, int end_pos2)

  832. {

  833.     int s_index;

  834.     int i;

  835.     int last_pos, bits_left;

  836.     VLC *vlc;

  837.     int end_pos = FFMIN(end_pos2, s->gb.size_in_bits - s->extrasize * 8);

  838. 

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

  840.     s_index = 0;

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

  842.         int j, k, l, linbits;

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

  844.         if (j == 0)

  845.             continue;

  846.         /* select vlc table */

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

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

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

  850.         vlc     = &huff_vlc[l];

  851. 

  852.         if (!l) {

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

  854.             s_index += 2 * j;

  855.             continue;

  856.         }

  857. 

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

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

  860.             int exponent, x, y;

  861.             int v;

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

  863. 

  864.             if (pos >= end_pos){

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

  866.                 if (pos >= end_pos)

  867.                     break;

  868.             }

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

  870. 

  871.             if (!y) {

  872.                 g->sb_hybrid[s_index  ] =

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

  874.                 s_index += 2;

  875.                 continue;

  876.             }

  877. 

  878.             exponent= exponents[s_index];

  879. 

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

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

  882.             if (y & 16) {

  883.                 x = y >> 5;

  884.                 y = y & 0x0f;

  885.                 if (x < 15) {

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

  887.                 } else {

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

  889.                     v  = l3_unscale(x, exponent);

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

  891.                         v = -v;

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

  893.                 }

  894.                 if (y < 15) {

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

  896.                 } else {

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

  898.                     v  = l3_unscale(y, exponent);

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

  900.                         v = -v;

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

  902.                 }

  903.             } else {

  904.                 x = y >> 5;

  905.                 y = y & 0x0f;

  906.                 x += y;

  907.                 if (x < 15) {

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

  909.                 } else {

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

  911.                     v  = l3_unscale(x, exponent);

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

  913.                         v = -v;

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

  915.                 }

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

  917.             }

  918.             s_index += 2;

  919.         }

  920.     }

  921. 

  922.     /* high frequencies */

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

  924.     last_pos = 0;

  925.     while (s_index <= 572) {

  926.         int pos, code;

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

  928.         if (pos >= end_pos) {

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

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

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

  932.                 s_index -= 4;

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

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

  935.                 if(s->err_recognition & AV_EF_BITSTREAM)

  936.                     s_index=0;

  937.                 break;

  938.             }

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

  940.             if (pos >= end_pos)

  941.                 break;

  942.         }

  943.         last_pos = pos;

  944. 

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

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

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

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

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

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

  951.         while (code) {

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

  953.             int v;

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

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

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

  957.         }

  958.         s_index += 4;

  959.     }

  960.     /* skip extension bits */

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

  962.     if (bits_left < 0 && (s->err_recognition & AV_EF_BUFFER)) {

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

  964.         s_index=0;

  965.     } else if (bits_left > 0 && (s->err_recognition & AV_EF_BUFFER)) {

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

  967.         s_index = 0;

  968.     }

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

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

  971. 

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

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

  974. 

  975.     return 0;

  976. }

  977. 

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

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

  980.    complicated */

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

  982. {

  983.     int i, j, len;

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

  985.     INTFLOAT tmp[576];

  986. 

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

  988.         return;

  989. 

  990.     if (g->switch_point) {

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

  992.             ptr = g->sb_hybrid + 36;

  993.         else

  994.             ptr = g->sb_hybrid + 72;

  995.     } else {

  996.         ptr = g->sb_hybrid;

  997.     }

  998. 

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

  1000.         len  = band_size_short[s->sample_rate_index][i];

  1001.         ptr1 = ptr;

  1002.         dst  = tmp;

  1003.         for (j = len; j > 0; j--) {

  1004.             *dst++ = ptr[0*len];

  1005.             *dst++ = ptr[1*len];

  1006.             *dst++ = ptr[2*len];

  1007.             ptr++;

  1008.         }

  1009.         ptr += 2 * len;

  1010.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1011.     }

  1012. }

  1013. 

  1014. #define ISQRT2 FIXR(0.70710678118654752440)

  1015. 

  1016. static void compute_stereo(MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)

  1017. {

  1018.     int i, j, k, l;

  1019.     int sf_max, sf, len, non_zero_found;

  1020.     INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;

  1021.     int non_zero_found_short[3];

  1022. 

  1023.     /* intensity stereo */

  1024.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1025.         if (!s->lsf) {

  1026.             is_tab = is_table;

  1027.             sf_max = 7;

  1028.         } else {

  1029.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1030.             sf_max = 16;

  1031.         }

  1032. 

  1033.         tab0 = g0->sb_hybrid + 576;

  1034.         tab1 = g1->sb_hybrid + 576;

  1035. 

  1036.         non_zero_found_short[0] = 0;

  1037.         non_zero_found_short[1] = 0;

  1038.         non_zero_found_short[2] = 0;

  1039.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1040.         for (i = 12; i >= g1->short_start; i--) {

  1041.             /* for last band, use previous scale factor */

  1042.             if (i != 11)

  1043.                 k -= 3;

  1044.             len = band_size_short[s->sample_rate_index][i];

  1045.             for (l = 2; l >= 0; l--) {

  1046.                 tab0 -= len;

  1047.                 tab1 -= len;

  1048.                 if (!non_zero_found_short[l]) {

  1049.                     /* test if non zero band. if so, stop doing i-stereo */

  1050.                     for (j = 0; j < len; j++) {

  1051.                         if (tab1[j] != 0) {

  1052.                             non_zero_found_short[l] = 1;

  1053.                             goto found1;

  1054.                         }

  1055.                     }

  1056.                     sf = g1->scale_factors[k + l];

  1057.                     if (sf >= sf_max)

  1058.                         goto found1;

  1059. 

  1060.                     v1 = is_tab[0][sf];

  1061.                     v2 = is_tab[1][sf];

  1062.                     for (j = 0; j < len; j++) {

  1063.                         tmp0    = tab0[j];

  1064.                         tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1065.                         tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1066.                     }

  1067.                 } else {

  1068. found1:

  1069.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1070.                         /* lower part of the spectrum : do ms stereo

  1071.                            if enabled */

  1072.                         for (j = 0; j < len; j++) {

  1073.                             tmp0    = tab0[j];

  1074.                             tmp1    = tab1[j];

  1075.                             tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1076.                             tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1077.                         }

  1078.                     }

  1079.                 }

  1080.             }

  1081.         }

  1082. 

  1083.         non_zero_found = non_zero_found_short[0] |

  1084.                          non_zero_found_short[1] |

  1085.                          non_zero_found_short[2];

  1086. 

  1087.         for (i = g1->long_end - 1;i >= 0;i--) {

  1088.             len   = band_size_long[s->sample_rate_index][i];

  1089.             tab0 -= len;

  1090.             tab1 -= len;

  1091.             /* test if non zero band. if so, stop doing i-stereo */

  1092.             if (!non_zero_found) {

  1093.                 for (j = 0; j < len; j++) {

  1094.                     if (tab1[j] != 0) {

  1095.                         non_zero_found = 1;

  1096.                         goto found2;

  1097.                     }

  1098.                 }

  1099.                 /* for last band, use previous scale factor */

  1100.                 k  = (i == 21) ? 20 : i;

  1101.                 sf = g1->scale_factors[k];

  1102.                 if (sf >= sf_max)

  1103.                     goto found2;

  1104.                 v1 = is_tab[0][sf];

  1105.                 v2 = is_tab[1][sf];

  1106.                 for (j = 0; j < len; j++) {

  1107.                     tmp0    = tab0[j];

  1108.                     tab0[j] = MULLx(tmp0, v1, FRAC_BITS);

  1109.                     tab1[j] = MULLx(tmp0, v2, FRAC_BITS);

  1110.                 }

  1111.             } else {

  1112. found2:

  1113.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1114.                     /* lower part of the spectrum : do ms stereo

  1115.                        if enabled */

  1116.                     for (j = 0; j < len; j++) {

  1117.                         tmp0    = tab0[j];

  1118.                         tmp1    = tab1[j];

  1119.                         tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);

  1120.                         tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);

  1121.                     }

  1122.                 }

  1123.             }

  1124.         }

  1125.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1126.         /* ms stereo ONLY */

  1127.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1128.            global gain */

  1129. #if CONFIG_FLOAT

  1130.        s->fdsp.butterflies_float(g0->sb_hybrid, g1->sb_hybrid, 576);

  1131. #else

  1132.         tab0 = g0->sb_hybrid;

  1133.         tab1 = g1->sb_hybrid;

  1134.         for (i = 0; i < 576; i++) {

  1135.             tmp0    = tab0[i];

  1136.             tmp1    = tab1[i];

  1137.             tab0[i] = tmp0 + tmp1;

  1138.             tab1[i] = tmp0 - tmp1;

  1139.         }

  1140. #endif

  1141.     }

  1142. }

  1143. 

  1144. #if CONFIG_FLOAT

  1145. #define AA(j) do {                                                      \

  1146.         float tmp0 = ptr[-1-j];                                         \

  1147.         float tmp1 = ptr[   j];                                         \

  1148.         ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1];    \

  1149.         ptr[   j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0];    \

  1150.     } while (0)

  1151. #else

  1152. #define AA(j) do {                                              \

  1153.         int tmp0 = ptr[-1-j];                                   \

  1154.         int tmp1 = ptr[   j];                                   \

  1155.         int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]);          \

  1156.         ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2]));   \

  1157.         ptr[   j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3]));   \

  1158.     } while (0)

  1159. #endif

  1160. 

  1161. static void compute_antialias(MPADecodeContext *s, GranuleDef *g)

  1162. {

  1163.     INTFLOAT *ptr;

  1164.     int n, i;

  1165. 

  1166.     /* we antialias only "long" bands */

  1167.     if (g->block_type == 2) {

  1168.         if (!g->switch_point)

  1169.             return;

  1170.         /* XXX: check this for 8000Hz case */

  1171.         n = 1;

  1172.     } else {

  1173.         n = SBLIMIT - 1;

  1174.     }

  1175. 

  1176.     ptr = g->sb_hybrid + 18;

  1177.     for (i = n; i > 0; i--) {

  1178.         AA(0);

  1179.         AA(1);

  1180.         AA(2);

  1181.         AA(3);

  1182.         AA(4);

  1183.         AA(5);

  1184.         AA(6);

  1185.         AA(7);

  1186. 

  1187.         ptr += 18;

  1188.     }

  1189. }

  1190. 

  1191. static void compute_imdct(MPADecodeContext *s, GranuleDef *g,

  1192.                           INTFLOAT *sb_samples, INTFLOAT *mdct_buf)

  1193. {

  1194.     INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;

  1195.     INTFLOAT out2[12];

  1196.     int i, j, mdct_long_end, sblimit;

  1197. 

  1198.     /* find last non zero block */

  1199.     ptr  = g->sb_hybrid + 576;

  1200.     ptr1 = g->sb_hybrid + 2 * 18;

  1201.     while (ptr >= ptr1) {

  1202.         int32_t *p;

  1203.         ptr -= 6;

  1204.         p    = (int32_t*)ptr;

  1205.         if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])

  1206.             break;

  1207.     }

  1208.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  1209. 

  1210.     if (g->block_type == 2) {

  1211.         /* XXX: check for 8000 Hz */

  1212.         if (g->switch_point)

  1213.             mdct_long_end = 2;

  1214.         else

  1215.             mdct_long_end = 0;

  1216.     } else {

  1217.         mdct_long_end = sblimit;

  1218.     }

  1219. 

  1220.     s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,

  1221.                                      mdct_long_end, g->switch_point,

  1222.                                      g->block_type);

  1223. 

  1224.     buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);

  1225.     ptr = g->sb_hybrid + 18 * mdct_long_end;

  1226. 

  1227.     for (j = mdct_long_end; j < sblimit; j++) {

  1228.         /* select frequency inversion */

  1229.         win     = RENAME(ff_mdct_win)[2 + (4  & -(j & 1))];

  1230.         out_ptr = sb_samples + j;

  1231. 

  1232.         for (i = 0; i < 6; i++) {

  1233.             *out_ptr = buf[4*i];

  1234.             out_ptr += SBLIMIT;

  1235.         }

  1236.         imdct12(out2, ptr + 0);

  1237.         for (i = 0; i < 6; i++) {

  1238.             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*1)];

  1239.             buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);

  1240.             out_ptr += SBLIMIT;

  1241.         }

  1242.         imdct12(out2, ptr + 1);

  1243.         for (i = 0; i < 6; i++) {

  1244.             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*2)];

  1245.             buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);

  1246.             out_ptr += SBLIMIT;

  1247.         }

  1248.         imdct12(out2, ptr + 2);

  1249.         for (i = 0; i < 6; i++) {

  1250.             buf[4*(i + 6*0)] = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*0)];

  1251.             buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);

  1252.             buf[4*(i + 6*2)] = 0;

  1253.         }

  1254.         ptr += 18;

  1255.         buf += (j&3) != 3 ? 1 : (4*18-3);

  1256.     }

  1257.     /* zero bands */

  1258.     for (j = sblimit; j < SBLIMIT; j++) {

  1259.         /* overlap */

  1260.         out_ptr = sb_samples + j;

  1261.         for (i = 0; i < 18; i++) {

  1262.             *out_ptr = buf[4*i];

  1263.             buf[4*i]   = 0;

  1264.             out_ptr += SBLIMIT;

  1265.         }

  1266.         buf += (j&3) != 3 ? 1 : (4*18-3);

  1267.     }

  1268. }

  1269. 

  1270. /* main layer3 decoding function */

  1271. static int mp_decode_layer3(MPADecodeContext *s)

  1272. {

  1273.     int nb_granules, main_data_begin;

  1274.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  1275.     GranuleDef *g;

  1276.     int16_t exponents[576]; //FIXME try INTFLOAT

  1277. 

  1278.     /* read side info */

  1279.     if (s->lsf) {

  1280.         main_data_begin = get_bits(&s->gb, 8);

  1281.         skip_bits(&s->gb, s->nb_channels);

  1282.         nb_granules = 1;

  1283.     } else {

  1284.         main_data_begin = get_bits(&s->gb, 9);

  1285.         if (s->nb_channels == 2)

  1286.             skip_bits(&s->gb, 3);

  1287.         else

  1288.             skip_bits(&s->gb, 5);

  1289.         nb_granules = 2;

  1290.         for (ch = 0; ch < s->nb_channels; ch++) {

  1291.             s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */

  1292.             s->granules[ch][1].scfsi = get_bits(&s->gb, 4);

  1293.         }

  1294.     }

  1295. 

  1296.     for (gr = 0; gr < nb_granules; gr++) {

  1297.         for (ch = 0; ch < s->nb_channels; ch++) {

  1298.             ff_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);

  1299.             g = &s->granules[ch][gr];

  1300.             g->part2_3_length = get_bits(&s->gb, 12);

  1301.             g->big_values     = get_bits(&s->gb,  9);

  1302.             if (g->big_values > 288) {

  1303.                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");

  1304.                 return AVERROR_INVALIDDATA;

  1305.             }

  1306. 

  1307.             g->global_gain = get_bits(&s->gb, 8);

  1308.             /* if MS stereo only is selected, we precompute the

  1309.                1/sqrt(2) renormalization factor */

  1310.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  1311.                 MODE_EXT_MS_STEREO)

  1312.                 g->global_gain -= 2;

  1313.             if (s->lsf)

  1314.                 g->scalefac_compress = get_bits(&s->gb, 9);

  1315.             else

  1316.                 g->scalefac_compress = get_bits(&s->gb, 4);

  1317.             blocksplit_flag = get_bits1(&s->gb);

  1318.             if (blocksplit_flag) {

  1319.                 g->block_type = get_bits(&s->gb, 2);

  1320.                 if (g->block_type == 0) {

  1321.                     av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");

  1322.                     return AVERROR_INVALIDDATA;

  1323.                 }

  1324.                 g->switch_point = get_bits1(&s->gb);

  1325.                 for (i = 0; i < 2; i++)

  1326.                     g->table_select[i] = get_bits(&s->gb, 5);

  1327.                 for (i = 0; i < 3; i++)

  1328.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  1329.                 init_short_region(s, g);

  1330.             } else {

  1331.                 int region_address1, region_address2;

  1332.                 g->block_type = 0;

  1333.                 g->switch_point = 0;

  1334.                 for (i = 0; i < 3; i++)

  1335.                     g->table_select[i] = get_bits(&s->gb, 5);

  1336.                 /* compute huffman coded region sizes */

  1337.                 region_address1 = get_bits(&s->gb, 4);

  1338.                 region_address2 = get_bits(&s->gb, 3);

  1339.                 ff_dlog(s->avctx, "region1=%d region2=%d\n",

  1340.                         region_address1, region_address2);

  1341.                 init_long_region(s, g, region_address1, region_address2);

  1342.             }

  1343.             region_offset2size(g);

  1344.             compute_band_indexes(s, g);

  1345. 

  1346.             g->preflag = 0;

  1347.             if (!s->lsf)

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

  1349.             g->scalefac_scale     = get_bits1(&s->gb);

  1350.             g->count1table_select = get_bits1(&s->gb);

  1351.             ff_dlog(s->avctx, "block_type=%d switch_point=%d\n",

  1352.                     g->block_type, g->switch_point);

  1353.         }

  1354.     }

  1355. 

  1356.     if (!s->adu_mode) {

  1357.         int skip;

  1358.         const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  1359.         s->extrasize = av_clip((get_bits_left(&s->gb) >> 3) - s->extrasize, 0,

  1360.                                FFMAX(0, LAST_BUF_SIZE - s->last_buf_size));

  1361.         assert((get_bits_count(&s->gb) & 7) == 0);

  1362.         /* now we get bits from the main_data_begin offset */

  1363.         ff_dlog(s->avctx, "seekback:%d, lastbuf:%d\n",

  1364.                 main_data_begin, s->last_buf_size);

  1365. 

  1366.         memcpy(s->last_buf + s->last_buf_size, ptr, s->extrasize);

  1367.         s->in_gb = s->gb;

  1368.         init_get_bits(&s->gb, s->last_buf, (s->last_buf_size + s->extrasize) * 8);

  1369.         s->last_buf_size <<= 3;

  1370.         for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) {

  1371.             for (ch = 0; ch < s->nb_channels; ch++) {

  1372.                 g = &s->granules[ch][gr];

  1373.                 s->last_buf_size += g->part2_3_length;

  1374.                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));

  1375.                 compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  1376.             }

  1377.         }

  1378.         skip = s->last_buf_size - 8 * main_data_begin;

  1379.         if (skip >= s->gb.size_in_bits - s->extrasize * 8 && s->in_gb.buffer) {

  1380.             skip_bits_long(&s->in_gb, skip - s->gb.size_in_bits + s->extrasize * 8);

  1381.             s->gb           = s->in_gb;

  1382.             s->in_gb.buffer = NULL;

  1383.             s->extrasize    = 0;

  1384.         } else {

  1385.             skip_bits_long(&s->gb, skip);

  1386.         }

  1387.     } else {

  1388.         gr = 0;

  1389.         s->extrasize = 0;

  1390.     }

  1391. 

  1392.     for (; gr < nb_granules; gr++) {

  1393.         for (ch = 0; ch < s->nb_channels; ch++) {

  1394.             g = &s->granules[ch][gr];

  1395.             bits_pos = get_bits_count(&s->gb);

  1396. 

  1397.             if (!s->lsf) {

  1398.                 uint8_t *sc;

  1399.                 int slen, slen1, slen2;

  1400. 

  1401.                 /* MPEG-1 scale factors */

  1402.                 slen1 = slen_table[0][g->scalefac_compress];

  1403.                 slen2 = slen_table[1][g->scalefac_compress];

  1404.                 ff_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);

  1405.                 if (g->block_type == 2) {

  1406.                     n = g->switch_point ? 17 : 18;

  1407.                     j = 0;

  1408.                     if (slen1) {

  1409.                         for (i = 0; i < n; i++)

  1410.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  1411.                     } else {

  1412.                         for (i = 0; i < n; i++)

  1413.                             g->scale_factors[j++] = 0;

  1414.                     }

  1415.                     if (slen2) {

  1416.                         for (i = 0; i < 18; i++)

  1417.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  1418.                         for (i = 0; i < 3; i++)

  1419.                             g->scale_factors[j++] = 0;

  1420.                     } else {

  1421.                         for (i = 0; i < 21; i++)

  1422.                             g->scale_factors[j++] = 0;

  1423.                     }

  1424.                 } else {

  1425.                     sc = s->granules[ch][0].scale_factors;

  1426.                     j = 0;

  1427.                     for (k = 0; k < 4; k++) {

  1428.                         n = k == 0 ? 6 : 5;

  1429.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  1430.                             slen = (k < 2) ? slen1 : slen2;

  1431.                             if (slen) {

  1432.                                 for (i = 0; i < n; i++)

  1433.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  1434.                             } else {

  1435.                                 for (i = 0; i < n; i++)

  1436.                                     g->scale_factors[j++] = 0;

  1437.                             }

  1438.                         } else {

  1439.                             /* simply copy from last granule */

  1440.                             for (i = 0; i < n; i++) {

  1441.                                 g->scale_factors[j] = sc[j];

  1442.                                 j++;

  1443.                             }

  1444.                         }

  1445.                     }

  1446.                     g->scale_factors[j++] = 0;

  1447.                 }

  1448.             } else {

  1449.                 int tindex, tindex2, slen[4], sl, sf;

  1450. 

  1451.                 /* LSF scale factors */

  1452.                 if (g->block_type == 2)

  1453.                     tindex = g->switch_point ? 2 : 1;

  1454.                 else

  1455.                     tindex = 0;

  1456. 

  1457.                 sf = g->scalefac_compress;

  1458.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  1459.                     /* intensity stereo case */

  1460.                     sf >>= 1;

  1461.                     if (sf < 180) {

  1462.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  1463.                         tindex2 = 3;

  1464.                     } else if (sf < 244) {

  1465.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  1466.                         tindex2 = 4;

  1467.                     } else {

  1468.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  1469.                         tindex2 = 5;

  1470.                     }

  1471.                 } else {

  1472.                     /* normal case */

  1473.                     if (sf < 400) {

  1474.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  1475.                         tindex2 = 0;

  1476.                     } else if (sf < 500) {

  1477.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  1478.                         tindex2 = 1;

  1479.                     } else {

  1480.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  1481.                         tindex2 = 2;

  1482.                         g->preflag = 1;

  1483.                     }

  1484.                 }

  1485. 

  1486.                 j = 0;

  1487.                 for (k = 0; k < 4; k++) {

  1488.                     n  = lsf_nsf_table[tindex2][tindex][k];

  1489.                     sl = slen[k];

  1490.                     if (sl) {

  1491.                         for (i = 0; i < n; i++)

  1492.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  1493.                     } else {

  1494.                         for (i = 0; i < n; i++)

  1495.                             g->scale_factors[j++] = 0;

  1496.                     }

  1497.                 }

  1498.                 /* XXX: should compute exact size */

  1499.                 for (; j < 40; j++)

  1500.                     g->scale_factors[j] = 0;

  1501.             }

  1502. 

  1503.             exponents_from_scale_factors(s, g, exponents);

  1504. 

  1505.             /* read Huffman coded residue */

  1506.             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);

  1507.         } /* ch */

  1508. 

  1509.         if (s->mode == MPA_JSTEREO)

  1510.             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);

  1511. 

  1512.         for (ch = 0; ch < s->nb_channels; ch++) {

  1513.             g = &s->granules[ch][gr];

  1514. 

  1515.             reorder_block(s, g);

  1516.             compute_antialias(s, g);

  1517.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  1518.         }

  1519.     } /* gr */

  1520.     if (get_bits_count(&s->gb) < 0)

  1521.         skip_bits_long(&s->gb, -get_bits_count(&s->gb));

  1522.     return nb_granules * 18;

  1523. }

  1524. 

  1525. static int mp_decode_frame(MPADecodeContext *s, OUT_INT **samples,

  1526.                            const uint8_t *buf, int buf_size)

  1527. {

  1528.     int i, nb_frames, ch, ret;

  1529.     OUT_INT *samples_ptr;

  1530. 

  1531.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);

  1532. 

  1533.     /* skip error protection field */

  1534.     if (s->error_protection)

  1535.         skip_bits(&s->gb, 16);

  1536. 

  1537.     switch(s->layer) {

  1538.     case 1:

  1539.         s->avctx->frame_size = 384;

  1540.         nb_frames = mp_decode_layer1(s);

  1541.         break;

  1542.     case 2:

  1543.         s->avctx->frame_size = 1152;

  1544.         nb_frames = mp_decode_layer2(s);

  1545.         break;

  1546.     case 3:

  1547.         s->avctx->frame_size = s->lsf ? 576 : 1152;

  1548.     default:

  1549.         nb_frames = mp_decode_layer3(s);

  1550. 

  1551.         if (nb_frames < 0)

  1552.             return nb_frames;

  1553. 

  1554.         s->last_buf_size=0;

  1555.         if (s->in_gb.buffer) {

  1556.             align_get_bits(&s->gb);

  1557.             i = (get_bits_left(&s->gb) >> 3) - s->extrasize;

  1558.             if (i >= 0 && i <= BACKSTEP_SIZE) {

  1559.                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);

  1560.                 s->last_buf_size=i;

  1561.             } else

  1562.                 av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);

  1563.             s->gb           = s->in_gb;

  1564.             s->in_gb.buffer = NULL;

  1565.             s->extrasize    = 0;

  1566.         }

  1567. 

  1568.         align_get_bits(&s->gb);

  1569.         assert((get_bits_count(&s->gb) & 7) == 0);

  1570.         i = (get_bits_left(&s->gb) >> 3) - s->extrasize;

  1571.         if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {

  1572.             if (i < 0)

  1573.                 av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);

  1574.             i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);

  1575.         }

  1576.         assert(i <= buf_size - HEADER_SIZE && i >= 0);

  1577.         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);

  1578.         s->last_buf_size += i;

  1579.     }

  1580. 

  1581.     /* get output buffer */

  1582.     if (!samples) {

  1583.         av_assert0(s->frame != NULL);

  1584.         s->frame->nb_samples = s->avctx->frame_size;

  1585.         if ((ret = ff_get_buffer(s->avctx, s->frame, 0)) < 0) {

  1586.             av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  1587.             return ret;

  1588.         }

  1589.         samples = (OUT_INT **)s->frame->extended_data;

  1590.     }

  1591. 

  1592.     /* apply the synthesis filter */

  1593.     for (ch = 0; ch < s->nb_channels; ch++) {

  1594.         int sample_stride;

  1595.         if (s->avctx->sample_fmt == OUT_FMT_P) {

  1596.             samples_ptr   = samples[ch];

  1597.             sample_stride = 1;

  1598.         } else {

  1599.             samples_ptr   = samples[0] + ch;

  1600.             sample_stride = s->nb_channels;

  1601.         }

  1602.         for (i = 0; i < nb_frames; i++) {

  1603.             RENAME(ff_mpa_synth_filter)(&s->mpadsp, s->synth_buf[ch],

  1604.                                         &(s->synth_buf_offset[ch]),

  1605.                                         RENAME(ff_mpa_synth_window),

  1606.                                         &s->dither_state, samples_ptr,

  1607.                                         sample_stride, s->sb_samples[ch][i]);

  1608.             samples_ptr += 32 * sample_stride;

  1609.         }

  1610.     }

  1611. 

  1612.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  1613. }

  1614. 

  1615. static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,

  1616.                         AVPacket *avpkt)

  1617. {

  1618.     const uint8_t *buf  = avpkt->data;

  1619.     int buf_size        = avpkt->size;

  1620.     MPADecodeContext *s = avctx->priv_data;

  1621.     uint32_t header;

  1622.     int ret;

  1623. 

  1624.     if (buf_size < HEADER_SIZE)

  1625.         return AVERROR_INVALIDDATA;

  1626. 

  1627.     header = AV_RB32(buf);

  1628. 

  1629.     ret = avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);

  1630.     if (ret < 0) {

  1631.         av_log(avctx, AV_LOG_ERROR, "Header missing\n");

  1632.         return AVERROR_INVALIDDATA;

  1633.     } else if (ret == 1) {

  1634.         /* free format: prepare to compute frame size */

  1635.         s->frame_size = -1;

  1636.         return AVERROR_INVALIDDATA;

  1637.     }

  1638.     /* update codec info */

  1639.     avctx->channels       = s->nb_channels;

  1640.     avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;

  1641.     if (!avctx->bit_rate)

  1642.         avctx->bit_rate = s->bit_rate;

  1643. 

  1644.     s->frame = data;

  1645. 

  1646.     ret = mp_decode_frame(s, NULL, buf, buf_size);

  1647.     if (ret >= 0) {

  1648.         s->frame->nb_samples = avctx->frame_size;

  1649.         *got_frame_ptr       = 1;

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

  1651.         //FIXME maybe move the other codec info stuff from above here too

  1652.     } else {

  1653.         av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");

  1654.         /* Only return an error if the bad frame makes up the whole packet or

  1655.          * the error is related to buffer management.

  1656.          * If there is more data in the packet, just consume the bad frame

  1657.          * instead of returning an error, which would discard the whole

  1658.          * packet. */

  1659.         *got_frame_ptr = 0;

  1660.         if (buf_size == avpkt->size || ret != AVERROR_INVALIDDATA)

  1661.             return ret;

  1662.     }

  1663.     s->frame_size = 0;

  1664.     return buf_size;

  1665. }

  1666. 

  1667. static void mp_flush(MPADecodeContext *ctx)

  1668. {

  1669.     memset(ctx->synth_buf, 0, sizeof(ctx->synth_buf));

  1670.     ctx->last_buf_size = 0;

  1671. }

  1672. 

  1673. static void flush(AVCodecContext *avctx)

  1674. {

  1675.     mp_flush(avctx->priv_data);

  1676. }

  1677. 

  1678. #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER

  1679. static int decode_frame_adu(AVCodecContext *avctx, void *data,

  1680.                             int *got_frame_ptr, AVPacket *avpkt)

  1681. {

  1682.     const uint8_t *buf  = avpkt->data;

  1683.     int buf_size        = avpkt->size;

  1684.     MPADecodeContext *s = avctx->priv_data;

  1685.     uint32_t header;

  1686.     int len, ret;

  1687. 

  1688.     len = buf_size;

  1689. 

  1690.     // Discard too short frames

  1691.     if (buf_size < HEADER_SIZE) {

  1692.         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");

  1693.         return AVERROR_INVALIDDATA;

  1694.     }

  1695. 

  1696. 

  1697.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  1698.         len = MPA_MAX_CODED_FRAME_SIZE;

  1699. 

  1700.     // Get header and restore sync word

  1701.     header = AV_RB32(buf) | 0xffe00000;

  1702. 

  1703.     ret = avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);

  1704.     if (ret < 0) {

  1705.         av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");

  1706.         return ret;

  1707.     }

  1708.     /* update codec info */

  1709.     avctx->sample_rate = s->sample_rate;

  1710.     avctx->channels    = s->nb_channels;

  1711.     avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;

  1712.     if (!avctx->bit_rate)

  1713.         avctx->bit_rate = s->bit_rate;

  1714. 

  1715.     s->frame_size = len;

  1716. 

  1717.     s->frame = data;

  1718. 

  1719.     ret = mp_decode_frame(s, NULL, buf, buf_size);

  1720.     if (ret < 0) {

  1721.         av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");

  1722.         return ret;

  1723.     }

  1724. 

  1725.     *got_frame_ptr = 1;

  1726. 

  1727.     return buf_size;

  1728. }

  1729. #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */

  1730. 

  1731. #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER

  1732. 

  1733. /**

  1734.  * Context for MP3On4 decoder

  1735.  */

  1736. typedef struct MP3On4DecodeContext {

  1737.     int frames;                     ///< number of mp3 frames per block (number of mp3 decoder instances)

  1738.     int syncword;                   ///< syncword patch

  1739.     const uint8_t *coff;            ///< channel offsets in output buffer

  1740.     MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance

  1741. } MP3On4DecodeContext;

  1742. 

  1743. #include "mpeg4audio.h"

  1744. 

  1745. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  1746. 

  1747. /* number of mp3 decoder instances */

  1748. static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };

  1749. 

  1750. /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */

  1751. static const uint8_t chan_offset[8][5] = {

  1752.     { 0             },

  1753.     { 0             },  // C

  1754.     { 0             },  // FLR

  1755.     { 2, 0          },  // C FLR

  1756.     { 2, 0, 3       },  // C FLR BS

  1757.     { 2, 0, 3       },  // C FLR BLRS

  1758.     { 2, 0, 4, 3    },  // C FLR BLRS LFE

  1759.     { 2, 0, 6, 4, 3 },  // C FLR BLRS BLR LFE

  1760. };

  1761. 

  1762. /* mp3on4 channel layouts */

  1763. static const int16_t chan_layout[8] = {

  1764.     0,

  1765.     AV_CH_LAYOUT_MONO,

  1766.     AV_CH_LAYOUT_STEREO,

  1767.     AV_CH_LAYOUT_SURROUND,

  1768.     AV_CH_LAYOUT_4POINT0,

  1769.     AV_CH_LAYOUT_5POINT0,

  1770.     AV_CH_LAYOUT_5POINT1,

  1771.     AV_CH_LAYOUT_7POINT1

  1772. };

  1773. 

  1774. static av_cold int decode_close_mp3on4(AVCodecContext * avctx)

  1775. {

  1776.     MP3On4DecodeContext *s = avctx->priv_data;

  1777.     int i;

  1778. 

  1779.     for (i = 0; i < s->frames; i++)

  1780.         av_free(s->mp3decctx[i]);

  1781. 

  1782.     return 0;

  1783. }

  1784. 

  1785. 

  1786. static av_cold int decode_init_mp3on4(AVCodecContext * avctx)

  1787. {

  1788.     MP3On4DecodeContext *s = avctx->priv_data;

  1789.     MPEG4AudioConfig cfg;

  1790.     int i;

  1791. 

  1792.     if ((avctx->extradata_size < 2) || !avctx->extradata) {

  1793.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  1794.         return AVERROR_INVALIDDATA;

  1795.     }

  1796. 

  1797.     avpriv_mpeg4audio_get_config(&cfg, avctx->extradata,

  1798.                                  avctx->extradata_size * 8, 1);

  1799.     if (!cfg.chan_config || cfg.chan_config > 7) {

  1800.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  1801.         return AVERROR_INVALIDDATA;

  1802.     }

  1803.     s->frames             = mp3Frames[cfg.chan_config];

  1804.     s->coff               = chan_offset[cfg.chan_config];

  1805.     avctx->channels       = ff_mpeg4audio_channels[cfg.chan_config];

  1806.     avctx->channel_layout = chan_layout[cfg.chan_config];

  1807. 

  1808.     if (cfg.sample_rate < 16000)

  1809.         s->syncword = 0xffe00000;

  1810.     else

  1811.         s->syncword = 0xfff00000;

  1812. 

  1813.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  1814.      * We replace avctx->priv_data with the context of the first decoder so that

  1815.      * decode_init() does not have to be changed.

  1816.      * Other decoders will be initialized here copying data from the first context

  1817.      */

  1818.     // Allocate zeroed memory for the first decoder context

  1819.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  1820.     if (!s->mp3decctx[0])

  1821.         goto alloc_fail;

  1822.     // Put decoder context in place to make init_decode() happy

  1823.     avctx->priv_data = s->mp3decctx[0];

  1824.     decode_init(avctx);

  1825.     // Restore mp3on4 context pointer

  1826.     avctx->priv_data = s;

  1827.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  1828. 

  1829.     /* Create a separate codec/context for each frame (first is already ok).

  1830.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  1831.      */

  1832.     for (i = 1; i < s->frames; i++) {

  1833.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  1834.         if (!s->mp3decctx[i])

  1835.             goto alloc_fail;

  1836.         s->mp3decctx[i]->adu_mode = 1;

  1837.         s->mp3decctx[i]->avctx = avctx;

  1838.         s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;

  1839.     }

  1840. 

  1841.     return 0;

  1842. alloc_fail:

  1843.     decode_close_mp3on4(avctx);

  1844.     return AVERROR(ENOMEM);

  1845. }

  1846. 

  1847. 

  1848. static void flush_mp3on4(AVCodecContext *avctx)

  1849. {

  1850.     int i;

  1851.     MP3On4DecodeContext *s = avctx->priv_data;

  1852. 

  1853.     for (i = 0; i < s->frames; i++)

  1854.         mp_flush(s->mp3decctx[i]);

  1855. }

  1856. 

  1857. 

  1858. static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,

  1859.                                int *got_frame_ptr, AVPacket *avpkt)

  1860. {

  1861.     AVFrame *frame         = data;

  1862.     const uint8_t *buf     = avpkt->data;

  1863.     int buf_size           = avpkt->size;

  1864.     MP3On4DecodeContext *s = avctx->priv_data;

  1865.     MPADecodeContext *m;

  1866.     int fsize, len = buf_size, out_size = 0;

  1867.     uint32_t header;

  1868.     OUT_INT **out_samples;

  1869.     OUT_INT *outptr[2];

  1870.     int fr, ch, ret;

  1871. 

  1872.     /* get output buffer */

  1873.     frame->nb_samples = MPA_FRAME_SIZE;

  1874.     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {

  1875.         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  1876.         return ret;

  1877.     }

  1878.     out_samples = (OUT_INT **)frame->extended_data;

  1879. 

  1880.     // Discard too short frames

  1881.     if (buf_size < HEADER_SIZE)

  1882.         return AVERROR_INVALIDDATA;

  1883. 

  1884.     avctx->bit_rate = 0;

  1885. 

  1886.     ch = 0;

  1887.     for (fr = 0; fr < s->frames; fr++) {

  1888.         fsize = AV_RB16(buf) >> 4;

  1889.         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);

  1890.         m     = s->mp3decctx[fr];

  1891.         assert(m != NULL);

  1892. 

  1893.         if (fsize < HEADER_SIZE) {

  1894.             av_log(avctx, AV_LOG_ERROR, "Frame size smaller than header size\n");

  1895.             return AVERROR_INVALIDDATA;

  1896.         }

  1897.         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header

  1898. 

  1899.         ret = avpriv_mpegaudio_decode_header((MPADecodeHeader *)m, header);

  1900.         if (ret < 0) // Bad header, discard block

  1901.             break;

  1902. 

  1903.         if (ch + m->nb_channels > avctx->channels ||

  1904.             s->coff[fr] + m->nb_channels > avctx->channels) {

  1905.             av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "

  1906.                                         "channel count\n");

  1907.             return AVERROR_INVALIDDATA;

  1908.         }

  1909.         ch += m->nb_channels;

  1910. 

  1911.         outptr[0] = out_samples[s->coff[fr]];

  1912.         if (m->nb_channels > 1)

  1913.             outptr[1] = out_samples[s->coff[fr] + 1];

  1914. 

  1915.         if ((ret = mp_decode_frame(m, outptr, buf, fsize)) < 0)

  1916.             return ret;

  1917. 

  1918.         out_size += ret;

  1919.         buf      += fsize;

  1920.         len      -= fsize;

  1921. 

  1922.         avctx->bit_rate += m->bit_rate;

  1923.     }

  1924. 

  1925.     /* update codec info */

  1926.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  1927. 

  1928.     frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));

  1929.     *got_frame_ptr    = 1;

  1930. 

  1931.     return buf_size;

  1932. }

  1933. #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */