falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
6448 Commits
32 Branches
944MB
Tree: 716d73b47d
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from '716d73b47d'
${ noResults }
FFmpeg/libavcodec/mpegaudiodec.c

2876 lines
85KB
Raw Blame History 

  1. /*

  2.  * MPEG Audio decoder

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

  4.  *

  5.  * This library is free software; you can redistribute it and/or

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

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

  8.  * version 2 of the License, or (at your option) any later version.

  9.  *

  10.  * This library is distributed in the hope that it will be useful,

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

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

  13.  * Lesser General Public License for more details.

  14.  *

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

  16.  * License along with this library; if not, write to the Free Software

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

  18.  */

  19. 

  20. /**

  21.  * @file mpegaudiodec.c

  22.  * MPEG Audio decoder.

  23.  */

  24. 

  25. //#define DEBUG

  26. #include "avcodec.h"

  27. #include "bitstream.h"

  28. #include "dsputil.h"

  29. 

  30. /*

  31.  * TODO:

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

  33.  *  - test lsf / mpeg25 extensively.

  34.  */

  35. 

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

  37.    audio decoder */

  38. #ifdef CONFIG_MPEGAUDIO_HP

  39. #   define USE_HIGHPRECISION

  40. #endif

  41. 

  42. #include "mpegaudio.h"

  43. 

  44. #define FRAC_ONE    (1 << FRAC_BITS)

  45. 

  46. #ifdef ARCH_X86

  47. #   define MULL(ra, rb) \

  48.         ({ int rt, dummy; asm (\

  49.             "imull %3               \n\t"\

  50.             "shrdl %4, %%edx, %%eax \n\t"\

  51.             : "=a"(rt), "=d"(dummy)\

  52.             : "a" (ra), "rm" (rb), "i"(FRAC_BITS));\

  53.          rt; })

  54. #   define MUL64(ra, rb) \

  55.         ({ int64_t rt; asm ("imull %2\n\t" : "=A"(rt) : "a" (ra), "g" (rb)); rt; })

  56. #   define MULH(ra, rb) \

  57.         ({ int rt, dummy; asm ("imull %3\n\t" : "=d"(rt), "=a"(dummy): "a" (ra), "rm" (rb)); rt; })

  58. #elif defined(ARCH_ARMV4L)

  59. #   define MULL(a, b) \

  60.         ({  int lo, hi;\

  61.             asm("smull %0, %1, %2, %3     \n\t"\

  62.                 "mov   %0, %0,     lsr %4\n\t"\

  63.                 "add   %1, %0, %1, lsl %5\n\t"\

  64.             : "=&r"(lo), "=&r"(hi)\

  65.             : "r"(b), "r"(a), "i"(FRAC_BITS), "i"(32-FRAC_BITS));\

  66.          hi; })

  67. #   define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))

  68. #   define MULH(a, b) ({ int lo, hi; asm ("smull %0, %1, %2, %3" : "=&r"(lo), "=&r"(hi) : "r"(b), "r"(a)); hi; })

  69. #else

  70. #   define MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)

  71. #   define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))

  72. //#define MULH(a,b) (((int64_t)(a) * (int64_t)(b))>>32) //gcc 3.4 creates an incredibly bloated mess out of this

  73. static always_inline int MULH(int a, int b){

  74.     return ((int64_t)(a) * (int64_t)(b))>>32;

  75. }

  76. #endif

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

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

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

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

  81. 

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

  83. 

  84. /****************/

  85. 

  86. #define HEADER_SIZE 4

  87. #define BACKSTEP_SIZE 512

  88. #define EXTRABYTES 24

  89. 

  90. struct GranuleDef;

  91. 

  92. typedef struct MPADecodeContext {

  93.     DECLARE_ALIGNED_8(uint8_t, last_buf[BACKSTEP_SIZE + EXTRABYTES + MPA_MAX_CODED_FRAME_SIZE]); //FIXME we dont need that much

  94.     int last_buf_size;

  95.     int frame_size;

  96.     int free_format_frame_size; /* frame size in case of free format

  97.                                    (zero if currently unknown) */

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

  99.     uint32_t free_format_next_header;

  100.     int error_protection;

  101.     int layer;

  102.     int sample_rate;

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

  104.     int bit_rate;

  105.     GetBitContext gb;

  106.     GetBitContext in_gb;

  107.     int nb_channels;

  108.     int mode;

  109.     int mode_ext;

  110.     int lsf;

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

  112.     int synth_buf_offset[MPA_MAX_CHANNELS];

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

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

  115. #ifdef DEBUG

  116.     int frame_count;

  117. #endif

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

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

  120.     unsigned int dither_state;

  121. } MPADecodeContext;

  122. 

  123. /**

  124.  * Context for MP3On4 decoder

  125.  */

  126. typedef struct MP3On4DecodeContext {

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

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

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

  130. } MP3On4DecodeContext;

  131. 

  132. /* layer 3 "granule" */

  133. typedef struct GranuleDef {

  134.     uint8_t scfsi;

  135.     int part2_3_length;

  136.     int big_values;

  137.     int global_gain;

  138.     int scalefac_compress;

  139.     uint8_t block_type;

  140.     uint8_t switch_point;

  141.     int table_select[3];

  142.     int subblock_gain[3];

  143.     uint8_t scalefac_scale;

  144.     uint8_t count1table_select;

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

  146.     int preflag;

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

  148.     uint8_t scale_factors[40];

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

  150. } GranuleDef;

  151. 

  152. #define MODE_EXT_MS_STEREO 2

  153. #define MODE_EXT_I_STEREO  1

  154. 

  155. /* layer 3 huffman tables */

  156. typedef struct HuffTable {

  157.     int xsize;

  158.     const uint8_t *bits;

  159.     const uint16_t *codes;

  160. } HuffTable;

  161. 

  162. #include "mpegaudiodectab.h"

  163. 

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

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

  166. 

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

  168. static VLC huff_vlc[16];

  169. static VLC huff_quad_vlc[2];

  170. /* computed from band_size_long */

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

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

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

  174. static int8_t  *table_4_3_exp;

  175. static uint32_t *table_4_3_value;

  176. static uint32_t exp_table[512];

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

  178. /* intensity stereo coef table */

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

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

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

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

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

  184. 

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

  186. static uint16_t scale_factor_modshift[64];

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

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

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

  190. 

  191. #define SCALE_GEN(v) \

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

  193. 

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

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

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

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

  198. };

  199. 

  200. void ff_mpa_synth_init(MPA_INT *window);

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

  202. 

  203. /* layer 1 unscaling */

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

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

  206. {

  207.     int shift, mod;

  208.     int64_t val;

  209. 

  210.     shift = scale_factor_modshift[scale_factor];

  211.     mod = shift & 3;

  212.     shift >>= 2;

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

  214.     shift += n;

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

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

  217. }

  218. 

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

  220. {

  221.     int shift, mod, val;

  222. 

  223.     shift = scale_factor_modshift[scale_factor];

  224.     mod = shift & 3;

  225.     shift >>= 2;

  226. 

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

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

  229.     if (shift > 0)

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

  231.     return val;

  232. }

  233. 

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

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

  236. {

  237.     unsigned int m;

  238.     int e;

  239. 

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

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

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

  243.     assert(e>=1);

  244.     if (e > 31)

  245.         return 0;

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

  247. 

  248.     return m;

  249. }

  250. 

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

  252. #define DEV_ORDER 13

  253. 

  254. #define POW_FRAC_BITS 24

  255. #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)

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

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

  258. 

  259. static int dev_4_3_coefs[DEV_ORDER];

  260. 

  261. #if 0 /* unused */

  262. static int pow_mult3[3] = {

  263.     POW_FIX(1.0),

  264.     POW_FIX(1.25992104989487316476),

  265.     POW_FIX(1.58740105196819947474),

  266. };

  267. #endif

  268. 

  269. static void int_pow_init(void)

  270. {

  271.     int i, a;

  272. 

  273.     a = POW_FIX(1.0);

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

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

  276.         dev_4_3_coefs[i] = a;

  277.     }

  278. }

  279. 

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

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

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

  283. {

  284.     int e, er, eq, j;

  285.     int a, a1;

  286. 

  287.     /* renormalize */

  288.     a = i;

  289.     e = POW_FRAC_BITS;

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

  291.         a = a << 1;

  292.         e--;

  293.     }

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

  295.     a1 = 0;

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

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

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

  299.     /* exponent compute (exact) */

  300.     e = e * 4;

  301.     er = e % 3;

  302.     eq = e / 3;

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

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

  305.         a = a >> 1;

  306.         eq++;

  307.     }

  308.     /* convert to float */

  309.     while (a < POW_FRAC_ONE) {

  310.         a = a << 1;

  311.         eq--;

  312.     }

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

  314. #if POW_FRAC_BITS > FRAC_BITS

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

  316.     /* correct overflow */

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

  318.         a = a >> 1;

  319.         eq++;

  320.     }

  321. #endif

  322.     *exp_ptr = eq;

  323.     return a;

  324. }

  325. #endif

  326. 

  327. static int decode_init(AVCodecContext * avctx)

  328. {

  329.     MPADecodeContext *s = avctx->priv_data;

  330.     static int init=0;

  331.     int i, j, k;

  332. 

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

  334.     avctx->sample_fmt= SAMPLE_FMT_S32;

  335. #else

  336.     avctx->sample_fmt= SAMPLE_FMT_S16;

  337. #endif

  338. 

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

  340.         s->compute_antialias= compute_antialias_integer;

  341.     else

  342.         s->compute_antialias= compute_antialias_float;

  343. 

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

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

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

  347.             int shift, mod;

  348.             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  349.             shift = (i / 3);

  350.             mod = i % 3;

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

  352.         }

  353. 

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

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

  356.             int n, norm;

  357.             n = i + 2;

  358.             norm = ((int64_t_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);

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

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

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

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

  363.                     i, norm,

  364.                     scale_factor_mult[i][0],

  365.                     scale_factor_mult[i][1],

  366.                     scale_factor_mult[i][2]);

  367.         }

  368. 

  369.         ff_mpa_synth_init(window);

  370. 

  371.         /* huffman decode tables */

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

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

  374.             int xsize, x, y;

  375.             unsigned int n;

  376.             uint8_t  tmp_bits [512];

  377.             uint16_t tmp_codes[512];

  378. 

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

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

  381. 

  382.             xsize = h->xsize;

  383.             n = xsize * xsize;

  384. 

  385.             j = 0;

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

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

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

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

  390.                 }

  391.             }

  392. 

  393.             /* XXX: fail test */

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

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

  396.         }

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

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

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

  400.         }

  401. 

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

  403.             k = 0;

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

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

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

  407.             }

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

  409.         }

  410. 

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

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

  413.         if(!table_4_3_exp)

  414.             return -1;

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

  416.         if(!table_4_3_value)

  417.             return -1;

  418. 

  419.         int_pow_init();

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

  421.             double f, fm;

  422.             int e, m;

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

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

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

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

  427. 

  428.             /* normalized to FRAC_BITS */

  429.             table_4_3_value[i] = m;

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

  431.             table_4_3_exp[i] = -e;

  432.         }

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

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

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

  436.             expval_table[exponent][i&15]= lrintf(f);

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

  438.                 exp_table[exponent]= lrintf(f);

  439.         }

  440. 

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

  442.             float f;

  443.             int v;

  444.             if (i != 6) {

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

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

  447.             } else {

  448.                 v = FIXR(1.0);

  449.             }

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

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

  452.         }

  453.         /* invalid values */

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

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

  456. 

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

  458.             double f;

  459.             int e, k;

  460. 

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

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

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

  464.                 k = i & 1;

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

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

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

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

  469.             }

  470.         }

  471. 

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

  473.             float ci, cs, ca;

  474.             ci = ci_table[i];

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

  476.             ca = cs * ci;

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

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

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

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

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

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

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

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

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

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

  487.         }

  488. 

  489.         /* compute mdct windows */

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

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

  492.                 double d;

  493. 

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

  495.                     continue;

  496. 

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

  498.                 if(j==1){

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

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

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

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

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

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

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

  506.                 }

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

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

  509. 

  510.                 if(j==2)

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

  512.                 else

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

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

  515.             }

  516.         }

  517. 

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

  519.            the sign of the right window coefs */

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

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

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

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

  524.             }

  525.         }

  526. 

  527. #if defined(DEBUG)

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

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

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

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

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

  533.         }

  534. #endif

  535.         init = 1;

  536.     }

  537. 

  538. #ifdef DEBUG

  539.     s->frame_count = 0;

  540. #endif

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

  542.         s->adu_mode = 1;

  543.     return 0;

  544. }

  545. 

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

  547. 

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

  549. 

  550. #define COS0_0  FIXHR(0.50060299823519630134/2)

  551. #define COS0_1  FIXHR(0.50547095989754365998/2)

  552. #define COS0_2  FIXHR(0.51544730992262454697/2)

  553. #define COS0_3  FIXHR(0.53104259108978417447/2)

  554. #define COS0_4  FIXHR(0.55310389603444452782/2)

  555. #define COS0_5  FIXHR(0.58293496820613387367/2)

  556. #define COS0_6  FIXHR(0.62250412303566481615/2)

  557. #define COS0_7  FIXHR(0.67480834145500574602/2)

  558. #define COS0_8  FIXHR(0.74453627100229844977/2)

  559. #define COS0_9  FIXHR(0.83934964541552703873/2)

  560. #define COS0_10 FIXHR(0.97256823786196069369/2)

  561. #define COS0_11 FIXHR(1.16943993343288495515/4)

  562. #define COS0_12 FIXHR(1.48416461631416627724/4)

  563. #define COS0_13 FIXHR(2.05778100995341155085/8)

  564. #define COS0_14 FIXHR(3.40760841846871878570/8)

  565. #define COS0_15 FIXHR(10.19000812354805681150/32)

  566. 

  567. #define COS1_0 FIXHR(0.50241928618815570551/2)

  568. #define COS1_1 FIXHR(0.52249861493968888062/2)

  569. #define COS1_2 FIXHR(0.56694403481635770368/2)

  570. #define COS1_3 FIXHR(0.64682178335999012954/2)

  571. #define COS1_4 FIXHR(0.78815462345125022473/2)

  572. #define COS1_5 FIXHR(1.06067768599034747134/4)

  573. #define COS1_6 FIXHR(1.72244709823833392782/4)

  574. #define COS1_7 FIXHR(5.10114861868916385802/16)

  575. 

  576. #define COS2_0 FIXHR(0.50979557910415916894/2)

  577. #define COS2_1 FIXHR(0.60134488693504528054/2)

  578. #define COS2_2 FIXHR(0.89997622313641570463/2)

  579. #define COS2_3 FIXHR(2.56291544774150617881/8)

  580. 

  581. #define COS3_0 FIXHR(0.54119610014619698439/2)

  582. #define COS3_1 FIXHR(1.30656296487637652785/4)

  583. 

  584. #define COS4_0 FIXHR(0.70710678118654752439/2)

  585. 

  586. /* butterfly operator */

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

  588. {\

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

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

  591.     tab[a] = tmp0;\

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

  593. }

  594. 

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

  596. {\

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

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

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

  600. }

  601. 

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

  603. {\

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

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

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

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

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

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

  610. }

  611. 

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

  613. 

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

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

  616. {

  617.     int tmp0, tmp1;

  618. 

  619.     /* pass 1 */

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

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

  622.     /* pass 2 */

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

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

  625.     /* pass 1 */

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

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

  628.     /* pass 2 */

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

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

  631.     /* pass 3 */

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

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

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

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

  636.     /* pass 1 */

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

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

  639.     /* pass 2 */

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

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

  642.     /* pass 1 */

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

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

  645.     /* pass 2 */

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

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

  648.     /* pass 3 */

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

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

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

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

  653.     /* pass 4 */

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

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

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

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

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

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

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

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

  662. 

  663. 

  664. 

  665.     /* pass 1 */

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

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

  668.     /* pass 2 */

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

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

  671.     /* pass 1 */

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

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

  674.     /* pass 2 */

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

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

  677.     /* pass 3 */

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

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

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

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

  682. 

  683.     /* pass 1 */

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

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

  686.     /* pass 2 */

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

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

  689.     /* pass 1 */

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

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

  692.     /* pass 2 */

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

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

  695.     /* pass 3 */

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

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

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

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

  700.     /* pass 4 */

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

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

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

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

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

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

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

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

  709. 

  710.     /* pass 5 */

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

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

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

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

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

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

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

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

  719. 

  720.     /* pass 6 */

  721. 

  722.     ADD( 8, 12);

  723.     ADD(12, 10);

  724.     ADD(10, 14);

  725.     ADD(14,  9);

  726.     ADD( 9, 13);

  727.     ADD(13, 11);

  728.     ADD(11, 15);

  729. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  746. 

  747.     ADD(24, 28);

  748.     ADD(28, 26);

  749.     ADD(26, 30);

  750.     ADD(30, 25);

  751.     ADD(25, 29);

  752.     ADD(29, 27);

  753.     ADD(27, 31);

  754. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  771. }

  772. 

  773. #if FRAC_BITS <= 15

  774. 

  775. static inline int round_sample(int *sum)

  776. {

  777.     int sum1;

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

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

  780.     if (sum1 < OUT_MIN)

  781.         sum1 = OUT_MIN;

  782.     else if (sum1 > OUT_MAX)

  783.         sum1 = OUT_MAX;

  784.     return sum1;

  785. }

  786. 

  787. #   if defined(ARCH_POWERPC_405)

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

  789. #       define MACS(rt, ra, rb) \

  790.             asm ("maclhw %0, %2, %3" : "=r" (rt) : "0" (rt), "r" (ra), "r" (rb));

  791. 

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

  793. #       define MULS(ra, rb) \

  794.             ({ int __rt; asm ("mullhw %0, %1, %2" : "=r" (__rt) : "r" (ra), "r" (rb)); __rt; })

  795. #   else

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

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

  798. 

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

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

  801. #   endif

  802. #else

  803. 

  804. static inline int round_sample(int64_t *sum)

  805. {

  806.     int sum1;

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

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

  809.     if (sum1 < OUT_MIN)

  810.         sum1 = OUT_MIN;

  811.     else if (sum1 > OUT_MAX)

  812.         sum1 = OUT_MAX;

  813.     return sum1;

  814. }

  815. 

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

  817. #endif

  818. 

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

  820. {                                               \

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

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

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

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

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

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

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

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

  829. }

  830. 

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

  832. {                                               \

  833.     int tmp;\

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  858. }

  859. 

  860. void ff_mpa_synth_init(MPA_INT *window)

  861. {

  862.     int i;

  863. 

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

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

  866.         int v;

  867.         v = mpa_enwindow[i];

  868. #if WFRAC_BITS < 16

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

  870. #endif

  871.         window[i] = v;

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

  873.             v = -v;

  874.         if (i != 0)

  875.             window[512 - i] = v;

  876.     }

  877. }

  878. 

  879. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

  880.    32 samples. */

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

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

  883.                          MPA_INT *window, int *dither_state,

  884.                          OUT_INT *samples, int incr,

  885.                          int32_t sb_samples[SBLIMIT])

  886. {

  887.     int32_t tmp[32];

  888.     register MPA_INT *synth_buf;

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

  890.     int j, offset, v;

  891.     OUT_INT *samples2;

  892. #if FRAC_BITS <= 15

  893.     int sum, sum2;

  894. #else

  895.     int64_t sum, sum2;

  896. #endif

  897. 

  898.     dct32(tmp, sb_samples);

  899. 

  900.     offset = *synth_buf_offset;

  901.     synth_buf = synth_buf_ptr + offset;

  902. 

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

  904.         v = tmp[j];

  905. #if FRAC_BITS <= 15

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

  907.            sound */

  908.         if (v > 32767)

  909.             v = 32767;

  910.         else if (v < -32768)

  911.             v = -32768;

  912. #endif

  913.         synth_buf[j] = v;

  914.     }

  915.     /* copy to avoid wrap */

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

  917. 

  918.     samples2 = samples + 31 * incr;

  919.     w = window;

  920.     w2 = window + 31;

  921. 

  922.     sum = *dither_state;

  923.     p = synth_buf + 16;

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

  925.     p = synth_buf + 48;

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

  927.     *samples = round_sample(&sum);

  928.     samples += incr;

  929.     w++;

  930. 

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

  932.        access per two sample */

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

  934.         sum2 = 0;

  935.         p = synth_buf + 16 + j;

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

  937.         p = synth_buf + 48 - j;

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

  939. 

  940.         *samples = round_sample(&sum);

  941.         samples += incr;

  942.         sum += sum2;

  943.         *samples2 = round_sample(&sum);

  944.         samples2 -= incr;

  945.         w++;

  946.         w2--;

  947.     }

  948. 

  949.     p = synth_buf + 32;

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

  951.     *samples = round_sample(&sum);

  952.     *dither_state= sum;

  953. 

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

  955.     *synth_buf_offset = offset;

  956. }

  957. 

  958. #define C3 FIXHR(0.86602540378443864676/2)

  959. 

  960. /* 0.5 / cos(pi*(2*i+1)/36) */

  961. static const int icos36[9] = {

  962.     FIXR(0.50190991877167369479),

  963.     FIXR(0.51763809020504152469), //0

  964.     FIXR(0.55168895948124587824),

  965.     FIXR(0.61038729438072803416),

  966.     FIXR(0.70710678118654752439), //1

  967.     FIXR(0.87172339781054900991),

  968.     FIXR(1.18310079157624925896),

  969.     FIXR(1.93185165257813657349), //2

  970.     FIXR(5.73685662283492756461),

  971. };

  972. 

  973. /* 0.5 / cos(pi*(2*i+1)/36) */

  974. static const int icos36h[9] = {

  975.     FIXHR(0.50190991877167369479/2),

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

  977.     FIXHR(0.55168895948124587824/2),

  978.     FIXHR(0.61038729438072803416/2),

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

  980.     FIXHR(0.87172339781054900991/2),

  981.     FIXHR(1.18310079157624925896/4),

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

  983. //    FIXHR(5.73685662283492756461),

  984. };

  985. 

  986. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  987.    cases. */

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

  989. {

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

  991. 

  992.     in0= in[0*3];

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

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

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

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

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

  998.     in5 += in3;

  999.     in3 += in1;

  1000. 

  1001.     in2= MULH(2*in2, C3);

  1002.     in3= MULH(4*in3, C3);

  1003. 

  1004.     t1 = in0 - in4;

  1005.     t2 = MULH(2*(in1 - in5), icos36h[4]);

  1006. 

  1007.     out[ 7]=

  1008.     out[10]= t1 + t2;

  1009.     out[ 1]=

  1010.     out[ 4]= t1 - t2;

  1011. 

  1012.     in0 += in4>>1;

  1013.     in4 = in0 + in2;

  1014.     in5 += 2*in1;

  1015.     in1 = MULH(in5 + in3, icos36h[1]);

  1016.     out[ 8]=

  1017.     out[ 9]= in4 + in1;

  1018.     out[ 2]=

  1019.     out[ 3]= in4 - in1;

  1020. 

  1021.     in0 -= in2;

  1022.     in5 = MULH(2*(in5 - in3), icos36h[7]);

  1023.     out[ 0]=

  1024.     out[ 5]= in0 - in5;

  1025.     out[ 6]=

  1026.     out[11]= in0 + in5;

  1027. }

  1028. 

  1029. /* cos(pi*i/18) */

  1030. #define C1 FIXHR(0.98480775301220805936/2)

  1031. #define C2 FIXHR(0.93969262078590838405/2)

  1032. #define C3 FIXHR(0.86602540378443864676/2)

  1033. #define C4 FIXHR(0.76604444311897803520/2)

  1034. #define C5 FIXHR(0.64278760968653932632/2)

  1035. #define C6 FIXHR(0.5/2)

  1036. #define C7 FIXHR(0.34202014332566873304/2)

  1037. #define C8 FIXHR(0.17364817766693034885/2)

  1038. 

  1039. 

  1040. /* using Lee like decomposition followed by hand coded 9 points DCT */

  1041. static void imdct36(int *out, int *buf, int *in, int *win)

  1042. {

  1043.     int i, j, t0, t1, t2, t3, s0, s1, s2, s3;

  1044.     int tmp[18], *tmp1, *in1;

  1045. 

  1046.     for(i=17;i>=1;i--)

  1047.         in[i] += in[i-1];

  1048.     for(i=17;i>=3;i-=2)

  1049.         in[i] += in[i-2];

  1050. 

  1051.     for(j=0;j<2;j++) {

  1052.         tmp1 = tmp + j;

  1053.         in1 = in + j;

  1054. #if 0

  1055. //more accurate but slower

  1056.         int64_t t0, t1, t2, t3;

  1057.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1058. 

  1059.         t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;

  1060.         t1 = in1[2*0] - in1[2*6];

  1061.         tmp1[ 6] = t1 - (t2>>1);

  1062.         tmp1[16] = t1 + t2;

  1063. 

  1064.         t0 = MUL64(2*(in1[2*2] + in1[2*4]),    C2);

  1065.         t1 = MUL64(   in1[2*4] - in1[2*8] , -2*C8);

  1066.         t2 = MUL64(2*(in1[2*2] + in1[2*8]),   -C4);

  1067. 

  1068.         tmp1[10] = (t3 - t0 - t2) >> 32;

  1069.         tmp1[ 2] = (t3 + t0 + t1) >> 32;

  1070.         tmp1[14] = (t3 + t2 - t1) >> 32;

  1071. 

  1072.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1073.         t2 = MUL64(2*(in1[2*1] + in1[2*5]),    C1);

  1074.         t3 = MUL64(   in1[2*5] - in1[2*7] , -2*C7);

  1075.         t0 = MUL64(2*in1[2*3], C3);

  1076. 

  1077.         t1 = MUL64(2*(in1[2*1] + in1[2*7]),   -C5);

  1078. 

  1079.         tmp1[ 0] = (t2 + t3 + t0) >> 32;

  1080.         tmp1[12] = (t2 + t1 - t0) >> 32;

  1081.         tmp1[ 8] = (t3 - t1 - t0) >> 32;

  1082. #else

  1083.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1084. 

  1085.         t3 = in1[2*0] + (in1[2*6]>>1);

  1086.         t1 = in1[2*0] - in1[2*6];

  1087.         tmp1[ 6] = t1 - (t2>>1);

  1088.         tmp1[16] = t1 + t2;

  1089. 

  1090.         t0 = MULH(2*(in1[2*2] + in1[2*4]),    C2);

  1091.         t1 = MULH(   in1[2*4] - in1[2*8] , -2*C8);

  1092.         t2 = MULH(2*(in1[2*2] + in1[2*8]),   -C4);

  1093. 

  1094.         tmp1[10] = t3 - t0 - t2;

  1095.         tmp1[ 2] = t3 + t0 + t1;

  1096.         tmp1[14] = t3 + t2 - t1;

  1097. 

  1098.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1099.         t2 = MULH(2*(in1[2*1] + in1[2*5]),    C1);

  1100.         t3 = MULH(   in1[2*5] - in1[2*7] , -2*C7);

  1101.         t0 = MULH(2*in1[2*3], C3);

  1102. 

  1103.         t1 = MULH(2*(in1[2*1] + in1[2*7]),   -C5);

  1104. 

  1105.         tmp1[ 0] = t2 + t3 + t0;

  1106.         tmp1[12] = t2 + t1 - t0;

  1107.         tmp1[ 8] = t3 - t1 - t0;

  1108. #endif

  1109.     }

  1110. 

  1111.     i = 0;

  1112.     for(j=0;j<4;j++) {

  1113.         t0 = tmp[i];

  1114.         t1 = tmp[i + 2];

  1115.         s0 = t1 + t0;

  1116.         s2 = t1 - t0;

  1117. 

  1118.         t2 = tmp[i + 1];

  1119.         t3 = tmp[i + 3];

  1120.         s1 = MULH(2*(t3 + t2), icos36h[j]);

  1121.         s3 = MULL(t3 - t2, icos36[8 - j]);

  1122. 

  1123.         t0 = s0 + s1;

  1124.         t1 = s0 - s1;

  1125.         out[(9 + j)*SBLIMIT] =  MULH(t1, win[9 + j]) + buf[9 + j];

  1126.         out[(8 - j)*SBLIMIT] =  MULH(t1, win[8 - j]) + buf[8 - j];

  1127.         buf[9 + j] = MULH(t0, win[18 + 9 + j]);

  1128.         buf[8 - j] = MULH(t0, win[18 + 8 - j]);

  1129. 

  1130.         t0 = s2 + s3;

  1131.         t1 = s2 - s3;

  1132.         out[(9 + 8 - j)*SBLIMIT] =  MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];

  1133.         out[(        j)*SBLIMIT] =  MULH(t1, win[        j]) + buf[        j];

  1134.         buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);

  1135.         buf[      + j] = MULH(t0, win[18         + j]);

  1136.         i += 4;

  1137.     }

  1138. 

  1139.     s0 = tmp[16];

  1140.     s1 = MULH(2*tmp[17], icos36h[4]);

  1141.     t0 = s0 + s1;

  1142.     t1 = s0 - s1;

  1143.     out[(9 + 4)*SBLIMIT] =  MULH(t1, win[9 + 4]) + buf[9 + 4];

  1144.     out[(8 - 4)*SBLIMIT] =  MULH(t1, win[8 - 4]) + buf[8 - 4];

  1145.     buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);

  1146.     buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);

  1147. }

  1148. 

  1149. /* header decoding. MUST check the header before because no

  1150.    consistency check is done there. Return 1 if free format found and

  1151.    that the frame size must be computed externally */

  1152. static int decode_header(MPADecodeContext *s, uint32_t header)

  1153. {

  1154.     int sample_rate, frame_size, mpeg25, padding;

  1155.     int sample_rate_index, bitrate_index;

  1156.     if (header & (1<<20)) {

  1157.         s->lsf = (header & (1<<19)) ? 0 : 1;

  1158.         mpeg25 = 0;

  1159.     } else {

  1160.         s->lsf = 1;

  1161.         mpeg25 = 1;

  1162.     }

  1163. 

  1164.     s->layer = 4 - ((header >> 17) & 3);

  1165.     /* extract frequency */

  1166.     sample_rate_index = (header >> 10) & 3;

  1167.     sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);

  1168.     sample_rate_index += 3 * (s->lsf + mpeg25);

  1169.     s->sample_rate_index = sample_rate_index;

  1170.     s->error_protection = ((header >> 16) & 1) ^ 1;

  1171.     s->sample_rate = sample_rate;

  1172. 

  1173.     bitrate_index = (header >> 12) & 0xf;

  1174.     padding = (header >> 9) & 1;

  1175.     //extension = (header >> 8) & 1;

  1176.     s->mode = (header >> 6) & 3;

  1177.     s->mode_ext = (header >> 4) & 3;

  1178.     //copyright = (header >> 3) & 1;

  1179.     //original = (header >> 2) & 1;

  1180.     //emphasis = header & 3;

  1181. 

  1182.     if (s->mode == MPA_MONO)

  1183.         s->nb_channels = 1;

  1184.     else

  1185.         s->nb_channels = 2;

  1186. 

  1187.     if (bitrate_index != 0) {

  1188.         frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];

  1189.         s->bit_rate = frame_size * 1000;

  1190.         switch(s->layer) {

  1191.         case 1:

  1192.             frame_size = (frame_size * 12000) / sample_rate;

  1193.             frame_size = (frame_size + padding) * 4;

  1194.             break;

  1195.         case 2:

  1196.             frame_size = (frame_size * 144000) / sample_rate;

  1197.             frame_size += padding;

  1198.             break;

  1199.         default:

  1200.         case 3:

  1201.             frame_size = (frame_size * 144000) / (sample_rate << s->lsf);

  1202.             frame_size += padding;

  1203.             break;

  1204.         }

  1205.         s->frame_size = frame_size;

  1206.     } else {

  1207.         /* if no frame size computed, signal it */

  1208.         if (!s->free_format_frame_size)

  1209.             return 1;

  1210.         /* free format: compute bitrate and real frame size from the

  1211.            frame size we extracted by reading the bitstream */

  1212.         s->frame_size = s->free_format_frame_size;

  1213.         switch(s->layer) {

  1214.         case 1:

  1215.             s->frame_size += padding  * 4;

  1216.             s->bit_rate = (s->frame_size * sample_rate) / 48000;

  1217.             break;

  1218.         case 2:

  1219.             s->frame_size += padding;

  1220.             s->bit_rate = (s->frame_size * sample_rate) / 144000;

  1221.             break;

  1222.         default:

  1223.         case 3:

  1224.             s->frame_size += padding;

  1225.             s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;

  1226.             break;

  1227.         }

  1228.     }

  1229. 

  1230. #if defined(DEBUG)

  1231.     dprintf("layer%d, %d Hz, %d kbits/s, ",

  1232.            s->layer, s->sample_rate, s->bit_rate);

  1233.     if (s->nb_channels == 2) {

  1234.         if (s->layer == 3) {

  1235.             if (s->mode_ext & MODE_EXT_MS_STEREO)

  1236.                 dprintf("ms-");

  1237.             if (s->mode_ext & MODE_EXT_I_STEREO)

  1238.                 dprintf("i-");

  1239.         }

  1240.         dprintf("stereo");

  1241.     } else {

  1242.         dprintf("mono");

  1243.     }

  1244.     dprintf("\n");

  1245. #endif

  1246.     return 0;

  1247. }

  1248. 

  1249. /* useful helper to get mpeg audio stream infos. Return -1 if error in

  1250.    header, otherwise the coded frame size in bytes */

  1251. int mpa_decode_header(AVCodecContext *avctx, uint32_t head)

  1252. {

  1253.     MPADecodeContext s1, *s = &s1;

  1254. 

  1255.     if (ff_mpa_check_header(head) != 0)

  1256.         return -1;

  1257. 

  1258.     if (decode_header(s, head) != 0) {

  1259.         return -1;

  1260.     }

  1261. 

  1262.     switch(s->layer) {

  1263.     case 1:

  1264.         avctx->frame_size = 384;

  1265.         break;

  1266.     case 2:

  1267.         avctx->frame_size = 1152;

  1268.         break;

  1269.     default:

  1270.     case 3:

  1271.         if (s->lsf)

  1272.             avctx->frame_size = 576;

  1273.         else

  1274.             avctx->frame_size = 1152;

  1275.         break;

  1276.     }

  1277. 

  1278.     avctx->sample_rate = s->sample_rate;

  1279.     avctx->channels = s->nb_channels;

  1280.     avctx->bit_rate = s->bit_rate;

  1281.     avctx->sub_id = s->layer;

  1282.     return s->frame_size;

  1283. }

  1284. 

  1285. /* return the number of decoded frames */

  1286. static int mp_decode_layer1(MPADecodeContext *s)

  1287. {

  1288.     int bound, i, v, n, ch, j, mant;

  1289.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  1290.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  1291. 

  1292.     if (s->mode == MPA_JSTEREO)

  1293.         bound = (s->mode_ext + 1) * 4;

  1294.     else

  1295.         bound = SBLIMIT;

  1296. 

  1297.     /* allocation bits */

  1298.     for(i=0;i<bound;i++) {

  1299.         for(ch=0;ch<s->nb_channels;ch++) {

  1300.             allocation[ch][i] = get_bits(&s->gb, 4);

  1301.         }

  1302.     }

  1303.     for(i=bound;i<SBLIMIT;i++) {

  1304.         allocation[0][i] = get_bits(&s->gb, 4);

  1305.     }

  1306. 

  1307.     /* scale factors */

  1308.     for(i=0;i<bound;i++) {

  1309.         for(ch=0;ch<s->nb_channels;ch++) {

  1310.             if (allocation[ch][i])

  1311.                 scale_factors[ch][i] = get_bits(&s->gb, 6);

  1312.         }

  1313.     }

  1314.     for(i=bound;i<SBLIMIT;i++) {

  1315.         if (allocation[0][i]) {

  1316.             scale_factors[0][i] = get_bits(&s->gb, 6);

  1317.             scale_factors[1][i] = get_bits(&s->gb, 6);

  1318.         }

  1319.     }

  1320. 

  1321.     /* compute samples */

  1322.     for(j=0;j<12;j++) {

  1323.         for(i=0;i<bound;i++) {

  1324.             for(ch=0;ch<s->nb_channels;ch++) {

  1325.                 n = allocation[ch][i];

  1326.                 if (n) {

  1327.                     mant = get_bits(&s->gb, n + 1);

  1328.                     v = l1_unscale(n, mant, scale_factors[ch][i]);

  1329.                 } else {

  1330.                     v = 0;

  1331.                 }

  1332.                 s->sb_samples[ch][j][i] = v;

  1333.             }

  1334.         }

  1335.         for(i=bound;i<SBLIMIT;i++) {

  1336.             n = allocation[0][i];

  1337.             if (n) {

  1338.                 mant = get_bits(&s->gb, n + 1);

  1339.                 v = l1_unscale(n, mant, scale_factors[0][i]);

  1340.                 s->sb_samples[0][j][i] = v;

  1341.                 v = l1_unscale(n, mant, scale_factors[1][i]);

  1342.                 s->sb_samples[1][j][i] = v;

  1343.             } else {

  1344.                 s->sb_samples[0][j][i] = 0;

  1345.                 s->sb_samples[1][j][i] = 0;

  1346.             }

  1347.         }

  1348.     }

  1349.     return 12;

  1350. }

  1351. 

  1352. /* bitrate is in kb/s */

  1353. int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)

  1354. {

  1355.     int ch_bitrate, table;

  1356. 

  1357.     ch_bitrate = bitrate / nb_channels;

  1358.     if (!lsf) {

  1359.         if ((freq == 48000 && ch_bitrate >= 56) ||

  1360.             (ch_bitrate >= 56 && ch_bitrate <= 80))

  1361.             table = 0;

  1362.         else if (freq != 48000 && ch_bitrate >= 96)

  1363.             table = 1;

  1364.         else if (freq != 32000 && ch_bitrate <= 48)

  1365.             table = 2;

  1366.         else

  1367.             table = 3;

  1368.     } else {

  1369.         table = 4;

  1370.     }

  1371.     return table;

  1372. }

  1373. 

  1374. static int mp_decode_layer2(MPADecodeContext *s)

  1375. {

  1376.     int sblimit; /* number of used subbands */

  1377.     const unsigned char *alloc_table;

  1378.     int table, bit_alloc_bits, i, j, ch, bound, v;

  1379.     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];

  1380.     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];

  1381.     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;

  1382.     int scale, qindex, bits, steps, k, l, m, b;

  1383. 

  1384.     /* select decoding table */

  1385.     table = l2_select_table(s->bit_rate / 1000, s->nb_channels,

  1386.                             s->sample_rate, s->lsf);

  1387.     sblimit = sblimit_table[table];

  1388.     alloc_table = alloc_tables[table];

  1389. 

  1390.     if (s->mode == MPA_JSTEREO)

  1391.         bound = (s->mode_ext + 1) * 4;

  1392.     else

  1393.         bound = sblimit;

  1394. 

  1395.     dprintf("bound=%d sblimit=%d\n", bound, sblimit);

  1396. 

  1397.     /* sanity check */

  1398.     if( bound > sblimit ) bound = sblimit;

  1399. 

  1400.     /* parse bit allocation */

  1401.     j = 0;

  1402.     for(i=0;i<bound;i++) {

  1403.         bit_alloc_bits = alloc_table[j];

  1404.         for(ch=0;ch<s->nb_channels;ch++) {

  1405.             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);

  1406.         }

  1407.         j += 1 << bit_alloc_bits;

  1408.     }

  1409.     for(i=bound;i<sblimit;i++) {

  1410.         bit_alloc_bits = alloc_table[j];

  1411.         v = get_bits(&s->gb, bit_alloc_bits);

  1412.         bit_alloc[0][i] = v;

  1413.         bit_alloc[1][i] = v;

  1414.         j += 1 << bit_alloc_bits;

  1415.     }

  1416. 

  1417. #ifdef DEBUG

  1418.     {

  1419.         for(ch=0;ch<s->nb_channels;ch++) {

  1420.             for(i=0;i<sblimit;i++)

  1421.                 dprintf(" %d", bit_alloc[ch][i]);

  1422.             dprintf("\n");

  1423.         }

  1424.     }

  1425. #endif

  1426. 

  1427.     /* scale codes */

  1428.     for(i=0;i<sblimit;i++) {

  1429.         for(ch=0;ch<s->nb_channels;ch++) {

  1430.             if (bit_alloc[ch][i])

  1431.                 scale_code[ch][i] = get_bits(&s->gb, 2);

  1432.         }

  1433.     }

  1434. 

  1435.     /* scale factors */

  1436.     for(i=0;i<sblimit;i++) {

  1437.         for(ch=0;ch<s->nb_channels;ch++) {

  1438.             if (bit_alloc[ch][i]) {

  1439.                 sf = scale_factors[ch][i];

  1440.                 switch(scale_code[ch][i]) {

  1441.                 default:

  1442.                 case 0:

  1443.                     sf[0] = get_bits(&s->gb, 6);

  1444.                     sf[1] = get_bits(&s->gb, 6);

  1445.                     sf[2] = get_bits(&s->gb, 6);

  1446.                     break;

  1447.                 case 2:

  1448.                     sf[0] = get_bits(&s->gb, 6);

  1449.                     sf[1] = sf[0];

  1450.                     sf[2] = sf[0];

  1451.                     break;

  1452.                 case 1:

  1453.                     sf[0] = get_bits(&s->gb, 6);

  1454.                     sf[2] = get_bits(&s->gb, 6);

  1455.                     sf[1] = sf[0];

  1456.                     break;

  1457.                 case 3:

  1458.                     sf[0] = get_bits(&s->gb, 6);

  1459.                     sf[2] = get_bits(&s->gb, 6);

  1460.                     sf[1] = sf[2];

  1461.                     break;

  1462.                 }

  1463.             }

  1464.         }

  1465.     }

  1466. 

  1467. #ifdef DEBUG

  1468.     for(ch=0;ch<s->nb_channels;ch++) {

  1469.         for(i=0;i<sblimit;i++) {

  1470.             if (bit_alloc[ch][i]) {

  1471.                 sf = scale_factors[ch][i];

  1472.                 dprintf(" %d %d %d", sf[0], sf[1], sf[2]);

  1473.             } else {

  1474.                 dprintf(" -");

  1475.             }

  1476.         }

  1477.         dprintf("\n");

  1478.     }

  1479. #endif

  1480. 

  1481.     /* samples */

  1482.     for(k=0;k<3;k++) {

  1483.         for(l=0;l<12;l+=3) {

  1484.             j = 0;

  1485.             for(i=0;i<bound;i++) {

  1486.                 bit_alloc_bits = alloc_table[j];

  1487.                 for(ch=0;ch<s->nb_channels;ch++) {

  1488.                     b = bit_alloc[ch][i];

  1489.                     if (b) {

  1490.                         scale = scale_factors[ch][i][k];

  1491.                         qindex = alloc_table[j+b];

  1492.                         bits = quant_bits[qindex];

  1493.                         if (bits < 0) {

  1494.                             /* 3 values at the same time */

  1495.                             v = get_bits(&s->gb, -bits);

  1496.                             steps = quant_steps[qindex];

  1497.                             s->sb_samples[ch][k * 12 + l + 0][i] =

  1498.                                 l2_unscale_group(steps, v % steps, scale);

  1499.                             v = v / steps;

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

  1501.                                 l2_unscale_group(steps, v % steps, scale);

  1502.                             v = v / steps;

  1503.                             s->sb_samples[ch][k * 12 + l + 2][i] =

  1504.                                 l2_unscale_group(steps, v, scale);

  1505.                         } else {

  1506.                             for(m=0;m<3;m++) {

  1507.                                 v = get_bits(&s->gb, bits);

  1508.                                 v = l1_unscale(bits - 1, v, scale);

  1509.                                 s->sb_samples[ch][k * 12 + l + m][i] = v;

  1510.                             }

  1511.                         }

  1512.                     } else {

  1513.                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1514.                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1515.                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1516.                     }

  1517.                 }

  1518.                 /* next subband in alloc table */

  1519.                 j += 1 << bit_alloc_bits;

  1520.             }

  1521.             /* XXX: find a way to avoid this duplication of code */

  1522.             for(i=bound;i<sblimit;i++) {

  1523.                 bit_alloc_bits = alloc_table[j];

  1524.                 b = bit_alloc[0][i];

  1525.                 if (b) {

  1526.                     int mant, scale0, scale1;

  1527.                     scale0 = scale_factors[0][i][k];

  1528.                     scale1 = scale_factors[1][i][k];

  1529.                     qindex = alloc_table[j+b];

  1530.                     bits = quant_bits[qindex];

  1531.                     if (bits < 0) {

  1532.                         /* 3 values at the same time */

  1533.                         v = get_bits(&s->gb, -bits);

  1534.                         steps = quant_steps[qindex];

  1535.                         mant = v % steps;

  1536.                         v = v / steps;

  1537.                         s->sb_samples[0][k * 12 + l + 0][i] =

  1538.                             l2_unscale_group(steps, mant, scale0);

  1539.                         s->sb_samples[1][k * 12 + l + 0][i] =

  1540.                             l2_unscale_group(steps, mant, scale1);

  1541.                         mant = v % steps;

  1542.                         v = v / steps;

  1543.                         s->sb_samples[0][k * 12 + l + 1][i] =

  1544.                             l2_unscale_group(steps, mant, scale0);

  1545.                         s->sb_samples[1][k * 12 + l + 1][i] =

  1546.                             l2_unscale_group(steps, mant, scale1);

  1547.                         s->sb_samples[0][k * 12 + l + 2][i] =

  1548.                             l2_unscale_group(steps, v, scale0);

  1549.                         s->sb_samples[1][k * 12 + l + 2][i] =

  1550.                             l2_unscale_group(steps, v, scale1);

  1551.                     } else {

  1552.                         for(m=0;m<3;m++) {

  1553.                             mant = get_bits(&s->gb, bits);

  1554.                             s->sb_samples[0][k * 12 + l + m][i] =

  1555.                                 l1_unscale(bits - 1, mant, scale0);

  1556.                             s->sb_samples[1][k * 12 + l + m][i] =

  1557.                                 l1_unscale(bits - 1, mant, scale1);

  1558.                         }

  1559.                     }

  1560.                 } else {

  1561.                     s->sb_samples[0][k * 12 + l + 0][i] = 0;

  1562.                     s->sb_samples[0][k * 12 + l + 1][i] = 0;

  1563.                     s->sb_samples[0][k * 12 + l + 2][i] = 0;

  1564.                     s->sb_samples[1][k * 12 + l + 0][i] = 0;

  1565.                     s->sb_samples[1][k * 12 + l + 1][i] = 0;

  1566.                     s->sb_samples[1][k * 12 + l + 2][i] = 0;

  1567.                 }

  1568.                 /* next subband in alloc table */

  1569.                 j += 1 << bit_alloc_bits;

  1570.             }

  1571.             /* fill remaining samples to zero */

  1572.             for(i=sblimit;i<SBLIMIT;i++) {

  1573.                 for(ch=0;ch<s->nb_channels;ch++) {

  1574.                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1575.                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1576.                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1577.                 }

  1578.             }

  1579.         }

  1580.     }

  1581.     return 3 * 12;

  1582. }

  1583. 

  1584. static inline void lsf_sf_expand(int *slen,

  1585.                                  int sf, int n1, int n2, int n3)

  1586. {

  1587.     if (n3) {

  1588.         slen[3] = sf % n3;

  1589.         sf /= n3;

  1590.     } else {

  1591.         slen[3] = 0;

  1592.     }

  1593.     if (n2) {

  1594.         slen[2] = sf % n2;

  1595.         sf /= n2;

  1596.     } else {

  1597.         slen[2] = 0;

  1598.     }

  1599.     slen[1] = sf % n1;

  1600.     sf /= n1;

  1601.     slen[0] = sf;

  1602. }

  1603. 

  1604. static void exponents_from_scale_factors(MPADecodeContext *s,

  1605.                                          GranuleDef *g,

  1606.                                          int16_t *exponents)

  1607. {

  1608.     const uint8_t *bstab, *pretab;

  1609.     int len, i, j, k, l, v0, shift, gain, gains[3];

  1610.     int16_t *exp_ptr;

  1611. 

  1612.     exp_ptr = exponents;

  1613.     gain = g->global_gain - 210;

  1614.     shift = g->scalefac_scale + 1;

  1615. 

  1616.     bstab = band_size_long[s->sample_rate_index];

  1617.     pretab = mpa_pretab[g->preflag];

  1618.     for(i=0;i<g->long_end;i++) {

  1619.         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;

  1620.         len = bstab[i];

  1621.         for(j=len;j>0;j--)

  1622.             *exp_ptr++ = v0;

  1623.     }

  1624. 

  1625.     if (g->short_start < 13) {

  1626.         bstab = band_size_short[s->sample_rate_index];

  1627.         gains[0] = gain - (g->subblock_gain[0] << 3);

  1628.         gains[1] = gain - (g->subblock_gain[1] << 3);

  1629.         gains[2] = gain - (g->subblock_gain[2] << 3);

  1630.         k = g->long_end;

  1631.         for(i=g->short_start;i<13;i++) {

  1632.             len = bstab[i];

  1633.             for(l=0;l<3;l++) {

  1634.                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;

  1635.                 for(j=len;j>0;j--)

  1636.                 *exp_ptr++ = v0;

  1637.             }

  1638.         }

  1639.     }

  1640. }

  1641. 

  1642. /* handle n = 0 too */

  1643. static inline int get_bitsz(GetBitContext *s, int n)

  1644. {

  1645.     if (n == 0)

  1646.         return 0;

  1647.     else

  1648.         return get_bits(s, n);

  1649. }

  1650. 

  1651. static int huffman_decode(MPADecodeContext *s, GranuleDef *g,

  1652.                           int16_t *exponents, int end_pos2)

  1653. {

  1654.     int s_index;

  1655.     int i;

  1656.     int last_pos, bits_left;

  1657.     VLC *vlc;

  1658.     int end_pos= FFMIN(end_pos2, s->gb.size_in_bits);

  1659. 

  1660.     /* low frequencies (called big values) */

  1661.     s_index = 0;

  1662.     for(i=0;i<3;i++) {

  1663.         int j, k, l, linbits;

  1664.         j = g->region_size[i];

  1665.         if (j == 0)

  1666.             continue;

  1667.         /* select vlc table */

  1668.         k = g->table_select[i];

  1669.         l = mpa_huff_data[k][0];

  1670.         linbits = mpa_huff_data[k][1];

  1671.         vlc = &huff_vlc[l];

  1672. 

  1673.         if(!l){

  1674.             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*2*j);

  1675.             s_index += 2*j;

  1676.             continue;

  1677.         }

  1678. 

  1679.         /* read huffcode and compute each couple */

  1680.         for(;j>0;j--) {

  1681.             int exponent, x, y, v;

  1682.             int pos= get_bits_count(&s->gb);

  1683. 

  1684.             if (pos >= end_pos){

  1685. //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1686.                 if(s->in_gb.buffer && pos >= s->gb.size_in_bits){

  1687.                     s->gb= s->in_gb;

  1688.                     s->in_gb.buffer=NULL;

  1689.                     assert((get_bits_count(&s->gb) & 7) == 0);

  1690.                     skip_bits_long(&s->gb, pos - end_pos);

  1691.                     end_pos= end_pos2 + get_bits_count(&s->gb) - pos;

  1692.                     pos= get_bits_count(&s->gb);

  1693.                 }

  1694. //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);

  1695.                 if(pos >= end_pos)

  1696.                     break;

  1697.             }

  1698.             y = get_vlc2(&s->gb, vlc->table, 7, 3);

  1699. 

  1700.             if(!y){

  1701.                 g->sb_hybrid[s_index  ] =

  1702.                 g->sb_hybrid[s_index+1] = 0;

  1703.                 s_index += 2;

  1704.                 continue;

  1705.             }

  1706. 

  1707.             exponent= exponents[s_index];

  1708. 

  1709.             dprintf("region=%d n=%d x=%d y=%d exp=%d\n",

  1710.                     i, g->region_size[i] - j, x, y, exponent);

  1711.             if(y&16){

  1712.                 x = y >> 5;

  1713.                 y = y & 0x0f;

  1714.                 if (x < 15){

  1715.                     v = expval_table[ exponent ][ x ];

  1716. //                      v = expval_table[ (exponent&3) ][ x ] >> FFMIN(0 - (exponent>>2), 31);

  1717.                 }else{

  1718.                     x += get_bitsz(&s->gb, linbits);

  1719.                     v = l3_unscale(x, exponent);

  1720.                 }

  1721.                 if (get_bits1(&s->gb))

  1722.                     v = -v;

  1723.                 g->sb_hybrid[s_index] = v;

  1724.                 if (y < 15){

  1725.                     v = expval_table[ exponent ][ y ];

  1726.                 }else{

  1727.                     y += get_bitsz(&s->gb, linbits);

  1728.                     v = l3_unscale(y, exponent);

  1729.                 }

  1730.                 if (get_bits1(&s->gb))

  1731.                     v = -v;

  1732.                 g->sb_hybrid[s_index+1] = v;

  1733.             }else{

  1734.                 x = y >> 5;

  1735.                 y = y & 0x0f;

  1736.                 x += y;

  1737.                 if (x < 15){

  1738.                     v = expval_table[ exponent ][ x ];

  1739.                 }else{

  1740.                     x += get_bitsz(&s->gb, linbits);

  1741.                     v = l3_unscale(x, exponent);

  1742.                 }

  1743.                 if (get_bits1(&s->gb))

  1744.                     v = -v;

  1745.                 g->sb_hybrid[s_index+!!y] = v;

  1746.                 g->sb_hybrid[s_index+ !y] = 0;

  1747.             }

  1748.             s_index+=2;

  1749.         }

  1750.     }

  1751. 

  1752.     /* high frequencies */

  1753.     vlc = &huff_quad_vlc[g->count1table_select];

  1754.     last_pos=0;

  1755.     while (s_index <= 572) {

  1756.         int pos, code;

  1757.         pos = get_bits_count(&s->gb);

  1758.         if (pos >= end_pos) {

  1759. //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

  1760.             if(s->in_gb.buffer && pos >= s->gb.size_in_bits){

  1761.                 s->gb= s->in_gb;

  1762.                 s->in_gb.buffer=NULL;

  1763.                 assert((get_bits_count(&s->gb) & 7) == 0);

  1764.                 skip_bits_long(&s->gb, pos - end_pos);

  1765.                 end_pos= end_pos2 + get_bits_count(&s->gb) - pos;

  1766.                 pos= get_bits_count(&s->gb);

  1767.             }

  1768. //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);

  1769.             if (pos > end_pos && last_pos){ //FIXME last_pos is messed if we switch buffers

  1770.                 /* some encoders generate an incorrect size for this

  1771.                    part. We must go back into the data */

  1772.                 s_index -= 4;

  1773.                 skip_bits_long(&s->gb, last_pos - pos);

  1774.                 av_log(NULL, AV_LOG_ERROR, "overread, skip %d\n", last_pos&7);

  1775.             }

  1776.             if(pos >= end_pos)

  1777.                 break;

  1778.         }

  1779.         last_pos= pos;

  1780. 

  1781.         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);

  1782.         dprintf("t=%d code=%d\n", g->count1table_select, code);

  1783.         g->sb_hybrid[s_index+0]=

  1784.         g->sb_hybrid[s_index+1]=

  1785.         g->sb_hybrid[s_index+2]=

  1786.         g->sb_hybrid[s_index+3]= 0;

  1787.         while(code){

  1788.             const static int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};

  1789.             int v;

  1790.             int pos= s_index+idxtab[code];

  1791.             code ^= 8>>idxtab[code];

  1792.             v = exp_table[ exponents[pos] ];

  1793. //            v = exp_table[ (exponents[pos]&3) ] >> FFMIN(0 - (exponents[pos]>>2), 31);

  1794.             if(get_bits1(&s->gb))

  1795.                 v = -v;

  1796.             g->sb_hybrid[pos] = v;

  1797.         }

  1798.         s_index+=4;

  1799.     }

  1800.     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*(576 - s_index));

  1801. 

  1802.     /* skip extension bits */

  1803.     bits_left = end_pos - get_bits_count(&s->gb);

  1804. //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);

  1805.     if (bits_left < 0) {

  1806.         dprintf("bits_left=%d\n", bits_left);

  1807.         return -1;

  1808.     }

  1809.     skip_bits_long(&s->gb, bits_left);

  1810. 

  1811.     return 0;

  1812. }

  1813. 

  1814. /* Reorder short blocks from bitstream order to interleaved order. It

  1815.    would be faster to do it in parsing, but the code would be far more

  1816.    complicated */

  1817. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1818. {

  1819.     int i, j, len;

  1820.     int32_t *ptr, *dst, *ptr1;

  1821.     int32_t tmp[576];

  1822. 

  1823.     if (g->block_type != 2)

  1824.         return;

  1825. 

  1826.     if (g->switch_point) {

  1827.         if (s->sample_rate_index != 8) {

  1828.             ptr = g->sb_hybrid + 36;

  1829.         } else {

  1830.             ptr = g->sb_hybrid + 48;

  1831.         }

  1832.     } else {

  1833.         ptr = g->sb_hybrid;

  1834.     }

  1835. 

  1836.     for(i=g->short_start;i<13;i++) {

  1837.         len = band_size_short[s->sample_rate_index][i];

  1838.         ptr1 = ptr;

  1839.         dst = tmp;

  1840.         for(j=len;j>0;j--) {

  1841.             *dst++ = ptr[0*len];

  1842.             *dst++ = ptr[1*len];

  1843.             *dst++ = ptr[2*len];

  1844.             ptr++;

  1845.         }

  1846.         ptr+=2*len;

  1847.         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));

  1848.     }

  1849. }

  1850. 

  1851. #define ISQRT2 FIXR(0.70710678118654752440)

  1852. 

  1853. static void compute_stereo(MPADecodeContext *s,

  1854.                            GranuleDef *g0, GranuleDef *g1)

  1855. {

  1856.     int i, j, k, l;

  1857.     int32_t v1, v2;

  1858.     int sf_max, tmp0, tmp1, sf, len, non_zero_found;

  1859.     int32_t (*is_tab)[16];

  1860.     int32_t *tab0, *tab1;

  1861.     int non_zero_found_short[3];

  1862. 

  1863.     /* intensity stereo */

  1864.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1865.         if (!s->lsf) {

  1866.             is_tab = is_table;

  1867.             sf_max = 7;

  1868.         } else {

  1869.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1870.             sf_max = 16;

  1871.         }

  1872. 

  1873.         tab0 = g0->sb_hybrid + 576;

  1874.         tab1 = g1->sb_hybrid + 576;

  1875. 

  1876.         non_zero_found_short[0] = 0;

  1877.         non_zero_found_short[1] = 0;

  1878.         non_zero_found_short[2] = 0;

  1879.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1880.         for(i = 12;i >= g1->short_start;i--) {

  1881.             /* for last band, use previous scale factor */

  1882.             if (i != 11)

  1883.                 k -= 3;

  1884.             len = band_size_short[s->sample_rate_index][i];

  1885.             for(l=2;l>=0;l--) {

  1886.                 tab0 -= len;

  1887.                 tab1 -= len;

  1888.                 if (!non_zero_found_short[l]) {

  1889.                     /* test if non zero band. if so, stop doing i-stereo */

  1890.                     for(j=0;j<len;j++) {

  1891.                         if (tab1[j] != 0) {

  1892.                             non_zero_found_short[l] = 1;

  1893.                             goto found1;

  1894.                         }

  1895.                     }

  1896.                     sf = g1->scale_factors[k + l];

  1897.                     if (sf >= sf_max)

  1898.                         goto found1;

  1899. 

  1900.                     v1 = is_tab[0][sf];

  1901.                     v2 = is_tab[1][sf];

  1902.                     for(j=0;j<len;j++) {

  1903.                         tmp0 = tab0[j];

  1904.                         tab0[j] = MULL(tmp0, v1);

  1905.                         tab1[j] = MULL(tmp0, v2);

  1906.                     }

  1907.                 } else {

  1908.                 found1:

  1909.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1910.                         /* lower part of the spectrum : do ms stereo

  1911.                            if enabled */

  1912.                         for(j=0;j<len;j++) {

  1913.                             tmp0 = tab0[j];

  1914.                             tmp1 = tab1[j];

  1915.                             tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1916.                             tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1917.                         }

  1918.                     }

  1919.                 }

  1920.             }

  1921.         }

  1922. 

  1923.         non_zero_found = non_zero_found_short[0] |

  1924.             non_zero_found_short[1] |

  1925.             non_zero_found_short[2];

  1926. 

  1927.         for(i = g1->long_end - 1;i >= 0;i--) {

  1928.             len = band_size_long[s->sample_rate_index][i];

  1929.             tab0 -= len;

  1930.             tab1 -= len;

  1931.             /* test if non zero band. if so, stop doing i-stereo */

  1932.             if (!non_zero_found) {

  1933.                 for(j=0;j<len;j++) {

  1934.                     if (tab1[j] != 0) {

  1935.                         non_zero_found = 1;

  1936.                         goto found2;

  1937.                     }

  1938.                 }

  1939.                 /* for last band, use previous scale factor */

  1940.                 k = (i == 21) ? 20 : i;

  1941.                 sf = g1->scale_factors[k];

  1942.                 if (sf >= sf_max)

  1943.                     goto found2;

  1944.                 v1 = is_tab[0][sf];

  1945.                 v2 = is_tab[1][sf];

  1946.                 for(j=0;j<len;j++) {

  1947.                     tmp0 = tab0[j];

  1948.                     tab0[j] = MULL(tmp0, v1);

  1949.                     tab1[j] = MULL(tmp0, v2);

  1950.                 }

  1951.             } else {

  1952.             found2:

  1953.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1954.                     /* lower part of the spectrum : do ms stereo

  1955.                        if enabled */

  1956.                     for(j=0;j<len;j++) {

  1957.                         tmp0 = tab0[j];

  1958.                         tmp1 = tab1[j];

  1959.                         tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1960.                         tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1961.                     }

  1962.                 }

  1963.             }

  1964.         }

  1965.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1966.         /* ms stereo ONLY */

  1967.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1968.            global gain */

  1969.         tab0 = g0->sb_hybrid;

  1970.         tab1 = g1->sb_hybrid;

  1971.         for(i=0;i<576;i++) {

  1972.             tmp0 = tab0[i];

  1973.             tmp1 = tab1[i];

  1974.             tab0[i] = tmp0 + tmp1;

  1975.             tab1[i] = tmp0 - tmp1;

  1976.         }

  1977.     }

  1978. }

  1979. 

  1980. static void compute_antialias_integer(MPADecodeContext *s,

  1981.                               GranuleDef *g)

  1982. {

  1983.     int32_t *ptr, *csa;

  1984.     int n, i;

  1985. 

  1986.     /* we antialias only "long" bands */

  1987.     if (g->block_type == 2) {

  1988.         if (!g->switch_point)

  1989.             return;

  1990.         /* XXX: check this for 8000Hz case */

  1991.         n = 1;

  1992.     } else {

  1993.         n = SBLIMIT - 1;

  1994.     }

  1995. 

  1996.     ptr = g->sb_hybrid + 18;

  1997.     for(i = n;i > 0;i--) {

  1998.         int tmp0, tmp1, tmp2;

  1999.         csa = &csa_table[0][0];

  2000. #define INT_AA(j) \

  2001.             tmp0 = ptr[-1-j];\

  2002.             tmp1 = ptr[   j];\

  2003.             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\

  2004.             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\

  2005.             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));

  2006. 

  2007.         INT_AA(0)

  2008.         INT_AA(1)

  2009.         INT_AA(2)

  2010.         INT_AA(3)

  2011.         INT_AA(4)

  2012.         INT_AA(5)

  2013.         INT_AA(6)

  2014.         INT_AA(7)

  2015. 

  2016.         ptr += 18;

  2017.     }

  2018. }

  2019. 

  2020. static void compute_antialias_float(MPADecodeContext *s,

  2021.                               GranuleDef *g)

  2022. {

  2023.     int32_t *ptr;

  2024.     int n, i;

  2025. 

  2026.     /* we antialias only "long" bands */

  2027.     if (g->block_type == 2) {

  2028.         if (!g->switch_point)

  2029.             return;

  2030.         /* XXX: check this for 8000Hz case */

  2031.         n = 1;

  2032.     } else {

  2033.         n = SBLIMIT - 1;

  2034.     }

  2035. 

  2036.     ptr = g->sb_hybrid + 18;

  2037.     for(i = n;i > 0;i--) {

  2038.         float tmp0, tmp1;

  2039.         float *csa = &csa_table_float[0][0];

  2040. #define FLOAT_AA(j)\

  2041.         tmp0= ptr[-1-j];\

  2042.         tmp1= ptr[   j];\

  2043.         ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\

  2044.         ptr[   j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);

  2045. 

  2046.         FLOAT_AA(0)

  2047.         FLOAT_AA(1)

  2048.         FLOAT_AA(2)

  2049.         FLOAT_AA(3)

  2050.         FLOAT_AA(4)

  2051.         FLOAT_AA(5)

  2052.         FLOAT_AA(6)

  2053.         FLOAT_AA(7)

  2054. 

  2055.         ptr += 18;

  2056.     }

  2057. }

  2058. 

  2059. static void compute_imdct(MPADecodeContext *s,

  2060.                           GranuleDef *g,

  2061.                           int32_t *sb_samples,

  2062.                           int32_t *mdct_buf)

  2063. {

  2064.     int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;

  2065.     int32_t out2[12];

  2066.     int i, j, mdct_long_end, v, sblimit;

  2067. 

  2068.     /* find last non zero block */

  2069.     ptr = g->sb_hybrid + 576;

  2070.     ptr1 = g->sb_hybrid + 2 * 18;

  2071.     while (ptr >= ptr1) {

  2072.         ptr -= 6;

  2073.         v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];

  2074.         if (v != 0)

  2075.             break;

  2076.     }

  2077.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  2078. 

  2079.     if (g->block_type == 2) {

  2080.         /* XXX: check for 8000 Hz */

  2081.         if (g->switch_point)

  2082.             mdct_long_end = 2;

  2083.         else

  2084.             mdct_long_end = 0;

  2085.     } else {

  2086.         mdct_long_end = sblimit;

  2087.     }

  2088. 

  2089.     buf = mdct_buf;

  2090.     ptr = g->sb_hybrid;

  2091.     for(j=0;j<mdct_long_end;j++) {

  2092.         /* apply window & overlap with previous buffer */

  2093.         out_ptr = sb_samples + j;

  2094.         /* select window */

  2095.         if (g->switch_point && j < 2)

  2096.             win1 = mdct_win[0];

  2097.         else

  2098.             win1 = mdct_win[g->block_type];

  2099.         /* select frequency inversion */

  2100.         win = win1 + ((4 * 36) & -(j & 1));

  2101.         imdct36(out_ptr, buf, ptr, win);

  2102.         out_ptr += 18*SBLIMIT;

  2103.         ptr += 18;

  2104.         buf += 18;

  2105.     }

  2106.     for(j=mdct_long_end;j<sblimit;j++) {

  2107.         /* select frequency inversion */

  2108.         win = mdct_win[2] + ((4 * 36) & -(j & 1));

  2109.         out_ptr = sb_samples + j;

  2110. 

  2111.         for(i=0; i<6; i++){

  2112.             *out_ptr = buf[i];

  2113.             out_ptr += SBLIMIT;

  2114.         }

  2115.         imdct12(out2, ptr + 0);

  2116.         for(i=0;i<6;i++) {

  2117.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];

  2118.             buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);

  2119.             out_ptr += SBLIMIT;

  2120.         }

  2121.         imdct12(out2, ptr + 1);

  2122.         for(i=0;i<6;i++) {

  2123.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];

  2124.             buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);

  2125.             out_ptr += SBLIMIT;

  2126.         }

  2127.         imdct12(out2, ptr + 2);

  2128.         for(i=0;i<6;i++) {

  2129.             buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];

  2130.             buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);

  2131.             buf[i + 6*2] = 0;

  2132.         }

  2133.         ptr += 18;

  2134.         buf += 18;

  2135.     }

  2136.     /* zero bands */

  2137.     for(j=sblimit;j<SBLIMIT;j++) {

  2138.         /* overlap */

  2139.         out_ptr = sb_samples + j;

  2140.         for(i=0;i<18;i++) {

  2141.             *out_ptr = buf[i];

  2142.             buf[i] = 0;

  2143.             out_ptr += SBLIMIT;

  2144.         }

  2145.         buf += 18;

  2146.     }

  2147. }

  2148. 

  2149. #if defined(DEBUG)

  2150. void sample_dump(int fnum, int32_t *tab, int n)

  2151. {

  2152.     static FILE *files[16], *f;

  2153.     char buf[512];

  2154.     int i;

  2155.     int32_t v;

  2156. 

  2157.     f = files[fnum];

  2158.     if (!f) {

  2159.         snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm",

  2160.                 fnum,

  2161. #ifdef USE_HIGHPRECISION

  2162.                 "hp"

  2163. #else

  2164.                 "lp"

  2165. #endif

  2166.                 );

  2167.         f = fopen(buf, "w");

  2168.         if (!f)

  2169.             return;

  2170.         files[fnum] = f;

  2171.     }

  2172. 

  2173.     if (fnum == 0) {

  2174.         static int pos = 0;

  2175.         av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos);

  2176.         for(i=0;i<n;i++) {

  2177.             av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE);

  2178.             if ((i % 18) == 17)

  2179.                 av_log(NULL, AV_LOG_DEBUG, "\n");

  2180.         }

  2181.         pos += n;

  2182.     }

  2183.     for(i=0;i<n;i++) {

  2184.         /* normalize to 23 frac bits */

  2185.         v = tab[i] << (23 - FRAC_BITS);

  2186.         fwrite(&v, 1, sizeof(int32_t), f);

  2187.     }

  2188. }

  2189. #endif

  2190. 

  2191. 

  2192. /* main layer3 decoding function */

  2193. static int mp_decode_layer3(MPADecodeContext *s)

  2194. {

  2195.     int nb_granules, main_data_begin, private_bits;

  2196.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

  2197.     GranuleDef granules[2][2], *g;

  2198.     int16_t exponents[576];

  2199. 

  2200.     /* read side info */

  2201.     if (s->lsf) {

  2202.         main_data_begin = get_bits(&s->gb, 8);

  2203.         private_bits = get_bits(&s->gb, s->nb_channels);

  2204.         nb_granules = 1;

  2205.     } else {

  2206.         main_data_begin = get_bits(&s->gb, 9);

  2207.         if (s->nb_channels == 2)

  2208.             private_bits = get_bits(&s->gb, 3);

  2209.         else

  2210.             private_bits = get_bits(&s->gb, 5);

  2211.         nb_granules = 2;

  2212.         for(ch=0;ch<s->nb_channels;ch++) {

  2213.             granules[ch][0].scfsi = 0; /* all scale factors are transmitted */

  2214.             granules[ch][1].scfsi = get_bits(&s->gb, 4);

  2215.         }

  2216.     }

  2217. 

  2218.     for(gr=0;gr<nb_granules;gr++) {

  2219.         for(ch=0;ch<s->nb_channels;ch++) {

  2220.             dprintf("gr=%d ch=%d: side_info\n", gr, ch);

  2221.             g = &granules[ch][gr];

  2222.             g->part2_3_length = get_bits(&s->gb, 12);

  2223.             g->big_values = get_bits(&s->gb, 9);

  2224.             g->global_gain = get_bits(&s->gb, 8);

  2225.             /* if MS stereo only is selected, we precompute the

  2226.                1/sqrt(2) renormalization factor */

  2227.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==

  2228.                 MODE_EXT_MS_STEREO)

  2229.                 g->global_gain -= 2;

  2230.             if (s->lsf)

  2231.                 g->scalefac_compress = get_bits(&s->gb, 9);

  2232.             else

  2233.                 g->scalefac_compress = get_bits(&s->gb, 4);

  2234.             blocksplit_flag = get_bits(&s->gb, 1);

  2235.             if (blocksplit_flag) {

  2236.                 g->block_type = get_bits(&s->gb, 2);

  2237.                 if (g->block_type == 0)

  2238.                     return -1;

  2239.                 g->switch_point = get_bits(&s->gb, 1);

  2240.                 for(i=0;i<2;i++)

  2241.                     g->table_select[i] = get_bits(&s->gb, 5);

  2242.                 for(i=0;i<3;i++)

  2243.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  2244.                 /* compute huffman coded region sizes */

  2245.                 if (g->block_type == 2)

  2246.                     g->region_size[0] = (36 / 2);

  2247.                 else {

  2248.                     if (s->sample_rate_index <= 2)

  2249.                         g->region_size[0] = (36 / 2);

  2250.                     else if (s->sample_rate_index != 8)

  2251.                         g->region_size[0] = (54 / 2);

  2252.                     else

  2253.                         g->region_size[0] = (108 / 2);

  2254.                 }

  2255.                 g->region_size[1] = (576 / 2);

  2256.             } else {

  2257.                 int region_address1, region_address2, l;

  2258.                 g->block_type = 0;

  2259.                 g->switch_point = 0;

  2260.                 for(i=0;i<3;i++)

  2261.                     g->table_select[i] = get_bits(&s->gb, 5);

  2262.                 /* compute huffman coded region sizes */

  2263.                 region_address1 = get_bits(&s->gb, 4);

  2264.                 region_address2 = get_bits(&s->gb, 3);

  2265.                 dprintf("region1=%d region2=%d\n",

  2266.                         region_address1, region_address2);

  2267.                 g->region_size[0] =

  2268.                     band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;

  2269.                 l = region_address1 + region_address2 + 2;

  2270.                 /* should not overflow */

  2271.                 if (l > 22)

  2272.                     l = 22;

  2273.                 g->region_size[1] =

  2274.                     band_index_long[s->sample_rate_index][l] >> 1;

  2275.             }

  2276.             /* convert region offsets to region sizes and truncate

  2277.                size to big_values */

  2278.             g->region_size[2] = (576 / 2);

  2279.             j = 0;

  2280.             for(i=0;i<3;i++) {

  2281.                 k = FFMIN(g->region_size[i], g->big_values);

  2282.                 g->region_size[i] = k - j;

  2283.                 j = k;

  2284.             }

  2285. 

  2286.             /* compute band indexes */

  2287.             if (g->block_type == 2) {

  2288.                 if (g->switch_point) {

  2289.                     /* if switched mode, we handle the 36 first samples as

  2290.                        long blocks.  For 8000Hz, we handle the 48 first

  2291.                        exponents as long blocks (XXX: check this!) */

  2292.                     if (s->sample_rate_index <= 2)

  2293.                         g->long_end = 8;

  2294.                     else if (s->sample_rate_index != 8)

  2295.                         g->long_end = 6;

  2296.                     else

  2297.                         g->long_end = 4; /* 8000 Hz */

  2298. 

  2299.                     g->short_start = 2 + (s->sample_rate_index != 8);

  2300.                 } else {

  2301.                     g->long_end = 0;

  2302.                     g->short_start = 0;

  2303.                 }

  2304.             } else {

  2305.                 g->short_start = 13;

  2306.                 g->long_end = 22;

  2307.             }

  2308. 

  2309.             g->preflag = 0;

  2310.             if (!s->lsf)

  2311.                 g->preflag = get_bits(&s->gb, 1);

  2312.             g->scalefac_scale = get_bits(&s->gb, 1);

  2313.             g->count1table_select = get_bits(&s->gb, 1);

  2314.             dprintf("block_type=%d switch_point=%d\n",

  2315.                     g->block_type, g->switch_point);

  2316.         }

  2317.     }

  2318. 

  2319.   if (!s->adu_mode) {

  2320.     const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);

  2321.     /* now we get bits from the main_data_begin offset */

  2322.     dprintf("seekback: %d\n", main_data_begin);

  2323. //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);

  2324.     if(main_data_begin > s->last_buf_size)

  2325.         s->last_buf_size= main_data_begin;

  2326. 

  2327.     memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);

  2328.     s->in_gb= s->gb;

  2329.     init_get_bits(&s->gb, s->last_buf + s->last_buf_size - main_data_begin, main_data_begin*8);

  2330.   }

  2331. 

  2332.     for(gr=0;gr<nb_granules;gr++) {

  2333.         for(ch=0;ch<s->nb_channels;ch++) {

  2334.             g = &granules[ch][gr];

  2335. 

  2336.             bits_pos = get_bits_count(&s->gb);

  2337. 

  2338.             if (!s->lsf) {

  2339.                 uint8_t *sc;

  2340.                 int slen, slen1, slen2;

  2341. 

  2342.                 /* MPEG1 scale factors */

  2343.                 slen1 = slen_table[0][g->scalefac_compress];

  2344.                 slen2 = slen_table[1][g->scalefac_compress];

  2345.                 dprintf("slen1=%d slen2=%d\n", slen1, slen2);

  2346.                 if (g->block_type == 2) {

  2347.                     n = g->switch_point ? 17 : 18;

  2348.                     j = 0;

  2349.                     if(slen1){

  2350.                         for(i=0;i<n;i++)

  2351.                             g->scale_factors[j++] = get_bits(&s->gb, slen1);

  2352.                     }else{

  2353.                         for(i=0;i<n;i++)

  2354.                             g->scale_factors[j++] = 0;

  2355.                     }

  2356.                     if(slen2){

  2357.                         for(i=0;i<18;i++)

  2358.                             g->scale_factors[j++] = get_bits(&s->gb, slen2);

  2359.                         for(i=0;i<3;i++)

  2360.                             g->scale_factors[j++] = 0;

  2361.                     }else{

  2362.                         for(i=0;i<21;i++)

  2363.                             g->scale_factors[j++] = 0;

  2364.                     }

  2365.                 } else {

  2366.                     sc = granules[ch][0].scale_factors;

  2367.                     j = 0;

  2368.                     for(k=0;k<4;k++) {

  2369.                         n = (k == 0 ? 6 : 5);

  2370.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  2371.                             slen = (k < 2) ? slen1 : slen2;

  2372.                             if(slen){

  2373.                                 for(i=0;i<n;i++)

  2374.                                     g->scale_factors[j++] = get_bits(&s->gb, slen);

  2375.                             }else{

  2376.                                 for(i=0;i<n;i++)

  2377.                                     g->scale_factors[j++] = 0;

  2378.                             }

  2379.                         } else {

  2380.                             /* simply copy from last granule */

  2381.                             for(i=0;i<n;i++) {

  2382.                                 g->scale_factors[j] = sc[j];

  2383.                                 j++;

  2384.                             }

  2385.                         }

  2386.                     }

  2387.                     g->scale_factors[j++] = 0;

  2388.                 }

  2389. #if defined(DEBUG)

  2390.                 {

  2391.                     dprintf("scfsi=%x gr=%d ch=%d scale_factors:\n",

  2392.                            g->scfsi, gr, ch);

  2393.                     for(i=0;i<j;i++)

  2394.                         dprintf(" %d", g->scale_factors[i]);

  2395.                     dprintf("\n");

  2396.                 }

  2397. #endif

  2398.             } else {

  2399.                 int tindex, tindex2, slen[4], sl, sf;

  2400. 

  2401.                 /* LSF scale factors */

  2402.                 if (g->block_type == 2) {

  2403.                     tindex = g->switch_point ? 2 : 1;

  2404.                 } else {

  2405.                     tindex = 0;

  2406.                 }

  2407.                 sf = g->scalefac_compress;

  2408.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  2409.                     /* intensity stereo case */

  2410.                     sf >>= 1;

  2411.                     if (sf < 180) {

  2412.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  2413.                         tindex2 = 3;

  2414.                     } else if (sf < 244) {

  2415.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  2416.                         tindex2 = 4;

  2417.                     } else {

  2418.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  2419.                         tindex2 = 5;

  2420.                     }

  2421.                 } else {

  2422.                     /* normal case */

  2423.                     if (sf < 400) {

  2424.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  2425.                         tindex2 = 0;

  2426.                     } else if (sf < 500) {

  2427.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  2428.                         tindex2 = 1;

  2429.                     } else {

  2430.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  2431.                         tindex2 = 2;

  2432.                         g->preflag = 1;

  2433.                     }

  2434.                 }

  2435. 

  2436.                 j = 0;

  2437.                 for(k=0;k<4;k++) {

  2438.                     n = lsf_nsf_table[tindex2][tindex][k];

  2439.                     sl = slen[k];

  2440.                     if(sl){

  2441.                         for(i=0;i<n;i++)

  2442.                             g->scale_factors[j++] = get_bits(&s->gb, sl);

  2443.                     }else{

  2444.                         for(i=0;i<n;i++)

  2445.                             g->scale_factors[j++] = 0;

  2446.                     }

  2447.                 }

  2448.                 /* XXX: should compute exact size */

  2449.                 for(;j<40;j++)

  2450.                     g->scale_factors[j] = 0;

  2451. #if defined(DEBUG)

  2452.                 {

  2453.                     dprintf("gr=%d ch=%d scale_factors:\n",

  2454.                            gr, ch);

  2455.                     for(i=0;i<40;i++)

  2456.                         dprintf(" %d", g->scale_factors[i]);

  2457.                     dprintf("\n");

  2458.                 }

  2459. #endif

  2460.             }

  2461. 

  2462.             exponents_from_scale_factors(s, g, exponents);

  2463. 

  2464.             /* read Huffman coded residue */

  2465.             if (huffman_decode(s, g, exponents,

  2466.                                bits_pos + g->part2_3_length) < 0)

  2467.                 return -1;

  2468. #if defined(DEBUG)

  2469.             sample_dump(0, g->sb_hybrid, 576);

  2470. #endif

  2471.         } /* ch */

  2472. 

  2473.         if (s->nb_channels == 2)

  2474.             compute_stereo(s, &granules[0][gr], &granules[1][gr]);

  2475. 

  2476.         for(ch=0;ch<s->nb_channels;ch++) {

  2477.             g = &granules[ch][gr];

  2478. 

  2479.             reorder_block(s, g);

  2480. #if defined(DEBUG)

  2481.             sample_dump(0, g->sb_hybrid, 576);

  2482. #endif

  2483.             s->compute_antialias(s, g);

  2484. #if defined(DEBUG)

  2485.             sample_dump(1, g->sb_hybrid, 576);

  2486. #endif

  2487.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);

  2488. #if defined(DEBUG)

  2489.             sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);

  2490. #endif

  2491.         }

  2492.     } /* gr */

  2493.     return nb_granules * 18;

  2494. }

  2495. 

  2496. static int mp_decode_frame(MPADecodeContext *s,

  2497.                            OUT_INT *samples, const uint8_t *buf, int buf_size)

  2498. {

  2499.     int i, nb_frames, ch;

  2500.     OUT_INT *samples_ptr;

  2501. 

  2502.     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)*8);

  2503. 

  2504.     /* skip error protection field */

  2505.     if (s->error_protection)

  2506.         get_bits(&s->gb, 16);

  2507. 

  2508.     dprintf("frame %d:\n", s->frame_count);

  2509.     switch(s->layer) {

  2510.     case 1:

  2511.         nb_frames = mp_decode_layer1(s);

  2512.         break;

  2513.     case 2:

  2514.         nb_frames = mp_decode_layer2(s);

  2515.         break;

  2516.     case 3:

  2517.     default:

  2518.         nb_frames = mp_decode_layer3(s);

  2519. 

  2520.         if(s->in_gb.buffer)

  2521.             s->gb= s->in_gb;

  2522.         align_get_bits(&s->gb);

  2523.         assert((get_bits_count(&s->gb) & 7) == 0);

  2524.         s->last_buf_size= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;

  2525.         memcpy(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), s->last_buf_size);

  2526. 

  2527.         break;

  2528.     }

  2529. #if defined(DEBUG)

  2530.     for(i=0;i<nb_frames;i++) {

  2531.         for(ch=0;ch<s->nb_channels;ch++) {

  2532.             int j;

  2533.             dprintf("%d-%d:", i, ch);

  2534.             for(j=0;j<SBLIMIT;j++)

  2535.                 dprintf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);

  2536.             dprintf("\n");

  2537.         }

  2538.     }

  2539. #endif

  2540.     /* apply the synthesis filter */

  2541.     for(ch=0;ch<s->nb_channels;ch++) {

  2542.         samples_ptr = samples + ch;

  2543.         for(i=0;i<nb_frames;i++) {

  2544.             ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  2545.                          window, &s->dither_state,

  2546.                          samples_ptr, s->nb_channels,

  2547.                          s->sb_samples[ch][i]);

  2548.             samples_ptr += 32 * s->nb_channels;

  2549.         }

  2550.     }

  2551. #ifdef DEBUG

  2552.     s->frame_count++;

  2553. #endif

  2554.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  2555. }

  2556. 

  2557. static int decode_frame(AVCodecContext * avctx,

  2558.                         void *data, int *data_size,

  2559.                         uint8_t * buf, int buf_size)

  2560. {

  2561.     MPADecodeContext *s = avctx->priv_data;

  2562.     uint32_t header;

  2563.     int out_size;

  2564.     OUT_INT *out_samples = data;

  2565. 

  2566. retry:

  2567.     if(buf_size < HEADER_SIZE)

  2568.         return -1;

  2569. 

  2570.     header = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];

  2571.     if(ff_mpa_check_header(header) < 0){

  2572.         buf++;

  2573. //        buf_size--;

  2574.         av_log(avctx, AV_LOG_ERROR, "header missing skiping one byte\n");

  2575.         goto retry;

  2576.     }

  2577. 

  2578.     if (decode_header(s, header) == 1) {

  2579.         /* free format: prepare to compute frame size */

  2580.         s->frame_size = -1;

  2581.         return -1;

  2582.     }

  2583.     /* update codec info */

  2584.     avctx->sample_rate = s->sample_rate;

  2585.     avctx->channels = s->nb_channels;

  2586.     avctx->bit_rate = s->bit_rate;

  2587.     avctx->sub_id = s->layer;

  2588.     switch(s->layer) {

  2589.     case 1:

  2590.         avctx->frame_size = 384;

  2591.         break;

  2592.     case 2:

  2593.         avctx->frame_size = 1152;

  2594.         break;

  2595.     case 3:

  2596.         if (s->lsf)

  2597.             avctx->frame_size = 576;

  2598.         else

  2599.             avctx->frame_size = 1152;

  2600.         break;

  2601.     }

  2602. 

  2603.     if(s->frame_size<=0 || s->frame_size < buf_size){

  2604.         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

  2605.         return -1;

  2606.     }

  2607. 

  2608.     out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2609.     if(out_size>=0)

  2610.         *data_size = out_size;

  2611.     else

  2612.         av_log(avctx, AV_LOG_DEBUG, "Error while decoding mpeg audio frame\n"); //FIXME return -1 / but also return the number of bytes consumed

  2613.     s->frame_size = 0;

  2614.     return buf_size;

  2615. }

  2616. 

  2617. 

  2618. static int decode_frame_adu(AVCodecContext * avctx,

  2619.                         void *data, int *data_size,

  2620.                         uint8_t * buf, int buf_size)

  2621. {

  2622.     MPADecodeContext *s = avctx->priv_data;

  2623.     uint32_t header;

  2624.     int len, out_size;

  2625.     OUT_INT *out_samples = data;

  2626. 

  2627.     len = buf_size;

  2628. 

  2629.     // Discard too short frames

  2630.     if (buf_size < HEADER_SIZE) {

  2631.         *data_size = 0;

  2632.         return buf_size;

  2633.     }

  2634. 

  2635. 

  2636.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  2637.         len = MPA_MAX_CODED_FRAME_SIZE;

  2638. 

  2639.     // Get header and restore sync word

  2640.     header = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3] | 0xffe00000;

  2641. 

  2642.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  2643.         *data_size = 0;

  2644.         return buf_size;

  2645.     }

  2646. 

  2647.     decode_header(s, header);

  2648.     /* update codec info */

  2649.     avctx->sample_rate = s->sample_rate;

  2650.     avctx->channels = s->nb_channels;

  2651.     avctx->bit_rate = s->bit_rate;

  2652.     avctx->sub_id = s->layer;

  2653. 

  2654.     avctx->frame_size=s->frame_size = len;

  2655. 

  2656.     if (avctx->parse_only) {

  2657.         out_size = buf_size;

  2658.     } else {

  2659.         out_size = mp_decode_frame(s, out_samples, buf, buf_size);

  2660.     }

  2661. 

  2662.     *data_size = out_size;

  2663.     return buf_size;

  2664. }

  2665. 

  2666. 

  2667. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  2668. static int mp3Frames[16] = {0,1,1,2,3,3,4,5,2};   /* number of mp3 decoder instances */

  2669. static int mp3Channels[16] = {0,1,2,3,4,5,6,8,4}; /* total output channels */

  2670. /* offsets into output buffer, assume output order is FL FR BL BR C LFE */

  2671. static int chan_offset[9][5] = {

  2672.     {0},

  2673.     {0},            // C

  2674.     {0},            // FLR

  2675.     {2,0},          // C FLR

  2676.     {2,0,3},        // C FLR BS

  2677.     {4,0,2},        // C FLR BLRS

  2678.     {4,0,2,5},      // C FLR BLRS LFE

  2679.     {4,0,2,6,5},    // C FLR BLRS BLR LFE

  2680.     {0,2}           // FLR BLRS

  2681. };

  2682. 

  2683. 

  2684. static int decode_init_mp3on4(AVCodecContext * avctx)

  2685. {

  2686.     MP3On4DecodeContext *s = avctx->priv_data;

  2687.     int i;

  2688. 

  2689.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  2690.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  2691.         return -1;

  2692.     }

  2693. 

  2694.     s->chan_cfg = (((unsigned char *)avctx->extradata)[1] >> 3) & 0x0f;

  2695.     s->frames = mp3Frames[s->chan_cfg];

  2696.     if(!s->frames) {

  2697.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  2698.         return -1;

  2699.     }

  2700.     avctx->channels = mp3Channels[s->chan_cfg];

  2701. 

  2702.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  2703.      * We replace avctx->priv_data with the context of the first decoder so that

  2704.      * decode_init() does not have to be changed.

  2705.      * Other decoders will be inited here copying data from the first context

  2706.      */

  2707.     // Allocate zeroed memory for the first decoder context

  2708.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  2709.     // Put decoder context in place to make init_decode() happy

  2710.     avctx->priv_data = s->mp3decctx[0];

  2711.     decode_init(avctx);

  2712.     // Restore mp3on4 context pointer

  2713.     avctx->priv_data = s;

  2714.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  2715. 

  2716.     /* Create a separate codec/context for each frame (first is already ok).

  2717.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  2718.      */

  2719.     for (i = 1; i < s->frames; i++) {

  2720.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  2721.         s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;

  2722.         s->mp3decctx[i]->adu_mode = 1;

  2723.     }

  2724. 

  2725.     return 0;

  2726. }

  2727. 

  2728. 

  2729. static int decode_close_mp3on4(AVCodecContext * avctx)

  2730. {

  2731.     MP3On4DecodeContext *s = avctx->priv_data;

  2732.     int i;

  2733. 

  2734.     for (i = 0; i < s->frames; i++)

  2735.         if (s->mp3decctx[i])

  2736.             av_free(s->mp3decctx[i]);

  2737. 

  2738.     return 0;

  2739. }

  2740. 

  2741. 

  2742. static int decode_frame_mp3on4(AVCodecContext * avctx,

  2743.                         void *data, int *data_size,

  2744.                         uint8_t * buf, int buf_size)

  2745. {

  2746.     MP3On4DecodeContext *s = avctx->priv_data;

  2747.     MPADecodeContext *m;

  2748.     int len, out_size = 0;

  2749.     uint32_t header;

  2750.     OUT_INT *out_samples = data;

  2751.     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];

  2752.     OUT_INT *outptr, *bp;

  2753.     int fsize;

  2754.     unsigned char *start2 = buf, *start;

  2755.     int fr, i, j, n;

  2756.     int off = avctx->channels;

  2757.     int *coff = chan_offset[s->chan_cfg];

  2758. 

  2759.     len = buf_size;

  2760. 

  2761.     // Discard too short frames

  2762.     if (buf_size < HEADER_SIZE) {

  2763.         *data_size = 0;

  2764.         return buf_size;

  2765.     }

  2766. 

  2767.     // If only one decoder interleave is not needed

  2768.     outptr = s->frames == 1 ? out_samples : decoded_buf;

  2769. 

  2770.     for (fr = 0; fr < s->frames; fr++) {

  2771.         start = start2;

  2772.         fsize = (start[0] << 4) | (start[1] >> 4);

  2773.         start2 += fsize;

  2774.         if (fsize > len)

  2775.             fsize = len;

  2776.         len -= fsize;

  2777.         if (fsize > MPA_MAX_CODED_FRAME_SIZE)

  2778.             fsize = MPA_MAX_CODED_FRAME_SIZE;

  2779.         m = s->mp3decctx[fr];

  2780.         assert (m != NULL);

  2781. 

  2782.         // Get header

  2783.         header = (start[0] << 24) | (start[1] << 16) | (start[2] << 8) | start[3] | 0xfff00000;

  2784. 

  2785.         if (ff_mpa_check_header(header) < 0) { // Bad header, discard block

  2786.             *data_size = 0;

  2787.             return buf_size;

  2788.         }

  2789. 

  2790.         decode_header(m, header);

  2791.         mp_decode_frame(m, decoded_buf, start, fsize);

  2792. 

  2793.         n = MPA_FRAME_SIZE * m->nb_channels;

  2794.         out_size += n * sizeof(OUT_INT);

  2795.         if(s->frames > 1) {

  2796.             /* interleave output data */

  2797.             bp = out_samples + coff[fr];

  2798.             if(m->nb_channels == 1) {

  2799.                 for(j = 0; j < n; j++) {

  2800.                     *bp = decoded_buf[j];

  2801.                     bp += off;

  2802.                 }

  2803.             } else {

  2804.                 for(j = 0; j < n; j++) {

  2805.                     bp[0] = decoded_buf[j++];

  2806.                     bp[1] = decoded_buf[j];

  2807.                     bp += off;

  2808.                 }

  2809.             }

  2810.         }

  2811.     }

  2812. 

  2813.     /* update codec info */

  2814.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  2815.     avctx->frame_size= buf_size;

  2816.     avctx->bit_rate = 0;

  2817.     for (i = 0; i < s->frames; i++)

  2818.         avctx->bit_rate += s->mp3decctx[i]->bit_rate;

  2819. 

  2820.     *data_size = out_size;

  2821.     return buf_size;

  2822. }

  2823. 

  2824. 

  2825. AVCodec mp2_decoder =

  2826. {

  2827.     "mp2",

  2828.     CODEC_TYPE_AUDIO,

  2829.     CODEC_ID_MP2,

  2830.     sizeof(MPADecodeContext),

  2831.     decode_init,

  2832.     NULL,

  2833.     NULL,

  2834.     decode_frame,

  2835.     CODEC_CAP_PARSE_ONLY,

  2836. };

  2837. 

  2838. AVCodec mp3_decoder =

  2839. {

  2840.     "mp3",

  2841.     CODEC_TYPE_AUDIO,

  2842.     CODEC_ID_MP3,

  2843.     sizeof(MPADecodeContext),

  2844.     decode_init,

  2845.     NULL,

  2846.     NULL,

  2847.     decode_frame,

  2848.     CODEC_CAP_PARSE_ONLY,

  2849. };

  2850. 

  2851. AVCodec mp3adu_decoder =

  2852. {

  2853.     "mp3adu",

  2854.     CODEC_TYPE_AUDIO,

  2855.     CODEC_ID_MP3ADU,

  2856.     sizeof(MPADecodeContext),

  2857.     decode_init,

  2858.     NULL,

  2859.     NULL,

  2860.     decode_frame_adu,

  2861.     CODEC_CAP_PARSE_ONLY,

  2862. };

  2863. 

  2864. AVCodec mp3on4_decoder =

  2865. {

  2866.     "mp3on4",

  2867.     CODEC_TYPE_AUDIO,

  2868.     CODEC_ID_MP3ON4,

  2869.     sizeof(MP3On4DecodeContext),

  2870.     decode_init_mp3on4,

  2871.     NULL,

  2872.     decode_close_mp3on4,

  2873.     decode_frame_mp3on4,

  2874.     0

  2875. };