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FFmpeg/libavcodec/mpegaudiodec.c

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  1. /*

  2.  * MPEG Audio decoder

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

  4.  *

  5.  * This 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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 "mpegaudio.h"

  29. #include "dsputil.h"

  30. 

  31. /*

  32.  * TODO:

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

  34.  *  - test lsf / mpeg25 extensively.

  35.  */

  36. 

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

  38.    audio decoder */

  39. #ifdef CONFIG_MPEGAUDIO_HP

  40. #define USE_HIGHPRECISION

  41. #endif

  42. 

  43. #ifdef USE_HIGHPRECISION

  44. #define FRAC_BITS   23   /* fractional bits for sb_samples and dct */

  45. #define WFRAC_BITS  16   /* fractional bits for window */

  46. #else

  47. #define FRAC_BITS   15   /* fractional bits for sb_samples and dct */

  48. #define WFRAC_BITS  14   /* fractional bits for window */

  49. #endif

  50. 

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

  52. typedef int32_t OUT_INT;

  53. #define OUT_MAX INT32_MAX

  54. #define OUT_MIN INT32_MIN

  55. #define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 31)

  56. #else

  57. typedef int16_t OUT_INT;

  58. #define OUT_MAX INT16_MAX

  59. #define OUT_MIN INT16_MIN

  60. #define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)

  61. #endif

  62. 

  63. #define FRAC_ONE    (1 << FRAC_BITS)

  64. 

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

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

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

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

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

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

  71. 

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

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

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

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

  76. }

  77. 

  78. #if FRAC_BITS <= 15

  79. typedef int16_t MPA_INT;

  80. #else

  81. typedef int32_t MPA_INT;

  82. #endif

  83. 

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

  85. 

  86. #define HEADER_SIZE 4

  87. #define BACKSTEP_SIZE 512

  88. 

  89. struct GranuleDef;

  90. 

  91. typedef struct MPADecodeContext {

  92.     uint8_t inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE];	/* input buffer */

  93.     int inbuf_index;

  94.     uint8_t *inbuf_ptr, *inbuf;

  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.     int old_frame_size;

  106.     GetBitContext 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 uint8_t *huff_code_table[16];

  170. static VLC huff_quad_vlc[2];

  171. /* computed from band_size_long */

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

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

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

  175. static int8_t  *table_4_3_exp;

  176. static uint32_t *table_4_3_value;

  177. /* intensity stereo coef table */

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

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

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

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

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

  183. 

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

  185. static uint16_t scale_factor_modshift[64];

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

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

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

  189. 

  190. #define SCALE_GEN(v) \

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

  192. 

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

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

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

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

  197. };

  198. 

  199. void ff_mpa_synth_init(MPA_INT *window);

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

  201.     

  202. /* layer 1 unscaling */

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

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

  205. {

  206.     int shift, mod;

  207.     int64_t val;

  208. 

  209.     shift = scale_factor_modshift[scale_factor];

  210.     mod = shift & 3;

  211.     shift >>= 2;

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

  213.     shift += n;

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

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

  216. }

  217. 

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

  219. {

  220.     int shift, mod, val;

  221. 

  222.     shift = scale_factor_modshift[scale_factor];

  223.     mod = shift & 3;

  224.     shift >>= 2;

  225. 

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

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

  228.     if (shift > 0)

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

  230.     return val;

  231. }

  232. 

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

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

  235. {

  236.     unsigned int m;

  237.     int e;

  238. 

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

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

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

  242.     assert(e>=1);

  243.     if (e > 31)

  244.         return 0;

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

  246. 

  247.     return m;

  248. }

  249. 

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

  251. #define DEV_ORDER 13

  252. 

  253. #define POW_FRAC_BITS 24

  254. #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)

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

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

  257. 

  258. static int dev_4_3_coefs[DEV_ORDER];

  259. 

  260. #if 0 /* unused */

  261. static int pow_mult3[3] = {

  262.     POW_FIX(1.0),

  263.     POW_FIX(1.25992104989487316476),

  264.     POW_FIX(1.58740105196819947474),

  265. };

  266. #endif

  267. 

  268. static void int_pow_init(void)

  269. {

  270.     int i, a;

  271. 

  272.     a = POW_FIX(1.0);

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

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

  275.         dev_4_3_coefs[i] = a;

  276.     }

  277. }

  278. 

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

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

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

  282. {

  283.     int e, er, eq, j;

  284.     int a, a1;

  285.     

  286.     /* renormalize */

  287.     a = i;

  288.     e = POW_FRAC_BITS;

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

  290.         a = a << 1;

  291.         e--;

  292.     }

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

  294.     a1 = 0;

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

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

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

  298.     /* exponent compute (exact) */

  299.     e = e * 4;

  300.     er = e % 3;

  301.     eq = e / 3;

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

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

  304.         a = a >> 1;

  305.         eq++;

  306.     }

  307.     /* convert to float */

  308.     while (a < POW_FRAC_ONE) {

  309.         a = a << 1;

  310.         eq--;

  311.     }

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

  313. #if POW_FRAC_BITS > FRAC_BITS

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

  315.     /* correct overflow */

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

  317.         a = a >> 1;

  318.         eq++;

  319.     }

  320. #endif

  321.     *exp_ptr = eq;

  322.     return a;

  323. }

  324. #endif

  325. 

  326. static int decode_init(AVCodecContext * avctx)

  327. {

  328.     MPADecodeContext *s = avctx->priv_data;

  329.     static int init=0;

  330.     int i, j, k;

  331. 

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

  333.     avctx->sample_fmt= SAMPLE_FMT_S32;

  334. #else

  335.     avctx->sample_fmt= SAMPLE_FMT_S16;

  336. #endif    

  337.     

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

  339.         s->compute_antialias= compute_antialias_integer;

  340.     else

  341.         s->compute_antialias= compute_antialias_float;

  342. 

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

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

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

  346.             int shift, mod;

  347.             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

  348.             shift = (i / 3);

  349.             mod = i % 3;

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

  351.         }

  352. 

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

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

  355.             int n, norm;

  356.             n = i + 2;

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

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

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

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

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

  362.                     i, norm, 

  363.                     scale_factor_mult[i][0],

  364.                     scale_factor_mult[i][1],

  365.                     scale_factor_mult[i][2]);

  366.         }

  367.         

  368. 	ff_mpa_synth_init(window);

  369.         

  370.         /* huffman decode tables */

  371.         huff_code_table[0] = NULL;

  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 *code_table;

  377. 

  378.             xsize = h->xsize;

  379.             n = xsize * xsize;

  380.             /* XXX: fail test */

  381.             init_vlc(&huff_vlc[i], 8, n, 

  382.                      h->bits, 1, 1, h->codes, 2, 2, 1);

  383.             

  384.             code_table = av_mallocz(n);

  385.             j = 0;

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

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

  388.                     code_table[j++] = (x << 4) | y;

  389.             }

  390.             huff_code_table[i] = code_table;

  391.         }

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

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

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

  395.         }

  396. 

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

  398.             k = 0;

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

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

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

  402.             }

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

  404.         }

  405. 

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

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

  408.         if(!table_4_3_exp)

  409. 	    return -1;

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

  411.         if(!table_4_3_value)

  412.             return -1;

  413.         

  414.         int_pow_init();

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

  416.             double f, fm;

  417.             int e, m;

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

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

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

  421.             e+= FRAC_BITS - 31 + 5;

  422. 

  423.             /* normalized to FRAC_BITS */

  424.             table_4_3_value[i] = m;

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

  426.             table_4_3_exp[i] = -e;

  427.         }

  428.         

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

  430.             float f;

  431.             int v;

  432.             if (i != 6) {

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

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

  435.             } else {

  436.                 v = FIXR(1.0);

  437.             }

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

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

  440.         }

  441.         /* invalid values */

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

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

  444. 

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

  446.             double f;

  447.             int e, k;

  448. 

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

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

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

  452.                 k = i & 1;

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

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

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

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

  457.             }

  458.         }

  459. 

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

  461.             float ci, cs, ca;

  462.             ci = ci_table[i];

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

  464.             ca = cs * ci;

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

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

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

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

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

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

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

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

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

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

  475.         }

  476. 

  477.         /* compute mdct windows */

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

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

  480.                 double d;

  481.                 

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

  483.                     continue;

  484.                 

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

  486.                 if(j==1){

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

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

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

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

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

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

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

  494.                 }

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

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

  497. 

  498.                 if(j==2)

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

  500.                 else

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

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

  503.             }

  504.         }

  505. 

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

  507.            the sign of the right window coefs */

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

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

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

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

  512.             }

  513.         }

  514. 

  515. #if defined(DEBUG)

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

  517.             printf("win%d=\n", j);

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

  519.                 printf("%f, ", (double)mdct_win[j][i] / FRAC_ONE);

  520.             printf("\n");

  521.         }

  522. #endif

  523.         init = 1;

  524.     }

  525. 

  526.     s->inbuf_index = 0;

  527.     s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];

  528.     s->inbuf_ptr = s->inbuf;

  529. #ifdef DEBUG

  530.     s->frame_count = 0;

  531. #endif

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

  533.         s->adu_mode = 1;

  534.     return 0;

  535. }

  536. 

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

  538. 

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

  540. 

  541. #define COS0_0  FIXR(0.50060299823519630134)

  542. #define COS0_1  FIXR(0.50547095989754365998)

  543. #define COS0_2  FIXR(0.51544730992262454697)

  544. #define COS0_3  FIXR(0.53104259108978417447)

  545. #define COS0_4  FIXR(0.55310389603444452782)

  546. #define COS0_5  FIXR(0.58293496820613387367)

  547. #define COS0_6  FIXR(0.62250412303566481615)

  548. #define COS0_7  FIXR(0.67480834145500574602)

  549. #define COS0_8  FIXR(0.74453627100229844977)

  550. #define COS0_9  FIXR(0.83934964541552703873)

  551. #define COS0_10 FIXR(0.97256823786196069369)

  552. #define COS0_11 FIXR(1.16943993343288495515)

  553. #define COS0_12 FIXR(1.48416461631416627724)

  554. #define COS0_13 FIXR(2.05778100995341155085)

  555. #define COS0_14 FIXR(3.40760841846871878570)

  556. #define COS0_15 FIXR(10.19000812354805681150)

  557. 

  558. #define COS1_0 FIXR(0.50241928618815570551)

  559. #define COS1_1 FIXR(0.52249861493968888062)

  560. #define COS1_2 FIXR(0.56694403481635770368)

  561. #define COS1_3 FIXR(0.64682178335999012954)

  562. #define COS1_4 FIXR(0.78815462345125022473)

  563. #define COS1_5 FIXR(1.06067768599034747134)

  564. #define COS1_6 FIXR(1.72244709823833392782)

  565. #define COS1_7 FIXR(5.10114861868916385802)

  566. 

  567. #define COS2_0 FIXR(0.50979557910415916894)

  568. #define COS2_1 FIXR(0.60134488693504528054)

  569. #define COS2_2 FIXR(0.89997622313641570463)

  570. #define COS2_3 FIXR(2.56291544774150617881)

  571. 

  572. #define COS3_0 FIXR(0.54119610014619698439)

  573. #define COS3_1 FIXR(1.30656296487637652785)

  574. 

  575. #define COS4_0 FIXR(0.70710678118654752439)

  576. 

  577. /* butterfly operator */

  578. #define BF(a, b, c)\

  579. {\

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

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

  582.     tab[a] = tmp0;\

  583.     tab[b] = MULL(tmp1, c);\

  584. }

  585. 

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

  587. {\

  588.     BF(a, b, COS4_0);\

  589.     BF(c, d, -COS4_0);\

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

  591. }

  592. 

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

  594. {\

  595.     BF(a, b, COS4_0);\

  596.     BF(c, d, -COS4_0);\

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

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

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

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

  601. }

  602. 

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

  604. 

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

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

  607. {

  608.     int tmp0, tmp1;

  609. 

  610.     /* pass 1 */

  611.     BF(0, 31, COS0_0);

  612.     BF(1, 30, COS0_1);

  613.     BF(2, 29, COS0_2);

  614.     BF(3, 28, COS0_3);

  615.     BF(4, 27, COS0_4);

  616.     BF(5, 26, COS0_5);

  617.     BF(6, 25, COS0_6);

  618.     BF(7, 24, COS0_7);

  619.     BF(8, 23, COS0_8);

  620.     BF(9, 22, COS0_9);

  621.     BF(10, 21, COS0_10);

  622.     BF(11, 20, COS0_11);

  623.     BF(12, 19, COS0_12);

  624.     BF(13, 18, COS0_13);

  625.     BF(14, 17, COS0_14);

  626.     BF(15, 16, COS0_15);

  627. 

  628.     /* pass 2 */

  629.     BF(0, 15, COS1_0);

  630.     BF(1, 14, COS1_1);

  631.     BF(2, 13, COS1_2);

  632.     BF(3, 12, COS1_3);

  633.     BF(4, 11, COS1_4);

  634.     BF(5, 10, COS1_5);

  635.     BF(6,  9, COS1_6);

  636.     BF(7,  8, COS1_7);

  637.     

  638.     BF(16, 31, -COS1_0);

  639.     BF(17, 30, -COS1_1);

  640.     BF(18, 29, -COS1_2);

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

  642.     BF(20, 27, -COS1_4);

  643.     BF(21, 26, -COS1_5);

  644.     BF(22, 25, -COS1_6);

  645.     BF(23, 24, -COS1_7);

  646.     

  647.     /* pass 3 */

  648.     BF(0, 7, COS2_0);

  649.     BF(1, 6, COS2_1);

  650.     BF(2, 5, COS2_2);

  651.     BF(3, 4, COS2_3);

  652.     

  653.     BF(8, 15, -COS2_0);

  654.     BF(9, 14, -COS2_1);

  655.     BF(10, 13, -COS2_2);

  656.     BF(11, 12, -COS2_3);

  657.     

  658.     BF(16, 23, COS2_0);

  659.     BF(17, 22, COS2_1);

  660.     BF(18, 21, COS2_2);

  661.     BF(19, 20, COS2_3);

  662.     

  663.     BF(24, 31, -COS2_0);

  664.     BF(25, 30, -COS2_1);

  665.     BF(26, 29, -COS2_2);

  666.     BF(27, 28, -COS2_3);

  667. 

  668.     /* pass 4 */

  669.     BF(0, 3, COS3_0);

  670.     BF(1, 2, COS3_1);

  671.     

  672.     BF(4, 7, -COS3_0);

  673.     BF(5, 6, -COS3_1);

  674.     

  675.     BF(8, 11, COS3_0);

  676.     BF(9, 10, COS3_1);

  677.     

  678.     BF(12, 15, -COS3_0);

  679.     BF(13, 14, -COS3_1);

  680.     

  681.     BF(16, 19, COS3_0);

  682.     BF(17, 18, COS3_1);

  683.     

  684.     BF(20, 23, -COS3_0);

  685.     BF(21, 22, -COS3_1);

  686.     

  687.     BF(24, 27, COS3_0);

  688.     BF(25, 26, COS3_1);

  689.     

  690.     BF(28, 31, -COS3_0);

  691.     BF(29, 30, -COS3_1);

  692.     

  693.     /* pass 5 */

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

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

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

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

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

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

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

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

  702.     

  703.     /* pass 6 */

  704.     

  705.     ADD( 8, 12);

  706.     ADD(12, 10);

  707.     ADD(10, 14);

  708.     ADD(14,  9);

  709.     ADD( 9, 13);

  710.     ADD(13, 11);

  711.     ADD(11, 15);

  712. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  729.     

  730.     ADD(24, 28);

  731.     ADD(28, 26);

  732.     ADD(26, 30);

  733.     ADD(30, 25);

  734.     ADD(25, 29);

  735.     ADD(29, 27);

  736.     ADD(27, 31);

  737. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  754. }

  755. 

  756. #if FRAC_BITS <= 15

  757. 

  758. static inline int round_sample(int *sum)

  759. {

  760.     int sum1;

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

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

  763.     if (sum1 < OUT_MIN)

  764.         sum1 = OUT_MIN;

  765.     else if (sum1 > OUT_MAX)

  766.         sum1 = OUT_MAX;

  767.     return sum1;

  768. }

  769. 

  770. #if defined(ARCH_POWERPC_405)

  771. 

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

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

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

  775. 

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

  777. #define MULS(ra, rb) \

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

  779. 

  780. #else

  781. 

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

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

  784. 

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

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

  787. 

  788. #endif

  789. 

  790. #else

  791. 

  792. static inline int round_sample(int64_t *sum) 

  793. {

  794.     int sum1;

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

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

  797.     if (sum1 < OUT_MIN)

  798.         sum1 = OUT_MIN;

  799.     else if (sum1 > OUT_MAX)

  800.         sum1 = OUT_MAX;

  801.     return sum1;

  802. }

  803. 

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

  805. 

  806. #endif

  807. 

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

  809. {                                               \

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

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

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

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

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

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

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

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

  818. }

  819. 

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

  821. {                                               \

  822.     int tmp;\

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  847. }

  848. 

  849. void ff_mpa_synth_init(MPA_INT *window)

  850. {

  851.     int i;

  852. 

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

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

  855.         int v;

  856.         v = mpa_enwindow[i];

  857. #if WFRAC_BITS < 16

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

  859. #endif

  860.         window[i] = v;

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

  862.             v = -v;

  863.         if (i != 0)

  864.             window[512 - i] = v;

  865.     }	

  866. }

  867. 

  868. /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

  869.    32 samples. */

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

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

  872. 			 MPA_INT *window, int *dither_state,

  873.                          OUT_INT *samples, int incr, 

  874.                          int32_t sb_samples[SBLIMIT])

  875. {

  876.     int32_t tmp[32];

  877.     register MPA_INT *synth_buf;

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

  879.     int j, offset, v;

  880.     OUT_INT *samples2;

  881. #if FRAC_BITS <= 15

  882.     int sum, sum2;

  883. #else

  884.     int64_t sum, sum2;

  885. #endif

  886. 

  887.     dct32(tmp, sb_samples);

  888.     

  889.     offset = *synth_buf_offset;

  890.     synth_buf = synth_buf_ptr + offset;

  891. 

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

  893.         v = tmp[j];

  894. #if FRAC_BITS <= 15

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

  896.            sound */

  897.         if (v > 32767)

  898.             v = 32767;

  899.         else if (v < -32768)

  900.             v = -32768;

  901. #endif

  902.         synth_buf[j] = v;

  903.     }

  904.     /* copy to avoid wrap */

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

  906. 

  907.     samples2 = samples + 31 * incr;

  908.     w = window;

  909.     w2 = window + 31;

  910. 

  911.     sum = *dither_state;

  912.     p = synth_buf + 16;

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

  914.     p = synth_buf + 48;

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

  916.     *samples = round_sample(&sum);

  917.     samples += incr;

  918.     w++;

  919. 

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

  921.        access per two sample */

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

  923.         sum2 = 0;

  924.         p = synth_buf + 16 + j;

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

  926.         p = synth_buf + 48 - j;

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

  928. 

  929.         *samples = round_sample(&sum);

  930.         samples += incr;

  931.         sum += sum2;

  932.         *samples2 = round_sample(&sum);

  933.         samples2 -= incr;

  934.         w++;

  935.         w2--;

  936.     }

  937.     

  938.     p = synth_buf + 32;

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

  940.     *samples = round_sample(&sum);

  941.     *dither_state= sum;

  942. 

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

  944.     *synth_buf_offset = offset;

  945. }

  946. 

  947. #define C3 FIXHR(0.86602540378443864676/2)

  948. 

  949. /* 0.5 / cos(pi*(2*i+1)/36) */

  950. static const int icos36[9] = {

  951.     FIXR(0.50190991877167369479),

  952.     FIXR(0.51763809020504152469), //0

  953.     FIXR(0.55168895948124587824),

  954.     FIXR(0.61038729438072803416),

  955.     FIXR(0.70710678118654752439), //1

  956.     FIXR(0.87172339781054900991),

  957.     FIXR(1.18310079157624925896),

  958.     FIXR(1.93185165257813657349), //2

  959.     FIXR(5.73685662283492756461),

  960. };

  961. 

  962. /* 12 points IMDCT. We compute it "by hand" by factorizing obvious

  963.    cases. */

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

  965. {

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

  967. 

  968.     in0= in[0*3];

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

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

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

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

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

  974.     in5 += in3;

  975.     in3 += in1;

  976. 

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

  978.     in3= MULH(2*in3, C3);

  979.     

  980.     t1 = in0 - in4;

  981.     t2 = MULL(in1 - in5, icos36[4]);

  982. 

  983.     out[ 7]= 

  984.     out[10]= t1 + t2;

  985.     out[ 1]=

  986.     out[ 4]= t1 - t2;

  987. 

  988.     in0 += in4>>1;

  989.     in4 = in0 + in2;

  990.     in1 += in5>>1;

  991.     in5 = MULL(in1 + in3, icos36[1]);    

  992.     out[ 8]= 

  993.     out[ 9]= in4 + in5;

  994.     out[ 2]=

  995.     out[ 3]= in4 - in5;

  996.     

  997.     in0 -= in2;

  998.     in1 = MULL(in1 - in3, icos36[7]);

  999.     out[ 0]=

  1000.     out[ 5]= in0 - in1;

  1001.     out[ 6]=

  1002.     out[11]= in0 + in1;    

  1003. }

  1004. 

  1005. /* cos(pi*i/18) */

  1006. #define C1 FIXHR(0.98480775301220805936/2)

  1007. #define C2 FIXHR(0.93969262078590838405/2)

  1008. #define C3 FIXHR(0.86602540378443864676/2)

  1009. #define C4 FIXHR(0.76604444311897803520/2)

  1010. #define C5 FIXHR(0.64278760968653932632/2)

  1011. #define C6 FIXHR(0.5/2)

  1012. #define C7 FIXHR(0.34202014332566873304/2)

  1013. #define C8 FIXHR(0.17364817766693034885/2)

  1014. 

  1015. 

  1016. /* using Lee like decomposition followed by hand coded 9 points DCT */

  1017. static void imdct36(int *out, int *buf, int *in, int *win)

  1018. {

  1019.     int i, j, t0, t1, t2, t3, s0, s1, s2, s3;

  1020.     int tmp[18], *tmp1, *in1;

  1021. 

  1022.     for(i=17;i>=1;i--)

  1023.         in[i] += in[i-1];

  1024.     for(i=17;i>=3;i-=2)

  1025.         in[i] += in[i-2];

  1026. 

  1027.     for(j=0;j<2;j++) {

  1028.         tmp1 = tmp + j;

  1029.         in1 = in + j;

  1030. #if 0

  1031. //more accurate but slower

  1032.         int64_t t0, t1, t2, t3;

  1033.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1034.         

  1035.         t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;

  1036.         t1 = in1[2*0] - in1[2*6];

  1037.         tmp1[ 6] = t1 - (t2>>1);

  1038.         tmp1[16] = t1 + t2;

  1039. 

  1040.         t0 = MUL64(2*(in1[2*2] + in1[2*4]),    C2);

  1041.         t1 = MUL64(   in1[2*4] - in1[2*8] , -2*C8);

  1042.         t2 = MUL64(2*(in1[2*2] + in1[2*8]),   -C4);

  1043.         

  1044.         tmp1[10] = (t3 - t0 - t2) >> 32;

  1045.         tmp1[ 2] = (t3 + t0 + t1) >> 32;

  1046.         tmp1[14] = (t3 + t2 - t1) >> 32;

  1047.         

  1048.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1049.         t2 = MUL64(2*(in1[2*1] + in1[2*5]),    C1);

  1050.         t3 = MUL64(   in1[2*5] - in1[2*7] , -2*C7);

  1051.         t0 = MUL64(2*in1[2*3], C3);

  1052. 

  1053.         t1 = MUL64(2*(in1[2*1] + in1[2*7]),   -C5);

  1054. 

  1055.         tmp1[ 0] = (t2 + t3 + t0) >> 32;

  1056.         tmp1[12] = (t2 + t1 - t0) >> 32;

  1057.         tmp1[ 8] = (t3 - t1 - t0) >> 32;

  1058. #else

  1059.         t2 = in1[2*4] + in1[2*8] - in1[2*2];

  1060.         

  1061.         t3 = in1[2*0] + (in1[2*6]>>1);

  1062.         t1 = in1[2*0] - in1[2*6];

  1063.         tmp1[ 6] = t1 - (t2>>1);

  1064.         tmp1[16] = t1 + t2;

  1065. 

  1066.         t0 = MULH(2*(in1[2*2] + in1[2*4]),    C2);

  1067.         t1 = MULH(   in1[2*4] - in1[2*8] , -2*C8);

  1068.         t2 = MULH(2*(in1[2*2] + in1[2*8]),   -C4);

  1069.         

  1070.         tmp1[10] = t3 - t0 - t2;

  1071.         tmp1[ 2] = t3 + t0 + t1;

  1072.         tmp1[14] = t3 + t2 - t1;

  1073.         

  1074.         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);

  1075.         t2 = MULH(2*(in1[2*1] + in1[2*5]),    C1);

  1076.         t3 = MULH(   in1[2*5] - in1[2*7] , -2*C7);

  1077.         t0 = MULH(2*in1[2*3], C3);

  1078. 

  1079.         t1 = MULH(2*(in1[2*1] + in1[2*7]),   -C5);

  1080. 

  1081.         tmp1[ 0] = t2 + t3 + t0;

  1082.         tmp1[12] = t2 + t1 - t0;

  1083.         tmp1[ 8] = t3 - t1 - t0;

  1084. #endif

  1085.     }

  1086. 

  1087.     i = 0;

  1088.     for(j=0;j<4;j++) {

  1089.         t0 = tmp[i];

  1090.         t1 = tmp[i + 2];

  1091.         s0 = t1 + t0;

  1092.         s2 = t1 - t0;

  1093. 

  1094.         t2 = tmp[i + 1];

  1095.         t3 = tmp[i + 3];

  1096.         s1 = MULL(t3 + t2, icos36[j]);

  1097.         s3 = MULL(t3 - t2, icos36[8 - j]);

  1098.         

  1099.         t0 = s0 + s1;

  1100.         t1 = s0 - s1;

  1101.         out[(9 + j)*SBLIMIT] =  MULH(t1, win[9 + j]) + buf[9 + j];

  1102.         out[(8 - j)*SBLIMIT] =  MULH(t1, win[8 - j]) + buf[8 - j];

  1103.         buf[9 + j] = MULH(t0, win[18 + 9 + j]);

  1104.         buf[8 - j] = MULH(t0, win[18 + 8 - j]);

  1105.         

  1106.         t0 = s2 + s3;

  1107.         t1 = s2 - s3;

  1108.         out[(9 + 8 - j)*SBLIMIT] =  MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];

  1109.         out[(        j)*SBLIMIT] =  MULH(t1, win[        j]) + buf[        j];

  1110.         buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);

  1111.         buf[      + j] = MULH(t0, win[18         + j]);

  1112.         i += 4;

  1113.     }

  1114. 

  1115.     s0 = tmp[16];

  1116.     s1 = MULL(tmp[17], icos36[4]);

  1117.     t0 = s0 + s1;

  1118.     t1 = s0 - s1;

  1119.     out[(9 + 4)*SBLIMIT] =  MULH(t1, win[9 + 4]) + buf[9 + 4];

  1120.     out[(8 - 4)*SBLIMIT] =  MULH(t1, win[8 - 4]) + buf[8 - 4];

  1121.     buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);

  1122.     buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);

  1123. }

  1124. 

  1125. /* header decoding. MUST check the header before because no

  1126.    consistency check is done there. Return 1 if free format found and

  1127.    that the frame size must be computed externally */

  1128. static int decode_header(MPADecodeContext *s, uint32_t header)

  1129. {

  1130.     int sample_rate, frame_size, mpeg25, padding;

  1131.     int sample_rate_index, bitrate_index;

  1132.     if (header & (1<<20)) {

  1133.         s->lsf = (header & (1<<19)) ? 0 : 1;

  1134.         mpeg25 = 0;

  1135.     } else {

  1136.         s->lsf = 1;

  1137.         mpeg25 = 1;

  1138.     }

  1139.     

  1140.     s->layer = 4 - ((header >> 17) & 3);

  1141.     /* extract frequency */

  1142.     sample_rate_index = (header >> 10) & 3;

  1143.     sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);

  1144.     sample_rate_index += 3 * (s->lsf + mpeg25);

  1145.     s->sample_rate_index = sample_rate_index;

  1146.     s->error_protection = ((header >> 16) & 1) ^ 1;

  1147.     s->sample_rate = sample_rate;

  1148. 

  1149.     bitrate_index = (header >> 12) & 0xf;

  1150.     padding = (header >> 9) & 1;

  1151.     //extension = (header >> 8) & 1;

  1152.     s->mode = (header >> 6) & 3;

  1153.     s->mode_ext = (header >> 4) & 3;

  1154.     //copyright = (header >> 3) & 1;

  1155.     //original = (header >> 2) & 1;

  1156.     //emphasis = header & 3;

  1157. 

  1158.     if (s->mode == MPA_MONO)

  1159.         s->nb_channels = 1;

  1160.     else

  1161.         s->nb_channels = 2;

  1162.     

  1163.     if (bitrate_index != 0) {

  1164.         frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];

  1165.         s->bit_rate = frame_size * 1000;

  1166.         switch(s->layer) {

  1167.         case 1:

  1168.             frame_size = (frame_size * 12000) / sample_rate;

  1169.             frame_size = (frame_size + padding) * 4;

  1170.             break;

  1171.         case 2:

  1172.             frame_size = (frame_size * 144000) / sample_rate;

  1173.             frame_size += padding;

  1174.             break;

  1175.         default:

  1176.         case 3:

  1177.             frame_size = (frame_size * 144000) / (sample_rate << s->lsf);

  1178.             frame_size += padding;

  1179.             break;

  1180.         }

  1181.         s->frame_size = frame_size;

  1182.     } else {

  1183.         /* if no frame size computed, signal it */

  1184.         if (!s->free_format_frame_size)

  1185.             return 1;

  1186.         /* free format: compute bitrate and real frame size from the

  1187.            frame size we extracted by reading the bitstream */

  1188.         s->frame_size = s->free_format_frame_size;

  1189.         switch(s->layer) {

  1190.         case 1:

  1191.             s->frame_size += padding  * 4;

  1192.             s->bit_rate = (s->frame_size * sample_rate) / 48000;

  1193.             break;

  1194.         case 2:

  1195.             s->frame_size += padding;

  1196.             s->bit_rate = (s->frame_size * sample_rate) / 144000;

  1197.             break;

  1198.         default:

  1199.         case 3:

  1200.             s->frame_size += padding;

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

  1202.             break;

  1203.         }

  1204.     }

  1205.     

  1206. #if defined(DEBUG)

  1207.     printf("layer%d, %d Hz, %d kbits/s, ",

  1208.            s->layer, s->sample_rate, s->bit_rate);

  1209.     if (s->nb_channels == 2) {

  1210.         if (s->layer == 3) {

  1211.             if (s->mode_ext & MODE_EXT_MS_STEREO)

  1212.                 printf("ms-");

  1213.             if (s->mode_ext & MODE_EXT_I_STEREO)

  1214.                 printf("i-");

  1215.         }

  1216.         printf("stereo");

  1217.     } else {

  1218.         printf("mono");

  1219.     }

  1220.     printf("\n");

  1221. #endif

  1222.     return 0;

  1223. }

  1224. 

  1225. /* useful helper to get mpeg audio stream infos. Return -1 if error in

  1226.    header, otherwise the coded frame size in bytes */

  1227. int mpa_decode_header(AVCodecContext *avctx, uint32_t head)

  1228. {

  1229.     MPADecodeContext s1, *s = &s1;

  1230.     memset( s, 0, sizeof(MPADecodeContext) );

  1231. 

  1232.     if (ff_mpa_check_header(head) != 0)

  1233.         return -1;

  1234. 

  1235.     if (decode_header(s, head) != 0) {

  1236.         return -1;

  1237.     }

  1238. 

  1239.     switch(s->layer) {

  1240.     case 1:

  1241.         avctx->frame_size = 384;

  1242.         break;

  1243.     case 2:

  1244.         avctx->frame_size = 1152;

  1245.         break;

  1246.     default:

  1247.     case 3:

  1248.         if (s->lsf)

  1249.             avctx->frame_size = 576;

  1250.         else

  1251.             avctx->frame_size = 1152;

  1252.         break;

  1253.     }

  1254. 

  1255.     avctx->sample_rate = s->sample_rate;

  1256.     avctx->channels = s->nb_channels;

  1257.     avctx->bit_rate = s->bit_rate;

  1258.     avctx->sub_id = s->layer;

  1259.     return s->frame_size;

  1260. }

  1261. 

  1262. /* return the number of decoded frames */

  1263. static int mp_decode_layer1(MPADecodeContext *s)

  1264. {

  1265.     int bound, i, v, n, ch, j, mant;

  1266.     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];

  1267.     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];

  1268. 

  1269.     if (s->mode == MPA_JSTEREO) 

  1270.         bound = (s->mode_ext + 1) * 4;

  1271.     else

  1272.         bound = SBLIMIT;

  1273. 

  1274.     /* allocation bits */

  1275.     for(i=0;i<bound;i++) {

  1276.         for(ch=0;ch<s->nb_channels;ch++) {

  1277.             allocation[ch][i] = get_bits(&s->gb, 4);

  1278.         }

  1279.     }

  1280.     for(i=bound;i<SBLIMIT;i++) {

  1281.         allocation[0][i] = get_bits(&s->gb, 4);

  1282.     }

  1283. 

  1284.     /* scale factors */

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

  1286.         for(ch=0;ch<s->nb_channels;ch++) {

  1287.             if (allocation[ch][i])

  1288.                 scale_factors[ch][i] = get_bits(&s->gb, 6);

  1289.         }

  1290.     }

  1291.     for(i=bound;i<SBLIMIT;i++) {

  1292.         if (allocation[0][i]) {

  1293.             scale_factors[0][i] = get_bits(&s->gb, 6);

  1294.             scale_factors[1][i] = get_bits(&s->gb, 6);

  1295.         }

  1296.     }

  1297.     

  1298.     /* compute samples */

  1299.     for(j=0;j<12;j++) {

  1300.         for(i=0;i<bound;i++) {

  1301.             for(ch=0;ch<s->nb_channels;ch++) {

  1302.                 n = allocation[ch][i];

  1303.                 if (n) {

  1304.                     mant = get_bits(&s->gb, n + 1);

  1305.                     v = l1_unscale(n, mant, scale_factors[ch][i]);

  1306.                 } else {

  1307.                     v = 0;

  1308.                 }

  1309.                 s->sb_samples[ch][j][i] = v;

  1310.             }

  1311.         }

  1312.         for(i=bound;i<SBLIMIT;i++) {

  1313.             n = allocation[0][i];

  1314.             if (n) {

  1315.                 mant = get_bits(&s->gb, n + 1);

  1316.                 v = l1_unscale(n, mant, scale_factors[0][i]);

  1317.                 s->sb_samples[0][j][i] = v;

  1318.                 v = l1_unscale(n, mant, scale_factors[1][i]);

  1319.                 s->sb_samples[1][j][i] = v;

  1320.             } else {

  1321.                 s->sb_samples[0][j][i] = 0;

  1322.                 s->sb_samples[1][j][i] = 0;

  1323.             }

  1324.         }

  1325.     }

  1326.     return 12;

  1327. }

  1328. 

  1329. /* bitrate is in kb/s */

  1330. int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)

  1331. {

  1332.     int ch_bitrate, table;

  1333.     

  1334.     ch_bitrate = bitrate / nb_channels;

  1335.     if (!lsf) {

  1336.         if ((freq == 48000 && ch_bitrate >= 56) ||

  1337.             (ch_bitrate >= 56 && ch_bitrate <= 80)) 

  1338.             table = 0;

  1339.         else if (freq != 48000 && ch_bitrate >= 96) 

  1340.             table = 1;

  1341.         else if (freq != 32000 && ch_bitrate <= 48) 

  1342.             table = 2;

  1343.         else 

  1344.             table = 3;

  1345.     } else {

  1346.         table = 4;

  1347.     }

  1348.     return table;

  1349. }

  1350. 

  1351. static int mp_decode_layer2(MPADecodeContext *s)

  1352. {

  1353.     int sblimit; /* number of used subbands */

  1354.     const unsigned char *alloc_table;

  1355.     int table, bit_alloc_bits, i, j, ch, bound, v;

  1356.     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];

  1357.     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];

  1358.     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;

  1359.     int scale, qindex, bits, steps, k, l, m, b;

  1360. 

  1361.     /* select decoding table */

  1362.     table = l2_select_table(s->bit_rate / 1000, s->nb_channels, 

  1363.                             s->sample_rate, s->lsf);

  1364.     sblimit = sblimit_table[table];

  1365.     alloc_table = alloc_tables[table];

  1366. 

  1367.     if (s->mode == MPA_JSTEREO) 

  1368.         bound = (s->mode_ext + 1) * 4;

  1369.     else

  1370.         bound = sblimit;

  1371. 

  1372.     dprintf("bound=%d sblimit=%d\n", bound, sblimit);

  1373. 

  1374.     /* sanity check */

  1375.     if( bound > sblimit ) bound = sblimit;

  1376. 

  1377.     /* parse bit allocation */

  1378.     j = 0;

  1379.     for(i=0;i<bound;i++) {

  1380.         bit_alloc_bits = alloc_table[j];

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

  1382.             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);

  1383.         }

  1384.         j += 1 << bit_alloc_bits;

  1385.     }

  1386.     for(i=bound;i<sblimit;i++) {

  1387.         bit_alloc_bits = alloc_table[j];

  1388.         v = get_bits(&s->gb, bit_alloc_bits);

  1389.         bit_alloc[0][i] = v;

  1390.         bit_alloc[1][i] = v;

  1391.         j += 1 << bit_alloc_bits;

  1392.     }

  1393. 

  1394. #ifdef DEBUG

  1395.     {

  1396.         for(ch=0;ch<s->nb_channels;ch++) {

  1397.             for(i=0;i<sblimit;i++)

  1398.                 printf(" %d", bit_alloc[ch][i]);

  1399.             printf("\n");

  1400.         }

  1401.     }

  1402. #endif

  1403. 

  1404.     /* scale codes */

  1405.     for(i=0;i<sblimit;i++) {

  1406.         for(ch=0;ch<s->nb_channels;ch++) {

  1407.             if (bit_alloc[ch][i]) 

  1408.                 scale_code[ch][i] = get_bits(&s->gb, 2);

  1409.         }

  1410.     }

  1411.     

  1412.     /* scale factors */

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

  1414.         for(ch=0;ch<s->nb_channels;ch++) {

  1415.             if (bit_alloc[ch][i]) {

  1416.                 sf = scale_factors[ch][i];

  1417.                 switch(scale_code[ch][i]) {

  1418.                 default:

  1419.                 case 0:

  1420.                     sf[0] = get_bits(&s->gb, 6);

  1421.                     sf[1] = get_bits(&s->gb, 6);

  1422.                     sf[2] = get_bits(&s->gb, 6);

  1423.                     break;

  1424.                 case 2:

  1425.                     sf[0] = get_bits(&s->gb, 6);

  1426.                     sf[1] = sf[0];

  1427.                     sf[2] = sf[0];

  1428.                     break;

  1429.                 case 1:

  1430.                     sf[0] = get_bits(&s->gb, 6);

  1431.                     sf[2] = get_bits(&s->gb, 6);

  1432.                     sf[1] = sf[0];

  1433.                     break;

  1434.                 case 3:

  1435.                     sf[0] = get_bits(&s->gb, 6);

  1436.                     sf[2] = get_bits(&s->gb, 6);

  1437.                     sf[1] = sf[2];

  1438.                     break;

  1439.                 }

  1440.             }

  1441.         }

  1442.     }

  1443. 

  1444. #ifdef DEBUG

  1445.     for(ch=0;ch<s->nb_channels;ch++) {

  1446.         for(i=0;i<sblimit;i++) {

  1447.             if (bit_alloc[ch][i]) {

  1448.                 sf = scale_factors[ch][i];

  1449.                 printf(" %d %d %d", sf[0], sf[1], sf[2]);

  1450.             } else {

  1451.                 printf(" -");

  1452.             }

  1453.         }

  1454.         printf("\n");

  1455.     }

  1456. #endif

  1457. 

  1458.     /* samples */

  1459.     for(k=0;k<3;k++) {

  1460.         for(l=0;l<12;l+=3) {

  1461.             j = 0;

  1462.             for(i=0;i<bound;i++) {

  1463.                 bit_alloc_bits = alloc_table[j];

  1464.                 for(ch=0;ch<s->nb_channels;ch++) {

  1465.                     b = bit_alloc[ch][i];

  1466.                     if (b) {

  1467.                         scale = scale_factors[ch][i][k];

  1468.                         qindex = alloc_table[j+b];

  1469.                         bits = quant_bits[qindex];

  1470.                         if (bits < 0) {

  1471.                             /* 3 values at the same time */

  1472.                             v = get_bits(&s->gb, -bits);

  1473.                             steps = quant_steps[qindex];

  1474.                             s->sb_samples[ch][k * 12 + l + 0][i] = 

  1475.                                 l2_unscale_group(steps, v % steps, scale);

  1476.                             v = v / steps;

  1477.                             s->sb_samples[ch][k * 12 + l + 1][i] = 

  1478.                                 l2_unscale_group(steps, v % steps, scale);

  1479.                             v = v / steps;

  1480.                             s->sb_samples[ch][k * 12 + l + 2][i] = 

  1481.                                 l2_unscale_group(steps, v, scale);

  1482.                         } else {

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

  1484.                                 v = get_bits(&s->gb, bits);

  1485.                                 v = l1_unscale(bits - 1, v, scale);

  1486.                                 s->sb_samples[ch][k * 12 + l + m][i] = v;

  1487.                             }

  1488.                         }

  1489.                     } else {

  1490.                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1491.                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1492.                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1493.                     }

  1494.                 }

  1495.                 /* next subband in alloc table */

  1496.                 j += 1 << bit_alloc_bits; 

  1497.             }

  1498.             /* XXX: find a way to avoid this duplication of code */

  1499.             for(i=bound;i<sblimit;i++) {

  1500.                 bit_alloc_bits = alloc_table[j];

  1501.                 b = bit_alloc[0][i];

  1502.                 if (b) {

  1503.                     int mant, scale0, scale1;

  1504.                     scale0 = scale_factors[0][i][k];

  1505.                     scale1 = scale_factors[1][i][k];

  1506.                     qindex = alloc_table[j+b];

  1507.                     bits = quant_bits[qindex];

  1508.                     if (bits < 0) {

  1509.                         /* 3 values at the same time */

  1510.                         v = get_bits(&s->gb, -bits);

  1511.                         steps = quant_steps[qindex];

  1512.                         mant = v % steps;

  1513.                         v = v / steps;

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

  1515.                             l2_unscale_group(steps, mant, scale0);

  1516.                         s->sb_samples[1][k * 12 + l + 0][i] = 

  1517.                             l2_unscale_group(steps, mant, scale1);

  1518.                         mant = v % steps;

  1519.                         v = v / steps;

  1520.                         s->sb_samples[0][k * 12 + l + 1][i] = 

  1521.                             l2_unscale_group(steps, mant, scale0);

  1522.                         s->sb_samples[1][k * 12 + l + 1][i] = 

  1523.                             l2_unscale_group(steps, mant, scale1);

  1524.                         s->sb_samples[0][k * 12 + l + 2][i] = 

  1525.                             l2_unscale_group(steps, v, scale0);

  1526.                         s->sb_samples[1][k * 12 + l + 2][i] = 

  1527.                             l2_unscale_group(steps, v, scale1);

  1528.                     } else {

  1529.                         for(m=0;m<3;m++) {

  1530.                             mant = get_bits(&s->gb, bits);

  1531.                             s->sb_samples[0][k * 12 + l + m][i] = 

  1532.                                 l1_unscale(bits - 1, mant, scale0);

  1533.                             s->sb_samples[1][k * 12 + l + m][i] = 

  1534.                                 l1_unscale(bits - 1, mant, scale1);

  1535.                         }

  1536.                     }

  1537.                 } else {

  1538.                     s->sb_samples[0][k * 12 + l + 0][i] = 0;

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

  1540.                     s->sb_samples[0][k * 12 + l + 2][i] = 0;

  1541.                     s->sb_samples[1][k * 12 + l + 0][i] = 0;

  1542.                     s->sb_samples[1][k * 12 + l + 1][i] = 0;

  1543.                     s->sb_samples[1][k * 12 + l + 2][i] = 0;

  1544.                 }

  1545.                 /* next subband in alloc table */

  1546.                 j += 1 << bit_alloc_bits; 

  1547.             }

  1548.             /* fill remaining samples to zero */

  1549.             for(i=sblimit;i<SBLIMIT;i++) {

  1550.                 for(ch=0;ch<s->nb_channels;ch++) {

  1551.                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;

  1552.                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;

  1553.                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;

  1554.                 }

  1555.             }

  1556.         }

  1557.     }

  1558.     return 3 * 12;

  1559. }

  1560. 

  1561. /*

  1562.  * Seek back in the stream for backstep bytes (at most 511 bytes)

  1563.  */

  1564. static void seek_to_maindata(MPADecodeContext *s, unsigned int backstep)

  1565. {

  1566.     uint8_t *ptr;

  1567. 

  1568.     /* compute current position in stream */

  1569.     ptr = (uint8_t *)(s->gb.buffer + (get_bits_count(&s->gb)>>3));

  1570. 

  1571.     /* copy old data before current one */

  1572.     ptr -= backstep;

  1573.     memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] + 

  1574.            BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);

  1575.     /* init get bits again */

  1576.     init_get_bits(&s->gb, ptr, (s->frame_size + backstep)*8);

  1577. 

  1578.     /* prepare next buffer */

  1579.     s->inbuf_index ^= 1;

  1580.     s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];

  1581.     s->old_frame_size = s->frame_size;

  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);

  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);

  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_pos)

  1653. {

  1654.     int s_index;

  1655.     int linbits, code, x, y, l, v, i, j, k, pos;

  1656.     GetBitContext last_gb;

  1657.     VLC *vlc;

  1658.     uint8_t *code_table;

  1659. 

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

  1661.     s_index = 0;

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

  1663.         j = g->region_size[i];

  1664.         if (j == 0)

  1665.             continue;

  1666.         /* select vlc table */

  1667.         k = g->table_select[i];

  1668.         l = mpa_huff_data[k][0];

  1669.         linbits = mpa_huff_data[k][1];

  1670.         vlc = &huff_vlc[l];

  1671.         code_table = huff_code_table[l];

  1672. 

  1673.         /* read huffcode and compute each couple */

  1674.         for(;j>0;j--) {

  1675.             if (get_bits_count(&s->gb) >= end_pos)

  1676.                 break;

  1677.             if (code_table) {

  1678.                 code = get_vlc(&s->gb, vlc);

  1679.                 if (code < 0)

  1680.                     return -1;

  1681.                 y = code_table[code];

  1682.                 x = y >> 4;

  1683.                 y = y & 0x0f;

  1684.             } else {

  1685.                 x = 0;

  1686.                 y = 0;

  1687.             }

  1688.             dprintf("region=%d n=%d x=%d y=%d exp=%d\n", 

  1689.                     i, g->region_size[i] - j, x, y, exponents[s_index]);

  1690.             if (x) {

  1691.                 if (x == 15)

  1692.                     x += get_bitsz(&s->gb, linbits);

  1693.                 v = l3_unscale(x, exponents[s_index]);

  1694.                 if (get_bits1(&s->gb))

  1695.                     v = -v;

  1696.             } else {

  1697.                 v = 0;

  1698.             }

  1699.             g->sb_hybrid[s_index++] = v;

  1700.             if (y) {

  1701.                 if (y == 15)

  1702.                     y += get_bitsz(&s->gb, linbits);

  1703.                 v = l3_unscale(y, exponents[s_index]);

  1704.                 if (get_bits1(&s->gb))

  1705.                     v = -v;

  1706.             } else {

  1707.                 v = 0;

  1708.             }

  1709.             g->sb_hybrid[s_index++] = v;

  1710.         }

  1711.     }

  1712.             

  1713.     /* high frequencies */

  1714.     vlc = &huff_quad_vlc[g->count1table_select];

  1715.     last_gb.buffer = NULL;

  1716.     while (s_index <= 572) {

  1717.         pos = get_bits_count(&s->gb);

  1718.         if (pos >= end_pos) {

  1719.             if (pos > end_pos && last_gb.buffer != NULL) {

  1720.                 /* some encoders generate an incorrect size for this

  1721.                    part. We must go back into the data */

  1722.                 s_index -= 4;

  1723.                 s->gb = last_gb;

  1724.             }

  1725.             break;

  1726.         }

  1727.         last_gb= s->gb;

  1728. 

  1729.         code = get_vlc(&s->gb, vlc);

  1730.         dprintf("t=%d code=%d\n", g->count1table_select, code);

  1731.         if (code < 0)

  1732.             return -1;

  1733.         for(i=0;i<4;i++) {

  1734.             if (code & (8 >> i)) {

  1735.                 /* non zero value. Could use a hand coded function for

  1736.                    'one' value */

  1737.                 v = l3_unscale(1, exponents[s_index]);

  1738.                 if(get_bits1(&s->gb))

  1739.                     v = -v;

  1740.             } else {

  1741.                 v = 0;

  1742.             }

  1743.             g->sb_hybrid[s_index++] = v;

  1744.         }

  1745.     }

  1746.     while (s_index < 576)

  1747.         g->sb_hybrid[s_index++] = 0;

  1748.     return 0;

  1749. }

  1750. 

  1751. /* Reorder short blocks from bitstream order to interleaved order. It

  1752.    would be faster to do it in parsing, but the code would be far more

  1753.    complicated */

  1754. static void reorder_block(MPADecodeContext *s, GranuleDef *g)

  1755. {

  1756.     int i, j, k, len;

  1757.     int32_t *ptr, *dst, *ptr1;

  1758.     int32_t tmp[576];

  1759. 

  1760.     if (g->block_type != 2)

  1761.         return;

  1762. 

  1763.     if (g->switch_point) {

  1764.         if (s->sample_rate_index != 8) {

  1765.             ptr = g->sb_hybrid + 36;

  1766.         } else {

  1767.             ptr = g->sb_hybrid + 48;

  1768.         }

  1769.     } else {

  1770.         ptr = g->sb_hybrid;

  1771.     }

  1772.     

  1773.     for(i=g->short_start;i<13;i++) {

  1774.         len = band_size_short[s->sample_rate_index][i];

  1775.         ptr1 = ptr;

  1776.         for(k=0;k<3;k++) {

  1777.             dst = tmp + k;

  1778.             for(j=len;j>0;j--) {

  1779.                 *dst = *ptr++;

  1780.                 dst += 3;

  1781.             }

  1782.         }

  1783.         memcpy(ptr1, tmp, len * 3 * sizeof(int32_t));

  1784.     }

  1785. }

  1786. 

  1787. #define ISQRT2 FIXR(0.70710678118654752440)

  1788. 

  1789. static void compute_stereo(MPADecodeContext *s,

  1790.                            GranuleDef *g0, GranuleDef *g1)

  1791. {

  1792.     int i, j, k, l;

  1793.     int32_t v1, v2;

  1794.     int sf_max, tmp0, tmp1, sf, len, non_zero_found;

  1795.     int32_t (*is_tab)[16];

  1796.     int32_t *tab0, *tab1;

  1797.     int non_zero_found_short[3];

  1798. 

  1799.     /* intensity stereo */

  1800.     if (s->mode_ext & MODE_EXT_I_STEREO) {

  1801.         if (!s->lsf) {

  1802.             is_tab = is_table;

  1803.             sf_max = 7;

  1804.         } else {

  1805.             is_tab = is_table_lsf[g1->scalefac_compress & 1];

  1806.             sf_max = 16;

  1807.         }

  1808.             

  1809.         tab0 = g0->sb_hybrid + 576;

  1810.         tab1 = g1->sb_hybrid + 576;

  1811. 

  1812.         non_zero_found_short[0] = 0;

  1813.         non_zero_found_short[1] = 0;

  1814.         non_zero_found_short[2] = 0;

  1815.         k = (13 - g1->short_start) * 3 + g1->long_end - 3;

  1816.         for(i = 12;i >= g1->short_start;i--) {

  1817.             /* for last band, use previous scale factor */

  1818.             if (i != 11)

  1819.                 k -= 3;

  1820.             len = band_size_short[s->sample_rate_index][i];

  1821.             for(l=2;l>=0;l--) {

  1822.                 tab0 -= len;

  1823.                 tab1 -= len;

  1824.                 if (!non_zero_found_short[l]) {

  1825.                     /* test if non zero band. if so, stop doing i-stereo */

  1826.                     for(j=0;j<len;j++) {

  1827.                         if (tab1[j] != 0) {

  1828.                             non_zero_found_short[l] = 1;

  1829.                             goto found1;

  1830.                         }

  1831.                     }

  1832.                     sf = g1->scale_factors[k + l];

  1833.                     if (sf >= sf_max)

  1834.                         goto found1;

  1835. 

  1836.                     v1 = is_tab[0][sf];

  1837.                     v2 = is_tab[1][sf];

  1838.                     for(j=0;j<len;j++) {

  1839.                         tmp0 = tab0[j];

  1840.                         tab0[j] = MULL(tmp0, v1);

  1841.                         tab1[j] = MULL(tmp0, v2);

  1842.                     }

  1843.                 } else {

  1844.                 found1:

  1845.                     if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1846.                         /* lower part of the spectrum : do ms stereo

  1847.                            if enabled */

  1848.                         for(j=0;j<len;j++) {

  1849.                             tmp0 = tab0[j];

  1850.                             tmp1 = tab1[j];

  1851.                             tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1852.                             tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1853.                         }

  1854.                     }

  1855.                 }

  1856.             }

  1857.         }

  1858. 

  1859.         non_zero_found = non_zero_found_short[0] | 

  1860.             non_zero_found_short[1] | 

  1861.             non_zero_found_short[2];

  1862. 

  1863.         for(i = g1->long_end - 1;i >= 0;i--) {

  1864.             len = band_size_long[s->sample_rate_index][i];

  1865.             tab0 -= len;

  1866.             tab1 -= len;

  1867.             /* test if non zero band. if so, stop doing i-stereo */

  1868.             if (!non_zero_found) {

  1869.                 for(j=0;j<len;j++) {

  1870.                     if (tab1[j] != 0) {

  1871.                         non_zero_found = 1;

  1872.                         goto found2;

  1873.                     }

  1874.                 }

  1875.                 /* for last band, use previous scale factor */

  1876.                 k = (i == 21) ? 20 : i;

  1877.                 sf = g1->scale_factors[k];

  1878.                 if (sf >= sf_max)

  1879.                     goto found2;

  1880.                 v1 = is_tab[0][sf];

  1881.                 v2 = is_tab[1][sf];

  1882.                 for(j=0;j<len;j++) {

  1883.                     tmp0 = tab0[j];

  1884.                     tab0[j] = MULL(tmp0, v1);

  1885.                     tab1[j] = MULL(tmp0, v2);

  1886.                 }

  1887.             } else {

  1888.             found2:

  1889.                 if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1890.                     /* lower part of the spectrum : do ms stereo

  1891.                        if enabled */

  1892.                     for(j=0;j<len;j++) {

  1893.                         tmp0 = tab0[j];

  1894.                         tmp1 = tab1[j];

  1895.                         tab0[j] = MULL(tmp0 + tmp1, ISQRT2);

  1896.                         tab1[j] = MULL(tmp0 - tmp1, ISQRT2);

  1897.                     }

  1898.                 }

  1899.             }

  1900.         }

  1901.     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {

  1902.         /* ms stereo ONLY */

  1903.         /* NOTE: the 1/sqrt(2) normalization factor is included in the

  1904.            global gain */

  1905.         tab0 = g0->sb_hybrid;

  1906.         tab1 = g1->sb_hybrid;

  1907.         for(i=0;i<576;i++) {

  1908.             tmp0 = tab0[i];

  1909.             tmp1 = tab1[i];

  1910.             tab0[i] = tmp0 + tmp1;

  1911.             tab1[i] = tmp0 - tmp1;

  1912.         }

  1913.     }

  1914. }

  1915. 

  1916. static void compute_antialias_integer(MPADecodeContext *s,

  1917.                               GranuleDef *g)

  1918. {

  1919.     int32_t *ptr, *csa;

  1920.     int n, i;

  1921. 

  1922.     /* we antialias only "long" bands */

  1923.     if (g->block_type == 2) {

  1924.         if (!g->switch_point)

  1925.             return;

  1926.         /* XXX: check this for 8000Hz case */

  1927.         n = 1;

  1928.     } else {

  1929.         n = SBLIMIT - 1;

  1930.     }

  1931.     

  1932.     ptr = g->sb_hybrid + 18;

  1933.     for(i = n;i > 0;i--) {

  1934.         int tmp0, tmp1, tmp2;

  1935.         csa = &csa_table[0][0];

  1936. #define INT_AA(j) \

  1937.             tmp0 = ptr[-1-j];\

  1938.             tmp1 = ptr[   j];\

  1939.             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\

  1940.             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\

  1941.             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));

  1942. 

  1943.         INT_AA(0)

  1944.         INT_AA(1)

  1945.         INT_AA(2)

  1946.         INT_AA(3)

  1947.         INT_AA(4)

  1948.         INT_AA(5)

  1949.         INT_AA(6)

  1950.         INT_AA(7)

  1951.             

  1952.         ptr += 18;       

  1953.     }

  1954. }

  1955. 

  1956. static void compute_antialias_float(MPADecodeContext *s,

  1957.                               GranuleDef *g)

  1958. {

  1959.     int32_t *ptr;

  1960.     int n, i;

  1961. 

  1962.     /* we antialias only "long" bands */

  1963.     if (g->block_type == 2) {

  1964.         if (!g->switch_point)

  1965.             return;

  1966.         /* XXX: check this for 8000Hz case */

  1967.         n = 1;

  1968.     } else {

  1969.         n = SBLIMIT - 1;

  1970.     }

  1971.     

  1972.     ptr = g->sb_hybrid + 18;

  1973.     for(i = n;i > 0;i--) {

  1974.         float tmp0, tmp1;

  1975.         float *csa = &csa_table_float[0][0];       

  1976. #define FLOAT_AA(j)\

  1977.         tmp0= ptr[-1-j];\

  1978.         tmp1= ptr[   j];\

  1979.         ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\

  1980.         ptr[   j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);

  1981.         

  1982.         FLOAT_AA(0)

  1983.         FLOAT_AA(1)

  1984.         FLOAT_AA(2)

  1985.         FLOAT_AA(3)

  1986.         FLOAT_AA(4)

  1987.         FLOAT_AA(5)

  1988.         FLOAT_AA(6)

  1989.         FLOAT_AA(7)

  1990. 

  1991.         ptr += 18;       

  1992.     }

  1993. }

  1994. 

  1995. static void compute_imdct(MPADecodeContext *s,

  1996.                           GranuleDef *g, 

  1997.                           int32_t *sb_samples,

  1998.                           int32_t *mdct_buf)

  1999. {

  2000.     int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;

  2001.     int32_t out2[12];

  2002.     int i, j, mdct_long_end, v, sblimit;

  2003. 

  2004.     /* find last non zero block */

  2005.     ptr = g->sb_hybrid + 576;

  2006.     ptr1 = g->sb_hybrid + 2 * 18;

  2007.     while (ptr >= ptr1) {

  2008.         ptr -= 6;

  2009.         v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];

  2010.         if (v != 0)

  2011.             break;

  2012.     }

  2013.     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;

  2014. 

  2015.     if (g->block_type == 2) {

  2016.         /* XXX: check for 8000 Hz */

  2017.         if (g->switch_point)

  2018.             mdct_long_end = 2;

  2019.         else

  2020.             mdct_long_end = 0;

  2021.     } else {

  2022.         mdct_long_end = sblimit;

  2023.     }

  2024. 

  2025.     buf = mdct_buf;

  2026.     ptr = g->sb_hybrid;

  2027.     for(j=0;j<mdct_long_end;j++) {

  2028.         /* apply window & overlap with previous buffer */

  2029.         out_ptr = sb_samples + j;

  2030.         /* select window */

  2031.         if (g->switch_point && j < 2)

  2032.             win1 = mdct_win[0];

  2033.         else

  2034.             win1 = mdct_win[g->block_type];

  2035.         /* select frequency inversion */

  2036.         win = win1 + ((4 * 36) & -(j & 1));

  2037.         imdct36(out_ptr, buf, ptr, win);

  2038.         out_ptr += 18*SBLIMIT;

  2039.         ptr += 18;

  2040.         buf += 18;

  2041.     }

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

  2043.         /* select frequency inversion */

  2044.         win = mdct_win[2] + ((4 * 36) & -(j & 1));

  2045.         out_ptr = sb_samples + j;

  2046.         

  2047.         for(i=0; i<6; i++){

  2048.             *out_ptr = buf[i];

  2049.             out_ptr += SBLIMIT;

  2050.         }

  2051.         imdct12(out2, ptr + 0);

  2052.         for(i=0;i<6;i++) {

  2053.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];

  2054.             buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);

  2055.             out_ptr += SBLIMIT;

  2056.         }

  2057.         imdct12(out2, ptr + 1);

  2058.         for(i=0;i<6;i++) {

  2059.             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];

  2060.             buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);

  2061.             out_ptr += SBLIMIT;

  2062.         }

  2063.         imdct12(out2, ptr + 2);

  2064.         for(i=0;i<6;i++) {

  2065.             buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];

  2066.             buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);

  2067.             buf[i + 6*2] = 0;

  2068.         }

  2069.         ptr += 18;

  2070.         buf += 18;

  2071.     }

  2072.     /* zero bands */

  2073.     for(j=sblimit;j<SBLIMIT;j++) {

  2074.         /* overlap */

  2075.         out_ptr = sb_samples + j;

  2076.         for(i=0;i<18;i++) {

  2077.             *out_ptr = buf[i];

  2078.             buf[i] = 0;

  2079.             out_ptr += SBLIMIT;

  2080.         }

  2081.         buf += 18;

  2082.     }

  2083. }

  2084. 

  2085. #if defined(DEBUG)

  2086. void sample_dump(int fnum, int32_t *tab, int n)

  2087. {

  2088.     static FILE *files[16], *f;

  2089.     char buf[512];

  2090.     int i;

  2091.     int32_t v;

  2092.     

  2093.     f = files[fnum];

  2094.     if (!f) {

  2095.         snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm", 

  2096.                 fnum, 

  2097. #ifdef USE_HIGHPRECISION

  2098.                 "hp"

  2099. #else

  2100.                 "lp"

  2101. #endif

  2102.                 );

  2103.         f = fopen(buf, "w");

  2104.         if (!f)

  2105.             return;

  2106.         files[fnum] = f;

  2107.     }

  2108.     

  2109.     if (fnum == 0) {

  2110.         static int pos = 0;

  2111.         av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos);

  2112.         for(i=0;i<n;i++) {

  2113.             av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE);

  2114.             if ((i % 18) == 17)

  2115.                 av_log(NULL, AV_LOG_DEBUG, "\n");

  2116.         }

  2117.         pos += n;

  2118.     }

  2119.     for(i=0;i<n;i++) {

  2120.         /* normalize to 23 frac bits */

  2121.         v = tab[i] << (23 - FRAC_BITS);

  2122.         fwrite(&v, 1, sizeof(int32_t), f);

  2123.     }

  2124. }

  2125. #endif

  2126. 

  2127. 

  2128. /* main layer3 decoding function */

  2129. static int mp_decode_layer3(MPADecodeContext *s)

  2130. {

  2131.     int nb_granules, main_data_begin, private_bits;

  2132.     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos, bits_left;

  2133.     GranuleDef granules[2][2], *g;

  2134.     int16_t exponents[576];

  2135. 

  2136.     /* read side info */

  2137.     if (s->lsf) {

  2138.         main_data_begin = get_bits(&s->gb, 8);

  2139.         if (s->nb_channels == 2)

  2140.             private_bits = get_bits(&s->gb, 2);

  2141.         else

  2142.             private_bits = get_bits(&s->gb, 1);

  2143.         nb_granules = 1;

  2144.     } else {

  2145.         main_data_begin = get_bits(&s->gb, 9);

  2146.         if (s->nb_channels == 2)

  2147.             private_bits = get_bits(&s->gb, 3);

  2148.         else

  2149.             private_bits = get_bits(&s->gb, 5);

  2150.         nb_granules = 2;

  2151.         for(ch=0;ch<s->nb_channels;ch++) {

  2152.             granules[ch][0].scfsi = 0; /* all scale factors are transmitted */

  2153.             granules[ch][1].scfsi = get_bits(&s->gb, 4);

  2154.         }

  2155.     }

  2156.     

  2157.     for(gr=0;gr<nb_granules;gr++) {

  2158.         for(ch=0;ch<s->nb_channels;ch++) {

  2159.             dprintf("gr=%d ch=%d: side_info\n", gr, ch);

  2160.             g = &granules[ch][gr];

  2161.             g->part2_3_length = get_bits(&s->gb, 12);

  2162.             g->big_values = get_bits(&s->gb, 9);

  2163.             g->global_gain = get_bits(&s->gb, 8);

  2164.             /* if MS stereo only is selected, we precompute the

  2165.                1/sqrt(2) renormalization factor */

  2166.             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) == 

  2167.                 MODE_EXT_MS_STEREO)

  2168.                 g->global_gain -= 2;

  2169.             if (s->lsf)

  2170.                 g->scalefac_compress = get_bits(&s->gb, 9);

  2171.             else

  2172.                 g->scalefac_compress = get_bits(&s->gb, 4);

  2173.             blocksplit_flag = get_bits(&s->gb, 1);

  2174.             if (blocksplit_flag) {

  2175.                 g->block_type = get_bits(&s->gb, 2);

  2176.                 if (g->block_type == 0)

  2177.                     return -1;

  2178.                 g->switch_point = get_bits(&s->gb, 1);

  2179.                 for(i=0;i<2;i++)

  2180.                     g->table_select[i] = get_bits(&s->gb, 5);

  2181.                 for(i=0;i<3;i++) 

  2182.                     g->subblock_gain[i] = get_bits(&s->gb, 3);

  2183.                 /* compute huffman coded region sizes */

  2184.                 if (g->block_type == 2)

  2185.                     g->region_size[0] = (36 / 2);

  2186.                 else {

  2187.                     if (s->sample_rate_index <= 2) 

  2188.                         g->region_size[0] = (36 / 2);

  2189.                     else if (s->sample_rate_index != 8) 

  2190.                         g->region_size[0] = (54 / 2);

  2191.                     else

  2192.                         g->region_size[0] = (108 / 2);

  2193.                 }

  2194.                 g->region_size[1] = (576 / 2);

  2195.             } else {

  2196.                 int region_address1, region_address2, l;

  2197.                 g->block_type = 0;

  2198.                 g->switch_point = 0;

  2199.                 for(i=0;i<3;i++)

  2200.                     g->table_select[i] = get_bits(&s->gb, 5);

  2201.                 /* compute huffman coded region sizes */

  2202.                 region_address1 = get_bits(&s->gb, 4);

  2203.                 region_address2 = get_bits(&s->gb, 3);

  2204.                 dprintf("region1=%d region2=%d\n", 

  2205.                         region_address1, region_address2);

  2206.                 g->region_size[0] = 

  2207.                     band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;

  2208.                 l = region_address1 + region_address2 + 2;

  2209.                 /* should not overflow */

  2210.                 if (l > 22)

  2211.                     l = 22;

  2212.                 g->region_size[1] = 

  2213.                     band_index_long[s->sample_rate_index][l] >> 1;

  2214.             }

  2215.             /* convert region offsets to region sizes and truncate

  2216.                size to big_values */

  2217.             g->region_size[2] = (576 / 2);

  2218.             j = 0;

  2219.             for(i=0;i<3;i++) {

  2220.                 k = g->region_size[i];

  2221.                 if (k > g->big_values)

  2222.                     k = g->big_values;

  2223.                 g->region_size[i] = k - j;

  2224.                 j = k;

  2225.             }

  2226. 

  2227.             /* compute band indexes */

  2228.             if (g->block_type == 2) {

  2229.                 if (g->switch_point) {

  2230.                     /* if switched mode, we handle the 36 first samples as

  2231.                        long blocks.  For 8000Hz, we handle the 48 first

  2232.                        exponents as long blocks (XXX: check this!) */

  2233.                     if (s->sample_rate_index <= 2)

  2234.                         g->long_end = 8;

  2235.                     else if (s->sample_rate_index != 8)

  2236.                         g->long_end = 6;

  2237.                     else

  2238.                         g->long_end = 4; /* 8000 Hz */

  2239.                     

  2240.                     if (s->sample_rate_index != 8)

  2241.                         g->short_start = 3;

  2242.                     else

  2243.                         g->short_start = 2; 

  2244.                 } else {

  2245.                     g->long_end = 0;

  2246.                     g->short_start = 0;

  2247.                 }

  2248.             } else {

  2249.                 g->short_start = 13;

  2250.                 g->long_end = 22;

  2251.             }

  2252.             

  2253.             g->preflag = 0;

  2254.             if (!s->lsf)

  2255.                 g->preflag = get_bits(&s->gb, 1);

  2256.             g->scalefac_scale = get_bits(&s->gb, 1);

  2257.             g->count1table_select = get_bits(&s->gb, 1);

  2258.             dprintf("block_type=%d switch_point=%d\n",

  2259.                     g->block_type, g->switch_point);

  2260.         }

  2261.     }

  2262. 

  2263.   if (!s->adu_mode) {

  2264.     /* now we get bits from the main_data_begin offset */

  2265.     dprintf("seekback: %d\n", main_data_begin);

  2266.     seek_to_maindata(s, main_data_begin);

  2267.   }

  2268. 

  2269.     for(gr=0;gr<nb_granules;gr++) {

  2270.         for(ch=0;ch<s->nb_channels;ch++) {

  2271.             g = &granules[ch][gr];

  2272.             

  2273.             bits_pos = get_bits_count(&s->gb);

  2274.             

  2275.             if (!s->lsf) {

  2276.                 uint8_t *sc;

  2277.                 int slen, slen1, slen2;

  2278. 

  2279.                 /* MPEG1 scale factors */

  2280.                 slen1 = slen_table[0][g->scalefac_compress];

  2281.                 slen2 = slen_table[1][g->scalefac_compress];

  2282.                 dprintf("slen1=%d slen2=%d\n", slen1, slen2);

  2283.                 if (g->block_type == 2) {

  2284.                     n = g->switch_point ? 17 : 18;

  2285.                     j = 0;

  2286.                     for(i=0;i<n;i++)

  2287.                         g->scale_factors[j++] = get_bitsz(&s->gb, slen1);

  2288.                     for(i=0;i<18;i++)

  2289.                         g->scale_factors[j++] = get_bitsz(&s->gb, slen2);

  2290.                     for(i=0;i<3;i++)

  2291.                         g->scale_factors[j++] = 0;

  2292.                 } else {

  2293.                     sc = granules[ch][0].scale_factors;

  2294.                     j = 0;

  2295.                     for(k=0;k<4;k++) {

  2296.                         n = (k == 0 ? 6 : 5);

  2297.                         if ((g->scfsi & (0x8 >> k)) == 0) {

  2298.                             slen = (k < 2) ? slen1 : slen2;

  2299.                             for(i=0;i<n;i++)

  2300.                                 g->scale_factors[j++] = get_bitsz(&s->gb, slen);

  2301.                         } else {

  2302.                             /* simply copy from last granule */

  2303.                             for(i=0;i<n;i++) {

  2304.                                 g->scale_factors[j] = sc[j];

  2305.                                 j++;

  2306.                             }

  2307.                         }

  2308.                     }

  2309.                     g->scale_factors[j++] = 0;

  2310.                 }

  2311. #if defined(DEBUG)

  2312.                 {

  2313.                     printf("scfsi=%x gr=%d ch=%d scale_factors:\n", 

  2314.                            g->scfsi, gr, ch);

  2315.                     for(i=0;i<j;i++)

  2316.                         printf(" %d", g->scale_factors[i]);

  2317.                     printf("\n");

  2318.                 }

  2319. #endif

  2320.             } else {

  2321.                 int tindex, tindex2, slen[4], sl, sf;

  2322. 

  2323.                 /* LSF scale factors */

  2324.                 if (g->block_type == 2) {

  2325.                     tindex = g->switch_point ? 2 : 1;

  2326.                 } else {

  2327.                     tindex = 0;

  2328.                 }

  2329.                 sf = g->scalefac_compress;

  2330.                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {

  2331.                     /* intensity stereo case */

  2332.                     sf >>= 1;

  2333.                     if (sf < 180) {

  2334.                         lsf_sf_expand(slen, sf, 6, 6, 0);

  2335.                         tindex2 = 3;

  2336.                     } else if (sf < 244) {

  2337.                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);

  2338.                         tindex2 = 4;

  2339.                     } else {

  2340.                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);

  2341.                         tindex2 = 5;

  2342.                     }

  2343.                 } else {

  2344.                     /* normal case */

  2345.                     if (sf < 400) {

  2346.                         lsf_sf_expand(slen, sf, 5, 4, 4);

  2347.                         tindex2 = 0;

  2348.                     } else if (sf < 500) {

  2349.                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);

  2350.                         tindex2 = 1;

  2351.                     } else {

  2352.                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);

  2353.                         tindex2 = 2;

  2354.                         g->preflag = 1;

  2355.                     }

  2356.                 }

  2357. 

  2358.                 j = 0;

  2359.                 for(k=0;k<4;k++) {

  2360.                     n = lsf_nsf_table[tindex2][tindex][k];

  2361.                     sl = slen[k];

  2362.                     for(i=0;i<n;i++)

  2363.                         g->scale_factors[j++] = get_bitsz(&s->gb, sl);

  2364.                 }

  2365.                 /* XXX: should compute exact size */

  2366.                 for(;j<40;j++)

  2367.                     g->scale_factors[j] = 0;

  2368. #if defined(DEBUG)

  2369.                 {

  2370.                     printf("gr=%d ch=%d scale_factors:\n", 

  2371.                            gr, ch);

  2372.                     for(i=0;i<40;i++)

  2373.                         printf(" %d", g->scale_factors[i]);

  2374.                     printf("\n");

  2375.                 }

  2376. #endif

  2377.             }

  2378. 

  2379.             exponents_from_scale_factors(s, g, exponents);

  2380. 

  2381.             /* read Huffman coded residue */

  2382.             if (huffman_decode(s, g, exponents,

  2383.                                bits_pos + g->part2_3_length) < 0)

  2384.                 return -1;

  2385. #if defined(DEBUG)

  2386.             sample_dump(0, g->sb_hybrid, 576);

  2387. #endif

  2388. 

  2389.             /* skip extension bits */

  2390.             bits_left = g->part2_3_length - (get_bits_count(&s->gb) - bits_pos);

  2391.             if (bits_left < 0) {

  2392.                 dprintf("bits_left=%d\n", bits_left);

  2393.                 return -1;

  2394.             }

  2395.             while (bits_left >= 16) {

  2396.                 skip_bits(&s->gb, 16);

  2397.                 bits_left -= 16;

  2398.             }

  2399.             if (bits_left > 0)

  2400.                 skip_bits(&s->gb, bits_left);

  2401.         } /* ch */

  2402. 

  2403.         if (s->nb_channels == 2)

  2404.             compute_stereo(s, &granules[0][gr], &granules[1][gr]);

  2405. 

  2406.         for(ch=0;ch<s->nb_channels;ch++) {

  2407.             g = &granules[ch][gr];

  2408. 

  2409.             reorder_block(s, g);

  2410. #if defined(DEBUG)

  2411.             sample_dump(0, g->sb_hybrid, 576);

  2412. #endif

  2413.             s->compute_antialias(s, g);

  2414. #if defined(DEBUG)

  2415.             sample_dump(1, g->sb_hybrid, 576);

  2416. #endif

  2417.             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]); 

  2418. #if defined(DEBUG)

  2419.             sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);

  2420. #endif

  2421.         }

  2422.     } /* gr */

  2423.     return nb_granules * 18;

  2424. }

  2425. 

  2426. static int mp_decode_frame(MPADecodeContext *s, 

  2427.                            OUT_INT *samples)

  2428. {

  2429.     int i, nb_frames, ch;

  2430.     OUT_INT *samples_ptr;

  2431. 

  2432.     init_get_bits(&s->gb, s->inbuf + HEADER_SIZE, 

  2433.                   (s->inbuf_ptr - s->inbuf - HEADER_SIZE)*8);

  2434.     

  2435.     /* skip error protection field */

  2436.     if (s->error_protection)

  2437.         get_bits(&s->gb, 16);

  2438. 

  2439.     dprintf("frame %d:\n", s->frame_count);

  2440.     switch(s->layer) {

  2441.     case 1:

  2442.         nb_frames = mp_decode_layer1(s);

  2443.         break;

  2444.     case 2:

  2445.         nb_frames = mp_decode_layer2(s);

  2446.         break;

  2447.     case 3:

  2448.     default:

  2449.         nb_frames = mp_decode_layer3(s);

  2450.         break;

  2451.     }

  2452. #if defined(DEBUG)

  2453.     for(i=0;i<nb_frames;i++) {

  2454.         for(ch=0;ch<s->nb_channels;ch++) {

  2455.             int j;

  2456.             printf("%d-%d:", i, ch);

  2457.             for(j=0;j<SBLIMIT;j++)

  2458.                 printf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);

  2459.             printf("\n");

  2460.         }

  2461.     }

  2462. #endif

  2463.     /* apply the synthesis filter */

  2464.     for(ch=0;ch<s->nb_channels;ch++) {

  2465.         samples_ptr = samples + ch;

  2466.         for(i=0;i<nb_frames;i++) {

  2467.             ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),

  2468. 			 window, &s->dither_state,

  2469. 			 samples_ptr, s->nb_channels,

  2470.                          s->sb_samples[ch][i]);

  2471.             samples_ptr += 32 * s->nb_channels;

  2472.         }

  2473.     }

  2474. #ifdef DEBUG

  2475.     s->frame_count++;        

  2476. #endif

  2477.     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;

  2478. }

  2479. 

  2480. static int decode_frame(AVCodecContext * avctx,

  2481. 			void *data, int *data_size,

  2482. 			uint8_t * buf, int buf_size)

  2483. {

  2484.     MPADecodeContext *s = avctx->priv_data;

  2485.     uint32_t header;

  2486.     uint8_t *buf_ptr;

  2487.     int len, out_size;

  2488.     OUT_INT *out_samples = data;

  2489. 

  2490.     buf_ptr = buf;

  2491.     while (buf_size > 0) {

  2492. 	len = s->inbuf_ptr - s->inbuf;

  2493. 	if (s->frame_size == 0) {

  2494.             /* special case for next header for first frame in free

  2495.                format case (XXX: find a simpler method) */

  2496.             if (s->free_format_next_header != 0) {

  2497.                 s->inbuf[0] = s->free_format_next_header >> 24;

  2498.                 s->inbuf[1] = s->free_format_next_header >> 16;

  2499.                 s->inbuf[2] = s->free_format_next_header >> 8;

  2500.                 s->inbuf[3] = s->free_format_next_header;

  2501.                 s->inbuf_ptr = s->inbuf + 4;

  2502.                 s->free_format_next_header = 0;

  2503.                 goto got_header;

  2504.             }

  2505. 	    /* no header seen : find one. We need at least HEADER_SIZE

  2506.                bytes to parse it */

  2507. 	    len = HEADER_SIZE - len;

  2508. 	    if (len > buf_size)

  2509. 		len = buf_size;

  2510. 	    if (len > 0) {

  2511. 		memcpy(s->inbuf_ptr, buf_ptr, len);

  2512. 		buf_ptr += len;

  2513. 		buf_size -= len;

  2514. 		s->inbuf_ptr += len;

  2515. 	    }

  2516. 	    if ((s->inbuf_ptr - s->inbuf) >= HEADER_SIZE) {

  2517.             got_header:

  2518. 		header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |

  2519. 		    (s->inbuf[2] << 8) | s->inbuf[3];

  2520. 

  2521. 		if (ff_mpa_check_header(header) < 0) {

  2522. 		    /* no sync found : move by one byte (inefficient, but simple!) */

  2523. 		    memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);

  2524. 		    s->inbuf_ptr--;

  2525.                     dprintf("skip %x\n", header);

  2526.                     /* reset free format frame size to give a chance

  2527.                        to get a new bitrate */

  2528.                     s->free_format_frame_size = 0;

  2529. 		} else {

  2530. 		    if (decode_header(s, header) == 1) {

  2531.                         /* free format: prepare to compute frame size */

  2532. 			s->frame_size = -1;

  2533.                     }

  2534.                     /* update codec info */

  2535.                     avctx->sample_rate = s->sample_rate;

  2536.                     avctx->channels = s->nb_channels;

  2537.                     avctx->bit_rate = s->bit_rate;

  2538.                     avctx->sub_id = s->layer;

  2539.                     switch(s->layer) {

  2540.                     case 1:

  2541.                         avctx->frame_size = 384;

  2542.                         break;

  2543.                     case 2:

  2544.                         avctx->frame_size = 1152;

  2545.                         break;

  2546.                     case 3:

  2547.                         if (s->lsf)

  2548.                             avctx->frame_size = 576;

  2549.                         else

  2550.                             avctx->frame_size = 1152;

  2551.                         break;

  2552.                     }

  2553. 		}

  2554. 	    }

  2555.         } else if (s->frame_size == -1) {

  2556.             /* free format : find next sync to compute frame size */

  2557. 	    len = MPA_MAX_CODED_FRAME_SIZE - len;

  2558. 	    if (len > buf_size)

  2559. 		len = buf_size;

  2560.             if (len == 0) {

  2561. 		/* frame too long: resync */

  2562.                 s->frame_size = 0;

  2563. 		memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);

  2564. 		s->inbuf_ptr--;

  2565.             } else {

  2566.                 uint8_t *p, *pend;

  2567.                 uint32_t header1;

  2568.                 int padding;

  2569. 

  2570.                 memcpy(s->inbuf_ptr, buf_ptr, len);

  2571.                 /* check for header */

  2572.                 p = s->inbuf_ptr - 3;

  2573.                 pend = s->inbuf_ptr + len - 4;

  2574.                 while (p <= pend) {

  2575.                     header = (p[0] << 24) | (p[1] << 16) |

  2576.                         (p[2] << 8) | p[3];

  2577.                     header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |

  2578.                         (s->inbuf[2] << 8) | s->inbuf[3];

  2579.                     /* check with high probability that we have a

  2580.                        valid header */

  2581.                     if ((header & SAME_HEADER_MASK) ==

  2582.                         (header1 & SAME_HEADER_MASK)) {

  2583.                         /* header found: update pointers */

  2584.                         len = (p + 4) - s->inbuf_ptr;

  2585.                         buf_ptr += len;

  2586.                         buf_size -= len;

  2587.                         s->inbuf_ptr = p;

  2588.                         /* compute frame size */

  2589.                         s->free_format_next_header = header;

  2590.                         s->free_format_frame_size = s->inbuf_ptr - s->inbuf;

  2591.                         padding = (header1 >> 9) & 1;

  2592.                         if (s->layer == 1)

  2593.                             s->free_format_frame_size -= padding * 4;

  2594.                         else

  2595.                             s->free_format_frame_size -= padding;

  2596.                         dprintf("free frame size=%d padding=%d\n", 

  2597.                                 s->free_format_frame_size, padding);

  2598.                         decode_header(s, header1);

  2599.                         goto next_data;

  2600.                     }

  2601.                     p++;

  2602.                 }

  2603.                 /* not found: simply increase pointers */

  2604.                 buf_ptr += len;

  2605.                 s->inbuf_ptr += len;

  2606.                 buf_size -= len;

  2607.             }

  2608. 	} else if (len < s->frame_size) {

  2609.             if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)

  2610.                 s->frame_size = MPA_MAX_CODED_FRAME_SIZE;

  2611. 	    len = s->frame_size - len;

  2612. 	    if (len > buf_size)

  2613. 		len = buf_size;

  2614. 	    memcpy(s->inbuf_ptr, buf_ptr, len);

  2615. 	    buf_ptr += len;

  2616. 	    s->inbuf_ptr += len;

  2617. 	    buf_size -= len;

  2618. 	}

  2619.     next_data:

  2620.         if (s->frame_size > 0 && 

  2621.             (s->inbuf_ptr - s->inbuf) >= s->frame_size) {

  2622.             if (avctx->parse_only) {

  2623.                 /* simply return the frame data */

  2624.                 *(uint8_t **)data = s->inbuf;

  2625.                 out_size = s->inbuf_ptr - s->inbuf;

  2626.             } else {

  2627.                 out_size = mp_decode_frame(s, out_samples);

  2628.             }

  2629. 	    s->inbuf_ptr = s->inbuf;

  2630. 	    s->frame_size = 0;

  2631.             if(out_size>=0)

  2632. 	        *data_size = out_size;

  2633.             else

  2634.                 av_log(avctx, AV_LOG_DEBUG, "Error while decoding mpeg audio frame\n"); //FIXME return -1 / but also return the number of bytes consumed

  2635. 	    break;

  2636. 	}

  2637.     }

  2638.     return buf_ptr - buf;

  2639. }

  2640. 

  2641. 

  2642. static int decode_frame_adu(AVCodecContext * avctx,

  2643. 			void *data, int *data_size,

  2644. 			uint8_t * buf, int buf_size)

  2645. {

  2646.     MPADecodeContext *s = avctx->priv_data;

  2647.     uint32_t header;

  2648.     int len, out_size;

  2649.     OUT_INT *out_samples = data;

  2650. 

  2651.     len = buf_size;

  2652. 

  2653.     // Discard too short frames

  2654.     if (buf_size < HEADER_SIZE) {

  2655.         *data_size = 0;

  2656.         return buf_size;

  2657.     }

  2658. 

  2659. 

  2660.     if (len > MPA_MAX_CODED_FRAME_SIZE)

  2661.         len = MPA_MAX_CODED_FRAME_SIZE;

  2662. 

  2663.     memcpy(s->inbuf, buf, len);

  2664.     s->inbuf_ptr = s->inbuf + len;

  2665. 

  2666.     // Get header and restore sync word

  2667.     header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |

  2668.               (s->inbuf[2] << 8) | s->inbuf[3] | 0xffe00000;

  2669. 

  2670.     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame

  2671.         *data_size = 0;

  2672.         return buf_size;

  2673.     }

  2674. 

  2675.     decode_header(s, header);

  2676.     /* update codec info */

  2677.     avctx->sample_rate = s->sample_rate;

  2678.     avctx->channels = s->nb_channels;

  2679.     avctx->bit_rate = s->bit_rate;

  2680.     avctx->sub_id = s->layer;

  2681. 

  2682.     avctx->frame_size=s->frame_size = len;

  2683. 

  2684.     if (avctx->parse_only) {

  2685.         /* simply return the frame data */

  2686.         *(uint8_t **)data = s->inbuf;

  2687.         out_size = s->inbuf_ptr - s->inbuf;

  2688.     } else {

  2689.         out_size = mp_decode_frame(s, out_samples);

  2690.     }

  2691. 

  2692.     *data_size = out_size;

  2693.     return buf_size;

  2694. }

  2695. 

  2696. 

  2697. /* Next 3 arrays are indexed by channel config number (passed via codecdata) */

  2698. static int mp3Frames[16] = {0,1,1,2,3,3,4,5,2};   /* number of mp3 decoder instances */

  2699. static int mp3Channels[16] = {0,1,2,3,4,5,6,8,4}; /* total output channels */

  2700. /* offsets into output buffer, assume output order is FL FR BL BR C LFE */

  2701. static int chan_offset[9][5] = {

  2702.     {0},

  2703.     {0},            // C

  2704.     {0},            // FLR

  2705.     {2,0},          // C FLR

  2706.     {2,0,3},        // C FLR BS

  2707.     {4,0,2},        // C FLR BLRS

  2708.     {4,0,2,5},      // C FLR BLRS LFE

  2709.     {4,0,2,6,5},    // C FLR BLRS BLR LFE

  2710.     {0,2}           // FLR BLRS

  2711. };

  2712. 

  2713. 

  2714. static int decode_init_mp3on4(AVCodecContext * avctx)

  2715. {

  2716.     MP3On4DecodeContext *s = avctx->priv_data;

  2717.     int i;

  2718. 

  2719.     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {

  2720.         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

  2721.         return -1;

  2722.     }

  2723. 

  2724.     s->chan_cfg = (((unsigned char *)avctx->extradata)[1] >> 3) & 0x0f;

  2725.     s->frames = mp3Frames[s->chan_cfg];

  2726.     if(!s->frames) {

  2727.         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

  2728.         return -1;

  2729.     }

  2730.     avctx->channels = mp3Channels[s->chan_cfg];

  2731. 

  2732.     /* Init the first mp3 decoder in standard way, so that all tables get builded

  2733.      * We replace avctx->priv_data with the context of the first decoder so that

  2734.      * decode_init() does not have to be changed.

  2735.      * Other decoders will be inited here copying data from the first context

  2736.      */

  2737.     // Allocate zeroed memory for the first decoder context

  2738.     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));

  2739.     // Put decoder context in place to make init_decode() happy

  2740.     avctx->priv_data = s->mp3decctx[0];

  2741.     decode_init(avctx);

  2742.     // Restore mp3on4 context pointer

  2743.     avctx->priv_data = s;

  2744.     s->mp3decctx[0]->adu_mode = 1; // Set adu mode

  2745. 

  2746.     /* Create a separate codec/context for each frame (first is already ok).

  2747.      * Each frame is 1 or 2 channels - up to 5 frames allowed

  2748.      */

  2749.     for (i = 1; i < s->frames; i++) {

  2750.         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

  2751.         s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;

  2752.         s->mp3decctx[i]->inbuf = &s->mp3decctx[i]->inbuf1[0][BACKSTEP_SIZE];

  2753.         s->mp3decctx[i]->inbuf_ptr = s->mp3decctx[i]->inbuf;

  2754.         s->mp3decctx[i]->adu_mode = 1;

  2755.     }

  2756. 

  2757.     return 0;

  2758. }

  2759. 

  2760. 

  2761. static int decode_close_mp3on4(AVCodecContext * avctx)

  2762. {

  2763.     MP3On4DecodeContext *s = avctx->priv_data;

  2764.     int i;

  2765. 

  2766.     for (i = 0; i < s->frames; i++)

  2767.         if (s->mp3decctx[i])

  2768.             av_free(s->mp3decctx[i]);

  2769. 

  2770.     return 0;

  2771. }

  2772. 

  2773. 

  2774. static int decode_frame_mp3on4(AVCodecContext * avctx,

  2775. 			void *data, int *data_size,

  2776. 			uint8_t * buf, int buf_size)

  2777. {

  2778.     MP3On4DecodeContext *s = avctx->priv_data;

  2779.     MPADecodeContext *m;

  2780.     int len, out_size = 0;

  2781.     uint32_t header;

  2782.     OUT_INT *out_samples = data;

  2783.     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];

  2784.     OUT_INT *outptr, *bp;

  2785.     int fsize;

  2786.     unsigned char *start2 = buf, *start;

  2787.     int fr, i, j, n;

  2788.     int off = avctx->channels;

  2789.     int *coff = chan_offset[s->chan_cfg];

  2790. 

  2791.     len = buf_size;

  2792. 

  2793.     // Discard too short frames

  2794.     if (buf_size < HEADER_SIZE) {

  2795.         *data_size = 0;

  2796.         return buf_size;

  2797.     }

  2798. 

  2799.     // If only one decoder interleave is not needed

  2800.     outptr = s->frames == 1 ? out_samples : decoded_buf;

  2801. 

  2802.     for (fr = 0; fr < s->frames; fr++) {

  2803.         start = start2;

  2804.         fsize = (start[0] << 4) | (start[1] >> 4);

  2805.         start2 += fsize;

  2806.         if (fsize > len)

  2807.             fsize = len;

  2808.         len -= fsize;

  2809.         if (fsize > MPA_MAX_CODED_FRAME_SIZE)

  2810.             fsize = MPA_MAX_CODED_FRAME_SIZE;

  2811.         m = s->mp3decctx[fr];

  2812.         assert (m != NULL);

  2813.         /* copy original to new */

  2814.         m->inbuf_ptr = m->inbuf + fsize;

  2815.         memcpy(m->inbuf, start, fsize);

  2816. 

  2817.         // Get header

  2818.         header = (m->inbuf[0] << 24) | (m->inbuf[1] << 16) |

  2819.                   (m->inbuf[2] << 8) | m->inbuf[3] | 0xfff00000;

  2820. 

  2821.         if (ff_mpa_check_header(header) < 0) { // Bad header, discard block

  2822.             *data_size = 0;

  2823.             return buf_size;

  2824.         }

  2825. 

  2826.         decode_header(m, header);

  2827.         mp_decode_frame(m, decoded_buf);

  2828. 

  2829.         n = MPA_FRAME_SIZE * m->nb_channels;

  2830.         out_size += n * sizeof(OUT_INT);

  2831.         if(s->frames > 1) {

  2832.             /* interleave output data */

  2833.             bp = out_samples + coff[fr];

  2834.             if(m->nb_channels == 1) {

  2835.                 for(j = 0; j < n; j++) {

  2836.                     *bp = decoded_buf[j];

  2837.                     bp += off;

  2838.                 }

  2839.             } else {

  2840.                 for(j = 0; j < n; j++) {

  2841.                     bp[0] = decoded_buf[j++];

  2842.                     bp[1] = decoded_buf[j];

  2843.                     bp += off;

  2844.                 }

  2845.             }

  2846.         }

  2847.     }

  2848. 

  2849.     /* update codec info */

  2850.     avctx->sample_rate = s->mp3decctx[0]->sample_rate;

  2851.     avctx->frame_size= buf_size;

  2852.     avctx->bit_rate = 0;

  2853.     for (i = 0; i < s->frames; i++)

  2854.         avctx->bit_rate += s->mp3decctx[i]->bit_rate;

  2855. 

  2856.     *data_size = out_size;

  2857.     return buf_size;

  2858. }

  2859. 

  2860. 

  2861. AVCodec mp2_decoder =

  2862. {

  2863.     "mp2",

  2864.     CODEC_TYPE_AUDIO,

  2865.     CODEC_ID_MP2,

  2866.     sizeof(MPADecodeContext),

  2867.     decode_init,

  2868.     NULL,

  2869.     NULL,

  2870.     decode_frame,

  2871.     CODEC_CAP_PARSE_ONLY,

  2872. };

  2873. 

  2874. AVCodec mp3_decoder =

  2875. {

  2876.     "mp3",

  2877.     CODEC_TYPE_AUDIO,

  2878.     CODEC_ID_MP3,

  2879.     sizeof(MPADecodeContext),

  2880.     decode_init,

  2881.     NULL,

  2882.     NULL,

  2883.     decode_frame,

  2884.     CODEC_CAP_PARSE_ONLY,

  2885. };

  2886. 

  2887. AVCodec mp3adu_decoder =

  2888. {

  2889.     "mp3adu",

  2890.     CODEC_TYPE_AUDIO,

  2891.     CODEC_ID_MP3ADU,

  2892.     sizeof(MPADecodeContext),

  2893.     decode_init,

  2894.     NULL,

  2895.     NULL,

  2896.     decode_frame_adu,

  2897.     CODEC_CAP_PARSE_ONLY,

  2898. };

  2899. 

  2900. AVCodec mp3on4_decoder =

  2901. {

  2902.     "mp3on4",

  2903.     CODEC_TYPE_AUDIO,

  2904.     CODEC_ID_MP3ON4,

  2905.     sizeof(MP3On4DecodeContext),

  2906.     decode_init_mp3on4,

  2907.     NULL,

  2908.     decode_close_mp3on4,

  2909.     decode_frame_mp3on4,

  2910.     0

  2911. };