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libavcodec/mpegaudiodec.c

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00001 /*
00002  * MPEG Audio decoder
00003  * Copyright (c) 2001, 2002 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "avcodec.h"
00028 #include "get_bits.h"
00029 #include "dsputil.h"
00030 
00031 /*
00032  * TODO:
00033  *  - in low precision mode, use more 16 bit multiplies in synth filter
00034  *  - test lsf / mpeg25 extensively.
00035  */
00036 
00037 #include "mpegaudio.h"
00038 #include "mpegaudiodecheader.h"
00039 
00040 #include "mathops.h"
00041 
00042 /* WARNING: only correct for posititive numbers */
00043 #define FIXR(a)   ((int)((a) * FRAC_ONE + 0.5))
00044 #define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)
00045 
00046 #define FIXHR(a) ((int)((a) * (1LL<<32) + 0.5))
00047 
00048 /****************/
00049 
00050 #define HEADER_SIZE 4
00051 
00052 #include "mpegaudiodata.h"
00053 #include "mpegaudiodectab.h"
00054 
00055 static void compute_antialias_integer(MPADecodeContext *s, GranuleDef *g);
00056 static void compute_antialias_float(MPADecodeContext *s, GranuleDef *g);
00057 
00058 /* vlc structure for decoding layer 3 huffman tables */
00059 static VLC huff_vlc[16];
00060 static VLC_TYPE huff_vlc_tables[
00061   0+128+128+128+130+128+154+166+
00062   142+204+190+170+542+460+662+414
00063   ][2];
00064 static const int huff_vlc_tables_sizes[16] = {
00065   0, 128, 128, 128, 130, 128, 154, 166,
00066   142, 204, 190, 170, 542, 460, 662, 414
00067 };
00068 static VLC huff_quad_vlc[2];
00069 static VLC_TYPE huff_quad_vlc_tables[128+16][2];
00070 static const int huff_quad_vlc_tables_sizes[2] = {
00071   128, 16
00072 };
00073 /* computed from band_size_long */
00074 static uint16_t band_index_long[9][23];
00075 #include "mpegaudio_tablegen.h"
00076 /* intensity stereo coef table */
00077 static int32_t is_table[2][16];
00078 static int32_t is_table_lsf[2][2][16];
00079 static int32_t csa_table[8][4];
00080 static float csa_table_float[8][4];
00081 static int32_t mdct_win[8][36];
00082 
00083 /* lower 2 bits: modulo 3, higher bits: shift */
00084 static uint16_t scale_factor_modshift[64];
00085 /* [i][j]:  2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
00086 static int32_t scale_factor_mult[15][3];
00087 /* mult table for layer 2 group quantization */
00088 
00089 #define SCALE_GEN(v) \
00090 { FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
00091 
00092 static const int32_t scale_factor_mult2[3][3] = {
00093     SCALE_GEN(4.0 / 3.0), /* 3 steps */
00094     SCALE_GEN(4.0 / 5.0), /* 5 steps */
00095     SCALE_GEN(4.0 / 9.0), /* 9 steps */
00096 };
00097 
00098 DECLARE_ALIGNED(16, MPA_INT, ff_mpa_synth_window)[512];
00099 
00104 static void ff_region_offset2size(GranuleDef *g){
00105     int i, k, j=0;
00106     g->region_size[2] = (576 / 2);
00107     for(i=0;i<3;i++) {
00108         k = FFMIN(g->region_size[i], g->big_values);
00109         g->region_size[i] = k - j;
00110         j = k;
00111     }
00112 }
00113 
00114 static void ff_init_short_region(MPADecodeContext *s, GranuleDef *g){
00115     if (g->block_type == 2)
00116         g->region_size[0] = (36 / 2);
00117     else {
00118         if (s->sample_rate_index <= 2)
00119             g->region_size[0] = (36 / 2);
00120         else if (s->sample_rate_index != 8)
00121             g->region_size[0] = (54 / 2);
00122         else
00123             g->region_size[0] = (108 / 2);
00124     }
00125     g->region_size[1] = (576 / 2);
00126 }
00127 
00128 static void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2){
00129     int l;
00130     g->region_size[0] =
00131         band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
00132     /* should not overflow */
00133     l = FFMIN(ra1 + ra2 + 2, 22);
00134     g->region_size[1] =
00135         band_index_long[s->sample_rate_index][l] >> 1;
00136 }
00137 
00138 static void ff_compute_band_indexes(MPADecodeContext *s, GranuleDef *g){
00139     if (g->block_type == 2) {
00140         if (g->switch_point) {
00141             /* if switched mode, we handle the 36 first samples as
00142                 long blocks.  For 8000Hz, we handle the 48 first
00143                 exponents as long blocks (XXX: check this!) */
00144             if (s->sample_rate_index <= 2)
00145                 g->long_end = 8;
00146             else if (s->sample_rate_index != 8)
00147                 g->long_end = 6;
00148             else
00149                 g->long_end = 4; /* 8000 Hz */
00150 
00151             g->short_start = 2 + (s->sample_rate_index != 8);
00152         } else {
00153             g->long_end = 0;
00154             g->short_start = 0;
00155         }
00156     } else {
00157         g->short_start = 13;
00158         g->long_end = 22;
00159     }
00160 }
00161 
00162 /* layer 1 unscaling */
00163 /* n = number of bits of the mantissa minus 1 */
00164 static inline int l1_unscale(int n, int mant, int scale_factor)
00165 {
00166     int shift, mod;
00167     int64_t val;
00168 
00169     shift = scale_factor_modshift[scale_factor];
00170     mod = shift & 3;
00171     shift >>= 2;
00172     val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
00173     shift += n;
00174     /* NOTE: at this point, 1 <= shift >= 21 + 15 */
00175     return (int)((val + (1LL << (shift - 1))) >> shift);
00176 }
00177 
00178 static inline int l2_unscale_group(int steps, int mant, int scale_factor)
00179 {
00180     int shift, mod, val;
00181 
00182     shift = scale_factor_modshift[scale_factor];
00183     mod = shift & 3;
00184     shift >>= 2;
00185 
00186     val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
00187     /* NOTE: at this point, 0 <= shift <= 21 */
00188     if (shift > 0)
00189         val = (val + (1 << (shift - 1))) >> shift;
00190     return val;
00191 }
00192 
00193 /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
00194 static inline int l3_unscale(int value, int exponent)
00195 {
00196     unsigned int m;
00197     int e;
00198 
00199     e = table_4_3_exp  [4*value + (exponent&3)];
00200     m = table_4_3_value[4*value + (exponent&3)];
00201     e -= (exponent >> 2);
00202     assert(e>=1);
00203     if (e > 31)
00204         return 0;
00205     m = (m + (1 << (e-1))) >> e;
00206 
00207     return m;
00208 }
00209 
00210 /* all integer n^(4/3) computation code */
00211 #define DEV_ORDER 13
00212 
00213 #define POW_FRAC_BITS 24
00214 #define POW_FRAC_ONE    (1 << POW_FRAC_BITS)
00215 #define POW_FIX(a)   ((int)((a) * POW_FRAC_ONE))
00216 #define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)
00217 
00218 static int dev_4_3_coefs[DEV_ORDER];
00219 
00220 #if 0 /* unused */
00221 static int pow_mult3[3] = {
00222     POW_FIX(1.0),
00223     POW_FIX(1.25992104989487316476),
00224     POW_FIX(1.58740105196819947474),
00225 };
00226 #endif
00227 
00228 static av_cold void int_pow_init(void)
00229 {
00230     int i, a;
00231 
00232     a = POW_FIX(1.0);
00233     for(i=0;i<DEV_ORDER;i++) {
00234         a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);
00235         dev_4_3_coefs[i] = a;
00236     }
00237 }
00238 
00239 #if 0 /* unused, remove? */
00240 /* return the mantissa and the binary exponent */
00241 static int int_pow(int i, int *exp_ptr)
00242 {
00243     int e, er, eq, j;
00244     int a, a1;
00245 
00246     /* renormalize */
00247     a = i;
00248     e = POW_FRAC_BITS;
00249     while (a < (1 << (POW_FRAC_BITS - 1))) {
00250         a = a << 1;
00251         e--;
00252     }
00253     a -= (1 << POW_FRAC_BITS);
00254     a1 = 0;
00255     for(j = DEV_ORDER - 1; j >= 0; j--)
00256         a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);
00257     a = (1 << POW_FRAC_BITS) + a1;
00258     /* exponent compute (exact) */
00259     e = e * 4;
00260     er = e % 3;
00261     eq = e / 3;
00262     a = POW_MULL(a, pow_mult3[er]);
00263     while (a >= 2 * POW_FRAC_ONE) {
00264         a = a >> 1;
00265         eq++;
00266     }
00267     /* convert to float */
00268     while (a < POW_FRAC_ONE) {
00269         a = a << 1;
00270         eq--;
00271     }
00272     /* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
00273 #if POW_FRAC_BITS > FRAC_BITS
00274     a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
00275     /* correct overflow */
00276     if (a >= 2 * (1 << FRAC_BITS)) {
00277         a = a >> 1;
00278         eq++;
00279     }
00280 #endif
00281     *exp_ptr = eq;
00282     return a;
00283 }
00284 #endif
00285 
00286 static av_cold int decode_init(AVCodecContext * avctx)
00287 {
00288     MPADecodeContext *s = avctx->priv_data;
00289     static int init=0;
00290     int i, j, k;
00291 
00292     s->avctx = avctx;
00293 
00294     avctx->sample_fmt= OUT_FMT;
00295     s->error_recognition= avctx->error_recognition;
00296 
00297     if(avctx->antialias_algo != FF_AA_FLOAT)
00298         s->compute_antialias= compute_antialias_integer;
00299     else
00300         s->compute_antialias= compute_antialias_float;
00301 
00302     if (!init && !avctx->parse_only) {
00303         int offset;
00304 
00305         /* scale factors table for layer 1/2 */
00306         for(i=0;i<64;i++) {
00307             int shift, mod;
00308             /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
00309             shift = (i / 3);
00310             mod = i % 3;
00311             scale_factor_modshift[i] = mod | (shift << 2);
00312         }
00313 
00314         /* scale factor multiply for layer 1 */
00315         for(i=0;i<15;i++) {
00316             int n, norm;
00317             n = i + 2;
00318             norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
00319             scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm, FRAC_BITS);
00320             scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm, FRAC_BITS);
00321             scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm, FRAC_BITS);
00322             dprintf(avctx, "%d: norm=%x s=%x %x %x\n",
00323                     i, norm,
00324                     scale_factor_mult[i][0],
00325                     scale_factor_mult[i][1],
00326                     scale_factor_mult[i][2]);
00327         }
00328 
00329         ff_mpa_synth_init(ff_mpa_synth_window);
00330 
00331         /* huffman decode tables */
00332         offset = 0;
00333         for(i=1;i<16;i++) {
00334             const HuffTable *h = &mpa_huff_tables[i];
00335             int xsize, x, y;
00336             uint8_t  tmp_bits [512];
00337             uint16_t tmp_codes[512];
00338 
00339             memset(tmp_bits , 0, sizeof(tmp_bits ));
00340             memset(tmp_codes, 0, sizeof(tmp_codes));
00341 
00342             xsize = h->xsize;
00343 
00344             j = 0;
00345             for(x=0;x<xsize;x++) {
00346                 for(y=0;y<xsize;y++){
00347                     tmp_bits [(x << 5) | y | ((x&&y)<<4)]= h->bits [j  ];
00348                     tmp_codes[(x << 5) | y | ((x&&y)<<4)]= h->codes[j++];
00349                 }
00350             }
00351 
00352             /* XXX: fail test */
00353             huff_vlc[i].table = huff_vlc_tables+offset;
00354             huff_vlc[i].table_allocated = huff_vlc_tables_sizes[i];
00355             init_vlc(&huff_vlc[i], 7, 512,
00356                      tmp_bits, 1, 1, tmp_codes, 2, 2,
00357                      INIT_VLC_USE_NEW_STATIC);
00358             offset += huff_vlc_tables_sizes[i];
00359         }
00360         assert(offset == FF_ARRAY_ELEMS(huff_vlc_tables));
00361 
00362         offset = 0;
00363         for(i=0;i<2;i++) {
00364             huff_quad_vlc[i].table = huff_quad_vlc_tables+offset;
00365             huff_quad_vlc[i].table_allocated = huff_quad_vlc_tables_sizes[i];
00366             init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
00367                      mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1,
00368                      INIT_VLC_USE_NEW_STATIC);
00369             offset += huff_quad_vlc_tables_sizes[i];
00370         }
00371         assert(offset == FF_ARRAY_ELEMS(huff_quad_vlc_tables));
00372 
00373         for(i=0;i<9;i++) {
00374             k = 0;
00375             for(j=0;j<22;j++) {
00376                 band_index_long[i][j] = k;
00377                 k += band_size_long[i][j];
00378             }
00379             band_index_long[i][22] = k;
00380         }
00381 
00382         /* compute n ^ (4/3) and store it in mantissa/exp format */
00383 
00384         int_pow_init();
00385         mpegaudio_tableinit();
00386 
00387         for(i=0;i<7;i++) {
00388             float f;
00389             int v;
00390             if (i != 6) {
00391                 f = tan((double)i * M_PI / 12.0);
00392                 v = FIXR(f / (1.0 + f));
00393             } else {
00394                 v = FIXR(1.0);
00395             }
00396             is_table[0][i] = v;
00397             is_table[1][6 - i] = v;
00398         }
00399         /* invalid values */
00400         for(i=7;i<16;i++)
00401             is_table[0][i] = is_table[1][i] = 0.0;
00402 
00403         for(i=0;i<16;i++) {
00404             double f;
00405             int e, k;
00406 
00407             for(j=0;j<2;j++) {
00408                 e = -(j + 1) * ((i + 1) >> 1);
00409                 f = pow(2.0, e / 4.0);
00410                 k = i & 1;
00411                 is_table_lsf[j][k ^ 1][i] = FIXR(f);
00412                 is_table_lsf[j][k][i] = FIXR(1.0);
00413                 dprintf(avctx, "is_table_lsf %d %d: %x %x\n",
00414                         i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);
00415             }
00416         }
00417 
00418         for(i=0;i<8;i++) {
00419             float ci, cs, ca;
00420             ci = ci_table[i];
00421             cs = 1.0 / sqrt(1.0 + ci * ci);
00422             ca = cs * ci;
00423             csa_table[i][0] = FIXHR(cs/4);
00424             csa_table[i][1] = FIXHR(ca/4);
00425             csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
00426             csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
00427             csa_table_float[i][0] = cs;
00428             csa_table_float[i][1] = ca;
00429             csa_table_float[i][2] = ca + cs;
00430             csa_table_float[i][3] = ca - cs;
00431         }
00432 
00433         /* compute mdct windows */
00434         for(i=0;i<36;i++) {
00435             for(j=0; j<4; j++){
00436                 double d;
00437 
00438                 if(j==2 && i%3 != 1)
00439                     continue;
00440 
00441                 d= sin(M_PI * (i + 0.5) / 36.0);
00442                 if(j==1){
00443                     if     (i>=30) d= 0;
00444                     else if(i>=24) d= sin(M_PI * (i - 18 + 0.5) / 12.0);
00445                     else if(i>=18) d= 1;
00446                 }else if(j==3){
00447                     if     (i<  6) d= 0;
00448                     else if(i< 12) d= sin(M_PI * (i -  6 + 0.5) / 12.0);
00449                     else if(i< 18) d= 1;
00450                 }
00451                 //merge last stage of imdct into the window coefficients
00452                 d*= 0.5 / cos(M_PI*(2*i + 19)/72);
00453 
00454                 if(j==2)
00455                     mdct_win[j][i/3] = FIXHR((d / (1<<5)));
00456                 else
00457                     mdct_win[j][i  ] = FIXHR((d / (1<<5)));
00458             }
00459         }
00460 
00461         /* NOTE: we do frequency inversion adter the MDCT by changing
00462            the sign of the right window coefs */
00463         for(j=0;j<4;j++) {
00464             for(i=0;i<36;i+=2) {
00465                 mdct_win[j + 4][i] = mdct_win[j][i];
00466                 mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];
00467             }
00468         }
00469 
00470         init = 1;
00471     }
00472 
00473     if (avctx->codec_id == CODEC_ID_MP3ADU)
00474         s->adu_mode = 1;
00475     return 0;
00476 }
00477 
00478 /* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */
00479 
00480 /* cos(i*pi/64) */
00481 
00482 #define COS0_0  FIXHR(0.50060299823519630134/2)
00483 #define COS0_1  FIXHR(0.50547095989754365998/2)
00484 #define COS0_2  FIXHR(0.51544730992262454697/2)
00485 #define COS0_3  FIXHR(0.53104259108978417447/2)
00486 #define COS0_4  FIXHR(0.55310389603444452782/2)
00487 #define COS0_5  FIXHR(0.58293496820613387367/2)
00488 #define COS0_6  FIXHR(0.62250412303566481615/2)
00489 #define COS0_7  FIXHR(0.67480834145500574602/2)
00490 #define COS0_8  FIXHR(0.74453627100229844977/2)
00491 #define COS0_9  FIXHR(0.83934964541552703873/2)
00492 #define COS0_10 FIXHR(0.97256823786196069369/2)
00493 #define COS0_11 FIXHR(1.16943993343288495515/4)
00494 #define COS0_12 FIXHR(1.48416461631416627724/4)
00495 #define COS0_13 FIXHR(2.05778100995341155085/8)
00496 #define COS0_14 FIXHR(3.40760841846871878570/8)
00497 #define COS0_15 FIXHR(10.19000812354805681150/32)
00498 
00499 #define COS1_0 FIXHR(0.50241928618815570551/2)
00500 #define COS1_1 FIXHR(0.52249861493968888062/2)
00501 #define COS1_2 FIXHR(0.56694403481635770368/2)
00502 #define COS1_3 FIXHR(0.64682178335999012954/2)
00503 #define COS1_4 FIXHR(0.78815462345125022473/2)
00504 #define COS1_5 FIXHR(1.06067768599034747134/4)
00505 #define COS1_6 FIXHR(1.72244709823833392782/4)
00506 #define COS1_7 FIXHR(5.10114861868916385802/16)
00507 
00508 #define COS2_0 FIXHR(0.50979557910415916894/2)
00509 #define COS2_1 FIXHR(0.60134488693504528054/2)
00510 #define COS2_2 FIXHR(0.89997622313641570463/2)
00511 #define COS2_3 FIXHR(2.56291544774150617881/8)
00512 
00513 #define COS3_0 FIXHR(0.54119610014619698439/2)
00514 #define COS3_1 FIXHR(1.30656296487637652785/4)
00515 
00516 #define COS4_0 FIXHR(0.70710678118654752439/2)
00517 
00518 /* butterfly operator */
00519 #define BF(a, b, c, s)\
00520 {\
00521     tmp0 = tab[a] + tab[b];\
00522     tmp1 = tab[a] - tab[b];\
00523     tab[a] = tmp0;\
00524     tab[b] = MULH(tmp1<<(s), c);\
00525 }
00526 
00527 #define BF1(a, b, c, d)\
00528 {\
00529     BF(a, b, COS4_0, 1);\
00530     BF(c, d,-COS4_0, 1);\
00531     tab[c] += tab[d];\
00532 }
00533 
00534 #define BF2(a, b, c, d)\
00535 {\
00536     BF(a, b, COS4_0, 1);\
00537     BF(c, d,-COS4_0, 1);\
00538     tab[c] += tab[d];\
00539     tab[a] += tab[c];\
00540     tab[c] += tab[b];\
00541     tab[b] += tab[d];\
00542 }
00543 
00544 #define ADD(a, b) tab[a] += tab[b]
00545 
00546 /* DCT32 without 1/sqrt(2) coef zero scaling. */
00547 static void dct32(int32_t *out, int32_t *tab)
00548 {
00549     int tmp0, tmp1;
00550 
00551     /* pass 1 */
00552     BF( 0, 31, COS0_0 , 1);
00553     BF(15, 16, COS0_15, 5);
00554     /* pass 2 */
00555     BF( 0, 15, COS1_0 , 1);
00556     BF(16, 31,-COS1_0 , 1);
00557     /* pass 1 */
00558     BF( 7, 24, COS0_7 , 1);
00559     BF( 8, 23, COS0_8 , 1);
00560     /* pass 2 */
00561     BF( 7,  8, COS1_7 , 4);
00562     BF(23, 24,-COS1_7 , 4);
00563     /* pass 3 */
00564     BF( 0,  7, COS2_0 , 1);
00565     BF( 8, 15,-COS2_0 , 1);
00566     BF(16, 23, COS2_0 , 1);
00567     BF(24, 31,-COS2_0 , 1);
00568     /* pass 1 */
00569     BF( 3, 28, COS0_3 , 1);
00570     BF(12, 19, COS0_12, 2);
00571     /* pass 2 */
00572     BF( 3, 12, COS1_3 , 1);
00573     BF(19, 28,-COS1_3 , 1);
00574     /* pass 1 */
00575     BF( 4, 27, COS0_4 , 1);
00576     BF(11, 20, COS0_11, 2);
00577     /* pass 2 */
00578     BF( 4, 11, COS1_4 , 1);
00579     BF(20, 27,-COS1_4 , 1);
00580     /* pass 3 */
00581     BF( 3,  4, COS2_3 , 3);
00582     BF(11, 12,-COS2_3 , 3);
00583     BF(19, 20, COS2_3 , 3);
00584     BF(27, 28,-COS2_3 , 3);
00585     /* pass 4 */
00586     BF( 0,  3, COS3_0 , 1);
00587     BF( 4,  7,-COS3_0 , 1);
00588     BF( 8, 11, COS3_0 , 1);
00589     BF(12, 15,-COS3_0 , 1);
00590     BF(16, 19, COS3_0 , 1);
00591     BF(20, 23,-COS3_0 , 1);
00592     BF(24, 27, COS3_0 , 1);
00593     BF(28, 31,-COS3_0 , 1);
00594 
00595 
00596 
00597     /* pass 1 */
00598     BF( 1, 30, COS0_1 , 1);
00599     BF(14, 17, COS0_14, 3);
00600     /* pass 2 */
00601     BF( 1, 14, COS1_1 , 1);
00602     BF(17, 30,-COS1_1 , 1);
00603     /* pass 1 */
00604     BF( 6, 25, COS0_6 , 1);
00605     BF( 9, 22, COS0_9 , 1);
00606     /* pass 2 */
00607     BF( 6,  9, COS1_6 , 2);
00608     BF(22, 25,-COS1_6 , 2);
00609     /* pass 3 */
00610     BF( 1,  6, COS2_1 , 1);
00611     BF( 9, 14,-COS2_1 , 1);
00612     BF(17, 22, COS2_1 , 1);
00613     BF(25, 30,-COS2_1 , 1);
00614 
00615     /* pass 1 */
00616     BF( 2, 29, COS0_2 , 1);
00617     BF(13, 18, COS0_13, 3);
00618     /* pass 2 */
00619     BF( 2, 13, COS1_2 , 1);
00620     BF(18, 29,-COS1_2 , 1);
00621     /* pass 1 */
00622     BF( 5, 26, COS0_5 , 1);
00623     BF(10, 21, COS0_10, 1);
00624     /* pass 2 */
00625     BF( 5, 10, COS1_5 , 2);
00626     BF(21, 26,-COS1_5 , 2);
00627     /* pass 3 */
00628     BF( 2,  5, COS2_2 , 1);
00629     BF(10, 13,-COS2_2 , 1);
00630     BF(18, 21, COS2_2 , 1);
00631     BF(26, 29,-COS2_2 , 1);
00632     /* pass 4 */
00633     BF( 1,  2, COS3_1 , 2);
00634     BF( 5,  6,-COS3_1 , 2);
00635     BF( 9, 10, COS3_1 , 2);
00636     BF(13, 14,-COS3_1 , 2);
00637     BF(17, 18, COS3_1 , 2);
00638     BF(21, 22,-COS3_1 , 2);
00639     BF(25, 26, COS3_1 , 2);
00640     BF(29, 30,-COS3_1 , 2);
00641 
00642     /* pass 5 */
00643     BF1( 0,  1,  2,  3);
00644     BF2( 4,  5,  6,  7);
00645     BF1( 8,  9, 10, 11);
00646     BF2(12, 13, 14, 15);
00647     BF1(16, 17, 18, 19);
00648     BF2(20, 21, 22, 23);
00649     BF1(24, 25, 26, 27);
00650     BF2(28, 29, 30, 31);
00651 
00652     /* pass 6 */
00653 
00654     ADD( 8, 12);
00655     ADD(12, 10);
00656     ADD(10, 14);
00657     ADD(14,  9);
00658     ADD( 9, 13);
00659     ADD(13, 11);
00660     ADD(11, 15);
00661 
00662     out[ 0] = tab[0];
00663     out[16] = tab[1];
00664     out[ 8] = tab[2];
00665     out[24] = tab[3];
00666     out[ 4] = tab[4];
00667     out[20] = tab[5];
00668     out[12] = tab[6];
00669     out[28] = tab[7];
00670     out[ 2] = tab[8];
00671     out[18] = tab[9];
00672     out[10] = tab[10];
00673     out[26] = tab[11];
00674     out[ 6] = tab[12];
00675     out[22] = tab[13];
00676     out[14] = tab[14];
00677     out[30] = tab[15];
00678 
00679     ADD(24, 28);
00680     ADD(28, 26);
00681     ADD(26, 30);
00682     ADD(30, 25);
00683     ADD(25, 29);
00684     ADD(29, 27);
00685     ADD(27, 31);
00686 
00687     out[ 1] = tab[16] + tab[24];
00688     out[17] = tab[17] + tab[25];
00689     out[ 9] = tab[18] + tab[26];
00690     out[25] = tab[19] + tab[27];
00691     out[ 5] = tab[20] + tab[28];
00692     out[21] = tab[21] + tab[29];
00693     out[13] = tab[22] + tab[30];
00694     out[29] = tab[23] + tab[31];
00695     out[ 3] = tab[24] + tab[20];
00696     out[19] = tab[25] + tab[21];
00697     out[11] = tab[26] + tab[22];
00698     out[27] = tab[27] + tab[23];
00699     out[ 7] = tab[28] + tab[18];
00700     out[23] = tab[29] + tab[19];
00701     out[15] = tab[30] + tab[17];
00702     out[31] = tab[31];
00703 }
00704 
00705 #if FRAC_BITS <= 15
00706 
00707 static inline int round_sample(int *sum)
00708 {
00709     int sum1;
00710     sum1 = (*sum) >> OUT_SHIFT;
00711     *sum &= (1<<OUT_SHIFT)-1;
00712     return av_clip(sum1, OUT_MIN, OUT_MAX);
00713 }
00714 
00715 /* signed 16x16 -> 32 multiply add accumulate */
00716 #define MACS(rt, ra, rb) MAC16(rt, ra, rb)
00717 
00718 /* signed 16x16 -> 32 multiply */
00719 #define MULS(ra, rb) MUL16(ra, rb)
00720 
00721 #define MLSS(rt, ra, rb) MLS16(rt, ra, rb)
00722 
00723 #else
00724 
00725 static inline int round_sample(int64_t *sum)
00726 {
00727     int sum1;
00728     sum1 = (int)((*sum) >> OUT_SHIFT);
00729     *sum &= (1<<OUT_SHIFT)-1;
00730     return av_clip(sum1, OUT_MIN, OUT_MAX);
00731 }
00732 
00733 #   define MULS(ra, rb) MUL64(ra, rb)
00734 #   define MACS(rt, ra, rb) MAC64(rt, ra, rb)
00735 #   define MLSS(rt, ra, rb) MLS64(rt, ra, rb)
00736 #endif
00737 
00738 #define SUM8(op, sum, w, p)               \
00739 {                                         \
00740     op(sum, (w)[0 * 64], (p)[0 * 64]);    \
00741     op(sum, (w)[1 * 64], (p)[1 * 64]);    \
00742     op(sum, (w)[2 * 64], (p)[2 * 64]);    \
00743     op(sum, (w)[3 * 64], (p)[3 * 64]);    \
00744     op(sum, (w)[4 * 64], (p)[4 * 64]);    \
00745     op(sum, (w)[5 * 64], (p)[5 * 64]);    \
00746     op(sum, (w)[6 * 64], (p)[6 * 64]);    \
00747     op(sum, (w)[7 * 64], (p)[7 * 64]);    \
00748 }
00749 
00750 #define SUM8P2(sum1, op1, sum2, op2, w1, w2, p) \
00751 {                                               \
00752     int tmp;\
00753     tmp = p[0 * 64];\
00754     op1(sum1, (w1)[0 * 64], tmp);\
00755     op2(sum2, (w2)[0 * 64], tmp);\
00756     tmp = p[1 * 64];\
00757     op1(sum1, (w1)[1 * 64], tmp);\
00758     op2(sum2, (w2)[1 * 64], tmp);\
00759     tmp = p[2 * 64];\
00760     op1(sum1, (w1)[2 * 64], tmp);\
00761     op2(sum2, (w2)[2 * 64], tmp);\
00762     tmp = p[3 * 64];\
00763     op1(sum1, (w1)[3 * 64], tmp);\
00764     op2(sum2, (w2)[3 * 64], tmp);\
00765     tmp = p[4 * 64];\
00766     op1(sum1, (w1)[4 * 64], tmp);\
00767     op2(sum2, (w2)[4 * 64], tmp);\
00768     tmp = p[5 * 64];\
00769     op1(sum1, (w1)[5 * 64], tmp);\
00770     op2(sum2, (w2)[5 * 64], tmp);\
00771     tmp = p[6 * 64];\
00772     op1(sum1, (w1)[6 * 64], tmp);\
00773     op2(sum2, (w2)[6 * 64], tmp);\
00774     tmp = p[7 * 64];\
00775     op1(sum1, (w1)[7 * 64], tmp);\
00776     op2(sum2, (w2)[7 * 64], tmp);\
00777 }
00778 
00779 void av_cold ff_mpa_synth_init(MPA_INT *window)
00780 {
00781     int i;
00782 
00783     /* max = 18760, max sum over all 16 coefs : 44736 */
00784     for(i=0;i<257;i++) {
00785         int v;
00786         v = ff_mpa_enwindow[i];
00787 #if WFRAC_BITS < 16
00788         v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
00789 #endif
00790         window[i] = v;
00791         if ((i & 63) != 0)
00792             v = -v;
00793         if (i != 0)
00794             window[512 - i] = v;
00795     }
00796 }
00797 
00798 /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
00799    32 samples. */
00800 /* XXX: optimize by avoiding ring buffer usage */
00801 void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
00802                          MPA_INT *window, int *dither_state,
00803                          OUT_INT *samples, int incr,
00804                          int32_t sb_samples[SBLIMIT])
00805 {
00806     register MPA_INT *synth_buf;
00807     register const MPA_INT *w, *w2, *p;
00808     int j, offset;
00809     OUT_INT *samples2;
00810 #if FRAC_BITS <= 15
00811     int32_t tmp[32];
00812     int sum, sum2;
00813 #else
00814     int64_t sum, sum2;
00815 #endif
00816 
00817     offset = *synth_buf_offset;
00818     synth_buf = synth_buf_ptr + offset;
00819 
00820 #if FRAC_BITS <= 15
00821     dct32(tmp, sb_samples);
00822     for(j=0;j<32;j++) {
00823         /* NOTE: can cause a loss in precision if very high amplitude
00824            sound */
00825         synth_buf[j] = av_clip_int16(tmp[j]);
00826     }
00827 #else
00828     dct32(synth_buf, sb_samples);
00829 #endif
00830 
00831     /* copy to avoid wrap */
00832     memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
00833 
00834     samples2 = samples + 31 * incr;
00835     w = window;
00836     w2 = window + 31;
00837 
00838     sum = *dither_state;
00839     p = synth_buf + 16;
00840     SUM8(MACS, sum, w, p);
00841     p = synth_buf + 48;
00842     SUM8(MLSS, sum, w + 32, p);
00843     *samples = round_sample(&sum);
00844     samples += incr;
00845     w++;
00846 
00847     /* we calculate two samples at the same time to avoid one memory
00848        access per two sample */
00849     for(j=1;j<16;j++) {
00850         sum2 = 0;
00851         p = synth_buf + 16 + j;
00852         SUM8P2(sum, MACS, sum2, MLSS, w, w2, p);
00853         p = synth_buf + 48 - j;
00854         SUM8P2(sum, MLSS, sum2, MLSS, w + 32, w2 + 32, p);
00855 
00856         *samples = round_sample(&sum);
00857         samples += incr;
00858         sum += sum2;
00859         *samples2 = round_sample(&sum);
00860         samples2 -= incr;
00861         w++;
00862         w2--;
00863     }
00864 
00865     p = synth_buf + 32;
00866     SUM8(MLSS, sum, w + 32, p);
00867     *samples = round_sample(&sum);
00868     *dither_state= sum;
00869 
00870     offset = (offset - 32) & 511;
00871     *synth_buf_offset = offset;
00872 }
00873 
00874 #define C3 FIXHR(0.86602540378443864676/2)
00875 
00876 /* 0.5 / cos(pi*(2*i+1)/36) */
00877 static const int icos36[9] = {
00878     FIXR(0.50190991877167369479),
00879     FIXR(0.51763809020504152469), //0
00880     FIXR(0.55168895948124587824),
00881     FIXR(0.61038729438072803416),
00882     FIXR(0.70710678118654752439), //1
00883     FIXR(0.87172339781054900991),
00884     FIXR(1.18310079157624925896),
00885     FIXR(1.93185165257813657349), //2
00886     FIXR(5.73685662283492756461),
00887 };
00888 
00889 /* 0.5 / cos(pi*(2*i+1)/36) */
00890 static const int icos36h[9] = {
00891     FIXHR(0.50190991877167369479/2),
00892     FIXHR(0.51763809020504152469/2), //0
00893     FIXHR(0.55168895948124587824/2),
00894     FIXHR(0.61038729438072803416/2),
00895     FIXHR(0.70710678118654752439/2), //1
00896     FIXHR(0.87172339781054900991/2),
00897     FIXHR(1.18310079157624925896/4),
00898     FIXHR(1.93185165257813657349/4), //2
00899 //    FIXHR(5.73685662283492756461),
00900 };
00901 
00902 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
00903    cases. */
00904 static void imdct12(int *out, int *in)
00905 {
00906     int in0, in1, in2, in3, in4, in5, t1, t2;
00907 
00908     in0= in[0*3];
00909     in1= in[1*3] + in[0*3];
00910     in2= in[2*3] + in[1*3];
00911     in3= in[3*3] + in[2*3];
00912     in4= in[4*3] + in[3*3];
00913     in5= in[5*3] + in[4*3];
00914     in5 += in3;
00915     in3 += in1;
00916 
00917     in2= MULH(2*in2, C3);
00918     in3= MULH(4*in3, C3);
00919 
00920     t1 = in0 - in4;
00921     t2 = MULH(2*(in1 - in5), icos36h[4]);
00922 
00923     out[ 7]=
00924     out[10]= t1 + t2;
00925     out[ 1]=
00926     out[ 4]= t1 - t2;
00927 
00928     in0 += in4>>1;
00929     in4 = in0 + in2;
00930     in5 += 2*in1;
00931     in1 = MULH(in5 + in3, icos36h[1]);
00932     out[ 8]=
00933     out[ 9]= in4 + in1;
00934     out[ 2]=
00935     out[ 3]= in4 - in1;
00936 
00937     in0 -= in2;
00938     in5 = MULH(2*(in5 - in3), icos36h[7]);
00939     out[ 0]=
00940     out[ 5]= in0 - in5;
00941     out[ 6]=
00942     out[11]= in0 + in5;
00943 }
00944 
00945 /* cos(pi*i/18) */
00946 #define C1 FIXHR(0.98480775301220805936/2)
00947 #define C2 FIXHR(0.93969262078590838405/2)
00948 #define C3 FIXHR(0.86602540378443864676/2)
00949 #define C4 FIXHR(0.76604444311897803520/2)
00950 #define C5 FIXHR(0.64278760968653932632/2)
00951 #define C6 FIXHR(0.5/2)
00952 #define C7 FIXHR(0.34202014332566873304/2)
00953 #define C8 FIXHR(0.17364817766693034885/2)
00954 
00955 
00956 /* using Lee like decomposition followed by hand coded 9 points DCT */
00957 static void imdct36(int *out, int *buf, int *in, int *win)
00958 {
00959     int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
00960     int tmp[18], *tmp1, *in1;
00961 
00962     for(i=17;i>=1;i--)
00963         in[i] += in[i-1];
00964     for(i=17;i>=3;i-=2)
00965         in[i] += in[i-2];
00966 
00967     for(j=0;j<2;j++) {
00968         tmp1 = tmp + j;
00969         in1 = in + j;
00970 #if 0
00971 //more accurate but slower
00972         int64_t t0, t1, t2, t3;
00973         t2 = in1[2*4] + in1[2*8] - in1[2*2];
00974 
00975         t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;
00976         t1 = in1[2*0] - in1[2*6];
00977         tmp1[ 6] = t1 - (t2>>1);
00978         tmp1[16] = t1 + t2;
00979 
00980         t0 = MUL64(2*(in1[2*2] + in1[2*4]),    C2);
00981         t1 = MUL64(   in1[2*4] - in1[2*8] , -2*C8);
00982         t2 = MUL64(2*(in1[2*2] + in1[2*8]),   -C4);
00983 
00984         tmp1[10] = (t3 - t0 - t2) >> 32;
00985         tmp1[ 2] = (t3 + t0 + t1) >> 32;
00986         tmp1[14] = (t3 + t2 - t1) >> 32;
00987 
00988         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);
00989         t2 = MUL64(2*(in1[2*1] + in1[2*5]),    C1);
00990         t3 = MUL64(   in1[2*5] - in1[2*7] , -2*C7);
00991         t0 = MUL64(2*in1[2*3], C3);
00992 
00993         t1 = MUL64(2*(in1[2*1] + in1[2*7]),   -C5);
00994 
00995         tmp1[ 0] = (t2 + t3 + t0) >> 32;
00996         tmp1[12] = (t2 + t1 - t0) >> 32;
00997         tmp1[ 8] = (t3 - t1 - t0) >> 32;
00998 #else
00999         t2 = in1[2*4] + in1[2*8] - in1[2*2];
01000 
01001         t3 = in1[2*0] + (in1[2*6]>>1);
01002         t1 = in1[2*0] - in1[2*6];
01003         tmp1[ 6] = t1 - (t2>>1);
01004         tmp1[16] = t1 + t2;
01005 
01006         t0 = MULH(2*(in1[2*2] + in1[2*4]),    C2);
01007         t1 = MULH(   in1[2*4] - in1[2*8] , -2*C8);
01008         t2 = MULH(2*(in1[2*2] + in1[2*8]),   -C4);
01009 
01010         tmp1[10] = t3 - t0 - t2;
01011         tmp1[ 2] = t3 + t0 + t1;
01012         tmp1[14] = t3 + t2 - t1;
01013 
01014         tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7] - in1[2*1]), -C3);
01015         t2 = MULH(2*(in1[2*1] + in1[2*5]),    C1);
01016         t3 = MULH(   in1[2*5] - in1[2*7] , -2*C7);
01017         t0 = MULH(2*in1[2*3], C3);
01018 
01019         t1 = MULH(2*(in1[2*1] + in1[2*7]),   -C5);
01020 
01021         tmp1[ 0] = t2 + t3 + t0;
01022         tmp1[12] = t2 + t1 - t0;
01023         tmp1[ 8] = t3 - t1 - t0;
01024 #endif
01025     }
01026 
01027     i = 0;
01028     for(j=0;j<4;j++) {
01029         t0 = tmp[i];
01030         t1 = tmp[i + 2];
01031         s0 = t1 + t0;
01032         s2 = t1 - t0;
01033 
01034         t2 = tmp[i + 1];
01035         t3 = tmp[i + 3];
01036         s1 = MULH(2*(t3 + t2), icos36h[j]);
01037         s3 = MULL(t3 - t2, icos36[8 - j], FRAC_BITS);
01038 
01039         t0 = s0 + s1;
01040         t1 = s0 - s1;
01041         out[(9 + j)*SBLIMIT] =  MULH(t1, win[9 + j]) + buf[9 + j];
01042         out[(8 - j)*SBLIMIT] =  MULH(t1, win[8 - j]) + buf[8 - j];
01043         buf[9 + j] = MULH(t0, win[18 + 9 + j]);
01044         buf[8 - j] = MULH(t0, win[18 + 8 - j]);
01045 
01046         t0 = s2 + s3;
01047         t1 = s2 - s3;
01048         out[(9 + 8 - j)*SBLIMIT] =  MULH(t1, win[9 + 8 - j]) + buf[9 + 8 - j];
01049         out[(        j)*SBLIMIT] =  MULH(t1, win[        j]) + buf[        j];
01050         buf[9 + 8 - j] = MULH(t0, win[18 + 9 + 8 - j]);
01051         buf[      + j] = MULH(t0, win[18         + j]);
01052         i += 4;
01053     }
01054 
01055     s0 = tmp[16];
01056     s1 = MULH(2*tmp[17], icos36h[4]);
01057     t0 = s0 + s1;
01058     t1 = s0 - s1;
01059     out[(9 + 4)*SBLIMIT] =  MULH(t1, win[9 + 4]) + buf[9 + 4];
01060     out[(8 - 4)*SBLIMIT] =  MULH(t1, win[8 - 4]) + buf[8 - 4];
01061     buf[9 + 4] = MULH(t0, win[18 + 9 + 4]);
01062     buf[8 - 4] = MULH(t0, win[18 + 8 - 4]);
01063 }
01064 
01065 /* return the number of decoded frames */
01066 static int mp_decode_layer1(MPADecodeContext *s)
01067 {
01068     int bound, i, v, n, ch, j, mant;
01069     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
01070     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
01071 
01072     if (s->mode == MPA_JSTEREO)
01073         bound = (s->mode_ext + 1) * 4;
01074     else
01075         bound = SBLIMIT;
01076 
01077     /* allocation bits */
01078     for(i=0;i<bound;i++) {
01079         for(ch=0;ch<s->nb_channels;ch++) {
01080             allocation[ch][i] = get_bits(&s->gb, 4);
01081         }
01082     }
01083     for(i=bound;i<SBLIMIT;i++) {
01084         allocation[0][i] = get_bits(&s->gb, 4);
01085     }
01086 
01087     /* scale factors */
01088     for(i=0;i<bound;i++) {
01089         for(ch=0;ch<s->nb_channels;ch++) {
01090             if (allocation[ch][i])
01091                 scale_factors[ch][i] = get_bits(&s->gb, 6);
01092         }
01093     }
01094     for(i=bound;i<SBLIMIT;i++) {
01095         if (allocation[0][i]) {
01096             scale_factors[0][i] = get_bits(&s->gb, 6);
01097             scale_factors[1][i] = get_bits(&s->gb, 6);
01098         }
01099     }
01100 
01101     /* compute samples */
01102     for(j=0;j<12;j++) {
01103         for(i=0;i<bound;i++) {
01104             for(ch=0;ch<s->nb_channels;ch++) {
01105                 n = allocation[ch][i];
01106                 if (n) {
01107                     mant = get_bits(&s->gb, n + 1);
01108                     v = l1_unscale(n, mant, scale_factors[ch][i]);
01109                 } else {
01110                     v = 0;
01111                 }
01112                 s->sb_samples[ch][j][i] = v;
01113             }
01114         }
01115         for(i=bound;i<SBLIMIT;i++) {
01116             n = allocation[0][i];
01117             if (n) {
01118                 mant = get_bits(&s->gb, n + 1);
01119                 v = l1_unscale(n, mant, scale_factors[0][i]);
01120                 s->sb_samples[0][j][i] = v;
01121                 v = l1_unscale(n, mant, scale_factors[1][i]);
01122                 s->sb_samples[1][j][i] = v;
01123             } else {
01124                 s->sb_samples[0][j][i] = 0;
01125                 s->sb_samples[1][j][i] = 0;
01126             }
01127         }
01128     }
01129     return 12;
01130 }
01131 
01132 static int mp_decode_layer2(MPADecodeContext *s)
01133 {
01134     int sblimit; /* number of used subbands */
01135     const unsigned char *alloc_table;
01136     int table, bit_alloc_bits, i, j, ch, bound, v;
01137     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
01138     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
01139     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
01140     int scale, qindex, bits, steps, k, l, m, b;
01141 
01142     /* select decoding table */
01143     table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,
01144                             s->sample_rate, s->lsf);
01145     sblimit = ff_mpa_sblimit_table[table];
01146     alloc_table = ff_mpa_alloc_tables[table];
01147 
01148     if (s->mode == MPA_JSTEREO)
01149         bound = (s->mode_ext + 1) * 4;
01150     else
01151         bound = sblimit;
01152 
01153     dprintf(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);
01154 
01155     /* sanity check */
01156     if( bound > sblimit ) bound = sblimit;
01157 
01158     /* parse bit allocation */
01159     j = 0;
01160     for(i=0;i<bound;i++) {
01161         bit_alloc_bits = alloc_table[j];
01162         for(ch=0;ch<s->nb_channels;ch++) {
01163             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
01164         }
01165         j += 1 << bit_alloc_bits;
01166     }
01167     for(i=bound;i<sblimit;i++) {
01168         bit_alloc_bits = alloc_table[j];
01169         v = get_bits(&s->gb, bit_alloc_bits);
01170         bit_alloc[0][i] = v;
01171         bit_alloc[1][i] = v;
01172         j += 1 << bit_alloc_bits;
01173     }
01174 
01175     /* scale codes */
01176     for(i=0;i<sblimit;i++) {
01177         for(ch=0;ch<s->nb_channels;ch++) {
01178             if (bit_alloc[ch][i])
01179                 scale_code[ch][i] = get_bits(&s->gb, 2);
01180         }
01181     }
01182 
01183     /* scale factors */
01184     for(i=0;i<sblimit;i++) {
01185         for(ch=0;ch<s->nb_channels;ch++) {
01186             if (bit_alloc[ch][i]) {
01187                 sf = scale_factors[ch][i];
01188                 switch(scale_code[ch][i]) {
01189                 default:
01190                 case 0:
01191                     sf[0] = get_bits(&s->gb, 6);
01192                     sf[1] = get_bits(&s->gb, 6);
01193                     sf[2] = get_bits(&s->gb, 6);
01194                     break;
01195                 case 2:
01196                     sf[0] = get_bits(&s->gb, 6);
01197                     sf[1] = sf[0];
01198                     sf[2] = sf[0];
01199                     break;
01200                 case 1:
01201                     sf[0] = get_bits(&s->gb, 6);
01202                     sf[2] = get_bits(&s->gb, 6);
01203                     sf[1] = sf[0];
01204                     break;
01205                 case 3:
01206                     sf[0] = get_bits(&s->gb, 6);
01207                     sf[2] = get_bits(&s->gb, 6);
01208                     sf[1] = sf[2];
01209                     break;
01210                 }
01211             }
01212         }
01213     }
01214 
01215     /* samples */
01216     for(k=0;k<3;k++) {
01217         for(l=0;l<12;l+=3) {
01218             j = 0;
01219             for(i=0;i<bound;i++) {
01220                 bit_alloc_bits = alloc_table[j];
01221                 for(ch=0;ch<s->nb_channels;ch++) {
01222                     b = bit_alloc[ch][i];
01223                     if (b) {
01224                         scale = scale_factors[ch][i][k];
01225                         qindex = alloc_table[j+b];
01226                         bits = ff_mpa_quant_bits[qindex];
01227                         if (bits < 0) {
01228                             /* 3 values at the same time */
01229                             v = get_bits(&s->gb, -bits);
01230                             steps = ff_mpa_quant_steps[qindex];
01231                             s->sb_samples[ch][k * 12 + l + 0][i] =
01232                                 l2_unscale_group(steps, v % steps, scale);
01233                             v = v / steps;
01234                             s->sb_samples[ch][k * 12 + l + 1][i] =
01235                                 l2_unscale_group(steps, v % steps, scale);
01236                             v = v / steps;
01237                             s->sb_samples[ch][k * 12 + l + 2][i] =
01238                                 l2_unscale_group(steps, v, scale);
01239                         } else {
01240                             for(m=0;m<3;m++) {
01241                                 v = get_bits(&s->gb, bits);
01242                                 v = l1_unscale(bits - 1, v, scale);
01243                                 s->sb_samples[ch][k * 12 + l + m][i] = v;
01244                             }
01245                         }
01246                     } else {
01247                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;
01248                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;
01249                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;
01250                     }
01251                 }
01252                 /* next subband in alloc table */
01253                 j += 1 << bit_alloc_bits;
01254             }
01255             /* XXX: find a way to avoid this duplication of code */
01256             for(i=bound;i<sblimit;i++) {
01257                 bit_alloc_bits = alloc_table[j];
01258                 b = bit_alloc[0][i];
01259                 if (b) {
01260                     int mant, scale0, scale1;
01261                     scale0 = scale_factors[0][i][k];
01262                     scale1 = scale_factors[1][i][k];
01263                     qindex = alloc_table[j+b];
01264                     bits = ff_mpa_quant_bits[qindex];
01265                     if (bits < 0) {
01266                         /* 3 values at the same time */
01267                         v = get_bits(&s->gb, -bits);
01268                         steps = ff_mpa_quant_steps[qindex];
01269                         mant = v % steps;
01270                         v = v / steps;
01271                         s->sb_samples[0][k * 12 + l + 0][i] =
01272                             l2_unscale_group(steps, mant, scale0);
01273                         s->sb_samples[1][k * 12 + l + 0][i] =
01274                             l2_unscale_group(steps, mant, scale1);
01275                         mant = v % steps;
01276                         v = v / steps;
01277                         s->sb_samples[0][k * 12 + l + 1][i] =
01278                             l2_unscale_group(steps, mant, scale0);
01279                         s->sb_samples[1][k * 12 + l + 1][i] =
01280                             l2_unscale_group(steps, mant, scale1);
01281                         s->sb_samples[0][k * 12 + l + 2][i] =
01282                             l2_unscale_group(steps, v, scale0);
01283                         s->sb_samples[1][k * 12 + l + 2][i] =
01284                             l2_unscale_group(steps, v, scale1);
01285                     } else {
01286                         for(m=0;m<3;m++) {
01287                             mant = get_bits(&s->gb, bits);
01288                             s->sb_samples[0][k * 12 + l + m][i] =
01289                                 l1_unscale(bits - 1, mant, scale0);
01290                             s->sb_samples[1][k * 12 + l + m][i] =
01291                                 l1_unscale(bits - 1, mant, scale1);
01292                         }
01293                     }
01294                 } else {
01295                     s->sb_samples[0][k * 12 + l + 0][i] = 0;
01296                     s->sb_samples[0][k * 12 + l + 1][i] = 0;
01297                     s->sb_samples[0][k * 12 + l + 2][i] = 0;
01298                     s->sb_samples[1][k * 12 + l + 0][i] = 0;
01299                     s->sb_samples[1][k * 12 + l + 1][i] = 0;
01300                     s->sb_samples[1][k * 12 + l + 2][i] = 0;
01301                 }
01302                 /* next subband in alloc table */
01303                 j += 1 << bit_alloc_bits;
01304             }
01305             /* fill remaining samples to zero */
01306             for(i=sblimit;i<SBLIMIT;i++) {
01307                 for(ch=0;ch<s->nb_channels;ch++) {
01308                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;
01309                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;
01310                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;
01311                 }
01312             }
01313         }
01314     }
01315     return 3 * 12;
01316 }
01317 
01318 #define SPLIT(dst,sf,n)\
01319     if(n==3){\
01320         int m= (sf*171)>>9;\
01321         dst= sf - 3*m;\
01322         sf=m;\
01323     }else if(n==4){\
01324         dst= sf&3;\
01325         sf>>=2;\
01326     }else if(n==5){\
01327         int m= (sf*205)>>10;\
01328         dst= sf - 5*m;\
01329         sf=m;\
01330     }else if(n==6){\
01331         int m= (sf*171)>>10;\
01332         dst= sf - 6*m;\
01333         sf=m;\
01334     }else{\
01335         dst=0;\
01336     }
01337 
01338 static av_always_inline void lsf_sf_expand(int *slen,
01339                                  int sf, int n1, int n2, int n3)
01340 {
01341     SPLIT(slen[3], sf, n3)
01342     SPLIT(slen[2], sf, n2)
01343     SPLIT(slen[1], sf, n1)
01344     slen[0] = sf;
01345 }
01346 
01347 static void exponents_from_scale_factors(MPADecodeContext *s,
01348                                          GranuleDef *g,
01349                                          int16_t *exponents)
01350 {
01351     const uint8_t *bstab, *pretab;
01352     int len, i, j, k, l, v0, shift, gain, gains[3];
01353     int16_t *exp_ptr;
01354 
01355     exp_ptr = exponents;
01356     gain = g->global_gain - 210;
01357     shift = g->scalefac_scale + 1;
01358 
01359     bstab = band_size_long[s->sample_rate_index];
01360     pretab = mpa_pretab[g->preflag];
01361     for(i=0;i<g->long_end;i++) {
01362         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;
01363         len = bstab[i];
01364         for(j=len;j>0;j--)
01365             *exp_ptr++ = v0;
01366     }
01367 
01368     if (g->short_start < 13) {
01369         bstab = band_size_short[s->sample_rate_index];
01370         gains[0] = gain - (g->subblock_gain[0] << 3);
01371         gains[1] = gain - (g->subblock_gain[1] << 3);
01372         gains[2] = gain - (g->subblock_gain[2] << 3);
01373         k = g->long_end;
01374         for(i=g->short_start;i<13;i++) {
01375             len = bstab[i];
01376             for(l=0;l<3;l++) {
01377                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;
01378                 for(j=len;j>0;j--)
01379                 *exp_ptr++ = v0;
01380             }
01381         }
01382     }
01383 }
01384 
01385 /* handle n = 0 too */
01386 static inline int get_bitsz(GetBitContext *s, int n)
01387 {
01388     if (n == 0)
01389         return 0;
01390     else
01391         return get_bits(s, n);
01392 }
01393 
01394 
01395 static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos, int *end_pos2){
01396     if(s->in_gb.buffer && *pos >= s->gb.size_in_bits){
01397         s->gb= s->in_gb;
01398         s->in_gb.buffer=NULL;
01399         assert((get_bits_count(&s->gb) & 7) == 0);
01400         skip_bits_long(&s->gb, *pos - *end_pos);
01401         *end_pos2=
01402         *end_pos= *end_pos2 + get_bits_count(&s->gb) - *pos;
01403         *pos= get_bits_count(&s->gb);
01404     }
01405 }
01406 
01407 static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
01408                           int16_t *exponents, int end_pos2)
01409 {
01410     int s_index;
01411     int i;
01412     int last_pos, bits_left;
01413     VLC *vlc;
01414     int end_pos= FFMIN(end_pos2, s->gb.size_in_bits);
01415 
01416     /* low frequencies (called big values) */
01417     s_index = 0;
01418     for(i=0;i<3;i++) {
01419         int j, k, l, linbits;
01420         j = g->region_size[i];
01421         if (j == 0)
01422             continue;
01423         /* select vlc table */
01424         k = g->table_select[i];
01425         l = mpa_huff_data[k][0];
01426         linbits = mpa_huff_data[k][1];
01427         vlc = &huff_vlc[l];
01428 
01429         if(!l){
01430             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*2*j);
01431             s_index += 2*j;
01432             continue;
01433         }
01434 
01435         /* read huffcode and compute each couple */
01436         for(;j>0;j--) {
01437             int exponent, x, y, v;
01438             int pos= get_bits_count(&s->gb);
01439 
01440             if (pos >= end_pos){
01441 //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);
01442                 switch_buffer(s, &pos, &end_pos, &end_pos2);
01443 //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);
01444                 if(pos >= end_pos)
01445                     break;
01446             }
01447             y = get_vlc2(&s->gb, vlc->table, 7, 3);
01448 
01449             if(!y){
01450                 g->sb_hybrid[s_index  ] =
01451                 g->sb_hybrid[s_index+1] = 0;
01452                 s_index += 2;
01453                 continue;
01454             }
01455 
01456             exponent= exponents[s_index];
01457 
01458             dprintf(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",
01459                     i, g->region_size[i] - j, x, y, exponent);
01460             if(y&16){
01461                 x = y >> 5;
01462                 y = y & 0x0f;
01463                 if (x < 15){
01464                     v = expval_table[ exponent ][ x ];
01465 //                      v = expval_table[ (exponent&3) ][ x ] >> FFMIN(0 - (exponent>>2), 31);
01466                 }else{
01467                     x += get_bitsz(&s->gb, linbits);
01468                     v = l3_unscale(x, exponent);
01469                 }
01470                 if (get_bits1(&s->gb))
01471                     v = -v;
01472                 g->sb_hybrid[s_index] = v;
01473                 if (y < 15){
01474                     v = expval_table[ exponent ][ y ];
01475                 }else{
01476                     y += get_bitsz(&s->gb, linbits);
01477                     v = l3_unscale(y, exponent);
01478                 }
01479                 if (get_bits1(&s->gb))
01480                     v = -v;
01481                 g->sb_hybrid[s_index+1] = v;
01482             }else{
01483                 x = y >> 5;
01484                 y = y & 0x0f;
01485                 x += y;
01486                 if (x < 15){
01487                     v = expval_table[ exponent ][ x ];
01488                 }else{
01489                     x += get_bitsz(&s->gb, linbits);
01490                     v = l3_unscale(x, exponent);
01491                 }
01492                 if (get_bits1(&s->gb))
01493                     v = -v;
01494                 g->sb_hybrid[s_index+!!y] = v;
01495                 g->sb_hybrid[s_index+ !y] = 0;
01496             }
01497             s_index+=2;
01498         }
01499     }
01500 
01501     /* high frequencies */
01502     vlc = &huff_quad_vlc[g->count1table_select];
01503     last_pos=0;
01504     while (s_index <= 572) {
01505         int pos, code;
01506         pos = get_bits_count(&s->gb);
01507         if (pos >= end_pos) {
01508             if (pos > end_pos2 && last_pos){
01509                 /* some encoders generate an incorrect size for this
01510                    part. We must go back into the data */
01511                 s_index -= 4;
01512                 skip_bits_long(&s->gb, last_pos - pos);
01513                 av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
01514                 if(s->error_recognition >= FF_ER_COMPLIANT)
01515                     s_index=0;
01516                 break;
01517             }
01518 //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);
01519             switch_buffer(s, &pos, &end_pos, &end_pos2);
01520 //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);
01521             if(pos >= end_pos)
01522                 break;
01523         }
01524         last_pos= pos;
01525 
01526         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);
01527         dprintf(s->avctx, "t=%d code=%d\n", g->count1table_select, code);
01528         g->sb_hybrid[s_index+0]=
01529         g->sb_hybrid[s_index+1]=
01530         g->sb_hybrid[s_index+2]=
01531         g->sb_hybrid[s_index+3]= 0;
01532         while(code){
01533             static const int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};
01534             int v;
01535             int pos= s_index+idxtab[code];
01536             code ^= 8>>idxtab[code];
01537             v = exp_table[ exponents[pos] ];
01538 //            v = exp_table[ (exponents[pos]&3) ] >> FFMIN(0 - (exponents[pos]>>2), 31);
01539             if(get_bits1(&s->gb))
01540                 v = -v;
01541             g->sb_hybrid[pos] = v;
01542         }
01543         s_index+=4;
01544     }
01545     /* skip extension bits */
01546     bits_left = end_pos2 - get_bits_count(&s->gb);
01547 //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);
01548     if (bits_left < 0 && s->error_recognition >= FF_ER_COMPLIANT) {
01549         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
01550         s_index=0;
01551     }else if(bits_left > 0 && s->error_recognition >= FF_ER_AGGRESSIVE){
01552         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
01553         s_index=0;
01554     }
01555     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid)*(576 - s_index));
01556     skip_bits_long(&s->gb, bits_left);
01557 
01558     i= get_bits_count(&s->gb);
01559     switch_buffer(s, &i, &end_pos, &end_pos2);
01560 
01561     return 0;
01562 }
01563 
01564 /* Reorder short blocks from bitstream order to interleaved order. It
01565    would be faster to do it in parsing, but the code would be far more
01566    complicated */
01567 static void reorder_block(MPADecodeContext *s, GranuleDef *g)
01568 {
01569     int i, j, len;
01570     int32_t *ptr, *dst, *ptr1;
01571     int32_t tmp[576];
01572 
01573     if (g->block_type != 2)
01574         return;
01575 
01576     if (g->switch_point) {
01577         if (s->sample_rate_index != 8) {
01578             ptr = g->sb_hybrid + 36;
01579         } else {
01580             ptr = g->sb_hybrid + 48;
01581         }
01582     } else {
01583         ptr = g->sb_hybrid;
01584     }
01585 
01586     for(i=g->short_start;i<13;i++) {
01587         len = band_size_short[s->sample_rate_index][i];
01588         ptr1 = ptr;
01589         dst = tmp;
01590         for(j=len;j>0;j--) {
01591             *dst++ = ptr[0*len];
01592             *dst++ = ptr[1*len];
01593             *dst++ = ptr[2*len];
01594             ptr++;
01595         }
01596         ptr+=2*len;
01597         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));
01598     }
01599 }
01600 
01601 #define ISQRT2 FIXR(0.70710678118654752440)
01602 
01603 static void compute_stereo(MPADecodeContext *s,
01604                            GranuleDef *g0, GranuleDef *g1)
01605 {
01606     int i, j, k, l;
01607     int32_t v1, v2;
01608     int sf_max, tmp0, tmp1, sf, len, non_zero_found;
01609     int32_t (*is_tab)[16];
01610     int32_t *tab0, *tab1;
01611     int non_zero_found_short[3];
01612 
01613     /* intensity stereo */
01614     if (s->mode_ext & MODE_EXT_I_STEREO) {
01615         if (!s->lsf) {
01616             is_tab = is_table;
01617             sf_max = 7;
01618         } else {
01619             is_tab = is_table_lsf[g1->scalefac_compress & 1];
01620             sf_max = 16;
01621         }
01622 
01623         tab0 = g0->sb_hybrid + 576;
01624         tab1 = g1->sb_hybrid + 576;
01625 
01626         non_zero_found_short[0] = 0;
01627         non_zero_found_short[1] = 0;
01628         non_zero_found_short[2] = 0;
01629         k = (13 - g1->short_start) * 3 + g1->long_end - 3;
01630         for(i = 12;i >= g1->short_start;i--) {
01631             /* for last band, use previous scale factor */
01632             if (i != 11)
01633                 k -= 3;
01634             len = band_size_short[s->sample_rate_index][i];
01635             for(l=2;l>=0;l--) {
01636                 tab0 -= len;
01637                 tab1 -= len;
01638                 if (!non_zero_found_short[l]) {
01639                     /* test if non zero band. if so, stop doing i-stereo */
01640                     for(j=0;j<len;j++) {
01641                         if (tab1[j] != 0) {
01642                             non_zero_found_short[l] = 1;
01643                             goto found1;
01644                         }
01645                     }
01646                     sf = g1->scale_factors[k + l];
01647                     if (sf >= sf_max)
01648                         goto found1;
01649 
01650                     v1 = is_tab[0][sf];
01651                     v2 = is_tab[1][sf];
01652                     for(j=0;j<len;j++) {
01653                         tmp0 = tab0[j];
01654                         tab0[j] = MULL(tmp0, v1, FRAC_BITS);
01655                         tab1[j] = MULL(tmp0, v2, FRAC_BITS);
01656                     }
01657                 } else {
01658                 found1:
01659                     if (s->mode_ext & MODE_EXT_MS_STEREO) {
01660                         /* lower part of the spectrum : do ms stereo
01661                            if enabled */
01662                         for(j=0;j<len;j++) {
01663                             tmp0 = tab0[j];
01664                             tmp1 = tab1[j];
01665                             tab0[j] = MULL(tmp0 + tmp1, ISQRT2, FRAC_BITS);
01666                             tab1[j] = MULL(tmp0 - tmp1, ISQRT2, FRAC_BITS);
01667                         }
01668                     }
01669                 }
01670             }
01671         }
01672 
01673         non_zero_found = non_zero_found_short[0] |
01674             non_zero_found_short[1] |
01675             non_zero_found_short[2];
01676 
01677         for(i = g1->long_end - 1;i >= 0;i--) {
01678             len = band_size_long[s->sample_rate_index][i];
01679             tab0 -= len;
01680             tab1 -= len;
01681             /* test if non zero band. if so, stop doing i-stereo */
01682             if (!non_zero_found) {
01683                 for(j=0;j<len;j++) {
01684                     if (tab1[j] != 0) {
01685                         non_zero_found = 1;
01686                         goto found2;
01687                     }
01688                 }
01689                 /* for last band, use previous scale factor */
01690                 k = (i == 21) ? 20 : i;
01691                 sf = g1->scale_factors[k];
01692                 if (sf >= sf_max)
01693                     goto found2;
01694                 v1 = is_tab[0][sf];
01695                 v2 = is_tab[1][sf];
01696                 for(j=0;j<len;j++) {
01697                     tmp0 = tab0[j];
01698                     tab0[j] = MULL(tmp0, v1, FRAC_BITS);
01699                     tab1[j] = MULL(tmp0, v2, FRAC_BITS);
01700                 }
01701             } else {
01702             found2:
01703                 if (s->mode_ext & MODE_EXT_MS_STEREO) {
01704                     /* lower part of the spectrum : do ms stereo
01705                        if enabled */
01706                     for(j=0;j<len;j++) {
01707                         tmp0 = tab0[j];
01708                         tmp1 = tab1[j];
01709                         tab0[j] = MULL(tmp0 + tmp1, ISQRT2, FRAC_BITS);
01710                         tab1[j] = MULL(tmp0 - tmp1, ISQRT2, FRAC_BITS);
01711                     }
01712                 }
01713             }
01714         }
01715     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
01716         /* ms stereo ONLY */
01717         /* NOTE: the 1/sqrt(2) normalization factor is included in the
01718            global gain */
01719         tab0 = g0->sb_hybrid;
01720         tab1 = g1->sb_hybrid;
01721         for(i=0;i<576;i++) {
01722             tmp0 = tab0[i];
01723             tmp1 = tab1[i];
01724             tab0[i] = tmp0 + tmp1;
01725             tab1[i] = tmp0 - tmp1;
01726         }
01727     }
01728 }
01729 
01730 static void compute_antialias_integer(MPADecodeContext *s,
01731                               GranuleDef *g)
01732 {
01733     int32_t *ptr, *csa;
01734     int n, i;
01735 
01736     /* we antialias only "long" bands */
01737     if (g->block_type == 2) {
01738         if (!g->switch_point)
01739             return;
01740         /* XXX: check this for 8000Hz case */
01741         n = 1;
01742     } else {
01743         n = SBLIMIT - 1;
01744     }
01745 
01746     ptr = g->sb_hybrid + 18;
01747     for(i = n;i > 0;i--) {
01748         int tmp0, tmp1, tmp2;
01749         csa = &csa_table[0][0];
01750 #define INT_AA(j) \
01751             tmp0 = ptr[-1-j];\
01752             tmp1 = ptr[   j];\
01753             tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\
01754             ptr[-1-j] = 4*(tmp2 - MULH(tmp1, csa[2+4*j]));\
01755             ptr[   j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j]));
01756 
01757         INT_AA(0)
01758         INT_AA(1)
01759         INT_AA(2)
01760         INT_AA(3)
01761         INT_AA(4)
01762         INT_AA(5)
01763         INT_AA(6)
01764         INT_AA(7)
01765 
01766         ptr += 18;
01767     }
01768 }
01769 
01770 static void compute_antialias_float(MPADecodeContext *s,
01771                               GranuleDef *g)
01772 {
01773     int32_t *ptr;
01774     int n, i;
01775 
01776     /* we antialias only "long" bands */
01777     if (g->block_type == 2) {
01778         if (!g->switch_point)
01779             return;
01780         /* XXX: check this for 8000Hz case */
01781         n = 1;
01782     } else {
01783         n = SBLIMIT - 1;
01784     }
01785 
01786     ptr = g->sb_hybrid + 18;
01787     for(i = n;i > 0;i--) {
01788         float tmp0, tmp1;
01789         float *csa = &csa_table_float[0][0];
01790 #define FLOAT_AA(j)\
01791         tmp0= ptr[-1-j];\
01792         tmp1= ptr[   j];\
01793         ptr[-1-j] = lrintf(tmp0 * csa[0+4*j] - tmp1 * csa[1+4*j]);\
01794         ptr[   j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]);
01795 
01796         FLOAT_AA(0)
01797         FLOAT_AA(1)
01798         FLOAT_AA(2)
01799         FLOAT_AA(3)
01800         FLOAT_AA(4)
01801         FLOAT_AA(5)
01802         FLOAT_AA(6)
01803         FLOAT_AA(7)
01804 
01805         ptr += 18;
01806     }
01807 }
01808 
01809 static void compute_imdct(MPADecodeContext *s,
01810                           GranuleDef *g,
01811                           int32_t *sb_samples,
01812                           int32_t *mdct_buf)
01813 {
01814     int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1;
01815     int32_t out2[12];
01816     int i, j, mdct_long_end, v, sblimit;
01817 
01818     /* find last non zero block */
01819     ptr = g->sb_hybrid + 576;
01820     ptr1 = g->sb_hybrid + 2 * 18;
01821     while (ptr >= ptr1) {
01822         ptr -= 6;
01823         v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];
01824         if (v != 0)
01825             break;
01826     }
01827     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
01828 
01829     if (g->block_type == 2) {
01830         /* XXX: check for 8000 Hz */
01831         if (g->switch_point)
01832             mdct_long_end = 2;
01833         else
01834             mdct_long_end = 0;
01835     } else {
01836         mdct_long_end = sblimit;
01837     }
01838 
01839     buf = mdct_buf;
01840     ptr = g->sb_hybrid;
01841     for(j=0;j<mdct_long_end;j++) {
01842         /* apply window & overlap with previous buffer */
01843         out_ptr = sb_samples + j;
01844         /* select window */
01845         if (g->switch_point && j < 2)
01846             win1 = mdct_win[0];
01847         else
01848             win1 = mdct_win[g->block_type];
01849         /* select frequency inversion */
01850         win = win1 + ((4 * 36) & -(j & 1));
01851         imdct36(out_ptr, buf, ptr, win);
01852         out_ptr += 18*SBLIMIT;
01853         ptr += 18;
01854         buf += 18;
01855     }
01856     for(j=mdct_long_end;j<sblimit;j++) {
01857         /* select frequency inversion */
01858         win = mdct_win[2] + ((4 * 36) & -(j & 1));
01859         out_ptr = sb_samples + j;
01860 
01861         for(i=0; i<6; i++){
01862             *out_ptr = buf[i];
01863             out_ptr += SBLIMIT;
01864         }
01865         imdct12(out2, ptr + 0);
01866         for(i=0;i<6;i++) {
01867             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1];
01868             buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]);
01869             out_ptr += SBLIMIT;
01870         }
01871         imdct12(out2, ptr + 1);
01872         for(i=0;i<6;i++) {
01873             *out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2];
01874             buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]);
01875             out_ptr += SBLIMIT;
01876         }
01877         imdct12(out2, ptr + 2);
01878         for(i=0;i<6;i++) {
01879             buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0];
01880             buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]);
01881             buf[i + 6*2] = 0;
01882         }
01883         ptr += 18;
01884         buf += 18;
01885     }
01886     /* zero bands */
01887     for(j=sblimit;j<SBLIMIT;j++) {
01888         /* overlap */
01889         out_ptr = sb_samples + j;
01890         for(i=0;i<18;i++) {
01891             *out_ptr = buf[i];
01892             buf[i] = 0;
01893             out_ptr += SBLIMIT;
01894         }
01895         buf += 18;
01896     }
01897 }
01898 
01899 /* main layer3 decoding function */
01900 static int mp_decode_layer3(MPADecodeContext *s)
01901 {
01902     int nb_granules, main_data_begin, private_bits;
01903     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;
01904     GranuleDef *g;
01905     int16_t exponents[576];
01906 
01907     /* read side info */
01908     if (s->lsf) {
01909         main_data_begin = get_bits(&s->gb, 8);
01910         private_bits = get_bits(&s->gb, s->nb_channels);
01911         nb_granules = 1;
01912     } else {
01913         main_data_begin = get_bits(&s->gb, 9);
01914         if (s->nb_channels == 2)
01915             private_bits = get_bits(&s->gb, 3);
01916         else
01917             private_bits = get_bits(&s->gb, 5);
01918         nb_granules = 2;
01919         for(ch=0;ch<s->nb_channels;ch++) {
01920             s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */
01921             s->granules[ch][1].scfsi = get_bits(&s->gb, 4);
01922         }
01923     }
01924 
01925     for(gr=0;gr<nb_granules;gr++) {
01926         for(ch=0;ch<s->nb_channels;ch++) {
01927             dprintf(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);
01928             g = &s->granules[ch][gr];
01929             g->part2_3_length = get_bits(&s->gb, 12);
01930             g->big_values = get_bits(&s->gb, 9);
01931             if(g->big_values > 288){
01932                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");
01933                 return -1;
01934             }
01935 
01936             g->global_gain = get_bits(&s->gb, 8);
01937             /* if MS stereo only is selected, we precompute the
01938                1/sqrt(2) renormalization factor */
01939             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
01940                 MODE_EXT_MS_STEREO)
01941                 g->global_gain -= 2;
01942             if (s->lsf)
01943                 g->scalefac_compress = get_bits(&s->gb, 9);
01944             else
01945                 g->scalefac_compress = get_bits(&s->gb, 4);
01946             blocksplit_flag = get_bits1(&s->gb);
01947             if (blocksplit_flag) {
01948                 g->block_type = get_bits(&s->gb, 2);
01949                 if (g->block_type == 0){
01950                     av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");
01951                     return -1;
01952                 }
01953                 g->switch_point = get_bits1(&s->gb);
01954                 for(i=0;i<2;i++)
01955                     g->table_select[i] = get_bits(&s->gb, 5);
01956                 for(i=0;i<3;i++)
01957                     g->subblock_gain[i] = get_bits(&s->gb, 3);
01958                 ff_init_short_region(s, g);
01959             } else {
01960                 int region_address1, region_address2;
01961                 g->block_type = 0;
01962                 g->switch_point = 0;
01963                 for(i=0;i<3;i++)
01964                     g->table_select[i] = get_bits(&s->gb, 5);
01965                 /* compute huffman coded region sizes */
01966                 region_address1 = get_bits(&s->gb, 4);
01967                 region_address2 = get_bits(&s->gb, 3);
01968                 dprintf(s->avctx, "region1=%d region2=%d\n",
01969                         region_address1, region_address2);
01970                 ff_init_long_region(s, g, region_address1, region_address2);
01971             }
01972             ff_region_offset2size(g);
01973             ff_compute_band_indexes(s, g);
01974 
01975             g->preflag = 0;
01976             if (!s->lsf)
01977                 g->preflag = get_bits1(&s->gb);
01978             g->scalefac_scale = get_bits1(&s->gb);
01979             g->count1table_select = get_bits1(&s->gb);
01980             dprintf(s->avctx, "block_type=%d switch_point=%d\n",
01981                     g->block_type, g->switch_point);
01982         }
01983     }
01984 
01985   if (!s->adu_mode) {
01986     const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
01987     assert((get_bits_count(&s->gb) & 7) == 0);
01988     /* now we get bits from the main_data_begin offset */
01989     dprintf(s->avctx, "seekback: %d\n", main_data_begin);
01990 //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);
01991 
01992     memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);
01993     s->in_gb= s->gb;
01994         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);
01995         skip_bits_long(&s->gb, 8*(s->last_buf_size - main_data_begin));
01996   }
01997 
01998     for(gr=0;gr<nb_granules;gr++) {
01999         for(ch=0;ch<s->nb_channels;ch++) {
02000             g = &s->granules[ch][gr];
02001             if(get_bits_count(&s->gb)<0){
02002                 av_log(s->avctx, AV_LOG_DEBUG, "mdb:%d, lastbuf:%d skipping granule %d\n",
02003                                             main_data_begin, s->last_buf_size, gr);
02004                 skip_bits_long(&s->gb, g->part2_3_length);
02005                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));
02006                 if(get_bits_count(&s->gb) >= s->gb.size_in_bits && s->in_gb.buffer){
02007                     skip_bits_long(&s->in_gb, get_bits_count(&s->gb) - s->gb.size_in_bits);
02008                     s->gb= s->in_gb;
02009                     s->in_gb.buffer=NULL;
02010                 }
02011                 continue;
02012             }
02013 
02014             bits_pos = get_bits_count(&s->gb);
02015 
02016             if (!s->lsf) {
02017                 uint8_t *sc;
02018                 int slen, slen1, slen2;
02019 
02020                 /* MPEG1 scale factors */
02021                 slen1 = slen_table[0][g->scalefac_compress];
02022                 slen2 = slen_table[1][g->scalefac_compress];
02023                 dprintf(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);
02024                 if (g->block_type == 2) {
02025                     n = g->switch_point ? 17 : 18;
02026                     j = 0;
02027                     if(slen1){
02028                         for(i=0;i<n;i++)
02029                             g->scale_factors[j++] = get_bits(&s->gb, slen1);
02030                     }else{
02031                         for(i=0;i<n;i++)
02032                             g->scale_factors[j++] = 0;
02033                     }
02034                     if(slen2){
02035                         for(i=0;i<18;i++)
02036                             g->scale_factors[j++] = get_bits(&s->gb, slen2);
02037                         for(i=0;i<3;i++)
02038                             g->scale_factors[j++] = 0;
02039                     }else{
02040                         for(i=0;i<21;i++)
02041                             g->scale_factors[j++] = 0;
02042                     }
02043                 } else {
02044                     sc = s->granules[ch][0].scale_factors;
02045                     j = 0;
02046                     for(k=0;k<4;k++) {
02047                         n = (k == 0 ? 6 : 5);
02048                         if ((g->scfsi & (0x8 >> k)) == 0) {
02049                             slen = (k < 2) ? slen1 : slen2;
02050                             if(slen){
02051                                 for(i=0;i<n;i++)
02052                                     g->scale_factors[j++] = get_bits(&s->gb, slen);
02053                             }else{
02054                                 for(i=0;i<n;i++)
02055                                     g->scale_factors[j++] = 0;
02056                             }
02057                         } else {
02058                             /* simply copy from last granule */
02059                             for(i=0;i<n;i++) {
02060                                 g->scale_factors[j] = sc[j];
02061                                 j++;
02062                             }
02063                         }
02064                     }
02065                     g->scale_factors[j++] = 0;
02066                 }
02067             } else {
02068                 int tindex, tindex2, slen[4], sl, sf;
02069 
02070                 /* LSF scale factors */
02071                 if (g->block_type == 2) {
02072                     tindex = g->switch_point ? 2 : 1;
02073                 } else {
02074                     tindex = 0;
02075                 }
02076                 sf = g->scalefac_compress;
02077                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
02078                     /* intensity stereo case */
02079                     sf >>= 1;
02080                     if (sf < 180) {
02081                         lsf_sf_expand(slen, sf, 6, 6, 0);
02082                         tindex2 = 3;
02083                     } else if (sf < 244) {
02084                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);
02085                         tindex2 = 4;
02086                     } else {
02087                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);
02088                         tindex2 = 5;
02089                     }
02090                 } else {
02091                     /* normal case */
02092                     if (sf < 400) {
02093                         lsf_sf_expand(slen, sf, 5, 4, 4);
02094                         tindex2 = 0;
02095                     } else if (sf < 500) {
02096                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);
02097                         tindex2 = 1;
02098                     } else {
02099                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);
02100                         tindex2 = 2;
02101                         g->preflag = 1;
02102                     }
02103                 }
02104 
02105                 j = 0;
02106                 for(k=0;k<4;k++) {
02107                     n = lsf_nsf_table[tindex2][tindex][k];
02108                     sl = slen[k];
02109                     if(sl){
02110                         for(i=0;i<n;i++)
02111                             g->scale_factors[j++] = get_bits(&s->gb, sl);
02112                     }else{
02113                         for(i=0;i<n;i++)
02114                             g->scale_factors[j++] = 0;
02115                     }
02116                 }
02117                 /* XXX: should compute exact size */
02118                 for(;j<40;j++)
02119                     g->scale_factors[j] = 0;
02120             }
02121 
02122             exponents_from_scale_factors(s, g, exponents);
02123 
02124             /* read Huffman coded residue */
02125             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
02126         } /* ch */
02127 
02128         if (s->nb_channels == 2)
02129             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
02130 
02131         for(ch=0;ch<s->nb_channels;ch++) {
02132             g = &s->granules[ch][gr];
02133 
02134             reorder_block(s, g);
02135             s->compute_antialias(s, g);
02136             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
02137         }
02138     } /* gr */
02139     if(get_bits_count(&s->gb)<0)
02140         skip_bits_long(&s->gb, -get_bits_count(&s->gb));
02141     return nb_granules * 18;
02142 }
02143 
02144 static int mp_decode_frame(MPADecodeContext *s,
02145                            OUT_INT *samples, const uint8_t *buf, int buf_size)
02146 {
02147     int i, nb_frames, ch;
02148     OUT_INT *samples_ptr;
02149 
02150     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)*8);
02151 
02152     /* skip error protection field */
02153     if (s->error_protection)
02154         skip_bits(&s->gb, 16);
02155 
02156     dprintf(s->avctx, "frame %d:\n", s->frame_count);
02157     switch(s->layer) {
02158     case 1:
02159         s->avctx->frame_size = 384;
02160         nb_frames = mp_decode_layer1(s);
02161         break;
02162     case 2:
02163         s->avctx->frame_size = 1152;
02164         nb_frames = mp_decode_layer2(s);
02165         break;
02166     case 3:
02167         s->avctx->frame_size = s->lsf ? 576 : 1152;
02168     default:
02169         nb_frames = mp_decode_layer3(s);
02170 
02171         s->last_buf_size=0;
02172         if(s->in_gb.buffer){
02173             align_get_bits(&s->gb);
02174             i= get_bits_left(&s->gb)>>3;
02175             if(i >= 0 && i <= BACKSTEP_SIZE){
02176                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
02177                 s->last_buf_size=i;
02178             }else
02179                 av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);
02180             s->gb= s->in_gb;
02181             s->in_gb.buffer= NULL;
02182         }
02183 
02184         align_get_bits(&s->gb);
02185         assert((get_bits_count(&s->gb) & 7) == 0);
02186         i= get_bits_left(&s->gb)>>3;
02187 
02188         if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){
02189             if(i<0)
02190                 av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);
02191             i= FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
02192         }
02193         assert(i <= buf_size - HEADER_SIZE && i>= 0);
02194         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
02195         s->last_buf_size += i;
02196 
02197         break;
02198     }
02199 
02200     /* apply the synthesis filter */
02201     for(ch=0;ch<s->nb_channels;ch++) {
02202         samples_ptr = samples + ch;
02203         for(i=0;i<nb_frames;i++) {
02204             ff_mpa_synth_filter(s->synth_buf[ch], &(s->synth_buf_offset[ch]),
02205                          ff_mpa_synth_window, &s->dither_state,
02206                          samples_ptr, s->nb_channels,
02207                          s->sb_samples[ch][i]);
02208             samples_ptr += 32 * s->nb_channels;
02209         }
02210     }
02211 
02212     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
02213 }
02214 
02215 static int decode_frame(AVCodecContext * avctx,
02216                         void *data, int *data_size,
02217                         AVPacket *avpkt)
02218 {
02219     const uint8_t *buf = avpkt->data;
02220     int buf_size = avpkt->size;
02221     MPADecodeContext *s = avctx->priv_data;
02222     uint32_t header;
02223     int out_size;
02224     OUT_INT *out_samples = data;
02225 
02226     if(buf_size < HEADER_SIZE)
02227         return -1;
02228 
02229     header = AV_RB32(buf);
02230     if(ff_mpa_check_header(header) < 0){
02231         av_log(avctx, AV_LOG_ERROR, "Header missing\n");
02232         return -1;
02233     }
02234 
02235     if (ff_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {
02236         /* free format: prepare to compute frame size */
02237         s->frame_size = -1;
02238         return -1;
02239     }
02240     /* update codec info */
02241     avctx->channels = s->nb_channels;
02242     avctx->bit_rate = s->bit_rate;
02243     avctx->sub_id = s->layer;
02244 
02245     if(*data_size < 1152*avctx->channels*sizeof(OUT_INT))
02246         return -1;
02247     *data_size = 0;
02248 
02249     if(s->frame_size<=0 || s->frame_size > buf_size){
02250         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
02251         return -1;
02252     }else if(s->frame_size < buf_size){
02253         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");
02254         buf_size= s->frame_size;
02255     }
02256 
02257     out_size = mp_decode_frame(s, out_samples, buf, buf_size);
02258     if(out_size>=0){
02259         *data_size = out_size;
02260         avctx->sample_rate = s->sample_rate;
02261         //FIXME maybe move the other codec info stuff from above here too
02262     }else
02263         av_log(avctx, AV_LOG_DEBUG, "Error while decoding MPEG audio frame.\n"); //FIXME return -1 / but also return the number of bytes consumed
02264     s->frame_size = 0;
02265     return buf_size;
02266 }
02267 
02268 static void flush(AVCodecContext *avctx){
02269     MPADecodeContext *s = avctx->priv_data;
02270     memset(s->synth_buf, 0, sizeof(s->synth_buf));
02271     s->last_buf_size= 0;
02272 }
02273 
02274 #if CONFIG_MP3ADU_DECODER
02275 static int decode_frame_adu(AVCodecContext * avctx,
02276                         void *data, int *data_size,
02277                         AVPacket *avpkt)
02278 {
02279     const uint8_t *buf = avpkt->data;
02280     int buf_size = avpkt->size;
02281     MPADecodeContext *s = avctx->priv_data;
02282     uint32_t header;
02283     int len, out_size;
02284     OUT_INT *out_samples = data;
02285 
02286     len = buf_size;
02287 
02288     // Discard too short frames
02289     if (buf_size < HEADER_SIZE) {
02290         *data_size = 0;
02291         return buf_size;
02292     }
02293 
02294 
02295     if (len > MPA_MAX_CODED_FRAME_SIZE)
02296         len = MPA_MAX_CODED_FRAME_SIZE;
02297 
02298     // Get header and restore sync word
02299     header = AV_RB32(buf) | 0xffe00000;
02300 
02301     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
02302         *data_size = 0;
02303         return buf_size;
02304     }
02305 
02306     ff_mpegaudio_decode_header((MPADecodeHeader *)s, header);
02307     /* update codec info */
02308     avctx->sample_rate = s->sample_rate;
02309     avctx->channels = s->nb_channels;
02310     avctx->bit_rate = s->bit_rate;
02311     avctx->sub_id = s->layer;
02312 
02313     s->frame_size = len;
02314 
02315     if (avctx->parse_only) {
02316         out_size = buf_size;
02317     } else {
02318         out_size = mp_decode_frame(s, out_samples, buf, buf_size);
02319     }
02320 
02321     *data_size = out_size;
02322     return buf_size;
02323 }
02324 #endif /* CONFIG_MP3ADU_DECODER */
02325 
02326 #if CONFIG_MP3ON4_DECODER
02327 
02331 typedef struct MP3On4DecodeContext {
02332     int frames;   
02333     int syncword; 
02334     const uint8_t *coff; 
02335     MPADecodeContext *mp3decctx[5]; 
02336 } MP3On4DecodeContext;
02337 
02338 #include "mpeg4audio.h"
02339 
02340 /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
02341 static const uint8_t mp3Frames[8] = {0,1,1,2,3,3,4,5};   /* number of mp3 decoder instances */
02342 /* offsets into output buffer, assume output order is FL FR BL BR C LFE */
02343 static const uint8_t chan_offset[8][5] = {
02344     {0},
02345     {0},            // C
02346     {0},            // FLR
02347     {2,0},          // C FLR
02348     {2,0,3},        // C FLR BS
02349     {4,0,2},        // C FLR BLRS
02350     {4,0,2,5},      // C FLR BLRS LFE
02351     {4,0,2,6,5},    // C FLR BLRS BLR LFE
02352 };
02353 
02354 
02355 static int decode_init_mp3on4(AVCodecContext * avctx)
02356 {
02357     MP3On4DecodeContext *s = avctx->priv_data;
02358     MPEG4AudioConfig cfg;
02359     int i;
02360 
02361     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {
02362         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
02363         return -1;
02364     }
02365 
02366     ff_mpeg4audio_get_config(&cfg, avctx->extradata, avctx->extradata_size);
02367     if (!cfg.chan_config || cfg.chan_config > 7) {
02368         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
02369         return -1;
02370     }
02371     s->frames = mp3Frames[cfg.chan_config];
02372     s->coff = chan_offset[cfg.chan_config];
02373     avctx->channels = ff_mpeg4audio_channels[cfg.chan_config];
02374 
02375     if (cfg.sample_rate < 16000)
02376         s->syncword = 0xffe00000;
02377     else
02378         s->syncword = 0xfff00000;
02379 
02380     /* Init the first mp3 decoder in standard way, so that all tables get builded
02381      * We replace avctx->priv_data with the context of the first decoder so that
02382      * decode_init() does not have to be changed.
02383      * Other decoders will be initialized here copying data from the first context
02384      */
02385     // Allocate zeroed memory for the first decoder context
02386     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
02387     // Put decoder context in place to make init_decode() happy
02388     avctx->priv_data = s->mp3decctx[0];
02389     decode_init(avctx);
02390     // Restore mp3on4 context pointer
02391     avctx->priv_data = s;
02392     s->mp3decctx[0]->adu_mode = 1; // Set adu mode
02393 
02394     /* Create a separate codec/context for each frame (first is already ok).
02395      * Each frame is 1 or 2 channels - up to 5 frames allowed
02396      */
02397     for (i = 1; i < s->frames; i++) {
02398         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
02399         s->mp3decctx[i]->compute_antialias = s->mp3decctx[0]->compute_antialias;
02400         s->mp3decctx[i]->adu_mode = 1;
02401         s->mp3decctx[i]->avctx = avctx;
02402     }
02403 
02404     return 0;
02405 }
02406 
02407 
02408 static av_cold int decode_close_mp3on4(AVCodecContext * avctx)
02409 {
02410     MP3On4DecodeContext *s = avctx->priv_data;
02411     int i;
02412 
02413     for (i = 0; i < s->frames; i++)
02414         if (s->mp3decctx[i])
02415             av_free(s->mp3decctx[i]);
02416 
02417     return 0;
02418 }
02419 
02420 
02421 static int decode_frame_mp3on4(AVCodecContext * avctx,
02422                         void *data, int *data_size,
02423                         AVPacket *avpkt)
02424 {
02425     const uint8_t *buf = avpkt->data;
02426     int buf_size = avpkt->size;
02427     MP3On4DecodeContext *s = avctx->priv_data;
02428     MPADecodeContext *m;
02429     int fsize, len = buf_size, out_size = 0;
02430     uint32_t header;
02431     OUT_INT *out_samples = data;
02432     OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS];
02433     OUT_INT *outptr, *bp;
02434     int fr, j, n;
02435 
02436     if(*data_size < MPA_FRAME_SIZE * MPA_MAX_CHANNELS * s->frames * sizeof(OUT_INT))
02437         return -1;
02438 
02439     *data_size = 0;
02440     // Discard too short frames
02441     if (buf_size < HEADER_SIZE)
02442         return -1;
02443 
02444     // If only one decoder interleave is not needed
02445     outptr = s->frames == 1 ? out_samples : decoded_buf;
02446 
02447     avctx->bit_rate = 0;
02448 
02449     for (fr = 0; fr < s->frames; fr++) {
02450         fsize = AV_RB16(buf) >> 4;
02451         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);
02452         m = s->mp3decctx[fr];
02453         assert (m != NULL);
02454 
02455         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header
02456 
02457         if (ff_mpa_check_header(header) < 0) // Bad header, discard block
02458             break;
02459 
02460         ff_mpegaudio_decode_header((MPADecodeHeader *)m, header);
02461         out_size += mp_decode_frame(m, outptr, buf, fsize);
02462         buf += fsize;
02463         len -= fsize;
02464 
02465         if(s->frames > 1) {
02466             n = m->avctx->frame_size*m->nb_channels;
02467             /* interleave output data */
02468             bp = out_samples + s->coff[fr];
02469             if(m->nb_channels == 1) {
02470                 for(j = 0; j < n; j++) {
02471                     *bp = decoded_buf[j];
02472                     bp += avctx->channels;
02473                 }
02474             } else {
02475                 for(j = 0; j < n; j++) {
02476                     bp[0] = decoded_buf[j++];
02477                     bp[1] = decoded_buf[j];
02478                     bp += avctx->channels;
02479                 }
02480             }
02481         }
02482         avctx->bit_rate += m->bit_rate;
02483     }
02484 
02485     /* update codec info */
02486     avctx->sample_rate = s->mp3decctx[0]->sample_rate;
02487 
02488     *data_size = out_size;
02489     return buf_size;
02490 }
02491 #endif /* CONFIG_MP3ON4_DECODER */
02492 
02493 #if CONFIG_MP1_DECODER
02494 AVCodec mp1_decoder =
02495 {
02496     "mp1",
02497     AVMEDIA_TYPE_AUDIO,
02498     CODEC_ID_MP1,
02499     sizeof(MPADecodeContext),
02500     decode_init,
02501     NULL,
02502     NULL,
02503     decode_frame,
02504     CODEC_CAP_PARSE_ONLY,
02505     .flush= flush,
02506     .long_name= NULL_IF_CONFIG_SMALL("MP1 (MPEG audio layer 1)"),
02507 };
02508 #endif
02509 #if CONFIG_MP2_DECODER
02510 AVCodec mp2_decoder =
02511 {
02512     "mp2",
02513     AVMEDIA_TYPE_AUDIO,
02514     CODEC_ID_MP2,
02515     sizeof(MPADecodeContext),
02516     decode_init,
02517     NULL,
02518     NULL,
02519     decode_frame,
02520     CODEC_CAP_PARSE_ONLY,
02521     .flush= flush,
02522     .long_name= NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
02523 };
02524 #endif
02525 #if CONFIG_MP3_DECODER
02526 AVCodec mp3_decoder =
02527 {
02528     "mp3",
02529     AVMEDIA_TYPE_AUDIO,
02530     CODEC_ID_MP3,
02531     sizeof(MPADecodeContext),
02532     decode_init,
02533     NULL,
02534     NULL,
02535     decode_frame,
02536     CODEC_CAP_PARSE_ONLY,
02537     .flush= flush,
02538     .long_name= NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
02539 };
02540 #endif
02541 #if CONFIG_MP3ADU_DECODER
02542 AVCodec mp3adu_decoder =
02543 {
02544     "mp3adu",
02545     AVMEDIA_TYPE_AUDIO,
02546     CODEC_ID_MP3ADU,
02547     sizeof(MPADecodeContext),
02548     decode_init,
02549     NULL,
02550     NULL,
02551     decode_frame_adu,
02552     CODEC_CAP_PARSE_ONLY,
02553     .flush= flush,
02554     .long_name= NULL_IF_CONFIG_SMALL("ADU (Application Data Unit) MP3 (MPEG audio layer 3)"),
02555 };
02556 #endif
02557 #if CONFIG_MP3ON4_DECODER
02558 AVCodec mp3on4_decoder =
02559 {
02560     "mp3on4",
02561     AVMEDIA_TYPE_AUDIO,
02562     CODEC_ID_MP3ON4,
02563     sizeof(MP3On4DecodeContext),
02564     decode_init_mp3on4,
02565     NULL,
02566     decode_close_mp3on4,
02567     decode_frame_mp3on4,
02568     .flush= flush,
02569     .long_name= NULL_IF_CONFIG_SMALL("MP3onMP4"),
02570 };
02571 #endif

Generated on Fri Sep 16 2011 17:17:40 for FFmpeg by  doxygen 1.7.1