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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 mpegaudiodec.c

  24.  * MPEG Audio decoder.

  25.  */

  26. 

  27. //#define DEBUG

  28. #include "avcodec.h"

  29. #include "bitstream.h"

  30. #include "dsputil.h"

  31. 

  32. /*

  33.  * TODO:

  34.  *  - in low precision mode, use more 16 bit multiplies in synth filter

  35.  *  - test lsf / mpeg25 extensively.

  36.  */

  37. 

  38. /* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg

  39.    audio decoder */

  40. #ifdef CONFIG_MPEGAUDIO_HP

  41. #   define USE_HIGHPRECISION

  42. #endif

  43. 

  44. #include "mpegaudio.h"

  45. 

  46. #include "mathops.h"

  47. 

  48. #define FRAC_ONE    (1 << FRAC_BITS)

  49. 

  50. #define FIX(a)   ((int)((a) * FRAC_ONE))

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

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

  53. #define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)

  54. 

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

  56. 

  57. /****************/

  58. 

  59. #define HEADER_SIZE 4

  60. #define BACKSTEP_SIZE 512

  61. #define EXTRABYTES 24

  62. 

  63. struct GranuleDef;

  64. 

  65. typedef struct MPADecodeContext {

  66.     DECLARE_ALIGNED_8(uint8_t, last_buf[2*BACKSTEP_SIZE + EXTRABYTES]);

  67.     int last_buf_size;

  68.     int frame_size;

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

  70.     uint32_t free_format_next_header;

  71.     int error_protection;

  72.     int layer;

  73.     int sample_rate;

  74.     int sample_rate_index; /* between 0 and 8 */

  75.     int bit_rate;

  76.     GetBitContext gb;

  77.     GetBitContext in_gb;

  78.     int nb_channels;

  79.     int mode;

  80.     int mode_ext;

  81.     int lsf;

  82.     MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2] __attribute__((aligned(16)));

  83.     int synth_buf_offset[MPA_MAX_CHANNELS];

  84.     int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT] __attribute__((aligned(16)));

  85.     int32_t mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */

  86. #ifdef DEBUG

  87.     int frame_count;

  88. #endif

  89.     void (*compute_antialias)(struct MPADecodeContext *s, struct GranuleDef *g);

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

  91.     int dither_state;

  92.     int error_resilience;

  93. } MPADecodeContext;

  94. 

  95. /**

  96.  * Context for MP3On4 decoder

  97.  */

  98. typedef struct MP3On4DecodeContext {

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

  100.     int chan_cfg; ///< channel config number

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

  102. } MP3On4DecodeContext;

  103. 

  104. /* layer 3 "granule" */

  105. typedef struct GranuleDef {

  106.     uint8_t scfsi;

  107.     int part2_3_length;

  108.     int big_values;

  109.     int global_gain;

  110.     int scalefac_compress;

  111.     uint8_t block_type;

  112.     uint8_t switch_point;

  113.     int table_select[3];

  114.     int subblock_gain[3];

  115.     uint8_t scalefac_scale;

  116.     uint8_t count1table_select;

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

  118.     int preflag;

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

  120.     uint8_t scale_factors[40];

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

  122. } GranuleDef;

  123. 

  124. #define MODE_EXT_MS_STEREO 2

  125. #define MODE_EXT_I_STEREO  1

  126. 

  127. /* layer 3 huffman tables */

  128. typedef struct HuffTable {

  129.     int xsize;

  130.     const uint8_t *bits;

  131.     const uint16_t *codes;

  132. } HuffTable;

  133. 

  134. #include "mpegaudiodectab.h"

  135. 

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

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

  138. 

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

  140. static VLC huff_vlc[16];

  141. static VLC huff_quad_vlc[2];

  142. /* computed from band_size_long */

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

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

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

  146. static int8_t  *table_4_3_exp;

  147. static uint32_t *table_4_3_value;

  148. static uint32_t exp_table[512];

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

  150. /* intensity stereo coef table */

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

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

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

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

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

  156. 

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

  158. static uint16_t scale_factor_modshift[64];

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

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

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

  162. 

  163. #define SCALE_GEN(v) \

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

  165. 

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

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

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

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

  170. };

  171. 

  172. static MPA_INT window[512] __attribute__((aligned(16)));

  173. 

  174. /* layer 1 unscaling */

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

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

  177. {

  178.     int shift, mod;

  179.     int64_t val;

  180. 

  181.     shift = scale_factor_modshift[scale_factor];

  182.     mod = shift & 3;

  183.     shift >>= 2;

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

  185.     shift += n;

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

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

  188. }

  189. 

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

  191. {

  192.     int shift, mod, val;

  193. 

  194.     shift = scale_factor_modshift[scale_factor];

  195.     mod = shift & 3;

  196.     shift >>= 2;

  197. 

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

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

  200.     if (shift > 0)

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

  202.     return val;

  203. }

  204. 

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

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

  207. {

  208.     unsigned int m;

  209.     int e;

  210. 

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

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

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

  214.     assert(e>=1);

  215.     if (e > 31)

  216.         return 0;

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

  218. 

  219.     return m;

  220. }

  221. 

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

  223. #define DEV_ORDER 13

  224. 

  225. #define POW_FRAC_BITS 24

  226. #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)

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

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

  229. 

  230. static int dev_4_3_coefs[DEV_ORDER];

  231. 

  232. #if 0 /* unused */

  233. static int pow_mult3[3] = {

  234.     POW_FIX(1.0),

  235.     POW_FIX(1.25992104989487316476),

  236.     POW_FIX(1.58740105196819947474),

  237. };

  238. #endif

  239. 

  240. static void int_pow_init(void)

  241. {

  242.     int i, a;

  243. 

  244.     a = POW_FIX(1.0);

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

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

  247.         dev_4_3_coefs[i] = a;

  248.     }

  249. }

  250. 

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

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

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

  254. {

  255.     int e, er, eq, j;

  256.     int a, a1;

  257. 

  258.     /* renormalize */

  259.     a = i;

  260.     e = POW_FRAC_BITS;

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

  262.         a = a << 1;

  263.         e--;

  264.     }

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

  266.     a1 = 0;

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

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

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

  270.     /* exponent compute (exact) */

  271.     e = e * 4;

  272.     er = e % 3;

  273.     eq = e / 3;

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

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

  276.         a = a >> 1;

  277.         eq++;

  278.     }

  279.     /* convert to float */

  280.     while (a < POW_FRAC_ONE) {

  281.         a = a << 1;

  282.         eq--;

  283.     }

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

  285. #if POW_FRAC_BITS > FRAC_BITS

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

  287.     /* correct overflow */

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

  289.         a = a >> 1;

  290.         eq++;

  291.     }

  292. #endif

  293.     *exp_ptr = eq;

  294.     return a;

  295. }

  296. #endif

  297. 

  298. static int decode_init(AVCodecContext * avctx)

  299. {

  300.     MPADecodeContext *s = avctx->priv_data;

  301.     static int init=0;

  302.     int i, j, k;

  303. 

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

  305.     avctx->sample_fmt= SAMPLE_FMT_S32;

  306. #else

  307.     avctx->sample_fmt= SAMPLE_FMT_S16;

  308. #endif

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

  310. 

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

  312.         s->compute_antialias= compute_antialias_integer;

  313.     else

  314.         s->compute_antialias= compute_antialias_float;

  315. 

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

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

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

  319.             int shift, mod;

  320.             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  321.             shift = (i / 3);

  322.             mod = i % 3;

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

  324.         }

  325. 

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

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

  328.             int n, norm;

  329.             n = i + 2;

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

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

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

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

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

  335.                     i, norm,

  336.                     scale_factor_mult[i][0],

  337.                     scale_factor_mult[i][1],

  338.                     scale_factor_mult[i][2]);

  339.         }

  340. 

  341.         ff_mpa_synth_init(window);

  342. 

  343.         /* huffman decode tables */

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

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

  346.             int xsize, x, y;

  347.             unsigned int n;

  348.             uint8_t  tmp_bits [512];

  349.             uint16_t tmp_codes[512];

  350. 

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

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

  353. 

  354.             xsize = h->xsize;

  355.             n = xsize * xsize;

  356. 

  357.             j = 0;

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

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

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

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

  362.                 }

  363.             }

  364. 

  365.             /* XXX: fail test */

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

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

  368.         }

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

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

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

  372.         }

  373. 

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

  375.             k = 0;

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

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

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

  379.             }

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

  381.         }

  382. 

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

  384.         table_4_3_exp= av_mallocz_static(TABLE_4_3_SIZE * sizeof(table_4_3_exp[0]));

  385.         if(!table_4_3_exp)

  386.             return -1;

  387.         table_4_3_value= av_mallocz_static(TABLE_4_3_SIZE * sizeof(table_4_3_value[0]));

  388.         if(!table_4_3_value)

  389.             return -1;

  390. 

  391.         int_pow_init();

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

  393.             double f, fm;

  394.             int e, m;

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

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

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

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

  399. 

  400.             /* normalized to FRAC_BITS */

  401.             table_4_3_value[i] = m;

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

  403.             table_4_3_exp[i] = -e;

  404.         }

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

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

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

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

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

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

  411.         }

  412. 

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

  414.             float f;

  415.             int v;

  416.             if (i != 6) {

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

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

  419.             } else {

  420.                 v = FIXR(1.0);

  421.             }

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

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

  424.         }

  425.         /* invalid values */

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

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

  428. 

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

  430.             double f;

  431.             int e, k;

  432. 

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

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

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

  436.                 k = i & 1;

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

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

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

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

  441.             }

  442.         }

  443. 

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

  445.             float ci, cs, ca;

  446.             ci = ci_table[i];

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

  448.             ca = cs * ci;

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

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

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

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

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

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

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

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

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

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

  459.         }

  460. 

  461.         /* compute mdct windows */

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

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

  464.                 double d;

  465. 

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

  467.                     continue;

  468. 

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

  470.                 if(j==1){

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

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

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

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

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

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

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

  478.                 }

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

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

  481. 

  482.                 if(j==2)

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

  484.                 else

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

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

  487.             }

  488.         }

  489. 

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

  491.            the sign of the right window coefs */

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

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

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

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

  496.             }

  497.         }

  498. 

  499. #if defined(DEBUG)

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

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

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

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

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

  505.         }

  506. #endif

  507.         init = 1;

  508.     }

  509. 

  510. #ifdef DEBUG

  511.     s->frame_count = 0;

  512. #endif

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

  514.         s->adu_mode = 1;

  515.     return 0;

  516. }

  517. 

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

  519. 

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

  521. 

  522. #define COS0_0  FIXHR(0.50060299823519630134/2)

  523. #define COS0_1  FIXHR(0.50547095989754365998/2)

  524. #define COS0_2  FIXHR(0.51544730992262454697/2)

  525. #define COS0_3  FIXHR(0.53104259108978417447/2)

  526. #define COS0_4  FIXHR(0.55310389603444452782/2)

  527. #define COS0_5  FIXHR(0.58293496820613387367/2)

  528. #define COS0_6  FIXHR(0.62250412303566481615/2)

  529. #define COS0_7  FIXHR(0.67480834145500574602/2)

  530. #define COS0_8  FIXHR(0.74453627100229844977/2)

  531. #define COS0_9  FIXHR(0.83934964541552703873/2)

  532. #define COS0_10 FIXHR(0.97256823786196069369/2)

  533. #define COS0_11 FIXHR(1.16943993343288495515/4)

  534. #define COS0_12 FIXHR(1.48416461631416627724/4)

  535. #define COS0_13 FIXHR(2.05778100995341155085/8)

  536. #define COS0_14 FIXHR(3.40760841846871878570/8)

  537. #define COS0_15 FIXHR(10.19000812354805681150/32)

  538. 

  539. #define COS1_0 FIXHR(0.50241928618815570551/2)

  540. #define COS1_1 FIXHR(0.52249861493968888062/2)

  541. #define COS1_2 FIXHR(0.56694403481635770368/2)

  542. #define COS1_3 FIXHR(0.64682178335999012954/2)

  543. #define COS1_4 FIXHR(0.78815462345125022473/2)

  544. #define COS1_5 FIXHR(1.06067768599034747134/4)

  545. #define COS1_6 FIXHR(1.72244709823833392782/4)

  546. #define COS1_7 FIXHR(5.10114861868916385802/16)

  547. 

  548. #define COS2_0 FIXHR(0.50979557910415916894/2)

  549. #define COS2_1 FIXHR(0.60134488693504528054/2)

  550. #define COS2_2 FIXHR(0.89997622313641570463/2)

  551. #define COS2_3 FIXHR(2.56291544774150617881/8)

  552. 

  553. #define COS3_0 FIXHR(0.54119610014619698439/2)

  554. #define COS3_1 FIXHR(1.30656296487637652785/4)

  555. 

  556. #define COS4_0 FIXHR(0.70710678118654752439/2)

  557. 

  558. /* butterfly operator */

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

  560. {\

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

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

  563.     tab[a] = tmp0;\

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

  565. }

  566. 

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

  568. {\

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

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

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

  572. }

  573. 

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

  575. {\

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

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

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

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

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

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

  582. }

  583. 

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

  585. 

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

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

  588. {

  589.     int tmp0, tmp1;

  590. 

  591.     /* pass 1 */

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

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

  594.     /* pass 2 */

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

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

  597.     /* pass 1 */

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

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

  600.     /* pass 2 */

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

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

  603.     /* pass 3 */

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

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

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

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

  608.     /* pass 1 */

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

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

  611.     /* pass 2 */

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

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

  614.     /* pass 1 */

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

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

  617.     /* pass 2 */

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

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

  620.     /* pass 3 */

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

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

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

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

  625.     /* pass 4 */

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

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

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

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

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

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

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

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

  634. 

  635. 

  636. 

  637.     /* pass 1 */

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

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

  640.     /* pass 2 */

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

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

  643.     /* pass 1 */

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

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

  646.     /* pass 2 */

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

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

  649.     /* pass 3 */

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

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

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

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

  654. 

  655.     /* pass 1 */

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

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

  658.     /* pass 2 */

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

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

  661.     /* pass 1 */

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

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

  664.     /* pass 2 */

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

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

  667.     /* pass 3 */

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

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

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

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

  672.     /* pass 4 */

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

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

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

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

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

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

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

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

  681. 

  682.     /* pass 5 */

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

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

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

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

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

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

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

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

  691. 

  692.     /* pass 6 */

  693. 

  694.     ADD( 8, 12);

  695.     ADD(12, 10);

  696.     ADD(10, 14);

  697.     ADD(14,  9);

  698.     ADD( 9, 13);

  699.     ADD(13, 11);

  700.     ADD(11, 15);

  701. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  718. 

  719.     ADD(24, 28);

  720.     ADD(28, 26);

  721.     ADD(26, 30);

  722.     ADD(30, 25);

  723.     ADD(25, 29);

  724.     ADD(29, 27);

  725.     ADD(27, 31);

  726. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  743. }

  744. 

  745. #if FRAC_BITS <= 15

  746. 

  747. static inline int round_sample(int *sum)

  748. {

  749.     int sum1;

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

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

  752.     if (sum1 < OUT_MIN)

  753.         sum1 = OUT_MIN;

  754.     else if (sum1 > OUT_MAX)

  755.         sum1 = OUT_MAX;

  756.     return sum1;

  757. }

  758. 

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

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

  761. 

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

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

  764. 

  765. #else

  766. 

  767. static inline int round_sample(int64_t *sum)

  768. {

  769.     int sum1;

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

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

  772.     if (sum1 < OUT_MIN)

  773.         sum1 = OUT_MIN;

  774.     else if (sum1 > OUT_MAX)

  775.         sum1 = OUT_MAX;

  776.     return sum1;

  777. }

  778. 

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

  780. #endif

  781. 

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

  783. {                                               \

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

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

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

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

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

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

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

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

  792. }

  793. 

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

  795. {                                               \

  796.     int tmp;\

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  821. }

  822. 

  823. void ff_mpa_synth_init(MPA_INT *window)

  824. {

  825.     int i;

  826. 

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

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

  829.         int v;

  830.         v = mpa_enwindow[i];

  831. #if WFRAC_BITS < 16

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

  833. #endif

  834.         window[i] = v;

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

  836.             v = -v;

  837.         if (i != 0)

  838.             window[512 - i] = v;

  839.     }

  840. }

  841. 

  842. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

  843.    32 samples. */

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

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

  846.                          MPA_INT *window, int *dither_state,

  847.                          OUT_INT *samples, int incr,

  848.                          int32_t sb_samples[SBLIMIT])

  849. {

  850.     int32_t tmp[32];

  851.     register MPA_INT *synth_buf;

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

  853.     int j, offset, v;

  854.     OUT_INT *samples2;

  855. #if FRAC_BITS <= 15

  856.     int sum, sum2;

  857. #else

  858.     int64_t sum, sum2;

  859. #endif

  860. 

  861.     dct32(tmp, sb_samples);

  862. 

  863.     offset = *synth_buf_offset;

  864.     synth_buf = synth_buf_ptr + offset;

  865. 

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

  867.         v = tmp[j];

  868. #if FRAC_BITS <= 15

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

  870.            sound */

  871.         if (v > 32767)

  872.             v = 32767;

  873.         else if (v < -32768)

  874.             v = -32768;

  875. #endif

  876.         synth_buf[j] = v;

  877.     }

  878.     /* copy to avoid wrap */

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

  880. 

  881.     samples2 = samples + 31 * incr;

  882.     w = window;

  883.     w2 = window + 31;

  884. 

  885.     sum = *dither_state;

  886.     p = synth_buf + 16;

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

  888.     p = synth_buf + 48;

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

  890.     *samples = round_sample(&sum);

  891.     samples += incr;

  892.     w++;

  893. 

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

  895.        access per two sample */

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

  897.         sum2 = 0;

  898.         p = synth_buf + 16 + j;

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

  900.         p = synth_buf + 48 - j;

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

  902. 

  903.         *samples = round_sample(&sum);

  904.         samples += incr;

  905.         sum += sum2;

  906.         *samples2 = round_sample(&sum);

  907.         samples2 -= incr;

  908.         w++;

  909.         w2--;

  910.     }

  911. 

  912.     p = synth_buf + 32;

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

  914.     *samples = round_sample(&sum);

  915.     *dither_state= sum;

  916. 

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

  918.     *synth_buf_offset = offset;

  919. }

  920. 

  921. #define C3 FIXHR(0.86602540378443864676/2)

  922. 

  923. /* 0.5 / cos(pi*(2*i+1)/36) */

  924. static const int icos36[9] = {

  925.     FIXR(0.50190991877167369479),

  926.     FIXR(0.51763809020504152469), //0

  927.     FIXR(0.55168895948124587824),

  928.     FIXR(0.61038729438072803416),

  929.     FIXR(0.70710678118654752439), //1

  930.     FIXR(0.87172339781054900991),

  931.     FIXR(1.18310079157624925896),

  932.     FIXR(1.93185165257813657349), //2

  933.     FIXR(5.73685662283492756461),

  934. };

  935. 

  936. /* 0.5 / cos(pi*(2*i+1)/36) */

  937. static const int icos36h[9] = {

  938.     FIXHR(0.50190991877167369479/2),

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

  940.     FIXHR(0.55168895948124587824/2),

  941.     FIXHR(0.61038729438072803416/2),

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

  943.     FIXHR(0.87172339781054900991/2),

  944.     FIXHR(1.18310079157624925896/4),

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

  946. //    FIXHR(5.73685662283492756461),

  947. };

  948. 

  949. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  950.    cases. */

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

  952. {

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

  954. 

  955.     in0= in[0*3];

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

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

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

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

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

  961.     in5 += in3;

  962.     in3 += in1;

  963. 

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

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

  966. 

  967.     t1 = in0 - in4;

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

  969. 

  970.     out[ 7]=

  971.     out[10]= t1 + t2;

  972.     out[ 1]=

  973.     out[ 4]= t1 - t2;

  974. 

  975.     in0 += in4>>1;

  976.     in4 = in0 + in2;

  977.     in5 += 2*in1;

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

  979.     out[ 8]=

  980.     out[ 9]= in4 + in1;

  981.     out[ 2]=

  982.     out[ 3]= in4 - in1;

  983. 

  984.     in0 -= in2;

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

  986.     out[ 0]=

  987.     out[ 5]= in0 - in5;

  988.     out[ 6]=

  989.     out[11]= in0 + in5;

  990. }

  991. 

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

  993. #define C1 FIXHR(0.98480775301220805936/2)

  994. #define C2 FIXHR(0.93969262078590838405/2)

  995. #define C3 FIXHR(0.86602540378443864676/2)

  996. #define C4 FIXHR(0.76604444311897803520/2)

  997. #define C5 FIXHR(0.64278760968653932632/2)

  998. #define C6 FIXHR(0.5/2)

  999. #define C7 FIXHR(0.34202014332566873304/2)

  1000. #define C8 FIXHR(0.17364817766693034885/2)

  1001. 

  1002. 

  1003. /* using Lee like decomposition followed by hand coded 9 points DCT */

  1004. static void imdct36(int *out, int *buf, int *in, int *win)

  1005. {

  1006.     int i, j, t0, t1, t2, t3, s0, s1, s2, s3;

  1007.     int tmp[18], *tmp1, *in1;

  1008. 

  1009.     for(i=17;i>=1;i--)

  1010.         in[i] += in[i-1];

  1011.     for(i=17;i>=3;i-=2)

  1012.         in[i] += in[i-2];

  1013. 

  1014.     for(j=0;j<2;j++) {

  1015.         tmp1 = tmp + j;

  1016.         in1 = in + j;

  1017. #if 0

  1018. //more accurate but slower

  1019.         int64_t t0, t1, t2, t3;

  1020.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1021. 

  1022.         t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;

  1023.         t1 = in1[2*0] - in1[2*6];

  1024.         tmp1[ 6] = t1 - (t2>>1);

  1025.         tmp1[16] = t1 + t2;

  1026. 

  1027.         t0 = MUL64(2*(in1[2*2] + in1[2*4]),    C2);

  1028.         t1 = MUL64(   in1[2*4] - in1[2*8] , -2*C8);

  1029.         t2 = MUL64(2*(in1[2*2] + in1[2*8]),   -C4);

  1030. 

  1031.         tmp1[10] = (t3 - t0 - t2) >> 32;

  1032.         tmp1[ 2] = (t3 + t0 + t1) >> 32;

  1033.         tmp1[14] = (t3 + t2 - t1) >> 32;

  1034. 

  1035.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1036.         t2 = MUL64(2*(in1[2*1] + in1[2*5]),    C1);

  1037.         t3 = MUL64(   in1[2*5] - in1[2*7] , -2*C7);

  1038.         t0 = MUL64(2*in1[2*3], C3);

  1039. 

  1040.         t1 = MUL64(2*(in1[2*1] + in1[2*7]),   -C5);

  1041. 

  1042.         tmp1[ 0] = (t2 + t3 + t0) >> 32;

  1043.         tmp1[12] = (t2 + t1 - t0) >> 32;

  1044.         tmp1[ 8] = (t3 - t1 - t0) >> 32;

  1045. #else

  1046.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1047. 

  1048.         t3 = in1[2*0] + (in1[2*6]>>1);

  1049.         t1 = in1[2*0] - in1[2*6];

  1050.         tmp1[ 6] = t1 - (t2>>1);

  1051.         tmp1[16] = t1 + t2;

  1052. 

  1053.         t0 = MULH(2*(in1[2*2] + in1[2*4]),    C2);

  1054.         t1 = MULH(   in1[2*4] - in1[2*8] , -2*C8);

  1055.         t2 = MULH(2*(in1[2*2] + in1[2*8]),   -C4);

  1056. 

  1057.         tmp1[10] = t3 - t0 - t2;

  1058.         tmp1[ 2] = t3 + t0 + t1;

  1059.         tmp1[14] = t3 + t2 - t1;

  1060. 

  1061.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1062.         t2 = MULH(2*(in1[2*1] + in1[2*5]),    C1);

  1063.         t3 = MULH(   in1[2*5] - in1[2*7] , -2*C7);

  1064.         t0 = MULH(2*in1[2*3], C3);

  1065. 

  1066.         t1 = MULH(2*(in1[2*1] + in1[2*7]),   -C5);

  1067. 

  1068.         tmp1[ 0] = t2 + t3 + t0;

  1069.         tmp1[12] = t2 + t1 - t0;

  1070.         tmp1[ 8] = t3 - t1 - t0;

  1071. #endif

  1072.     }

  1073. 

  1074.     i = 0;

  1075.     for(j=0;j<4;j++) {

  1076.         t0 = tmp[i];

  1077.         t1 = tmp[i + 2];

  1078.         s0 = t1 + t0;

  1079.         s2 = t1 - t0;

  1080. 

  1081.         t2 = tmp[i + 1];

  1082.         t3 = tmp[i + 3];

  1083.         s1 = MULH(2*(t3 + t2), icos36h[j]);

  1084.         s3 = MULL(t3 - t2, icos36[8 - j]);

  1085. 

  1086.         t0 = s0 + s1;

  1087.         t1 = s0 - s1;

  1088.         out[(9 + j)*SBLIMIT] =  MULH(t1, win[9 + j]) + buf[9 + j];

  1089.         out[(8 - j)*SBLIMIT] =  MULH(t1, win[8 - j]) + buf[8 - j];

  1090.         buf[9 + j] = MULH(t0, win[18 + 9 + j]);

  1091.         buf[8 - j] = MULH(t0, win[18 + 8 - j]);

  1092. 

  1093.         t0 = s2 + s3;

  1094.         t1 = s2 - s3;

  1095.         out[(9 + 8 - j)*SBLIMIT] =  MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];

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

  1097.         buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);

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

  1099.         i += 4;

  1100.     }

  1101. 

  1102.     s0 = tmp[16];

  1103.     s1 = MULH(2*tmp[17], icos36h[4]);

  1104.     t0 = s0 + s1;

  1105.     t1 = s0 - s1;

  1106.     out[(9 + 4)*SBLIMIT] =  MULH(t1, win[9 + 4]) + buf[9 + 4];

  1107.     out[(8 - 4)*SBLIMIT] =  MULH(t1, win[8 - 4]) + buf[8 - 4];

  1108.     buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);

  1109.     buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);

  1110. }

  1111. 

  1112. /* header decoding. MUST check the header before because no

  1113.    consistency check is done there. Return 1 if free format found and

  1114.    that the frame size must be computed externally */

  1115. static int decode_header(MPADecodeContext *s, uint32_t header)

  1116. {

  1117.     int sample_rate, frame_size, mpeg25, padding;

  1118.     int sample_rate_index, bitrate_index;

  1119.     if (header & (1<<20)) {

  1120.         s->lsf = (header & (1<<19)) ? 0 : 1;

  1121.         mpeg25 = 0;

  1122.     } else {

  1123.         s->lsf = 1;

  1124.         mpeg25 = 1;

  1125.     }

  1126. 

  1127.     s->layer = 4 - ((header >> 17) & 3);

  1128.     /* extract frequency */

  1129.     sample_rate_index = (header >> 10) & 3;

  1130.     sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);

  1131.     sample_rate_index += 3 * (s->lsf + mpeg25);

  1132.     s->sample_rate_index = sample_rate_index;

  1133.     s->error_protection = ((header >> 16) & 1) ^ 1;

  1134.     s->sample_rate = sample_rate;

  1135. 

  1136.     bitrate_index = (header >> 12) & 0xf;

  1137.     padding = (header >> 9) & 1;

  1138.     //extension = (header >> 8) & 1;

  1139.     s->mode = (header >> 6) & 3;

  1140.     s->mode_ext = (header >> 4) & 3;

  1141.     //copyright = (header >> 3) & 1;

  1142.     //original = (header >> 2) & 1;

  1143.     //emphasis = header & 3;

  1144. 

  1145.     if (s->mode == MPA_MONO)

  1146.         s->nb_channels = 1;

  1147.     else

  1148.         s->nb_channels = 2;

  1149. 

  1150.     if (bitrate_index != 0) {

  1151.         frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];

  1152.         s->bit_rate = frame_size * 1000;

  1153.         switch(s->layer) {

  1154.         case 1:

  1155.             frame_size = (frame_size * 12000) / sample_rate;

  1156.             frame_size = (frame_size + padding) * 4;

  1157.             break;

  1158.         case 2:

  1159.             frame_size = (frame_size * 144000) / sample_rate;

  1160.             frame_size += padding;

  1161.             break;

  1162.         default:

  1163.         case 3:

  1164.             frame_size = (frame_size * 144000) / (sample_rate << s->lsf);

  1165.             frame_size += padding;

  1166.             break;

  1167.         }

  1168.         s->frame_size = frame_size;

  1169.     } else {

  1170.         /* if no frame size computed, signal it */

  1171.         return 1;

  1172.     }

  1173. 

  1174. #if defined(DEBUG)

  1175.     dprintf("layer%d, %d Hz, %d kbits/s, ",

  1176.            s->layer, s->sample_rate, s->bit_rate);

  1177.     if (s->nb_channels == 2) {

  1178.         if (s->layer == 3) {

  1179.             if (s->mode_ext & MODE_EXT_MS_STEREO)

  1180.                 dprintf("ms-");

  1181.             if (s->mode_ext & MODE_EXT_I_STEREO)

  1182.                 dprintf("i-");

  1183.         }

  1184.         dprintf("stereo");

  1185.     } else {

  1186.         dprintf("mono");

  1187.     }

  1188.     dprintf("\n");

  1189. #endif

  1190.     return 0;

  1191. }

  1192. 

  1193. /* useful helper to get mpeg audio stream infos. Return -1 if error in

  1194.    header, otherwise the coded frame size in bytes */

  1195. int mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate)

  1196. {

  1197.     MPADecodeContext s1, *s = &s1;

  1198. 

  1199.     if (ff_mpa_check_header(head) != 0)

  1200.         return -1;

  1201. 

  1202.     if (decode_header(s, head) != 0) {

  1203.         return -1;

  1204.     }

  1205. 

  1206.     switch(s->layer) {

  1207.     case 1:

  1208.         avctx->frame_size = 384;

  1209.         break;

  1210.     case 2:

  1211.         avctx->frame_size = 1152;

  1212.         break;

  1213.     default:

  1214.     case 3:

  1215.         if (s->lsf)

  1216.             avctx->frame_size = 576;

  1217.         else

  1218.             avctx->frame_size = 1152;

  1219.         break;

  1220.     }

  1221. 

  1222.     *sample_rate = s->sample_rate;

  1223.     avctx->channels = s->nb_channels;

  1224.     avctx->bit_rate = s->bit_rate;

  1225.     avctx->sub_id = s->layer;

  1226.     return s->frame_size;

  1227. }

  1228. 

  1229. /* return the number of decoded frames */

  1230. static int mp_decode_layer1(MPADecodeContext *s)

  1231. {

  1232.     int bound, i, v, n, ch, j, mant;

  1233.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  1234.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  1235. 

  1236.     if (s->mode == MPA_JSTEREO)

  1237.         bound = (s->mode_ext + 1) * 4;

  1238.     else

  1239.         bound = SBLIMIT;

  1240. 

  1241.     /* allocation bits */

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

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

  1244.             allocation[ch][i] = get_bits(&s->gb, 4);

  1245.         }

  1246.     }

  1247.     for(i=bound;i<SBLIMIT;i++) {

  1248.         allocation[0][i] = get_bits(&s->gb, 4);

  1249.     }

  1250. 

  1251.     /* scale factors */

  1252.     for(i=0;i<bound;i++) {

  1253.         for(ch=0;ch<s->nb_channels;ch++) {

  1254.             if (allocation[ch][i])

  1255.                 scale_factors[ch][i] = get_bits(&s->gb, 6);

  1256.         }

  1257.     }

  1258.     for(i=bound;i<SBLIMIT;i++) {

  1259.         if (allocation[0][i]) {

  1260.             scale_factors[0][i] = get_bits(&s->gb, 6);

  1261.             scale_factors[1][i] = get_bits(&s->gb, 6);

  1262.         }

  1263.     }

  1264. 

  1265.     /* compute samples */

  1266.     for(j=0;j<12;j++) {

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

  1268.             for(ch=0;ch<s->nb_channels;ch++) {

  1269.                 n = allocation[ch][i];

  1270.                 if (n) {

  1271.                     mant = get_bits(&s->gb, n + 1);

  1272.                     v = l1_unscale(n, mant, scale_factors[ch][i]);

  1273.                 } else {

  1274.                     v = 0;

  1275.                 }

  1276.                 s->sb_samples[ch][j][i] = v;

  1277.             }

  1278.         }

  1279.         for(i=bound;i<SBLIMIT;i++) {

  1280.             n = allocation[0][i];

  1281.             if (n) {

  1282.                 mant = get_bits(&s->gb, n + 1);

  1283.                 v = l1_unscale(n, mant, scale_factors[0][i]);

  1284.                 s->sb_samples[0][j][i] = v;

  1285.                 v = l1_unscale(n, mant, scale_factors[1][i]);

  1286.                 s->sb_samples[1][j][i] = v;

  1287.             } else {

  1288.                 s->sb_samples[0][j][i] = 0;

  1289.                 s->sb_samples[1][j][i] = 0;

  1290.             }

  1291.         }

  1292.     }

  1293.     return 12;

  1294. }

  1295. 

  1296. /* bitrate is in kb/s */

  1297. int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)

  1298. {

  1299.     int ch_bitrate, table;

  1300. 

  1301.     ch_bitrate = bitrate / nb_channels;

  1302.     if (!lsf) {

  1303.         if ((freq == 48000 && ch_bitrate >= 56) ||

  1304.             (ch_bitrate >= 56 && ch_bitrate <= 80))

  1305.             table = 0;

  1306.         else if (freq != 48000 && ch_bitrate >= 96)

  1307.             table = 1;

  1308.         else if (freq != 32000 && ch_bitrate <= 48)

  1309.             table = 2;

  1310.         else

  1311.             table = 3;

  1312.     } else {

  1313.         table = 4;

  1314.     }

  1315.     return table;

  1316. }

  1317. 

  1318. static int mp_decode_layer2(MPADecodeContext *s)

  1319. {

  1320.     int sblimit; /* number of used subbands */

  1321.     const unsigned char *alloc_table;

  1322.     int table, bit_alloc_bits, i, j, ch, bound, v;

  1323.     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];

  1324.     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];

  1325.     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;

  1326.     int scale, qindex, bits, steps, k, l, m, b;

  1327. 

  1328.     /* select decoding table */

  1329.     table = l2_select_table(s->bit_rate / 1000, s->nb_channels,

  1330.                             s->sample_rate, s->lsf);

  1331.     sblimit = sblimit_table[table];

  1332.     alloc_table = alloc_tables[table];

  1333. 

  1334.     if (s->mode == MPA_JSTEREO)

  1335.         bound = (s->mode_ext + 1) * 4;

  1336.     else

  1337.         bound = sblimit;

  1338. 

  1339.     dprintf("bound=%d sblimit=%d\n", bound, sblimit);

  1340. 

  1341.     /* sanity check */

  1342.     if( bound > sblimit ) bound = sblimit;

  1343. 

  1344.     /* parse bit allocation */

  1345.     j = 0;

  1346.     for(i=0;i<bound;i++) {

  1347.         bit_alloc_bits = alloc_table[j];

  1348.         for(ch=0;ch<s->nb_channels;ch++) {

  1349.             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);

  1350.         }

  1351.         j += 1 << bit_alloc_bits;

  1352.     }

  1353.     for(i=bound;i<sblimit;i++) {

  1354.         bit_alloc_bits = alloc_table[j];

  1355.         v = get_bits(&s->gb, bit_alloc_bits);

  1356.         bit_alloc[0][i] = v;

  1357.         bit_alloc[1][i] = v;

  1358.         j += 1 << bit_alloc_bits;

  1359.     }

  1360. 

  1361. #ifdef DEBUG

  1362.     {

  1363.         for(ch=0;ch<s->nb_channels;ch++) {

  1364.             for(i=0;i<sblimit;i++)

  1365.                 dprintf(" %d", bit_alloc[ch][i]);

  1366.             dprintf("\n");

  1367.         }

  1368.     }

  1369. #endif

  1370. 

  1371.     /* scale codes */

  1372.     for(i=0;i<sblimit;i++) {

  1373.         for(ch=0;ch<s->nb_channels;ch++) {

  1374.             if (bit_alloc[ch][i])

  1375.                 scale_code[ch][i] = get_bits(&s->gb, 2);

  1376.         }

  1377.     }

  1378. 

  1379.     /* scale factors */

  1380.     for(i=0;i<sblimit;i++) {

  1381.         for(ch=0;ch<s->nb_channels;ch++) {

  1382.             if (bit_alloc[ch][i]) {

  1383.                 sf = scale_factors[ch][i];

  1384.                 switch(scale_code[ch][i]) {

  1385.                 default:

  1386.                 case 0:

  1387.                     sf[0] = get_bits(&s->gb, 6);

  1388.                     sf[1] = get_bits(&s->gb, 6);

  1389.                     sf[2] = get_bits(&s->gb, 6);

  1390.                     break;

  1391.                 case 2:

  1392.                     sf[0] = get_bits(&s->gb, 6);

  1393.                     sf[1] = sf[0];

  1394.                     sf[2] = sf[0];

  1395.                     break;

  1396.                 case 1:

  1397.                     sf[0] = get_bits(&s->gb, 6);

  1398.                     sf[2] = get_bits(&s->gb, 6);

  1399.                     sf[1] = sf[0];

  1400.                     break;

  1401.                 case 3:

  1402.                     sf[0] = get_bits(&s->gb, 6);

  1403.                     sf[2] = get_bits(&s->gb, 6);

  1404.                     sf[1] = sf[2];

  1405.                     break;

  1406.                 }

  1407.             }

  1408.         }

  1409.     }

  1410. 

  1411. #ifdef DEBUG

  1412.     for(ch=0;ch<s->nb_channels;ch++) {

  1413.         for(i=0;i<sblimit;i++) {

  1414.             if (bit_alloc[ch][i]) {

  1415.                 sf = scale_factors[ch][i];

  1416.                 dprintf(" %d %d %d", sf[0], sf[1], sf[2]);

  1417.             } else {

  1418.                 dprintf(" -");

  1419.             }

  1420.         }

  1421.         dprintf("\n");

  1422.     }

  1423. #endif

  1424. 

  1425.     /* samples */

  1426.     for(k=0;k<3;k++) {

  1427.         for(l=0;l<12;l+=3) {

  1428.             j = 0;

  1429.             for(i=0;i<bound;i++) {

  1430.                 bit_alloc_bits = alloc_table[j];

  1431.                 for(ch=0;ch<s->nb_channels;ch++) {

  1432.                     b = bit_alloc[ch][i];

  1433.                     if (b) {

  1434.                         scale = scale_factors[ch][i][k];

  1435.                         qindex = alloc_table[j+b];

  1436.                         bits = quant_bits[qindex];

  1437.                         if (bits < 0) {

  1438.                             /* 3 values at the same time */

  1439.                             v = get_bits(&s->gb, -bits);

  1440.                             steps = quant_steps[qindex];

  1441.                             s->sb_samples[ch][k * 12 + l + 0][i] =

  1442.                                 l2_unscale_group(steps, v % steps, scale);

  1443.                             v = v / steps;

  1444.                             s->sb_samples[ch][k * 12 + l + 1][i] =

  1445.                                 l2_unscale_group(steps, v % steps, scale);

  1446.                             v = v / steps;

  1447.                             s->sb_samples[ch][k * 12 + l + 2][i] =

  1448.                                 l2_unscale_group(steps, v, scale);

  1449.                         } else {

  1450.                             for(m=0;m<3;m++) {

  1451.                                 v = get_bits(&s->gb, bits);

  1452.                                 v = l1_unscale(bits - 1, v, scale);

  1453.                                 s->sb_samples[ch][k * 12 + l + m][i] = v;

  1454.                             }

  1455.                         }

  1456.                     } else {

  1457.                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1458.                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1459.                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1460.                     }

  1461.                 }

  1462.                 /* next subband in alloc table */

  1463.                 j += 1 << bit_alloc_bits;

  1464.             }

  1465.             /* XXX: find a way to avoid this duplication of code */

  1466.             for(i=bound;i<sblimit;i++) {

  1467.                 bit_alloc_bits = alloc_table[j];

  1468.                 b = bit_alloc[0][i];

  1469.                 if (b) {

  1470.                     int mant, scale0, scale1;

  1471.                     scale0 = scale_factors[0][i][k];

  1472.                     scale1 = scale_factors[1][i][k];

  1473.                     qindex = alloc_table[j+b];

  1474.                     bits = quant_bits[qindex];

  1475.                     if (bits < 0) {

  1476.                         /* 3 values at the same time */

  1477.                         v = get_bits(&s->gb, -bits);

  1478.                         steps = quant_steps[qindex];

  1479.                         mant = v % steps;

  1480.                         v = v / steps;

  1481.                         s->sb_samples[0][k * 12 + l + 0][i] =

  1482.                             l2_unscale_group(steps, mant, scale0);

  1483.                         s->sb_samples[1][k * 12 + l + 0][i] =

  1484.                             l2_unscale_group(steps, mant, scale1);

  1485.                         mant = v % steps;

  1486.                         v = v / steps;

  1487.                         s->sb_samples[0][k * 12 + l + 1][i] =

  1488.                             l2_unscale_group(steps, mant, scale0);

  1489.                         s->sb_samples[1][k * 12 + l + 1][i] =

  1490.                             l2_unscale_group(steps, mant, scale1);

  1491.                         s->sb_samples[0][k * 12 + l + 2][i] =

  1492.                             l2_unscale_group(steps, v, scale0);

  1493.                         s->sb_samples[1][k * 12 + l + 2][i] =

  1494.                             l2_unscale_group(steps, v, scale1);

  1495.                     } else {

  1496.                         for(m=0;m<3;m++) {

  1497.                             mant = get_bits(&s->gb, bits);

  1498.                             s->sb_samples[0][k * 12 + l + m][i] =

  1499.                                 l1_unscale(bits - 1, mant, scale0);

  1500.                             s->sb_samples[1][k * 12 + l + m][i] =

  1501.                                 l1_unscale(bits - 1, mant, scale1);

  1502.                         }

  1503.                     }

  1504.                 } else {

  1505.                     s->sb_samples[0][k * 12 + l + 0][i] = 0;

  1506.                     s->sb_samples[0][k * 12 + l + 1][i] = 0;

  1507.                     s->sb_samples[0][k * 12 + l + 2][i] = 0;

  1508.                     s->sb_samples[1][k * 12 + l + 0][i] = 0;

  1509.                     s->sb_samples[1][k * 12 + l + 1][i] = 0;

  1510.                     s->sb_samples[1][k * 12 + l + 2][i] = 0;

  1511.                 }

  1512.                 /* next subband in alloc table */

  1513.                 j += 1 << bit_alloc_bits;

  1514.             }

  1515.             /* fill remaining samples to zero */

  1516.             for(i=sblimit;i<SBLIMIT;i++) {

  1517.                 for(ch=0;ch<s->nb_channels;ch++) {

  1518.                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1519.                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1520.                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1521.                 }

  1522.             }

  1523.         }

  1524.     }

  1525.     return 3 * 12;

  1526. }

  1527. 

  1528. static inline void lsf_sf_expand(int *slen,

  1529.                                  int sf, int n1, int n2, int n3)

  1530. {

  1531.     if (n3) {

  1532.         slen[3] = sf % n3;

  1533.         sf /= n3;

  1534.     } else {

  1535.         slen[3] = 0;

  1536.     }

  1537.     if (n2) {

  1538.         slen[2] = sf % n2;

  1539.         sf /= n2;

  1540.     } else {

  1541.         slen[2] = 0;

  1542.     }

  1543.     slen[1] = sf % n1;

  1544.     sf /= n1;

  1545.     slen[0] = sf;

  1546. }

  1547. 

  1548. static void exponents_from_scale_factors(MPADecodeContext *s,

  1549.                                          GranuleDef *g,

  1550.                                          int16_t *exponents)

  1551. {

  1552.     const uint8_t *bstab, *pretab;

  1553.     int len, i, j, k, l, v0, shift, gain, gains[3];

  1554.     int16_t *exp_ptr;

  1555. 

  1556.     exp_ptr = exponents;

  1557.     gain = g->global_gain - 210;

  1558.     shift = g->scalefac_scale + 1;

  1559. 

  1560.     bstab = band_size_long[s->sample_rate_index];

  1561.     pretab = mpa_pretab[g->preflag];

  1562.     for(i=0;i<g->long_end;i++) {

  1563.         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;

  1564.         len = bstab[i];

  1565.         for(j=len;j>0;j--)

  1566.             *exp_ptr++ = v0;

  1567.     }

  1568. 

  1569.     if (g->short_start < 13) {

  1570.         bstab = band_size_short[s->sample_rate_index];

  1571.         gains[0] = gain - (g->subblock_gain[0] << 3);

  1572.         gains[1] = gain - (g->subblock_gain[1] << 3);

  1573.         gains[2] = gain - (g->subblock_gain[2] << 3);

  1574.         k = g->long_end;

  1575.         for(i=g->short_start;i<13;i++) {

  1576.             len = bstab[i];

  1577.             for(l=0;l<3;l++) {

  1578.                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;

  1579.                 for(j=len;j>0;j--)

  1580.                 *exp_ptr++ = v0;

  1581.             }

  1582.         }

  1583.     }

  1584. }

  1585. 

  1586. /* handle n = 0 too */

  1587. static inline int get_bitsz(GetBitContext *s, int n)

  1588. {

  1589.     if (n == 0)

  1590.         return 0;

  1591.     else

  1592.         return get_bits(s, n);

  1593. }

  1594. 

  1595. 

  1596. static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos, int *end_pos2){

  1597.     if(s->in_gb.buffer && *pos >= s->gb.size_in_bits){

  1598.         s->gb= s->in_gb;

  1599.         s->in_gb.buffer=NULL;

  1600.         assert((get_bits_count(&s->gb) & 7) == 0);

  1601.         skip_bits_long(&s->gb, *pos - *end_pos);

  1602.         *end_pos2=

  1603.         *end_pos= *end_pos2 + get_bits_count(&s->gb) - *pos;

  1604.         *pos= get_bits_count(&s->gb);

  1605.     }

  1606. }

  1607. 

  1608. static int huffman_decode(MPADecodeContext *s, GranuleDef *g,

  1609.                           int16_t *exponents, int end_pos2)

  1610. {

  1611.     int s_index;

  1612.     int i;

  1613.     int last_pos, bits_left;

  1614.     VLC *vlc;

  1615.     int end_pos= FFMIN(end_pos2, s->gb.size_in_bits);

  1616. 

  1617.     /* low frequencies (called big values) */

  1618.     s_index = 0;

  1619.     for(i=0;i<3;i++) {

  1620.         int j, k, l, linbits;

  1621.         j = g->region_size[i];

  1622.         if (j == 0)

  1623.             continue;

  1624.         /* select vlc table */

  1625.         k = g->table_select[i];

  1626.         l = mpa_huff_data[k][0];

  1627.         linbits = mpa_huff_data[k][1];

  1628.         vlc = &huff_vlc[l];

  1629. 

  1630.         if(!l){

  1631.             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*2*j);

  1632.             s_index += 2*j;

  1633.             continue;

  1634.         }

  1635. 

  1636.         /* read huffcode and compute each couple */

  1637.         for(;j>0;j--) {

  1638.             int exponent, x, y, v;

  1639.             int pos= get_bits_count(&s->gb);

  1640. 

  1641.             if (pos >= end_pos){

  1642. //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1643.                 switch_buffer(s, &pos, &end_pos, &end_pos2);

  1644. //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);

  1645.                 if(pos >= end_pos)

  1646.                     break;

  1647.             }

  1648.             y = get_vlc2(&s->gb, vlc->table, 7, 3);

  1649. 

  1650.             if(!y){

  1651.                 g->sb_hybrid[s_index  ] =

  1652.                 g->sb_hybrid[s_index+1] = 0;

  1653.                 s_index += 2;

  1654.                 continue;

  1655.             }

  1656. 

  1657.             exponent= exponents[s_index];

  1658. 

  1659.             dprintf("region=%d n=%d x=%d y=%d exp=%d\n",

  1660.                     i, g->region_size[i] - j, x, y, exponent);

  1661.             if(y&16){

  1662.                 x = y >> 5;

  1663.                 y = y & 0x0f;

  1664.                 if (x < 15){

  1665.                     v = expval_table[ exponent ][ x ];

  1666. //                      v = expval_table[ (exponent&3) ][ x ] >> FFMIN(0 - (exponent>>2), 31);

  1667.                 }else{

  1668.                     x += get_bitsz(&s->gb, linbits);

  1669.                     v = l3_unscale(x, exponent);

  1670.                 }

  1671.                 if (get_bits1(&s->gb))

  1672.                     v = -v;

  1673.                 g->sb_hybrid[s_index] = v;

  1674.                 if (y < 15){

  1675.                     v = expval_table[ exponent ][ y ];

  1676.                 }else{

  1677.                     y += get_bitsz(&s->gb, linbits);

  1678.                     v = l3_unscale(y, exponent);

  1679.                 }

  1680.                 if (get_bits1(&s->gb))

  1681.                     v = -v;

  1682.                 g->sb_hybrid[s_index+1] = v;

  1683.             }else{

  1684.                 x = y >> 5;

  1685.                 y = y & 0x0f;

  1686.                 x += y;

  1687.                 if (x < 15){

  1688.                     v = expval_table[ exponent ][ x ];

  1689.                 }else{

  1690.                     x += get_bitsz(&s->gb, linbits);

  1691.                     v = l3_unscale(x, exponent);

  1692.                 }

  1693.                 if (get_bits1(&s->gb))

  1694.                     v = -v;

  1695.                 g->sb_hybrid[s_index+!!y] = v;

  1696.                 g->sb_hybrid[s_index+ !y] = 0;

  1697.             }

  1698.             s_index+=2;

  1699.         }

  1700.     }

  1701. 

  1702.     /* high frequencies */

  1703.     vlc = &huff_quad_vlc[g->count1table_select];

  1704.     last_pos=0;

  1705.     while (s_index <= 572) {

  1706.         int pos, code;

  1707.         pos = get_bits_count(&s->gb);

  1708.         if (pos >= end_pos) {

  1709.             if (pos > end_pos2 && last_pos){

  1710.                 /* some encoders generate an incorrect size for this

  1711.                    part. We must go back into the data */

  1712.                 s_index -= 4;

  1713.                 skip_bits_long(&s->gb, last_pos - pos);

  1714.                 av_log(NULL, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);

  1715.                 if(s->error_resilience >= FF_ER_COMPLIANT)

  1716.                     s_index=0;

  1717.                 break;

  1718.             }

  1719. //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1720.             switch_buffer(s, &pos, &end_pos, &end_pos2);

  1721. //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);

  1722.             if(pos >= end_pos)

  1723.                 break;

  1724.         }

  1725.         last_pos= pos;

  1726. 

  1727.         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);

  1728.         dprintf("t=%d code=%d\n", g->count1table_select, code);

  1729.         g->sb_hybrid[s_index+0]=

  1730.         g->sb_hybrid[s_index+1]=

  1731.         g->sb_hybrid[s_index+2]=

  1732.         g->sb_hybrid[s_index+3]= 0;

  1733.         while(code){

  1734.             const static int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};

  1735.             int v;

  1736.             int pos= s_index+idxtab[code];

  1737.             code ^= 8>>idxtab[code];

  1738.             v = exp_table[ exponents[pos] ];

  1739. //            v = exp_table[ (exponents[pos]&3) ] >> FFMIN(0 - (exponents[pos]>>2), 31);

  1740.             if(get_bits1(&s->gb))

  1741.                 v = -v;

  1742.             g->sb_hybrid[pos] = v;

  1743.         }

  1744.         s_index+=4;

  1745.     }

  1746.     /* skip extension bits */

  1747.     bits_left = end_pos2 - get_bits_count(&s->gb);

  1748. //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);

  1749.     if (bits_left < 0/* || bits_left > 500*/) {

  1750.         av_log(NULL, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1751.         s_index=0;

  1752.     }else if(bits_left > 0 && s->error_resilience >= FF_ER_AGGRESSIVE){

  1753.         av_log(NULL, AV_LOG_ERROR, "bits_left=%d\n", bits_left);

  1754.         s_index=0;

  1755.     }

  1756.     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*(576 - s_index));

  1757.     skip_bits_long(&s->gb, bits_left);

  1758. 

  1759.     i= get_bits_count(&s->gb);

  1760.     switch_buffer(s, &i, &end_pos, &end_pos2);

  1761. 

  1762.     return 0;

  1763. }

  1764. 

  1765. /* Reorder short blocks from bitstream order to interleaved order. It

  1766.    would be faster to do it in parsing, but the code would be far more

  1767.    complicated */

  1768. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1769. {

  1770.     int i, j, len;

  1771.     int32_t *ptr, *dst, *ptr1;

  1772.     int32_t tmp[576];

  1773. 

  1774.     if (g->block_type != 2)

  1775.         return;

  1776. 

  1777.     if (g->switch_point) {

  1778.         if (s->sample_rate_index != 8) {

  1779.             ptr = g->sb_hybrid + 36;

  1780.         } else {

  1781.             ptr = g->sb_hybrid + 48;

  1782.         }

  1783.     } else {

  1784.         ptr = g->sb_hybrid;

  1785.     }

  1786. 

  1787.     for(i=g->short_start;i<13;i++) {

  1788.         len = band_size_short[s->sample_rate_index][i];

  1789.         ptr1 = ptr;

  1790.         dst = tmp;

  1791.         for(j=len;j>0;j--) {

  1792.             *dst++ = ptr[0*len];

  1793.             *dst++ = ptr[1*len];

  1794.             *dst++ = ptr[2*len];

  1795.             ptr++;

  1796.         }

  1797.         ptr+=2*len;

  1798.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1799.     }

  1800. }

  1801. 

  1802. #define ISQRT2 FIXR(0.70710678118654752440)

  1803. 

  1804. static void compute_stereo(MPADecodeContext *s,

  1805.                            GranuleDef *g0, GranuleDef *g1)

  1806. {

  1807.     int i, j, k, l;

  1808.     int32_t v1, v2;

  1809.     int sf_max, tmp0, tmp1, sf, len, non_zero_found;

  1810.     int32_t (*is_tab)[16];

  1811.     int32_t *tab0, *tab1;

  1812.     int non_zero_found_short[3];

  1813. 

  1814.     /* intensity stereo */

  1815.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1816.         if (!s->lsf) {

  1817.             is_tab = is_table;

  1818.             sf_max = 7;

  1819.         } else {

  1820.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1821.             sf_max = 16;

  1822.         }

  1823. 

  1824.         tab0 = g0->sb_hybrid + 576;

  1825.         tab1 = g1->sb_hybrid + 576;

  1826. 

  1827.         non_zero_found_short[0] = 0;

  1828.         non_zero_found_short[1] = 0;

  1829.         non_zero_found_short[2] = 0;

  1830.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1831.         for(i = 12;i >= g1->short_start;i--) {

  1832.             /* for last band, use previous scale factor */

  1833.             if (i != 11)

  1834.                 k -= 3;

  1835.             len = band_size_short[s->sample_rate_index][i];

  1836.             for(l=2;l>=0;l--) {

  1837.                 tab0 -= len;

  1838.                 tab1 -= len;

  1839.                 if (!non_zero_found_short[l]) {

  1840.                     /* test if non zero band. if so, stop doing i-stereo */

  1841.                     for(j=0;j<len;j++) {

  1842.                         if (tab1[j] != 0) {

  1843.                             non_zero_found_short[l] = 1;

  1844.                             goto found1;

  1845.                         }

  1846.                     }

  1847.                     sf = g1->scale_factors[k + l];

  1848.                     if (sf >= sf_max)

  1849.                         goto found1;

  1850. 

  1851.                     v1 = is_tab[0][sf];

  1852.                     v2 = is_tab[1][sf];

  1853.                     for(j=0;j<len;j++) {

  1854.                         tmp0 = tab0[j];

  1855.                         tab0[j] = MULL(tmp0, v1);

  1856.                         tab1[j] = MULL(tmp0, v2);

  1857.                     }

  1858.                 } else {

  1859.                 found1:

  1860.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1861.                         /* lower part of the spectrum : do ms stereo

  1862.                            if enabled */

  1863.                         for(j=0;j<len;j++) {

  1864.                             tmp0 = tab0[j];

  1865.                             tmp1 = tab1[j];

  1866.                             tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1867.                             tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1868.                         }

  1869.                     }

  1870.                 }

  1871.             }

  1872.         }

  1873. 

  1874.         non_zero_found = non_zero_found_short[0] |

  1875.             non_zero_found_short[1] |

  1876.             non_zero_found_short[2];

  1877. 

  1878.         for(i = g1->long_end - 1;i >= 0;i--) {

  1879.             len = band_size_long[s->sample_rate_index][i];

  1880.             tab0 -= len;

  1881.             tab1 -= len;

  1882.             /* test if non zero band. if so, stop doing i-stereo */

  1883.             if (!non_zero_found) {

  1884.                 for(j=0;j<len;j++) {

  1885.                     if (tab1[j] != 0) {

  1886.                         non_zero_found = 1;

  1887.                         goto found2;

  1888.                     }

  1889.                 }

  1890.                 /* for last band, use previous scale factor */

  1891.                 k = (i == 21) ? 20 : i;

  1892.                 sf = g1->scale_factors[k];

  1893.                 if (sf >= sf_max)

  1894.                     goto found2;

  1895.                 v1 = is_tab[0][sf];

  1896.                 v2 = is_tab[1][sf];

  1897.                 for(j=0;j<len;j++) {

  1898.                     tmp0 = tab0[j];

  1899.                     tab0[j] = MULL(tmp0, v1);

  1900.                     tab1[j] = MULL(tmp0, v2);

  1901.                 }

  1902.             } else {

  1903.             found2:

  1904.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1905.                     /* lower part of the spectrum : do ms stereo

  1906.                        if enabled */

  1907.                     for(j=0;j<len;j++) {

  1908.                         tmp0 = tab0[j];

  1909.                         tmp1 = tab1[j];

  1910.                         tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1911.                         tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1912.                     }

  1913.                 }

  1914.             }

  1915.         }

  1916.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1917.         /* ms stereo ONLY */

  1918.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1919.            global gain */

  1920.         tab0 = g0->sb_hybrid;

  1921.         tab1 = g1->sb_hybrid;

  1922.         for(i=0;i<576;i++) {

  1923.             tmp0 = tab0[i];

  1924.             tmp1 = tab1[i];

  1925.             tab0[i] = tmp0 + tmp1;

  1926.             tab1[i] = tmp0 - tmp1;

  1927.         }

  1928.     }

  1929. }

  1930. 

  1931. static void compute_antialias_integer(MPADecodeContext *s,

  1932.                               GranuleDef *g)

  1933. {

  1934.     int32_t *ptr, *csa;

  1935.     int n, i;

  1936. 

  1937.     /* we antialias only "long" bands */

  1938.     if (g->block_type == 2) {

  1939.         if (!g->switch_point)

  1940.             return;

  1941.         /* XXX: check this for 8000Hz case */

  1942.         n = 1;

  1943.     } else {

  1944.         n = SBLIMIT - 1;

  1945.     }

  1946. 

  1947.     ptr = g->sb_hybrid + 18;

  1948.     for(i = n;i > 0;i--) {

  1949.         int tmp0, tmp1, tmp2;

  1950.         csa = &csa_table[0][0];

  1951. #define INT_AA(j) \

  1952.             tmp0 = ptr[-1-j];\

  1953.             tmp1 = ptr[   j];\

  1954.             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\

  1955.             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\

  1956.             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));

  1957. 

  1958.         INT_AA(0)

  1959.         INT_AA(1)

  1960.         INT_AA(2)

  1961.         INT_AA(3)

  1962.         INT_AA(4)

  1963.         INT_AA(5)

  1964.         INT_AA(6)

  1965.         INT_AA(7)

  1966. 

  1967.         ptr += 18;

  1968.     }

  1969. }

  1970. 

  1971. static void compute_antialias_float(MPADecodeContext *s,

  1972.                               GranuleDef *g)

  1973. {

  1974.     int32_t *ptr;

  1975.     int n, i;

  1976. 

  1977.     /* we antialias only "long" bands */

  1978.     if (g->block_type == 2) {

  1979.         if (!g->switch_point)

  1980.             return;

  1981.         /* XXX: check this for 8000Hz case */

  1982.         n = 1;

  1983.     } else {

  1984.         n = SBLIMIT - 1;

  1985.     }

  1986. 

  1987.     ptr = g->sb_hybrid + 18;

  1988.     for(i = n;i > 0;i--) {

  1989.         float tmp0, tmp1;

  1990.         float *csa = &csa_table_float[0][0];

  1991. #define FLOAT_AA(j)\

  1992.         tmp0= ptr[-1-j];\

  1993.         tmp1= ptr[   j];\

  1994.         ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\

  1995.         ptr[   j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);

  1996. 

  1997.         FLOAT_AA(0)

  1998.         FLOAT_AA(1)

  1999.         FLOAT_AA(2)

  2000.         FLOAT_AA(3)

  2001.         FLOAT_AA(4)

  2002.         FLOAT_AA(5)

  2003.         FLOAT_AA(6)

  2004.         FLOAT_AA(7)

  2005. 

  2006.         ptr += 18;

  2007.     }

  2008. }

  2009. 

  2010. static void compute_imdct(MPADecodeContext *s,

  2011.                           GranuleDef *g,

  2012.                           int32_t *sb_samples,

  2013.                           int32_t *mdct_buf)

  2014. {

  2015.     int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;

  2016.     int32_t out2[12];

  2017.     int i, j, mdct_long_end, v, sblimit;

  2018. 

  2019.     /* find last non zero block */

  2020.     ptr = g->sb_hybrid + 576;

  2021.     ptr1 = g->sb_hybrid + 2 * 18;

  2022.     while (ptr >= ptr1) {

  2023.         ptr -= 6;

  2024.         v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];

  2025.         if (v != 0)

  2026.             break;

  2027.     }

  2028.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  2029. 

  2030.     if (g->block_type == 2) {

  2031.         /* XXX: check for 8000 Hz */

  2032.         if (g->switch_point)

  2033.             mdct_long_end = 2;

  2034.         else

  2035.             mdct_long_end = 0;

  2036.     } else {

  2037.         mdct_long_end = sblimit;

  2038.     }

  2039. 

  2040.     buf = mdct_buf;

  2041.     ptr = g->sb_hybrid;

  2042.     for(j=0;j<mdct_long_end;j++) {

  2043.         /* apply window & overlap with previous buffer */

  2044.         out_ptr = sb_samples + j;

  2045.         /* select window */

  2046.         if (g->switch_point && j < 2)

  2047.             win1 = mdct_win[0];

  2048.         else

  2049.             win1 = mdct_win[g->block_type];

  2050.         /* select frequency inversion */

  2051.         win = win1 + ((4 * 36) & -(j & 1));

  2052.         imdct36(out_ptr, buf, ptr, win);

  2053.         out_ptr += 18*SBLIMIT;

  2054.         ptr += 18;

  2055.         buf += 18;

  2056.     }

  2057.     for(j=mdct_long_end;j<sblimit;j++) {

  2058.         /* select frequency inversion */

  2059.         win = mdct_win[2] + ((4 * 36) & -(j & 1));

  2060.         out_ptr = sb_samples + j;

  2061. 

  2062.         for(i=0; i<6; i++){

  2063.             *out_ptr = buf[i];

  2064.             out_ptr += SBLIMIT;

  2065.         }

  2066.         imdct12(out2, ptr + 0);

  2067.         for(i=0;i<6;i++) {

  2068.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];

  2069.             buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);

  2070.             out_ptr += SBLIMIT;

  2071.         }

  2072.         imdct12(out2, ptr + 1);

  2073.         for(i=0;i<6;i++) {

  2074.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];

  2075.             buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);

  2076.             out_ptr += SBLIMIT;

  2077.         }

  2078.         imdct12(out2, ptr + 2);

  2079.         for(i=0;i<6;i++) {

  2080.             buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];

  2081.             buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);

  2082.             buf[i + 6*2] = 0;

  2083.         }

  2084.         ptr += 18;

  2085.         buf += 18;

  2086.     }

  2087.     /* zero bands */

  2088.     for(j=sblimit;j<SBLIMIT;j++) {

  2089.         /* overlap */

  2090.         out_ptr = sb_samples + j;

  2091.         for(i=0;i<18;i++) {

  2092.             *out_ptr = buf[i];

  2093.             buf[i] = 0;

  2094.             out_ptr += SBLIMIT;

  2095.         }

  2096.         buf += 18;

  2097.     }

  2098. }

  2099. 

  2100. #if defined(DEBUG)

  2101. void sample_dump(int fnum, int32_t *tab, int n)

  2102. {

  2103.     static FILE *files[16], *f;

  2104.     char buf[512];

  2105.     int i;

  2106.     int32_t v;

  2107. 

  2108.     f = files[fnum];

  2109.     if (!f) {

  2110.         snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm",

  2111.                 fnum,

  2112. #ifdef USE_HIGHPRECISION

  2113.                 "hp"

  2114. #else

  2115.                 "lp"

  2116. #endif

  2117.                 );

  2118.         f = fopen(buf, "w");

  2119.         if (!f)

  2120.             return;

  2121.         files[fnum] = f;

  2122.     }

  2123. 

  2124.     if (fnum == 0) {

  2125.         static int pos = 0;

  2126.         av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos);

  2127.         for(i=0;i<n;i++) {

  2128.             av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE);

  2129.             if ((i % 18) == 17)

  2130.                 av_log(NULL, AV_LOG_DEBUG, "\n");

  2131.         }

  2132.         pos += n;

  2133.     }

  2134.     for(i=0;i<n;i++) {

  2135.         /* normalize to 23 frac bits */

  2136.         v = tab[i] << (23 - FRAC_BITS);

  2137.         fwrite(&v, 1, sizeof(int32_t), f);

  2138.     }

  2139. }

  2140. #endif

  2141. 

  2142. 

  2143. /* main layer3 decoding function */

  2144. static int mp_decode_layer3(MPADecodeContext *s)

  2145. {

  2146.     int nb_granules, main_data_begin, private_bits;

  2147.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  2148.     GranuleDef granules[2][2], *g;

  2149.     int16_t exponents[576];

  2150. 

  2151.     /* read side info */

  2152.     if (s->lsf) {

  2153.         main_data_begin = get_bits(&s->gb, 8);

  2154.         private_bits = get_bits(&s->gb, s->nb_channels);

  2155.         nb_granules = 1;

  2156.     } else {

  2157.         main_data_begin = get_bits(&s->gb, 9);

  2158.         if (s->nb_channels == 2)

  2159.             private_bits = get_bits(&s->gb, 3);

  2160.         else

  2161.             private_bits = get_bits(&s->gb, 5);

  2162.         nb_granules = 2;

  2163.         for(ch=0;ch<s->nb_channels;ch++) {

  2164.             granules[ch][0].scfsi = 0; /* all scale factors are transmitted */

  2165.             granules[ch][1].scfsi = get_bits(&s->gb, 4);

  2166.         }

  2167.     }

  2168. 

  2169.     for(gr=0;gr<nb_granules;gr++) {

  2170.         for(ch=0;ch<s->nb_channels;ch++) {

  2171.             dprintf("gr=%d ch=%d: side_info\n", gr, ch);

  2172.             g = &granules[ch][gr];

  2173.             g->part2_3_length = get_bits(&s->gb, 12);

  2174.             g->big_values = get_bits(&s->gb, 9);

  2175.             if(g->big_values > 288){

  2176.                 av_log(NULL, AV_LOG_ERROR, "big_values too big\n");

  2177.                 return -1;

  2178.             }

  2179. 

  2180.             g->global_gain = get_bits(&s->gb, 8);

  2181.             /* if MS stereo only is selected, we precompute the

  2182.                1/sqrt(2) renormalization factor */

  2183.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  2184.                 MODE_EXT_MS_STEREO)

  2185.                 g->global_gain -= 2;

  2186.             if (s->lsf)

  2187.                 g->scalefac_compress = get_bits(&s->gb, 9);

  2188.             else

  2189.                 g->scalefac_compress = get_bits(&s->gb, 4);

  2190.             blocksplit_flag = get_bits(&s->gb, 1);

  2191.             if (blocksplit_flag) {

  2192.                 g->block_type = get_bits(&s->gb, 2);

  2193.                 if (g->block_type == 0){

  2194.                     av_log(NULL, AV_LOG_ERROR, "invalid block type\n");

  2195.                     return -1;

  2196.                 }

  2197.                 g->switch_point = get_bits(&s->gb, 1);

  2198.                 for(i=0;i<2;i++)

  2199.                     g->table_select[i] = get_bits(&s->gb, 5);

  2200.                 for(i=0;i<3;i++)

  2201.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  2202.                 /* compute huffman coded region sizes */

  2203.                 if (g->block_type == 2)

  2204.                     g->region_size[0] = (36 / 2);

  2205.                 else {

  2206.                     if (s->sample_rate_index <= 2)

  2207.                         g->region_size[0] = (36 / 2);

  2208.                     else if (s->sample_rate_index != 8)

  2209.                         g->region_size[0] = (54 / 2);

  2210.                     else

  2211.                         g->region_size[0] = (108 / 2);

  2212.                 }

  2213.                 g->region_size[1] = (576 / 2);

  2214.             } else {

  2215.                 int region_address1, region_address2, l;

  2216.                 g->block_type = 0;

  2217.                 g->switch_point = 0;

  2218.                 for(i=0;i<3;i++)

  2219.                     g->table_select[i] = get_bits(&s->gb, 5);

  2220.                 /* compute huffman coded region sizes */

  2221.                 region_address1 = get_bits(&s->gb, 4);

  2222.                 region_address2 = get_bits(&s->gb, 3);

  2223.                 dprintf("region1=%d region2=%d\n",

  2224.                         region_address1, region_address2);

  2225.                 g->region_size[0] =

  2226.                     band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;

  2227.                 l = region_address1 + region_address2 + 2;

  2228.                 /* should not overflow */

  2229.                 if (l > 22)

  2230.                     l = 22;

  2231.                 g->region_size[1] =

  2232.                     band_index_long[s->sample_rate_index][l] >> 1;

  2233.             }

  2234.             /* convert region offsets to region sizes and truncate

  2235.                size to big_values */

  2236.             g->region_size[2] = (576 / 2);

  2237.             j = 0;

  2238.             for(i=0;i<3;i++) {

  2239.                 k = FFMIN(g->region_size[i], g->big_values);

  2240.                 g->region_size[i] = k - j;

  2241.                 j = k;

  2242.             }

  2243. 

  2244.             /* compute band indexes */

  2245.             if (g->block_type == 2) {

  2246.                 if (g->switch_point) {

  2247.                     /* if switched mode, we handle the 36 first samples as

  2248.                        long blocks.  For 8000Hz, we handle the 48 first

  2249.                        exponents as long blocks (XXX: check this!) */

  2250.                     if (s->sample_rate_index <= 2)

  2251.                         g->long_end = 8;

  2252.                     else if (s->sample_rate_index != 8)

  2253.                         g->long_end = 6;

  2254.                     else

  2255.                         g->long_end = 4; /* 8000 Hz */

  2256. 

  2257.                     g->short_start = 2 + (s->sample_rate_index != 8);

  2258.                 } else {

  2259.                     g->long_end = 0;

  2260.                     g->short_start = 0;

  2261.                 }

  2262.             } else {

  2263.                 g->short_start = 13;

  2264.                 g->long_end = 22;

  2265.             }

  2266. 

  2267.             g->preflag = 0;

  2268.             if (!s->lsf)

  2269.                 g->preflag = get_bits(&s->gb, 1);

  2270.             g->scalefac_scale = get_bits(&s->gb, 1);

  2271.             g->count1table_select = get_bits(&s->gb, 1);

  2272.             dprintf("block_type=%d switch_point=%d\n",

  2273.                     g->block_type, g->switch_point);

  2274.         }

  2275.     }

  2276. 

  2277.   if (!s->adu_mode) {

  2278.     const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  2279.     assert((get_bits_count(&s->gb) & 7) == 0);

  2280.     /* now we get bits from the main_data_begin offset */

  2281.     dprintf("seekback: %d\n", main_data_begin);

  2282. //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);

  2283. 

  2284.     memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);

  2285.     s->in_gb= s->gb;

  2286.         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);

  2287.         skip_bits_long(&s->gb, 8*(s->last_buf_size - main_data_begin));

  2288.   }

  2289. 

  2290.     for(gr=0;gr<nb_granules;gr++) {

  2291.         for(ch=0;ch<s->nb_channels;ch++) {

  2292.             g = &granules[ch][gr];

  2293.             if(get_bits_count(&s->gb)<0){

  2294.                 av_log(NULL, AV_LOG_ERROR, "mdb:%d, lastbuf:%d skiping granule %d\n",

  2295.                                             main_data_begin, s->last_buf_size, gr);

  2296.                 skip_bits_long(&s->gb, g->part2_3_length);

  2297.                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));

  2298.                 if(get_bits_count(&s->gb) >= s->gb.size_in_bits && s->in_gb.buffer){

  2299.                     skip_bits_long(&s->in_gb, get_bits_count(&s->gb) - s->gb.size_in_bits);

  2300.                     s->gb= s->in_gb;

  2301.                     s->in_gb.buffer=NULL;

  2302.                 }

  2303.                 continue;

  2304.             }

  2305. 

  2306.             bits_pos = get_bits_count(&s->gb);

  2307. 

  2308.             if (!s->lsf) {

  2309.                 uint8_t *sc;

  2310.                 int slen, slen1, slen2;

  2311. 

  2312.                 /* MPEG1 scale factors */

  2313.                 slen1 = slen_table[0][g->scalefac_compress];

  2314.                 slen2 = slen_table[1][g->scalefac_compress];

  2315.                 dprintf("slen1=%d slen2=%d\n", slen1, slen2);

  2316.                 if (g->block_type == 2) {

  2317.                     n = g->switch_point ? 17 : 18;

  2318.                     j = 0;

  2319.                     if(slen1){

  2320.                         for(i=0;i<n;i++)

  2321.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  2322.                     }else{

  2323.                         for(i=0;i<n;i++)

  2324.                             g->scale_factors[j++] = 0;

  2325.                     }

  2326.                     if(slen2){

  2327.                         for(i=0;i<18;i++)

  2328.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  2329.                         for(i=0;i<3;i++)

  2330.                             g->scale_factors[j++] = 0;

  2331.                     }else{

  2332.                         for(i=0;i<21;i++)

  2333.                             g->scale_factors[j++] = 0;

  2334.                     }

  2335.                 } else {

  2336.                     sc = granules[ch][0].scale_factors;

  2337.                     j = 0;

  2338.                     for(k=0;k<4;k++) {

  2339.                         n = (k == 0 ? 6 : 5);

  2340.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  2341.                             slen = (k < 2) ? slen1 : slen2;

  2342.                             if(slen){

  2343.                                 for(i=0;i<n;i++)

  2344.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  2345.                             }else{

  2346.                                 for(i=0;i<n;i++)

  2347.                                     g->scale_factors[j++] = 0;

  2348.                             }

  2349.                         } else {

  2350.                             /* simply copy from last granule */

  2351.                             for(i=0;i<n;i++) {

  2352.                                 g->scale_factors[j] = sc[j];

  2353.                                 j++;

  2354.                             }

  2355.                         }

  2356.                     }

  2357.                     g->scale_factors[j++] = 0;

  2358.                 }

  2359. #if defined(DEBUG)

  2360.                 {

  2361.                     dprintf("scfsi=%x gr=%d ch=%d scale_factors:\n",

  2362.                            g->scfsi, gr, ch);

  2363.                     for(i=0;i<j;i++)

  2364.                         dprintf(" %d", g->scale_factors[i]);

  2365.                     dprintf("\n");

  2366.                 }

  2367. #endif

  2368.             } else {

  2369.                 int tindex, tindex2, slen[4], sl, sf;

  2370. 

  2371.                 /* LSF scale factors */

  2372.                 if (g->block_type == 2) {

  2373.                     tindex = g->switch_point ? 2 : 1;

  2374.                 } else {

  2375.                     tindex = 0;

  2376.                 }

  2377.                 sf = g->scalefac_compress;

  2378.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  2379.                     /* intensity stereo case */

  2380.                     sf >>= 1;

  2381.                     if (sf < 180) {

  2382.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  2383.                         tindex2 = 3;

  2384.                     } else if (sf < 244) {

  2385.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  2386.                         tindex2 = 4;

  2387.                     } else {

  2388.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  2389.                         tindex2 = 5;

  2390.                     }

  2391.                 } else {

  2392.                     /* normal case */

  2393.                     if (sf < 400) {

  2394.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  2395.                         tindex2 = 0;

  2396.                     } else if (sf < 500) {

  2397.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  2398.                         tindex2 = 1;

  2399.                     } else {

  2400.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  2401.                         tindex2 = 2;

  2402.                         g->preflag = 1;

  2403.                     }

  2404.                 }

  2405. 

  2406.                 j = 0;

  2407.                 for(k=0;k<4;k++) {

  2408.                     n = lsf_nsf_table[tindex2][tindex][k];

  2409.                     sl = slen[k];

  2410.                     if(sl){

  2411.                         for(i=0;i<n;i++)

  2412.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  2413.                     }else{

  2414.                         for(i=0;i<n;i++)

  2415.                             g->scale_factors[j++] = 0;

  2416.                     }

  2417.                 }

  2418.                 /* XXX: should compute exact size */

  2419.                 for(;j<40;j++)

  2420.                     g->scale_factors[j] = 0;

  2421. #if defined(DEBUG)

  2422.                 {

  2423.                     dprintf("gr=%d ch=%d scale_factors:\n",

  2424.                            gr, ch);

  2425.                     for(i=0;i<40;i++)

  2426.                         dprintf(" %d", g->scale_factors[i]);

  2427.                     dprintf("\n");

  2428.                 }

  2429. #endif

  2430.             }

  2431. 

  2432.             exponents_from_scale_factors(s, g, exponents);

  2433. 

  2434.             /* read Huffman coded residue */

  2435.             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);

  2436. #if defined(DEBUG)

  2437.             sample_dump(0, g->sb_hybrid, 576);

  2438. #endif

  2439.         } /* ch */

  2440. 

  2441.         if (s->nb_channels == 2)

  2442.             compute_stereo(s, &granules[0][gr], &granules[1][gr]);

  2443. 

  2444.         for(ch=0;ch<s->nb_channels;ch++) {

  2445.             g = &granules[ch][gr];

  2446. 

  2447.             reorder_block(s, g);

  2448. #if defined(DEBUG)

  2449.             sample_dump(0, g->sb_hybrid, 576);

  2450. #endif

  2451.             s->compute_antialias(s, g);

  2452. #if defined(DEBUG)

  2453.             sample_dump(1, g->sb_hybrid, 576);

  2454. #endif

  2455.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  2456. #if defined(DEBUG)

  2457.             sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);

  2458. #endif

  2459.         }

  2460.     } /* gr */

  2461.     if(get_bits_count(&s->gb)<0)

  2462.         skip_bits_long(&s->gb, -get_bits_count(&s->gb));

  2463.     return nb_granules * 18;

  2464. }

  2465. 

  2466. static int mp_decode_frame(MPADecodeContext *s,

  2467.                            OUT_INT *samples, const uint8_t *buf, int buf_size)

  2468. {

  2469.     int i, nb_frames, ch;

  2470.     OUT_INT *samples_ptr;

  2471. 

  2472.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)*8);

  2473. 

  2474.     /* skip error protection field */

  2475.     if (s->error_protection)

  2476.         get_bits(&s->gb, 16);

  2477. 

  2478.     dprintf("frame %d:\n", s->frame_count);

  2479.     switch(s->layer) {

  2480.     case 1:

  2481.         nb_frames = mp_decode_layer1(s);

  2482.         break;

  2483.     case 2:

  2484.         nb_frames = mp_decode_layer2(s);

  2485.         break;

  2486.     case 3:

  2487.     default:

  2488.         nb_frames = mp_decode_layer3(s);

  2489. 

  2490.         s->last_buf_size=0;

  2491.         if(s->in_gb.buffer){

  2492.             align_get_bits(&s->gb);

  2493.             i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;

  2494.             if(i >= 0 && i <= BACKSTEP_SIZE){

  2495.                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);

  2496.                 s->last_buf_size=i;

  2497.             }else

  2498.                 av_log(NULL, AV_LOG_ERROR, "invalid old backstep %d\n", i);

  2499.             s->gb= s->in_gb;

  2500.             s->in_gb.buffer= NULL;

  2501.         }

  2502. 

  2503.         align_get_bits(&s->gb);

  2504.         assert((get_bits_count(&s->gb) & 7) == 0);

  2505.         i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;

  2506. 

  2507.         if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){

  2508.             av_log(NULL, AV_LOG_ERROR, "invalid new backstep %d\n", i);

  2509.             i= FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);

  2510.         }

  2511.         assert(i <= buf_size - HEADER_SIZE && i>= 0);

  2512.         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);

  2513.         s->last_buf_size += i;

  2514. 

  2515.         break;

  2516.     }

  2517. #if defined(DEBUG)

  2518.     for(i=0;i<nb_frames;i++) {

  2519.         for(ch=0;ch<s->nb_channels;ch++) {

  2520.             int j;

  2521.             dprintf("%d-%d:", i, ch);

  2522.             for(j=0;j<SBLIMIT;j++)

  2523.                 dprintf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);

  2524.             dprintf("\n");

  2525.         }

  2526.     }

  2527. #endif

  2528.     /* apply the synthesis filter */

  2529.     for(ch=0;ch<s->nb_channels;ch++) {

  2530.         samples_ptr = samples + ch;

  2531.         for(i=0;i<nb_frames;i++) {

  2532.             ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  2533.                          window, &s->dither_state,

  2534.                          samples_ptr, s->nb_channels,

  2535.                          s->sb_samples[ch][i]);

  2536.             samples_ptr += 32 * s->nb_channels;

  2537.         }

  2538.     }

  2539. #ifdef DEBUG

  2540.     s->frame_count++;

  2541. #endif

  2542.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  2543. }

  2544. 

  2545. static int decode_frame(AVCodecContext * avctx,

  2546.                         void *data, int *data_size,

  2547.                         uint8_t * buf, int buf_size)

  2548. {

  2549.     MPADecodeContext *s = avctx->priv_data;

  2550.     uint32_t header;

  2551.     int out_size;

  2552.     OUT_INT *out_samples = data;

  2553. 

  2554. retry:

  2555.     if(buf_size < HEADER_SIZE)

  2556.         return -1;

  2557. 

  2558.     header = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];

  2559.     if(ff_mpa_check_header(header) < 0){

  2560.         buf++;

  2561. //        buf_size--;

  2562.         av_log(avctx, AV_LOG_ERROR, "Header missing skipping one byte.\n");

  2563.         goto retry;

  2564.     }

  2565. 

  2566.     if (decode_header(s, header) == 1) {

  2567.         /* free format: prepare to compute frame size */

  2568.         s->frame_size = -1;

  2569.         return -1;

  2570.     }

  2571.     /* update codec info */

  2572.     avctx->channels = s->nb_channels;

  2573.     avctx->bit_rate = s->bit_rate;

  2574.     avctx->sub_id = s->layer;

  2575.     switch(s->layer) {

  2576.     case 1:

  2577.         avctx->frame_size = 384;

  2578.         break;

  2579.     case 2:

  2580.         avctx->frame_size = 1152;

  2581.         break;

  2582.     case 3:

  2583.         if (s->lsf)

  2584.             avctx->frame_size = 576;

  2585.         else

  2586.             avctx->frame_size = 1152;

  2587.         break;

  2588.     }

  2589. 

  2590.     if(s->frame_size<=0 || s->frame_size > buf_size){

  2591.         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

  2592.         return -1;

  2593.     }else if(s->frame_size < buf_size){

  2594.         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");

  2595.     }

  2596. 

  2597.     out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2598.     if(out_size>=0){

  2599.         *data_size = out_size;

  2600.         avctx->sample_rate = s->sample_rate;

  2601.         //FIXME maybe move the other codec info stuff from above here too

  2602.     }else

  2603.         av_log(avctx, AV_LOG_DEBUG, "Error while decoding MPEG audio frame.\n"); //FIXME return -1 / but also return the number of bytes consumed

  2604.     s->frame_size = 0;

  2605.     return buf_size;

  2606. }

  2607. 

  2608. static void flush(AVCodecContext *avctx){

  2609.     MPADecodeContext *s = avctx->priv_data;

  2610.     s->last_buf_size= 0;

  2611. }

  2612. 

  2613. #ifdef CONFIG_MP3ADU_DECODER

  2614. static int decode_frame_adu(AVCodecContext * avctx,

  2615.                         void *data, int *data_size,

  2616.                         uint8_t * buf, int buf_size)

  2617. {

  2618.     MPADecodeContext *s = avctx->priv_data;

  2619.     uint32_t header;

  2620.     int len, out_size;

  2621.     OUT_INT *out_samples = data;

  2622. 

  2623.     len = buf_size;

  2624. 

  2625.     // Discard too short frames

  2626.     if (buf_size < HEADER_SIZE) {

  2627.         *data_size = 0;

  2628.         return buf_size;

  2629.     }

  2630. 

  2631. 

  2632.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  2633.         len = MPA_MAX_CODED_FRAME_SIZE;

  2634. 

  2635.     // Get header and restore sync word

  2636.     header = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3] | 0xffe00000;

  2637. 

  2638.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  2639.         *data_size = 0;

  2640.         return buf_size;

  2641.     }

  2642. 

  2643.     decode_header(s, header);

  2644.     /* update codec info */

  2645.     avctx->sample_rate = s->sample_rate;

  2646.     avctx->channels = s->nb_channels;

  2647.     avctx->bit_rate = s->bit_rate;

  2648.     avctx->sub_id = s->layer;

  2649. 

  2650.     avctx->frame_size=s->frame_size = len;

  2651. 

  2652.     if (avctx->parse_only) {

  2653.         out_size = buf_size;

  2654.     } else {

  2655.         out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2656.     }

  2657. 

  2658.     *data_size = out_size;

  2659.     return buf_size;

  2660. }

  2661. #endif /* CONFIG_MP3ADU_DECODER */

  2662. 

  2663. #ifdef CONFIG_MP3ON4_DECODER

  2664. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  2665. static int mp3Frames[16] = {0,1,1,2,3,3,4,5,2};   /* number of mp3 decoder instances */

  2666. static int mp3Channels[16] = {0,1,2,3,4,5,6,8,4}; /* total output channels */

  2667. /* offsets into output buffer, assume output order is FL FR BL BR C LFE */

  2668. static int chan_offset[9][5] = {

  2669.     {0},

  2670.     {0},            // C

  2671.     {0},            // FLR

  2672.     {2,0},          // C FLR

  2673.     {2,0,3},        // C FLR BS

  2674.     {4,0,2},        // C FLR BLRS

  2675.     {4,0,2,5},      // C FLR BLRS LFE

  2676.     {4,0,2,6,5},    // C FLR BLRS BLR LFE

  2677.     {0,2}           // FLR BLRS

  2678. };

  2679. 

  2680. 

  2681. static int decode_init_mp3on4(AVCodecContext * avctx)

  2682. {

  2683.     MP3On4DecodeContext *s = avctx->priv_data;

  2684.     int i;

  2685. 

  2686.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  2687.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  2688.         return -1;

  2689.     }

  2690. 

  2691.     s->chan_cfg = (((unsigned char *)avctx->extradata)[1] >> 3) & 0x0f;

  2692.     s->frames = mp3Frames[s->chan_cfg];

  2693.     if(!s->frames) {

  2694.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  2695.         return -1;

  2696.     }

  2697.     avctx->channels = mp3Channels[s->chan_cfg];

  2698. 

  2699.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  2700.      * We replace avctx->priv_data with the context of the first decoder so that

  2701.      * decode_init() does not have to be changed.

  2702.      * Other decoders will be inited here copying data from the first context

  2703.      */

  2704.     // Allocate zeroed memory for the first decoder context

  2705.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  2706.     // Put decoder context in place to make init_decode() happy

  2707.     avctx->priv_data = s->mp3decctx[0];

  2708.     decode_init(avctx);

  2709.     // Restore mp3on4 context pointer

  2710.     avctx->priv_data = s;

  2711.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  2712. 

  2713.     /* Create a separate codec/context for each frame (first is already ok).

  2714.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  2715.      */

  2716.     for (i = 1; i < s->frames; i++) {

  2717.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  2718.         s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;

  2719.         s->mp3decctx[i]->adu_mode = 1;

  2720.     }

  2721. 

  2722.     return 0;

  2723. }

  2724. 

  2725. 

  2726. static int decode_close_mp3on4(AVCodecContext * avctx)

  2727. {

  2728.     MP3On4DecodeContext *s = avctx->priv_data;

  2729.     int i;

  2730. 

  2731.     for (i = 0; i < s->frames; i++)

  2732.         if (s->mp3decctx[i])

  2733.             av_free(s->mp3decctx[i]);

  2734. 

  2735.     return 0;

  2736. }

  2737. 

  2738. 

  2739. static int decode_frame_mp3on4(AVCodecContext * avctx,

  2740.                         void *data, int *data_size,

  2741.                         uint8_t * buf, int buf_size)

  2742. {

  2743.     MP3On4DecodeContext *s = avctx->priv_data;

  2744.     MPADecodeContext *m;

  2745.     int len, out_size = 0;

  2746.     uint32_t header;

  2747.     OUT_INT *out_samples = data;

  2748.     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];

  2749.     OUT_INT *outptr, *bp;

  2750.     int fsize;

  2751.     unsigned char *start2 = buf, *start;

  2752.     int fr, i, j, n;

  2753.     int off = avctx->channels;

  2754.     int *coff = chan_offset[s->chan_cfg];

  2755. 

  2756.     len = buf_size;

  2757. 

  2758.     // Discard too short frames

  2759.     if (buf_size < HEADER_SIZE) {

  2760.         *data_size = 0;

  2761.         return buf_size;

  2762.     }

  2763. 

  2764.     // If only one decoder interleave is not needed

  2765.     outptr = s->frames == 1 ? out_samples : decoded_buf;

  2766. 

  2767.     for (fr = 0; fr < s->frames; fr++) {

  2768.         start = start2;

  2769.         fsize = (start[0] << 4) | (start[1] >> 4);

  2770.         start2 += fsize;

  2771.         if (fsize > len)

  2772.             fsize = len;

  2773.         len -= fsize;

  2774.         if (fsize > MPA_MAX_CODED_FRAME_SIZE)

  2775.             fsize = MPA_MAX_CODED_FRAME_SIZE;

  2776.         m = s->mp3decctx[fr];

  2777.         assert (m != NULL);

  2778. 

  2779.         // Get header

  2780.         header = (start[0] << 24) | (start[1] << 16) | (start[2] << 8) | start[3] | 0xfff00000;

  2781. 

  2782.         if (ff_mpa_check_header(header) < 0) { // Bad header, discard block

  2783.             *data_size = 0;

  2784.             return buf_size;

  2785.         }

  2786. 

  2787.         decode_header(m, header);

  2788.         mp_decode_frame(m, decoded_buf, start, fsize);

  2789. 

  2790.         n = MPA_FRAME_SIZE * m->nb_channels;

  2791.         out_size += n * sizeof(OUT_INT);

  2792.         if(s->frames > 1) {

  2793.             /* interleave output data */

  2794.             bp = out_samples + coff[fr];

  2795.             if(m->nb_channels == 1) {

  2796.                 for(j = 0; j < n; j++) {

  2797.                     *bp = decoded_buf[j];

  2798.                     bp += off;

  2799.                 }

  2800.             } else {

  2801.                 for(j = 0; j < n; j++) {

  2802.                     bp[0] = decoded_buf[j++];

  2803.                     bp[1] = decoded_buf[j];

  2804.                     bp += off;

  2805.                 }

  2806.             }

  2807.         }

  2808.     }

  2809. 

  2810.     /* update codec info */

  2811.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  2812.     avctx->frame_size= buf_size;

  2813.     avctx->bit_rate = 0;

  2814.     for (i = 0; i < s->frames; i++)

  2815.         avctx->bit_rate += s->mp3decctx[i]->bit_rate;

  2816. 

  2817.     *data_size = out_size;

  2818.     return buf_size;

  2819. }

  2820. #endif /* CONFIG_MP3ON4_DECODER */

  2821. 

  2822. #ifdef CONFIG_MP2_DECODER

  2823. AVCodec mp2_decoder =

  2824. {

  2825.     "mp2",

  2826.     CODEC_TYPE_AUDIO,

  2827.     CODEC_ID_MP2,

  2828.     sizeof(MPADecodeContext),

  2829.     decode_init,

  2830.     NULL,

  2831.     NULL,

  2832.     decode_frame,

  2833.     CODEC_CAP_PARSE_ONLY,

  2834. };

  2835. #endif

  2836. #ifdef CONFIG_MP3_DECODER

  2837. AVCodec mp3_decoder =

  2838. {

  2839.     "mp3",

  2840.     CODEC_TYPE_AUDIO,

  2841.     CODEC_ID_MP3,

  2842.     sizeof(MPADecodeContext),

  2843.     decode_init,

  2844.     NULL,

  2845.     NULL,

  2846.     decode_frame,

  2847.     CODEC_CAP_PARSE_ONLY,

  2848.     .flush= flush,

  2849. };

  2850. #endif

  2851. #ifdef CONFIG_MP3ADU_DECODER

  2852. AVCodec mp3adu_decoder =

  2853. {

  2854.     "mp3adu",

  2855.     CODEC_TYPE_AUDIO,

  2856.     CODEC_ID_MP3ADU,

  2857.     sizeof(MPADecodeContext),

  2858.     decode_init,

  2859.     NULL,

  2860.     NULL,

  2861.     decode_frame_adu,

  2862.     CODEC_CAP_PARSE_ONLY,

  2863.     .flush= flush,

  2864. };

  2865. #endif

  2866. #ifdef CONFIG_MP3ON4_DECODER

  2867. AVCodec mp3on4_decoder =

  2868. {

  2869.     "mp3on4",

  2870.     CODEC_TYPE_AUDIO,

  2871.     CODEC_ID_MP3ON4,

  2872.     sizeof(MP3On4DecodeContext),

  2873.     decode_init_mp3on4,

  2874.     NULL,

  2875.     decode_close_mp3on4,

  2876.     decode_frame_mp3on4,

  2877.     .flush= flush,

  2878. };

  2879. #endif