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 Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "libavutil/audioconvert.h"
00028 #include "avcodec.h"
00029 #include "internal.h"
00030 #include "get_bits.h"
00031 #include "mathops.h"
00032 #include "mpegaudiodsp.h"
00033 
00034 /*
00035  * TODO:
00036  *  - test lsf / mpeg25 extensively.
00037  */
00038 
00039 #include "mpegaudio.h"
00040 #include "mpegaudiodecheader.h"
00041 
00042 #define BACKSTEP_SIZE 512
00043 #define EXTRABYTES 24
00044 #define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES
00045 
00046 /* layer 3 "granule" */
00047 typedef struct GranuleDef {
00048     uint8_t scfsi;
00049     int part2_3_length;
00050     int big_values;
00051     int global_gain;
00052     int scalefac_compress;
00053     uint8_t block_type;
00054     uint8_t switch_point;
00055     int table_select[3];
00056     int subblock_gain[3];
00057     uint8_t scalefac_scale;
00058     uint8_t count1table_select;
00059     int region_size[3]; /* number of huffman codes in each region */
00060     int preflag;
00061     int short_start, long_end; /* long/short band indexes */
00062     uint8_t scale_factors[40];
00063     DECLARE_ALIGNED(16, INTFLOAT, sb_hybrid)[SBLIMIT * 18]; /* 576 samples */
00064 } GranuleDef;
00065 
00066 typedef struct MPADecodeContext {
00067     MPA_DECODE_HEADER
00068     uint8_t last_buf[LAST_BUF_SIZE];
00069     int last_buf_size;
00070     /* next header (used in free format parsing) */
00071     uint32_t free_format_next_header;
00072     GetBitContext gb;
00073     GetBitContext in_gb;
00074     DECLARE_ALIGNED(32, MPA_INT, synth_buf)[MPA_MAX_CHANNELS][512 * 2];
00075     int synth_buf_offset[MPA_MAX_CHANNELS];
00076     DECLARE_ALIGNED(32, INTFLOAT, sb_samples)[MPA_MAX_CHANNELS][36][SBLIMIT];
00077     INTFLOAT mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
00078     GranuleDef granules[2][2]; /* Used in Layer 3 */
00079     int adu_mode; 
00080     int dither_state;
00081     int err_recognition;
00082     AVCodecContext* avctx;
00083     MPADSPContext mpadsp;
00084     AVFrame frame;
00085 } MPADecodeContext;
00086 
00087 #if CONFIG_FLOAT
00088 #   define SHR(a,b)       ((a)*(1.0f/(1<<(b))))
00089 #   define FIXR_OLD(a)    ((int)((a) * FRAC_ONE + 0.5))
00090 #   define FIXR(x)        ((float)(x))
00091 #   define FIXHR(x)       ((float)(x))
00092 #   define MULH3(x, y, s) ((s)*(y)*(x))
00093 #   define MULLx(x, y, s) ((y)*(x))
00094 #   define RENAME(a) a ## _float
00095 #   define OUT_FMT AV_SAMPLE_FMT_FLT
00096 #else
00097 #   define SHR(a,b)       ((a)>>(b))
00098 /* WARNING: only correct for positive numbers */
00099 #   define FIXR_OLD(a)    ((int)((a) * FRAC_ONE + 0.5))
00100 #   define FIXR(a)        ((int)((a) * FRAC_ONE + 0.5))
00101 #   define FIXHR(a)       ((int)((a) * (1LL<<32) + 0.5))
00102 #   define MULH3(x, y, s) MULH((s)*(x), y)
00103 #   define MULLx(x, y, s) MULL(x,y,s)
00104 #   define RENAME(a)      a ## _fixed
00105 #   define OUT_FMT AV_SAMPLE_FMT_S16
00106 #endif
00107 
00108 /****************/
00109 
00110 #define HEADER_SIZE 4
00111 
00112 #include "mpegaudiodata.h"
00113 #include "mpegaudiodectab.h"
00114 
00115 /* vlc structure for decoding layer 3 huffman tables */
00116 static VLC huff_vlc[16];
00117 static VLC_TYPE huff_vlc_tables[
00118     0 + 128 + 128 + 128 + 130 + 128 + 154 + 166 +
00119   142 + 204 + 190 + 170 + 542 + 460 + 662 + 414
00120   ][2];
00121 static const int huff_vlc_tables_sizes[16] = {
00122     0,  128,  128,  128,  130,  128,  154,  166,
00123   142,  204,  190,  170,  542,  460,  662,  414
00124 };
00125 static VLC huff_quad_vlc[2];
00126 static VLC_TYPE  huff_quad_vlc_tables[128+16][2];
00127 static const int huff_quad_vlc_tables_sizes[2] = { 128, 16 };
00128 /* computed from band_size_long */
00129 static uint16_t band_index_long[9][23];
00130 #include "mpegaudio_tablegen.h"
00131 /* intensity stereo coef table */
00132 static INTFLOAT is_table[2][16];
00133 static INTFLOAT is_table_lsf[2][2][16];
00134 static INTFLOAT csa_table[8][4];
00135 
00136 static int16_t division_tab3[1<<6 ];
00137 static int16_t division_tab5[1<<8 ];
00138 static int16_t division_tab9[1<<11];
00139 
00140 static int16_t * const division_tabs[4] = {
00141     division_tab3, division_tab5, NULL, division_tab9
00142 };
00143 
00144 /* lower 2 bits: modulo 3, higher bits: shift */
00145 static uint16_t scale_factor_modshift[64];
00146 /* [i][j]:  2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
00147 static int32_t scale_factor_mult[15][3];
00148 /* mult table for layer 2 group quantization */
00149 
00150 #define SCALE_GEN(v) \
00151 { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }
00152 
00153 static const int32_t scale_factor_mult2[3][3] = {
00154     SCALE_GEN(4.0 / 3.0), /* 3 steps */
00155     SCALE_GEN(4.0 / 5.0), /* 5 steps */
00156     SCALE_GEN(4.0 / 9.0), /* 9 steps */
00157 };
00158 
00163 static void ff_region_offset2size(GranuleDef *g)
00164 {
00165     int i, k, j = 0;
00166     g->region_size[2] = 576 / 2;
00167     for (i = 0; i < 3; i++) {
00168         k = FFMIN(g->region_size[i], g->big_values);
00169         g->region_size[i] = k - j;
00170         j = k;
00171     }
00172 }
00173 
00174 static void ff_init_short_region(MPADecodeContext *s, GranuleDef *g)
00175 {
00176     if (g->block_type == 2)
00177         g->region_size[0] = (36 / 2);
00178     else {
00179         if (s->sample_rate_index <= 2)
00180             g->region_size[0] = (36 / 2);
00181         else if (s->sample_rate_index != 8)
00182             g->region_size[0] = (54 / 2);
00183         else
00184             g->region_size[0] = (108 / 2);
00185     }
00186     g->region_size[1] = (576 / 2);
00187 }
00188 
00189 static void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2)
00190 {
00191     int l;
00192     g->region_size[0] = band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
00193     /* should not overflow */
00194     l = FFMIN(ra1 + ra2 + 2, 22);
00195     g->region_size[1] = band_index_long[s->sample_rate_index][      l] >> 1;
00196 }
00197 
00198 static void ff_compute_band_indexes(MPADecodeContext *s, GranuleDef *g)
00199 {
00200     if (g->block_type == 2) {
00201         if (g->switch_point) {
00202             /* if switched mode, we handle the 36 first samples as
00203                 long blocks.  For 8000Hz, we handle the 48 first
00204                 exponents as long blocks (XXX: check this!) */
00205             if (s->sample_rate_index <= 2)
00206                 g->long_end = 8;
00207             else if (s->sample_rate_index != 8)
00208                 g->long_end = 6;
00209             else
00210                 g->long_end = 4; /* 8000 Hz */
00211 
00212             g->short_start = 3;
00213         } else {
00214             g->long_end    = 0;
00215             g->short_start = 0;
00216         }
00217     } else {
00218         g->short_start = 13;
00219         g->long_end    = 22;
00220     }
00221 }
00222 
00223 /* layer 1 unscaling */
00224 /* n = number of bits of the mantissa minus 1 */
00225 static inline int l1_unscale(int n, int mant, int scale_factor)
00226 {
00227     int shift, mod;
00228     int64_t val;
00229 
00230     shift   = scale_factor_modshift[scale_factor];
00231     mod     = shift & 3;
00232     shift >>= 2;
00233     val     = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
00234     shift  += n;
00235     /* NOTE: at this point, 1 <= shift >= 21 + 15 */
00236     return (int)((val + (1LL << (shift - 1))) >> shift);
00237 }
00238 
00239 static inline int l2_unscale_group(int steps, int mant, int scale_factor)
00240 {
00241     int shift, mod, val;
00242 
00243     shift   = scale_factor_modshift[scale_factor];
00244     mod     = shift & 3;
00245     shift >>= 2;
00246 
00247     val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
00248     /* NOTE: at this point, 0 <= shift <= 21 */
00249     if (shift > 0)
00250         val = (val + (1 << (shift - 1))) >> shift;
00251     return val;
00252 }
00253 
00254 /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
00255 static inline int l3_unscale(int value, int exponent)
00256 {
00257     unsigned int m;
00258     int e;
00259 
00260     e  = table_4_3_exp  [4 * value + (exponent & 3)];
00261     m  = table_4_3_value[4 * value + (exponent & 3)];
00262     e -= exponent >> 2;
00263     assert(e >= 1);
00264     if (e > 31)
00265         return 0;
00266     m = (m + (1 << (e - 1))) >> e;
00267 
00268     return m;
00269 }
00270 
00271 static av_cold void decode_init_static(void)
00272 {
00273     int i, j, k;
00274     int offset;
00275 
00276     /* scale factors table for layer 1/2 */
00277     for (i = 0; i < 64; i++) {
00278         int shift, mod;
00279         /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
00280         shift = i / 3;
00281         mod   = i % 3;
00282         scale_factor_modshift[i] = mod | (shift << 2);
00283     }
00284 
00285     /* scale factor multiply for layer 1 */
00286     for (i = 0; i < 15; i++) {
00287         int n, norm;
00288         n = i + 2;
00289         norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
00290         scale_factor_mult[i][0] = MULLx(norm, FIXR(1.0          * 2.0), FRAC_BITS);
00291         scale_factor_mult[i][1] = MULLx(norm, FIXR(0.7937005259 * 2.0), FRAC_BITS);
00292         scale_factor_mult[i][2] = MULLx(norm, FIXR(0.6299605249 * 2.0), FRAC_BITS);
00293         av_dlog(NULL, "%d: norm=%x s=%x %x %x\n", i, norm,
00294                 scale_factor_mult[i][0],
00295                 scale_factor_mult[i][1],
00296                 scale_factor_mult[i][2]);
00297     }
00298 
00299     RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));
00300 
00301     /* huffman decode tables */
00302     offset = 0;
00303     for (i = 1; i < 16; i++) {
00304         const HuffTable *h = &mpa_huff_tables[i];
00305         int xsize, x, y;
00306         uint8_t  tmp_bits [512];
00307         uint16_t tmp_codes[512];
00308 
00309         memset(tmp_bits , 0, sizeof(tmp_bits ));
00310         memset(tmp_codes, 0, sizeof(tmp_codes));
00311 
00312         xsize = h->xsize;
00313 
00314         j = 0;
00315         for (x = 0; x < xsize; x++) {
00316             for (y = 0; y < xsize; y++) {
00317                 tmp_bits [(x << 5) | y | ((x&&y)<<4)]= h->bits [j  ];
00318                 tmp_codes[(x << 5) | y | ((x&&y)<<4)]= h->codes[j++];
00319             }
00320         }
00321 
00322         /* XXX: fail test */
00323         huff_vlc[i].table = huff_vlc_tables+offset;
00324         huff_vlc[i].table_allocated = huff_vlc_tables_sizes[i];
00325         init_vlc(&huff_vlc[i], 7, 512,
00326                  tmp_bits, 1, 1, tmp_codes, 2, 2,
00327                  INIT_VLC_USE_NEW_STATIC);
00328         offset += huff_vlc_tables_sizes[i];
00329     }
00330     assert(offset == FF_ARRAY_ELEMS(huff_vlc_tables));
00331 
00332     offset = 0;
00333     for (i = 0; i < 2; i++) {
00334         huff_quad_vlc[i].table = huff_quad_vlc_tables+offset;
00335         huff_quad_vlc[i].table_allocated = huff_quad_vlc_tables_sizes[i];
00336         init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
00337                  mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1,
00338                  INIT_VLC_USE_NEW_STATIC);
00339         offset += huff_quad_vlc_tables_sizes[i];
00340     }
00341     assert(offset == FF_ARRAY_ELEMS(huff_quad_vlc_tables));
00342 
00343     for (i = 0; i < 9; i++) {
00344         k = 0;
00345         for (j = 0; j < 22; j++) {
00346             band_index_long[i][j] = k;
00347             k += band_size_long[i][j];
00348         }
00349         band_index_long[i][22] = k;
00350     }
00351 
00352     /* compute n ^ (4/3) and store it in mantissa/exp format */
00353 
00354     mpegaudio_tableinit();
00355 
00356     for (i = 0; i < 4; i++) {
00357         if (ff_mpa_quant_bits[i] < 0) {
00358             for (j = 0; j < (1 << (-ff_mpa_quant_bits[i]+1)); j++) {
00359                 int val1, val2, val3, steps;
00360                 int val = j;
00361                 steps   = ff_mpa_quant_steps[i];
00362                 val1    = val % steps;
00363                 val    /= steps;
00364                 val2    = val % steps;
00365                 val3    = val / steps;
00366                 division_tabs[i][j] = val1 + (val2 << 4) + (val3 << 8);
00367             }
00368         }
00369     }
00370 
00371 
00372     for (i = 0; i < 7; i++) {
00373         float f;
00374         INTFLOAT v;
00375         if (i != 6) {
00376             f = tan((double)i * M_PI / 12.0);
00377             v = FIXR(f / (1.0 + f));
00378         } else {
00379             v = FIXR(1.0);
00380         }
00381         is_table[0][    i] = v;
00382         is_table[1][6 - i] = v;
00383     }
00384     /* invalid values */
00385     for (i = 7; i < 16; i++)
00386         is_table[0][i] = is_table[1][i] = 0.0;
00387 
00388     for (i = 0; i < 16; i++) {
00389         double f;
00390         int e, k;
00391 
00392         for (j = 0; j < 2; j++) {
00393             e = -(j + 1) * ((i + 1) >> 1);
00394             f = pow(2.0, e / 4.0);
00395             k = i & 1;
00396             is_table_lsf[j][k ^ 1][i] = FIXR(f);
00397             is_table_lsf[j][k    ][i] = FIXR(1.0);
00398             av_dlog(NULL, "is_table_lsf %d %d: %f %f\n",
00399                     i, j, (float) is_table_lsf[j][0][i],
00400                     (float) is_table_lsf[j][1][i]);
00401         }
00402     }
00403 
00404     for (i = 0; i < 8; i++) {
00405         float ci, cs, ca;
00406         ci = ci_table[i];
00407         cs = 1.0 / sqrt(1.0 + ci * ci);
00408         ca = cs * ci;
00409 #if !CONFIG_FLOAT
00410         csa_table[i][0] = FIXHR(cs/4);
00411         csa_table[i][1] = FIXHR(ca/4);
00412         csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
00413         csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
00414 #else
00415         csa_table[i][0] = cs;
00416         csa_table[i][1] = ca;
00417         csa_table[i][2] = ca + cs;
00418         csa_table[i][3] = ca - cs;
00419 #endif
00420     }
00421 }
00422 
00423 static av_cold int decode_init(AVCodecContext * avctx)
00424 {
00425     static int initialized_tables = 0;
00426     MPADecodeContext *s = avctx->priv_data;
00427 
00428     if (!initialized_tables) {
00429         decode_init_static();
00430         initialized_tables = 1;
00431     }
00432 
00433     s->avctx = avctx;
00434 
00435     ff_mpadsp_init(&s->mpadsp);
00436 
00437     avctx->sample_fmt= OUT_FMT;
00438     s->err_recognition = avctx->err_recognition;
00439 
00440     if (avctx->codec_id == CODEC_ID_MP3ADU)
00441         s->adu_mode = 1;
00442 
00443     avcodec_get_frame_defaults(&s->frame);
00444     avctx->coded_frame = &s->frame;
00445 
00446     return 0;
00447 }
00448 
00449 #define C3 FIXHR(0.86602540378443864676/2)
00450 #define C4 FIXHR(0.70710678118654752439/2) //0.5 / cos(pi*(9)/36)
00451 #define C5 FIXHR(0.51763809020504152469/2) //0.5 / cos(pi*(5)/36)
00452 #define C6 FIXHR(1.93185165257813657349/4) //0.5 / cos(pi*(15)/36)
00453 
00454 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
00455    cases. */
00456 static void imdct12(INTFLOAT *out, INTFLOAT *in)
00457 {
00458     INTFLOAT in0, in1, in2, in3, in4, in5, t1, t2;
00459 
00460     in0  = in[0*3];
00461     in1  = in[1*3] + in[0*3];
00462     in2  = in[2*3] + in[1*3];
00463     in3  = in[3*3] + in[2*3];
00464     in4  = in[4*3] + in[3*3];
00465     in5  = in[5*3] + in[4*3];
00466     in5 += in3;
00467     in3 += in1;
00468 
00469     in2  = MULH3(in2, C3, 2);
00470     in3  = MULH3(in3, C3, 4);
00471 
00472     t1   = in0 - in4;
00473     t2   = MULH3(in1 - in5, C4, 2);
00474 
00475     out[ 7] =
00476     out[10] = t1 + t2;
00477     out[ 1] =
00478     out[ 4] = t1 - t2;
00479 
00480     in0    += SHR(in4, 1);
00481     in4     = in0 + in2;
00482     in5    += 2*in1;
00483     in1     = MULH3(in5 + in3, C5, 1);
00484     out[ 8] =
00485     out[ 9] = in4 + in1;
00486     out[ 2] =
00487     out[ 3] = in4 - in1;
00488 
00489     in0    -= in2;
00490     in5     = MULH3(in5 - in3, C6, 2);
00491     out[ 0] =
00492     out[ 5] = in0 - in5;
00493     out[ 6] =
00494     out[11] = in0 + in5;
00495 }
00496 
00497 /* return the number of decoded frames */
00498 static int mp_decode_layer1(MPADecodeContext *s)
00499 {
00500     int bound, i, v, n, ch, j, mant;
00501     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
00502     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
00503 
00504     if (s->mode == MPA_JSTEREO)
00505         bound = (s->mode_ext + 1) * 4;
00506     else
00507         bound = SBLIMIT;
00508 
00509     /* allocation bits */
00510     for (i = 0; i < bound; i++) {
00511         for (ch = 0; ch < s->nb_channels; ch++) {
00512             allocation[ch][i] = get_bits(&s->gb, 4);
00513         }
00514     }
00515     for (i = bound; i < SBLIMIT; i++)
00516         allocation[0][i] = get_bits(&s->gb, 4);
00517 
00518     /* scale factors */
00519     for (i = 0; i < bound; i++) {
00520         for (ch = 0; ch < s->nb_channels; ch++) {
00521             if (allocation[ch][i])
00522                 scale_factors[ch][i] = get_bits(&s->gb, 6);
00523         }
00524     }
00525     for (i = bound; i < SBLIMIT; i++) {
00526         if (allocation[0][i]) {
00527             scale_factors[0][i] = get_bits(&s->gb, 6);
00528             scale_factors[1][i] = get_bits(&s->gb, 6);
00529         }
00530     }
00531 
00532     /* compute samples */
00533     for (j = 0; j < 12; j++) {
00534         for (i = 0; i < bound; i++) {
00535             for (ch = 0; ch < s->nb_channels; ch++) {
00536                 n = allocation[ch][i];
00537                 if (n) {
00538                     mant = get_bits(&s->gb, n + 1);
00539                     v = l1_unscale(n, mant, scale_factors[ch][i]);
00540                 } else {
00541                     v = 0;
00542                 }
00543                 s->sb_samples[ch][j][i] = v;
00544             }
00545         }
00546         for (i = bound; i < SBLIMIT; i++) {
00547             n = allocation[0][i];
00548             if (n) {
00549                 mant = get_bits(&s->gb, n + 1);
00550                 v = l1_unscale(n, mant, scale_factors[0][i]);
00551                 s->sb_samples[0][j][i] = v;
00552                 v = l1_unscale(n, mant, scale_factors[1][i]);
00553                 s->sb_samples[1][j][i] = v;
00554             } else {
00555                 s->sb_samples[0][j][i] = 0;
00556                 s->sb_samples[1][j][i] = 0;
00557             }
00558         }
00559     }
00560     return 12;
00561 }
00562 
00563 static int mp_decode_layer2(MPADecodeContext *s)
00564 {
00565     int sblimit; /* number of used subbands */
00566     const unsigned char *alloc_table;
00567     int table, bit_alloc_bits, i, j, ch, bound, v;
00568     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
00569     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
00570     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
00571     int scale, qindex, bits, steps, k, l, m, b;
00572 
00573     /* select decoding table */
00574     table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,
00575                                    s->sample_rate, s->lsf);
00576     sblimit     = ff_mpa_sblimit_table[table];
00577     alloc_table = ff_mpa_alloc_tables[table];
00578 
00579     if (s->mode == MPA_JSTEREO)
00580         bound = (s->mode_ext + 1) * 4;
00581     else
00582         bound = sblimit;
00583 
00584     av_dlog(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);
00585 
00586     /* sanity check */
00587     if (bound > sblimit)
00588         bound = sblimit;
00589 
00590     /* parse bit allocation */
00591     j = 0;
00592     for (i = 0; i < bound; i++) {
00593         bit_alloc_bits = alloc_table[j];
00594         for (ch = 0; ch < s->nb_channels; ch++)
00595             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
00596         j += 1 << bit_alloc_bits;
00597     }
00598     for (i = bound; i < sblimit; i++) {
00599         bit_alloc_bits = alloc_table[j];
00600         v = get_bits(&s->gb, bit_alloc_bits);
00601         bit_alloc[0][i] = v;
00602         bit_alloc[1][i] = v;
00603         j += 1 << bit_alloc_bits;
00604     }
00605 
00606     /* scale codes */
00607     for (i = 0; i < sblimit; i++) {
00608         for (ch = 0; ch < s->nb_channels; ch++) {
00609             if (bit_alloc[ch][i])
00610                 scale_code[ch][i] = get_bits(&s->gb, 2);
00611         }
00612     }
00613 
00614     /* scale factors */
00615     for (i = 0; i < sblimit; i++) {
00616         for (ch = 0; ch < s->nb_channels; ch++) {
00617             if (bit_alloc[ch][i]) {
00618                 sf = scale_factors[ch][i];
00619                 switch (scale_code[ch][i]) {
00620                 default:
00621                 case 0:
00622                     sf[0] = get_bits(&s->gb, 6);
00623                     sf[1] = get_bits(&s->gb, 6);
00624                     sf[2] = get_bits(&s->gb, 6);
00625                     break;
00626                 case 2:
00627                     sf[0] = get_bits(&s->gb, 6);
00628                     sf[1] = sf[0];
00629                     sf[2] = sf[0];
00630                     break;
00631                 case 1:
00632                     sf[0] = get_bits(&s->gb, 6);
00633                     sf[2] = get_bits(&s->gb, 6);
00634                     sf[1] = sf[0];
00635                     break;
00636                 case 3:
00637                     sf[0] = get_bits(&s->gb, 6);
00638                     sf[2] = get_bits(&s->gb, 6);
00639                     sf[1] = sf[2];
00640                     break;
00641                 }
00642             }
00643         }
00644     }
00645 
00646     /* samples */
00647     for (k = 0; k < 3; k++) {
00648         for (l = 0; l < 12; l += 3) {
00649             j = 0;
00650             for (i = 0; i < bound; i++) {
00651                 bit_alloc_bits = alloc_table[j];
00652                 for (ch = 0; ch < s->nb_channels; ch++) {
00653                     b = bit_alloc[ch][i];
00654                     if (b) {
00655                         scale = scale_factors[ch][i][k];
00656                         qindex = alloc_table[j+b];
00657                         bits = ff_mpa_quant_bits[qindex];
00658                         if (bits < 0) {
00659                             int v2;
00660                             /* 3 values at the same time */
00661                             v = get_bits(&s->gb, -bits);
00662                             v2 = division_tabs[qindex][v];
00663                             steps  = ff_mpa_quant_steps[qindex];
00664 
00665                             s->sb_samples[ch][k * 12 + l + 0][i] =
00666                                 l2_unscale_group(steps,  v2       & 15, scale);
00667                             s->sb_samples[ch][k * 12 + l + 1][i] =
00668                                 l2_unscale_group(steps, (v2 >> 4) & 15, scale);
00669                             s->sb_samples[ch][k * 12 + l + 2][i] =
00670                                 l2_unscale_group(steps,  v2 >> 8      , scale);
00671                         } else {
00672                             for (m = 0; m < 3; m++) {
00673                                 v = get_bits(&s->gb, bits);
00674                                 v = l1_unscale(bits - 1, v, scale);
00675                                 s->sb_samples[ch][k * 12 + l + m][i] = v;
00676                             }
00677                         }
00678                     } else {
00679                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;
00680                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;
00681                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;
00682                     }
00683                 }
00684                 /* next subband in alloc table */
00685                 j += 1 << bit_alloc_bits;
00686             }
00687             /* XXX: find a way to avoid this duplication of code */
00688             for (i = bound; i < sblimit; i++) {
00689                 bit_alloc_bits = alloc_table[j];
00690                 b = bit_alloc[0][i];
00691                 if (b) {
00692                     int mant, scale0, scale1;
00693                     scale0 = scale_factors[0][i][k];
00694                     scale1 = scale_factors[1][i][k];
00695                     qindex = alloc_table[j+b];
00696                     bits = ff_mpa_quant_bits[qindex];
00697                     if (bits < 0) {
00698                         /* 3 values at the same time */
00699                         v = get_bits(&s->gb, -bits);
00700                         steps = ff_mpa_quant_steps[qindex];
00701                         mant = v % steps;
00702                         v = v / steps;
00703                         s->sb_samples[0][k * 12 + l + 0][i] =
00704                             l2_unscale_group(steps, mant, scale0);
00705                         s->sb_samples[1][k * 12 + l + 0][i] =
00706                             l2_unscale_group(steps, mant, scale1);
00707                         mant = v % steps;
00708                         v = v / steps;
00709                         s->sb_samples[0][k * 12 + l + 1][i] =
00710                             l2_unscale_group(steps, mant, scale0);
00711                         s->sb_samples[1][k * 12 + l + 1][i] =
00712                             l2_unscale_group(steps, mant, scale1);
00713                         s->sb_samples[0][k * 12 + l + 2][i] =
00714                             l2_unscale_group(steps, v, scale0);
00715                         s->sb_samples[1][k * 12 + l + 2][i] =
00716                             l2_unscale_group(steps, v, scale1);
00717                     } else {
00718                         for (m = 0; m < 3; m++) {
00719                             mant = get_bits(&s->gb, bits);
00720                             s->sb_samples[0][k * 12 + l + m][i] =
00721                                 l1_unscale(bits - 1, mant, scale0);
00722                             s->sb_samples[1][k * 12 + l + m][i] =
00723                                 l1_unscale(bits - 1, mant, scale1);
00724                         }
00725                     }
00726                 } else {
00727                     s->sb_samples[0][k * 12 + l + 0][i] = 0;
00728                     s->sb_samples[0][k * 12 + l + 1][i] = 0;
00729                     s->sb_samples[0][k * 12 + l + 2][i] = 0;
00730                     s->sb_samples[1][k * 12 + l + 0][i] = 0;
00731                     s->sb_samples[1][k * 12 + l + 1][i] = 0;
00732                     s->sb_samples[1][k * 12 + l + 2][i] = 0;
00733                 }
00734                 /* next subband in alloc table */
00735                 j += 1 << bit_alloc_bits;
00736             }
00737             /* fill remaining samples to zero */
00738             for (i = sblimit; i < SBLIMIT; i++) {
00739                 for (ch = 0; ch < s->nb_channels; ch++) {
00740                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;
00741                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;
00742                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;
00743                 }
00744             }
00745         }
00746     }
00747     return 3 * 12;
00748 }
00749 
00750 #define SPLIT(dst,sf,n)             \
00751     if (n == 3) {                   \
00752         int m = (sf * 171) >> 9;    \
00753         dst   = sf - 3 * m;         \
00754         sf    = m;                  \
00755     } else if (n == 4) {            \
00756         dst  = sf & 3;              \
00757         sf >>= 2;                   \
00758     } else if (n == 5) {            \
00759         int m = (sf * 205) >> 10;   \
00760         dst   = sf - 5 * m;         \
00761         sf    = m;                  \
00762     } else if (n == 6) {            \
00763         int m = (sf * 171) >> 10;   \
00764         dst   = sf - 6 * m;         \
00765         sf    = m;                  \
00766     } else {                        \
00767         dst = 0;                    \
00768     }
00769 
00770 static av_always_inline void lsf_sf_expand(int *slen, int sf, int n1, int n2,
00771                                            int n3)
00772 {
00773     SPLIT(slen[3], sf, n3)
00774     SPLIT(slen[2], sf, n2)
00775     SPLIT(slen[1], sf, n1)
00776     slen[0] = sf;
00777 }
00778 
00779 static void exponents_from_scale_factors(MPADecodeContext *s, GranuleDef *g,
00780                                          int16_t *exponents)
00781 {
00782     const uint8_t *bstab, *pretab;
00783     int len, i, j, k, l, v0, shift, gain, gains[3];
00784     int16_t *exp_ptr;
00785 
00786     exp_ptr = exponents;
00787     gain    = g->global_gain - 210;
00788     shift   = g->scalefac_scale + 1;
00789 
00790     bstab  = band_size_long[s->sample_rate_index];
00791     pretab = mpa_pretab[g->preflag];
00792     for (i = 0; i < g->long_end; i++) {
00793         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;
00794         len = bstab[i];
00795         for (j = len; j > 0; j--)
00796             *exp_ptr++ = v0;
00797     }
00798 
00799     if (g->short_start < 13) {
00800         bstab    = band_size_short[s->sample_rate_index];
00801         gains[0] = gain - (g->subblock_gain[0] << 3);
00802         gains[1] = gain - (g->subblock_gain[1] << 3);
00803         gains[2] = gain - (g->subblock_gain[2] << 3);
00804         k        = g->long_end;
00805         for (i = g->short_start; i < 13; i++) {
00806             len = bstab[i];
00807             for (l = 0; l < 3; l++) {
00808                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;
00809                 for (j = len; j > 0; j--)
00810                     *exp_ptr++ = v0;
00811             }
00812         }
00813     }
00814 }
00815 
00816 /* handle n = 0 too */
00817 static inline int get_bitsz(GetBitContext *s, int n)
00818 {
00819     return n ? get_bits(s, n) : 0;
00820 }
00821 
00822 
00823 static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos,
00824                           int *end_pos2)
00825 {
00826     if (s->in_gb.buffer && *pos >= s->gb.size_in_bits) {
00827         s->gb           = s->in_gb;
00828         s->in_gb.buffer = NULL;
00829         assert((get_bits_count(&s->gb) & 7) == 0);
00830         skip_bits_long(&s->gb, *pos - *end_pos);
00831         *end_pos2 =
00832         *end_pos  = *end_pos2 + get_bits_count(&s->gb) - *pos;
00833         *pos      = get_bits_count(&s->gb);
00834     }
00835 }
00836 
00837 /* Following is a optimized code for
00838             INTFLOAT v = *src
00839             if(get_bits1(&s->gb))
00840                 v = -v;
00841             *dst = v;
00842 */
00843 #if CONFIG_FLOAT
00844 #define READ_FLIP_SIGN(dst,src)                     \
00845     v = AV_RN32A(src) ^ (get_bits1(&s->gb) << 31);  \
00846     AV_WN32A(dst, v);
00847 #else
00848 #define READ_FLIP_SIGN(dst,src)     \
00849     v      = -get_bits1(&s->gb);    \
00850     *(dst) = (*(src) ^ v) - v;
00851 #endif
00852 
00853 static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
00854                           int16_t *exponents, int end_pos2)
00855 {
00856     int s_index;
00857     int i;
00858     int last_pos, bits_left;
00859     VLC *vlc;
00860     int end_pos = FFMIN(end_pos2, s->gb.size_in_bits);
00861 
00862     /* low frequencies (called big values) */
00863     s_index = 0;
00864     for (i = 0; i < 3; i++) {
00865         int j, k, l, linbits;
00866         j = g->region_size[i];
00867         if (j == 0)
00868             continue;
00869         /* select vlc table */
00870         k       = g->table_select[i];
00871         l       = mpa_huff_data[k][0];
00872         linbits = mpa_huff_data[k][1];
00873         vlc     = &huff_vlc[l];
00874 
00875         if (!l) {
00876             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * 2 * j);
00877             s_index += 2 * j;
00878             continue;
00879         }
00880 
00881         /* read huffcode and compute each couple */
00882         for (; j > 0; j--) {
00883             int exponent, x, y;
00884             int v;
00885             int pos = get_bits_count(&s->gb);
00886 
00887             if (pos >= end_pos){
00888 //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);
00889                 switch_buffer(s, &pos, &end_pos, &end_pos2);
00890 //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);
00891                 if (pos >= end_pos)
00892                     break;
00893             }
00894             y = get_vlc2(&s->gb, vlc->table, 7, 3);
00895 
00896             if (!y) {
00897                 g->sb_hybrid[s_index  ] =
00898                 g->sb_hybrid[s_index+1] = 0;
00899                 s_index += 2;
00900                 continue;
00901             }
00902 
00903             exponent= exponents[s_index];
00904 
00905             av_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",
00906                     i, g->region_size[i] - j, x, y, exponent);
00907             if (y & 16) {
00908                 x = y >> 5;
00909                 y = y & 0x0f;
00910                 if (x < 15) {
00911                     READ_FLIP_SIGN(g->sb_hybrid + s_index, RENAME(expval_table)[exponent] + x)
00912                 } else {
00913                     x += get_bitsz(&s->gb, linbits);
00914                     v  = l3_unscale(x, exponent);
00915                     if (get_bits1(&s->gb))
00916                         v = -v;
00917                     g->sb_hybrid[s_index] = v;
00918                 }
00919                 if (y < 15) {
00920                     READ_FLIP_SIGN(g->sb_hybrid + s_index + 1, RENAME(expval_table)[exponent] + y)
00921                 } else {
00922                     y += get_bitsz(&s->gb, linbits);
00923                     v  = l3_unscale(y, exponent);
00924                     if (get_bits1(&s->gb))
00925                         v = -v;
00926                     g->sb_hybrid[s_index+1] = v;
00927                 }
00928             } else {
00929                 x = y >> 5;
00930                 y = y & 0x0f;
00931                 x += y;
00932                 if (x < 15) {
00933                     READ_FLIP_SIGN(g->sb_hybrid + s_index + !!y, RENAME(expval_table)[exponent] + x)
00934                 } else {
00935                     x += get_bitsz(&s->gb, linbits);
00936                     v  = l3_unscale(x, exponent);
00937                     if (get_bits1(&s->gb))
00938                         v = -v;
00939                     g->sb_hybrid[s_index+!!y] = v;
00940                 }
00941                 g->sb_hybrid[s_index + !y] = 0;
00942             }
00943             s_index += 2;
00944         }
00945     }
00946 
00947     /* high frequencies */
00948     vlc = &huff_quad_vlc[g->count1table_select];
00949     last_pos = 0;
00950     while (s_index <= 572) {
00951         int pos, code;
00952         pos = get_bits_count(&s->gb);
00953         if (pos >= end_pos) {
00954             if (pos > end_pos2 && last_pos) {
00955                 /* some encoders generate an incorrect size for this
00956                    part. We must go back into the data */
00957                 s_index -= 4;
00958                 skip_bits_long(&s->gb, last_pos - pos);
00959                 av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
00960                 if(s->err_recognition & AV_EF_BITSTREAM)
00961                     s_index=0;
00962                 break;
00963             }
00964 //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);
00965             switch_buffer(s, &pos, &end_pos, &end_pos2);
00966 //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);
00967             if (pos >= end_pos)
00968                 break;
00969         }
00970         last_pos = pos;
00971 
00972         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);
00973         av_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);
00974         g->sb_hybrid[s_index+0] =
00975         g->sb_hybrid[s_index+1] =
00976         g->sb_hybrid[s_index+2] =
00977         g->sb_hybrid[s_index+3] = 0;
00978         while (code) {
00979             static const int idxtab[16] = { 3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0 };
00980             int v;
00981             int pos = s_index + idxtab[code];
00982             code   ^= 8 >> idxtab[code];
00983             READ_FLIP_SIGN(g->sb_hybrid + pos, RENAME(exp_table)+exponents[pos])
00984         }
00985         s_index += 4;
00986     }
00987     /* skip extension bits */
00988     bits_left = end_pos2 - get_bits_count(&s->gb);
00989 //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);
00990     if (bits_left < 0 && (s->err_recognition & AV_EF_BUFFER)) {
00991         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
00992         s_index=0;
00993     } else if (bits_left > 0 && (s->err_recognition & AV_EF_BUFFER)) {
00994         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
00995         s_index = 0;
00996     }
00997     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * (576 - s_index));
00998     skip_bits_long(&s->gb, bits_left);
00999 
01000     i = get_bits_count(&s->gb);
01001     switch_buffer(s, &i, &end_pos, &end_pos2);
01002 
01003     return 0;
01004 }
01005 
01006 /* Reorder short blocks from bitstream order to interleaved order. It
01007    would be faster to do it in parsing, but the code would be far more
01008    complicated */
01009 static void reorder_block(MPADecodeContext *s, GranuleDef *g)
01010 {
01011     int i, j, len;
01012     INTFLOAT *ptr, *dst, *ptr1;
01013     INTFLOAT tmp[576];
01014 
01015     if (g->block_type != 2)
01016         return;
01017 
01018     if (g->switch_point) {
01019         if (s->sample_rate_index != 8)
01020             ptr = g->sb_hybrid + 36;
01021         else
01022             ptr = g->sb_hybrid + 48;
01023     } else {
01024         ptr = g->sb_hybrid;
01025     }
01026 
01027     for (i = g->short_start; i < 13; i++) {
01028         len  = band_size_short[s->sample_rate_index][i];
01029         ptr1 = ptr;
01030         dst  = tmp;
01031         for (j = len; j > 0; j--) {
01032             *dst++ = ptr[0*len];
01033             *dst++ = ptr[1*len];
01034             *dst++ = ptr[2*len];
01035             ptr++;
01036         }
01037         ptr += 2 * len;
01038         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));
01039     }
01040 }
01041 
01042 #define ISQRT2 FIXR(0.70710678118654752440)
01043 
01044 static void compute_stereo(MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)
01045 {
01046     int i, j, k, l;
01047     int sf_max, sf, len, non_zero_found;
01048     INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;
01049     int non_zero_found_short[3];
01050 
01051     /* intensity stereo */
01052     if (s->mode_ext & MODE_EXT_I_STEREO) {
01053         if (!s->lsf) {
01054             is_tab = is_table;
01055             sf_max = 7;
01056         } else {
01057             is_tab = is_table_lsf[g1->scalefac_compress & 1];
01058             sf_max = 16;
01059         }
01060 
01061         tab0 = g0->sb_hybrid + 576;
01062         tab1 = g1->sb_hybrid + 576;
01063 
01064         non_zero_found_short[0] = 0;
01065         non_zero_found_short[1] = 0;
01066         non_zero_found_short[2] = 0;
01067         k = (13 - g1->short_start) * 3 + g1->long_end - 3;
01068         for (i = 12; i >= g1->short_start; i--) {
01069             /* for last band, use previous scale factor */
01070             if (i != 11)
01071                 k -= 3;
01072             len = band_size_short[s->sample_rate_index][i];
01073             for (l = 2; l >= 0; l--) {
01074                 tab0 -= len;
01075                 tab1 -= len;
01076                 if (!non_zero_found_short[l]) {
01077                     /* test if non zero band. if so, stop doing i-stereo */
01078                     for (j = 0; j < len; j++) {
01079                         if (tab1[j] != 0) {
01080                             non_zero_found_short[l] = 1;
01081                             goto found1;
01082                         }
01083                     }
01084                     sf = g1->scale_factors[k + l];
01085                     if (sf >= sf_max)
01086                         goto found1;
01087 
01088                     v1 = is_tab[0][sf];
01089                     v2 = is_tab[1][sf];
01090                     for (j = 0; j < len; j++) {
01091                         tmp0    = tab0[j];
01092                         tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
01093                         tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
01094                     }
01095                 } else {
01096 found1:
01097                     if (s->mode_ext & MODE_EXT_MS_STEREO) {
01098                         /* lower part of the spectrum : do ms stereo
01099                            if enabled */
01100                         for (j = 0; j < len; j++) {
01101                             tmp0    = tab0[j];
01102                             tmp1    = tab1[j];
01103                             tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
01104                             tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
01105                         }
01106                     }
01107                 }
01108             }
01109         }
01110 
01111         non_zero_found = non_zero_found_short[0] |
01112                          non_zero_found_short[1] |
01113                          non_zero_found_short[2];
01114 
01115         for (i = g1->long_end - 1;i >= 0;i--) {
01116             len   = band_size_long[s->sample_rate_index][i];
01117             tab0 -= len;
01118             tab1 -= len;
01119             /* test if non zero band. if so, stop doing i-stereo */
01120             if (!non_zero_found) {
01121                 for (j = 0; j < len; j++) {
01122                     if (tab1[j] != 0) {
01123                         non_zero_found = 1;
01124                         goto found2;
01125                     }
01126                 }
01127                 /* for last band, use previous scale factor */
01128                 k  = (i == 21) ? 20 : i;
01129                 sf = g1->scale_factors[k];
01130                 if (sf >= sf_max)
01131                     goto found2;
01132                 v1 = is_tab[0][sf];
01133                 v2 = is_tab[1][sf];
01134                 for (j = 0; j < len; j++) {
01135                     tmp0    = tab0[j];
01136                     tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
01137                     tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
01138                 }
01139             } else {
01140 found2:
01141                 if (s->mode_ext & MODE_EXT_MS_STEREO) {
01142                     /* lower part of the spectrum : do ms stereo
01143                        if enabled */
01144                     for (j = 0; j < len; j++) {
01145                         tmp0    = tab0[j];
01146                         tmp1    = tab1[j];
01147                         tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
01148                         tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
01149                     }
01150                 }
01151             }
01152         }
01153     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
01154         /* ms stereo ONLY */
01155         /* NOTE: the 1/sqrt(2) normalization factor is included in the
01156            global gain */
01157         tab0 = g0->sb_hybrid;
01158         tab1 = g1->sb_hybrid;
01159         for (i = 0; i < 576; i++) {
01160             tmp0    = tab0[i];
01161             tmp1    = tab1[i];
01162             tab0[i] = tmp0 + tmp1;
01163             tab1[i] = tmp0 - tmp1;
01164         }
01165     }
01166 }
01167 
01168 #if CONFIG_FLOAT
01169 #define AA(j) do {                                                      \
01170         float tmp0 = ptr[-1-j];                                         \
01171         float tmp1 = ptr[   j];                                         \
01172         ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1];    \
01173         ptr[   j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0];    \
01174     } while (0)
01175 #else
01176 #define AA(j) do {                                              \
01177         int tmp0 = ptr[-1-j];                                   \
01178         int tmp1 = ptr[   j];                                   \
01179         int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]);          \
01180         ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2]));   \
01181         ptr[   j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3]));   \
01182     } while (0)
01183 #endif
01184 
01185 static void compute_antialias(MPADecodeContext *s, GranuleDef *g)
01186 {
01187     INTFLOAT *ptr;
01188     int n, i;
01189 
01190     /* we antialias only "long" bands */
01191     if (g->block_type == 2) {
01192         if (!g->switch_point)
01193             return;
01194         /* XXX: check this for 8000Hz case */
01195         n = 1;
01196     } else {
01197         n = SBLIMIT - 1;
01198     }
01199 
01200     ptr = g->sb_hybrid + 18;
01201     for (i = n; i > 0; i--) {
01202         AA(0);
01203         AA(1);
01204         AA(2);
01205         AA(3);
01206         AA(4);
01207         AA(5);
01208         AA(6);
01209         AA(7);
01210 
01211         ptr += 18;
01212     }
01213 }
01214 
01215 static void compute_imdct(MPADecodeContext *s, GranuleDef *g,
01216                           INTFLOAT *sb_samples, INTFLOAT *mdct_buf)
01217 {
01218     INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;
01219     INTFLOAT out2[12];
01220     int i, j, mdct_long_end, sblimit;
01221 
01222     /* find last non zero block */
01223     ptr  = g->sb_hybrid + 576;
01224     ptr1 = g->sb_hybrid + 2 * 18;
01225     while (ptr >= ptr1) {
01226         int32_t *p;
01227         ptr -= 6;
01228         p    = (int32_t*)ptr;
01229         if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])
01230             break;
01231     }
01232     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
01233 
01234     if (g->block_type == 2) {
01235         /* XXX: check for 8000 Hz */
01236         if (g->switch_point)
01237             mdct_long_end = 2;
01238         else
01239             mdct_long_end = 0;
01240     } else {
01241         mdct_long_end = sblimit;
01242     }
01243 
01244     s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,
01245                                      mdct_long_end, g->switch_point,
01246                                      g->block_type);
01247 
01248     buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);
01249     ptr = g->sb_hybrid + 18 * mdct_long_end;
01250 
01251     for (j = mdct_long_end; j < sblimit; j++) {
01252         /* select frequency inversion */
01253         win     = RENAME(ff_mdct_win)[2 + (4  & -(j & 1))];
01254         out_ptr = sb_samples + j;
01255 
01256         for (i = 0; i < 6; i++) {
01257             *out_ptr = buf[4*i];
01258             out_ptr += SBLIMIT;
01259         }
01260         imdct12(out2, ptr + 0);
01261         for (i = 0; i < 6; i++) {
01262             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*1)];
01263             buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);
01264             out_ptr += SBLIMIT;
01265         }
01266         imdct12(out2, ptr + 1);
01267         for (i = 0; i < 6; i++) {
01268             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*2)];
01269             buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);
01270             out_ptr += SBLIMIT;
01271         }
01272         imdct12(out2, ptr + 2);
01273         for (i = 0; i < 6; i++) {
01274             buf[4*(i + 6*0)] = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*0)];
01275             buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);
01276             buf[4*(i + 6*2)] = 0;
01277         }
01278         ptr += 18;
01279         buf += (j&3) != 3 ? 1 : (4*18-3);
01280     }
01281     /* zero bands */
01282     for (j = sblimit; j < SBLIMIT; j++) {
01283         /* overlap */
01284         out_ptr = sb_samples + j;
01285         for (i = 0; i < 18; i++) {
01286             *out_ptr = buf[4*i];
01287             buf[4*i]   = 0;
01288             out_ptr += SBLIMIT;
01289         }
01290         buf += (j&3) != 3 ? 1 : (4*18-3);
01291     }
01292 }
01293 
01294 /* main layer3 decoding function */
01295 static int mp_decode_layer3(MPADecodeContext *s)
01296 {
01297     int nb_granules, main_data_begin;
01298     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;
01299     GranuleDef *g;
01300     int16_t exponents[576]; //FIXME try INTFLOAT
01301 
01302     /* read side info */
01303     if (s->lsf) {
01304         main_data_begin = get_bits(&s->gb, 8);
01305         skip_bits(&s->gb, s->nb_channels);
01306         nb_granules = 1;
01307     } else {
01308         main_data_begin = get_bits(&s->gb, 9);
01309         if (s->nb_channels == 2)
01310             skip_bits(&s->gb, 3);
01311         else
01312             skip_bits(&s->gb, 5);
01313         nb_granules = 2;
01314         for (ch = 0; ch < s->nb_channels; ch++) {
01315             s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */
01316             s->granules[ch][1].scfsi = get_bits(&s->gb, 4);
01317         }
01318     }
01319 
01320     for (gr = 0; gr < nb_granules; gr++) {
01321         for (ch = 0; ch < s->nb_channels; ch++) {
01322             av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);
01323             g = &s->granules[ch][gr];
01324             g->part2_3_length = get_bits(&s->gb, 12);
01325             g->big_values     = get_bits(&s->gb,  9);
01326             if (g->big_values > 288) {
01327                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");
01328                 return AVERROR_INVALIDDATA;
01329             }
01330 
01331             g->global_gain = get_bits(&s->gb, 8);
01332             /* if MS stereo only is selected, we precompute the
01333                1/sqrt(2) renormalization factor */
01334             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
01335                 MODE_EXT_MS_STEREO)
01336                 g->global_gain -= 2;
01337             if (s->lsf)
01338                 g->scalefac_compress = get_bits(&s->gb, 9);
01339             else
01340                 g->scalefac_compress = get_bits(&s->gb, 4);
01341             blocksplit_flag = get_bits1(&s->gb);
01342             if (blocksplit_flag) {
01343                 g->block_type = get_bits(&s->gb, 2);
01344                 if (g->block_type == 0) {
01345                     av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");
01346                     return AVERROR_INVALIDDATA;
01347                 }
01348                 g->switch_point = get_bits1(&s->gb);
01349                 for (i = 0; i < 2; i++)
01350                     g->table_select[i] = get_bits(&s->gb, 5);
01351                 for (i = 0; i < 3; i++)
01352                     g->subblock_gain[i] = get_bits(&s->gb, 3);
01353                 ff_init_short_region(s, g);
01354             } else {
01355                 int region_address1, region_address2;
01356                 g->block_type = 0;
01357                 g->switch_point = 0;
01358                 for (i = 0; i < 3; i++)
01359                     g->table_select[i] = get_bits(&s->gb, 5);
01360                 /* compute huffman coded region sizes */
01361                 region_address1 = get_bits(&s->gb, 4);
01362                 region_address2 = get_bits(&s->gb, 3);
01363                 av_dlog(s->avctx, "region1=%d region2=%d\n",
01364                         region_address1, region_address2);
01365                 ff_init_long_region(s, g, region_address1, region_address2);
01366             }
01367             ff_region_offset2size(g);
01368             ff_compute_band_indexes(s, g);
01369 
01370             g->preflag = 0;
01371             if (!s->lsf)
01372                 g->preflag = get_bits1(&s->gb);
01373             g->scalefac_scale     = get_bits1(&s->gb);
01374             g->count1table_select = get_bits1(&s->gb);
01375             av_dlog(s->avctx, "block_type=%d switch_point=%d\n",
01376                     g->block_type, g->switch_point);
01377         }
01378     }
01379 
01380     if (!s->adu_mode) {
01381         int skip;
01382         const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
01383         int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0,
01384                                 FFMAX(0, LAST_BUF_SIZE - s->last_buf_size));
01385         assert((get_bits_count(&s->gb) & 7) == 0);
01386         /* now we get bits from the main_data_begin offset */
01387         av_dlog(s->avctx, "seekback: %d\n", main_data_begin);
01388     //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);
01389 
01390         memcpy(s->last_buf + s->last_buf_size, ptr, extrasize);
01391         s->in_gb = s->gb;
01392         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);
01393 #if !UNCHECKED_BITSTREAM_READER
01394         s->gb.size_in_bits_plus8 += extrasize * 8;
01395 #endif
01396         s->last_buf_size <<= 3;
01397         for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) {
01398             for (ch = 0; ch < s->nb_channels; ch++) {
01399                 g = &s->granules[ch][gr];
01400                 s->last_buf_size += g->part2_3_length;
01401                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));
01402             }
01403         }
01404         skip = s->last_buf_size - 8 * main_data_begin;
01405         if (skip >= s->gb.size_in_bits && s->in_gb.buffer) {
01406             skip_bits_long(&s->in_gb, skip - s->gb.size_in_bits);
01407             s->gb           = s->in_gb;
01408             s->in_gb.buffer = NULL;
01409         } else {
01410             skip_bits_long(&s->gb, skip);
01411         }
01412     } else {
01413         gr = 0;
01414     }
01415 
01416     for (; gr < nb_granules; gr++) {
01417         for (ch = 0; ch < s->nb_channels; ch++) {
01418             g = &s->granules[ch][gr];
01419             bits_pos = get_bits_count(&s->gb);
01420 
01421             if (!s->lsf) {
01422                 uint8_t *sc;
01423                 int slen, slen1, slen2;
01424 
01425                 /* MPEG1 scale factors */
01426                 slen1 = slen_table[0][g->scalefac_compress];
01427                 slen2 = slen_table[1][g->scalefac_compress];
01428                 av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);
01429                 if (g->block_type == 2) {
01430                     n = g->switch_point ? 17 : 18;
01431                     j = 0;
01432                     if (slen1) {
01433                         for (i = 0; i < n; i++)
01434                             g->scale_factors[j++] = get_bits(&s->gb, slen1);
01435                     } else {
01436                         for (i = 0; i < n; i++)
01437                             g->scale_factors[j++] = 0;
01438                     }
01439                     if (slen2) {
01440                         for (i = 0; i < 18; i++)
01441                             g->scale_factors[j++] = get_bits(&s->gb, slen2);
01442                         for (i = 0; i < 3; i++)
01443                             g->scale_factors[j++] = 0;
01444                     } else {
01445                         for (i = 0; i < 21; i++)
01446                             g->scale_factors[j++] = 0;
01447                     }
01448                 } else {
01449                     sc = s->granules[ch][0].scale_factors;
01450                     j = 0;
01451                     for (k = 0; k < 4; k++) {
01452                         n = k == 0 ? 6 : 5;
01453                         if ((g->scfsi & (0x8 >> k)) == 0) {
01454                             slen = (k < 2) ? slen1 : slen2;
01455                             if (slen) {
01456                                 for (i = 0; i < n; i++)
01457                                     g->scale_factors[j++] = get_bits(&s->gb, slen);
01458                             } else {
01459                                 for (i = 0; i < n; i++)
01460                                     g->scale_factors[j++] = 0;
01461                             }
01462                         } else {
01463                             /* simply copy from last granule */
01464                             for (i = 0; i < n; i++) {
01465                                 g->scale_factors[j] = sc[j];
01466                                 j++;
01467                             }
01468                         }
01469                     }
01470                     g->scale_factors[j++] = 0;
01471                 }
01472             } else {
01473                 int tindex, tindex2, slen[4], sl, sf;
01474 
01475                 /* LSF scale factors */
01476                 if (g->block_type == 2)
01477                     tindex = g->switch_point ? 2 : 1;
01478                 else
01479                     tindex = 0;
01480 
01481                 sf = g->scalefac_compress;
01482                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
01483                     /* intensity stereo case */
01484                     sf >>= 1;
01485                     if (sf < 180) {
01486                         lsf_sf_expand(slen, sf, 6, 6, 0);
01487                         tindex2 = 3;
01488                     } else if (sf < 244) {
01489                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);
01490                         tindex2 = 4;
01491                     } else {
01492                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);
01493                         tindex2 = 5;
01494                     }
01495                 } else {
01496                     /* normal case */
01497                     if (sf < 400) {
01498                         lsf_sf_expand(slen, sf, 5, 4, 4);
01499                         tindex2 = 0;
01500                     } else if (sf < 500) {
01501                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);
01502                         tindex2 = 1;
01503                     } else {
01504                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);
01505                         tindex2 = 2;
01506                         g->preflag = 1;
01507                     }
01508                 }
01509 
01510                 j = 0;
01511                 for (k = 0; k < 4; k++) {
01512                     n  = lsf_nsf_table[tindex2][tindex][k];
01513                     sl = slen[k];
01514                     if (sl) {
01515                         for (i = 0; i < n; i++)
01516                             g->scale_factors[j++] = get_bits(&s->gb, sl);
01517                     } else {
01518                         for (i = 0; i < n; i++)
01519                             g->scale_factors[j++] = 0;
01520                     }
01521                 }
01522                 /* XXX: should compute exact size */
01523                 for (; j < 40; j++)
01524                     g->scale_factors[j] = 0;
01525             }
01526 
01527             exponents_from_scale_factors(s, g, exponents);
01528 
01529             /* read Huffman coded residue */
01530             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
01531         } /* ch */
01532 
01533         if (s->nb_channels == 2)
01534             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
01535 
01536         for (ch = 0; ch < s->nb_channels; ch++) {
01537             g = &s->granules[ch][gr];
01538 
01539             reorder_block(s, g);
01540             compute_antialias(s, g);
01541             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
01542         }
01543     } /* gr */
01544     if (get_bits_count(&s->gb) < 0)
01545         skip_bits_long(&s->gb, -get_bits_count(&s->gb));
01546     return nb_granules * 18;
01547 }
01548 
01549 static int mp_decode_frame(MPADecodeContext *s, OUT_INT *samples,
01550                            const uint8_t *buf, int buf_size)
01551 {
01552     int i, nb_frames, ch, ret;
01553     OUT_INT *samples_ptr;
01554 
01555     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);
01556 
01557     /* skip error protection field */
01558     if (s->error_protection)
01559         skip_bits(&s->gb, 16);
01560 
01561     switch(s->layer) {
01562     case 1:
01563         s->avctx->frame_size = 384;
01564         nb_frames = mp_decode_layer1(s);
01565         break;
01566     case 2:
01567         s->avctx->frame_size = 1152;
01568         nb_frames = mp_decode_layer2(s);
01569         break;
01570     case 3:
01571         s->avctx->frame_size = s->lsf ? 576 : 1152;
01572     default:
01573         nb_frames = mp_decode_layer3(s);
01574 
01575         if (nb_frames < 0)
01576             return nb_frames;
01577 
01578         s->last_buf_size=0;
01579         if (s->in_gb.buffer) {
01580             align_get_bits(&s->gb);
01581             i = get_bits_left(&s->gb)>>3;
01582             if (i >= 0 && i <= BACKSTEP_SIZE) {
01583                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
01584                 s->last_buf_size=i;
01585             } else
01586                 av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);
01587             s->gb           = s->in_gb;
01588             s->in_gb.buffer = NULL;
01589         }
01590 
01591         align_get_bits(&s->gb);
01592         assert((get_bits_count(&s->gb) & 7) == 0);
01593         i = get_bits_left(&s->gb) >> 3;
01594 
01595         if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {
01596             if (i < 0)
01597                 av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);
01598             i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
01599         }
01600         assert(i <= buf_size - HEADER_SIZE && i >= 0);
01601         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
01602         s->last_buf_size += i;
01603     }
01604 
01605     /* get output buffer */
01606     if (!samples) {
01607         s->frame.nb_samples = s->avctx->frame_size;
01608         if ((ret = ff_get_buffer(s->avctx, &s->frame)) < 0) {
01609             av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
01610             return ret;
01611         }
01612         samples = (OUT_INT *)s->frame.data[0];
01613     }
01614 
01615     /* apply the synthesis filter */
01616     for (ch = 0; ch < s->nb_channels; ch++) {
01617         samples_ptr = samples + ch;
01618         for (i = 0; i < nb_frames; i++) {
01619             RENAME(ff_mpa_synth_filter)(
01620                          &s->mpadsp,
01621                          s->synth_buf[ch], &(s->synth_buf_offset[ch]),
01622                          RENAME(ff_mpa_synth_window), &s->dither_state,
01623                          samples_ptr, s->nb_channels,
01624                          s->sb_samples[ch][i]);
01625             samples_ptr += 32 * s->nb_channels;
01626         }
01627     }
01628 
01629     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
01630 }
01631 
01632 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,
01633                         AVPacket *avpkt)
01634 {
01635     const uint8_t *buf  = avpkt->data;
01636     int buf_size        = avpkt->size;
01637     MPADecodeContext *s = avctx->priv_data;
01638     uint32_t header;
01639     int ret;
01640 
01641     if (buf_size < HEADER_SIZE)
01642         return AVERROR_INVALIDDATA;
01643 
01644     header = AV_RB32(buf);
01645     if (ff_mpa_check_header(header) < 0) {
01646         av_log(avctx, AV_LOG_ERROR, "Header missing\n");
01647         return AVERROR_INVALIDDATA;
01648     }
01649 
01650     if (avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {
01651         /* free format: prepare to compute frame size */
01652         s->frame_size = -1;
01653         return AVERROR_INVALIDDATA;
01654     }
01655     /* update codec info */
01656     avctx->channels       = s->nb_channels;
01657     avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
01658     if (!avctx->bit_rate)
01659         avctx->bit_rate = s->bit_rate;
01660     avctx->sub_id = s->layer;
01661 
01662     if (s->frame_size <= 0 || s->frame_size > buf_size) {
01663         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
01664         return AVERROR_INVALIDDATA;
01665     } else if (s->frame_size < buf_size) {
01666         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");
01667         buf_size= s->frame_size;
01668     }
01669 
01670     ret = mp_decode_frame(s, NULL, buf, buf_size);
01671     if (ret >= 0) {
01672         *got_frame_ptr   = 1;
01673         *(AVFrame *)data = s->frame;
01674         avctx->sample_rate = s->sample_rate;
01675         //FIXME maybe move the other codec info stuff from above here too
01676     } else {
01677         av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
01678         /* Only return an error if the bad frame makes up the whole packet or
01679          * the error is related to buffer management.
01680          * If there is more data in the packet, just consume the bad frame
01681          * instead of returning an error, which would discard the whole
01682          * packet. */
01683         *got_frame_ptr = 0;
01684         if (buf_size == avpkt->size || ret != AVERROR_INVALIDDATA)
01685             return ret;
01686     }
01687     s->frame_size = 0;
01688     return buf_size;
01689 }
01690 
01691 static void flush(AVCodecContext *avctx)
01692 {
01693     MPADecodeContext *s = avctx->priv_data;
01694     memset(s->synth_buf, 0, sizeof(s->synth_buf));
01695     s->last_buf_size = 0;
01696 }
01697 
01698 #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER
01699 static int decode_frame_adu(AVCodecContext *avctx, void *data,
01700                             int *got_frame_ptr, AVPacket *avpkt)
01701 {
01702     const uint8_t *buf  = avpkt->data;
01703     int buf_size        = avpkt->size;
01704     MPADecodeContext *s = avctx->priv_data;
01705     uint32_t header;
01706     int len, out_size, ret = 0;
01707 
01708     len = buf_size;
01709 
01710     // Discard too short frames
01711     if (buf_size < HEADER_SIZE) {
01712         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
01713         return AVERROR_INVALIDDATA;
01714     }
01715 
01716 
01717     if (len > MPA_MAX_CODED_FRAME_SIZE)
01718         len = MPA_MAX_CODED_FRAME_SIZE;
01719 
01720     // Get header and restore sync word
01721     header = AV_RB32(buf) | 0xffe00000;
01722 
01723     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
01724         av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");
01725         return AVERROR_INVALIDDATA;
01726     }
01727 
01728     avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);
01729     /* update codec info */
01730     avctx->sample_rate = s->sample_rate;
01731     avctx->channels    = s->nb_channels;
01732     if (!avctx->bit_rate)
01733         avctx->bit_rate = s->bit_rate;
01734     avctx->sub_id = s->layer;
01735 
01736     s->frame_size = len;
01737 
01738 #if FF_API_PARSE_FRAME
01739     if (avctx->parse_only)
01740         out_size = buf_size;
01741     else
01742 #endif
01743     ret = mp_decode_frame(s, NULL, buf, buf_size);
01744     if (ret < 0) {
01745         av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
01746         return ret;
01747     }
01748 
01749     *got_frame_ptr   = 1;
01750     *(AVFrame *)data = s->frame;
01751 
01752     return buf_size;
01753 }
01754 #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */
01755 
01756 #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER
01757 
01761 typedef struct MP3On4DecodeContext {
01762     AVFrame *frame;
01763     int frames;                     
01764     int syncword;                   
01765     const uint8_t *coff;            
01766     MPADecodeContext *mp3decctx[5]; 
01767     OUT_INT *decoded_buf;           
01768 } MP3On4DecodeContext;
01769 
01770 #include "mpeg4audio.h"
01771 
01772 /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
01773 
01774 /* number of mp3 decoder instances */
01775 static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };
01776 
01777 /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */
01778 static const uint8_t chan_offset[8][5] = {
01779     { 0             },
01780     { 0             },  // C
01781     { 0             },  // FLR
01782     { 2, 0          },  // C FLR
01783     { 2, 0, 3       },  // C FLR BS
01784     { 2, 0, 3       },  // C FLR BLRS
01785     { 2, 0, 4, 3    },  // C FLR BLRS LFE
01786     { 2, 0, 6, 4, 3 },  // C FLR BLRS BLR LFE
01787 };
01788 
01789 /* mp3on4 channel layouts */
01790 static const int16_t chan_layout[8] = {
01791     0,
01792     AV_CH_LAYOUT_MONO,
01793     AV_CH_LAYOUT_STEREO,
01794     AV_CH_LAYOUT_SURROUND,
01795     AV_CH_LAYOUT_4POINT0,
01796     AV_CH_LAYOUT_5POINT0,
01797     AV_CH_LAYOUT_5POINT1,
01798     AV_CH_LAYOUT_7POINT1
01799 };
01800 
01801 static av_cold int decode_close_mp3on4(AVCodecContext * avctx)
01802 {
01803     MP3On4DecodeContext *s = avctx->priv_data;
01804     int i;
01805 
01806     for (i = 0; i < s->frames; i++)
01807         av_free(s->mp3decctx[i]);
01808 
01809     av_freep(&s->decoded_buf);
01810 
01811     return 0;
01812 }
01813 
01814 
01815 static int decode_init_mp3on4(AVCodecContext * avctx)
01816 {
01817     MP3On4DecodeContext *s = avctx->priv_data;
01818     MPEG4AudioConfig cfg;
01819     int i;
01820 
01821     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {
01822         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
01823         return AVERROR_INVALIDDATA;
01824     }
01825 
01826     avpriv_mpeg4audio_get_config(&cfg, avctx->extradata,
01827                                  avctx->extradata_size * 8, 1);
01828     if (!cfg.chan_config || cfg.chan_config > 7) {
01829         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
01830         return AVERROR_INVALIDDATA;
01831     }
01832     s->frames             = mp3Frames[cfg.chan_config];
01833     s->coff               = chan_offset[cfg.chan_config];
01834     avctx->channels       = ff_mpeg4audio_channels[cfg.chan_config];
01835     avctx->channel_layout = chan_layout[cfg.chan_config];
01836 
01837     if (cfg.sample_rate < 16000)
01838         s->syncword = 0xffe00000;
01839     else
01840         s->syncword = 0xfff00000;
01841 
01842     /* Init the first mp3 decoder in standard way, so that all tables get builded
01843      * We replace avctx->priv_data with the context of the first decoder so that
01844      * decode_init() does not have to be changed.
01845      * Other decoders will be initialized here copying data from the first context
01846      */
01847     // Allocate zeroed memory for the first decoder context
01848     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
01849     if (!s->mp3decctx[0])
01850         goto alloc_fail;
01851     // Put decoder context in place to make init_decode() happy
01852     avctx->priv_data = s->mp3decctx[0];
01853     decode_init(avctx);
01854     s->frame = avctx->coded_frame;
01855     // Restore mp3on4 context pointer
01856     avctx->priv_data = s;
01857     s->mp3decctx[0]->adu_mode = 1; // Set adu mode
01858 
01859     /* Create a separate codec/context for each frame (first is already ok).
01860      * Each frame is 1 or 2 channels - up to 5 frames allowed
01861      */
01862     for (i = 1; i < s->frames; i++) {
01863         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
01864         if (!s->mp3decctx[i])
01865             goto alloc_fail;
01866         s->mp3decctx[i]->adu_mode = 1;
01867         s->mp3decctx[i]->avctx = avctx;
01868         s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;
01869     }
01870 
01871     /* Allocate buffer for multi-channel output if needed */
01872     if (s->frames > 1) {
01873         s->decoded_buf = av_malloc(MPA_FRAME_SIZE * MPA_MAX_CHANNELS *
01874                                    sizeof(*s->decoded_buf));
01875         if (!s->decoded_buf)
01876             goto alloc_fail;
01877     }
01878 
01879     return 0;
01880 alloc_fail:
01881     decode_close_mp3on4(avctx);
01882     return AVERROR(ENOMEM);
01883 }
01884 
01885 
01886 static void flush_mp3on4(AVCodecContext *avctx)
01887 {
01888     int i;
01889     MP3On4DecodeContext *s = avctx->priv_data;
01890 
01891     for (i = 0; i < s->frames; i++) {
01892         MPADecodeContext *m = s->mp3decctx[i];
01893         memset(m->synth_buf, 0, sizeof(m->synth_buf));
01894         m->last_buf_size = 0;
01895     }
01896 }
01897 
01898 
01899 static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,
01900                                int *got_frame_ptr, AVPacket *avpkt)
01901 {
01902     const uint8_t *buf     = avpkt->data;
01903     int buf_size           = avpkt->size;
01904     MP3On4DecodeContext *s = avctx->priv_data;
01905     MPADecodeContext *m;
01906     int fsize, len = buf_size, out_size = 0;
01907     uint32_t header;
01908     OUT_INT *out_samples;
01909     OUT_INT *outptr, *bp;
01910     int fr, j, n, ch, ret;
01911 
01912     /* get output buffer */
01913     s->frame->nb_samples = MPA_FRAME_SIZE;
01914     if ((ret = ff_get_buffer(avctx, s->frame)) < 0) {
01915         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
01916         return ret;
01917     }
01918     out_samples = (OUT_INT *)s->frame->data[0];
01919 
01920     // Discard too short frames
01921     if (buf_size < HEADER_SIZE)
01922         return AVERROR_INVALIDDATA;
01923 
01924     // If only one decoder interleave is not needed
01925     outptr = s->frames == 1 ? out_samples : s->decoded_buf;
01926 
01927     avctx->bit_rate = 0;
01928 
01929     ch = 0;
01930     for (fr = 0; fr < s->frames; fr++) {
01931         fsize = AV_RB16(buf) >> 4;
01932         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);
01933         m     = s->mp3decctx[fr];
01934         assert(m != NULL);
01935 
01936         if (fsize < HEADER_SIZE) {
01937             av_log(avctx, AV_LOG_ERROR, "Frame size smaller than header size\n");
01938             return AVERROR_INVALIDDATA;
01939         }
01940         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header
01941 
01942         if (ff_mpa_check_header(header) < 0) // Bad header, discard block
01943             break;
01944 
01945         avpriv_mpegaudio_decode_header((MPADecodeHeader *)m, header);
01946 
01947         if (ch + m->nb_channels > avctx->channels ||
01948             s->coff[fr] + m->nb_channels > avctx->channels) {
01949             av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "
01950                                         "channel count\n");
01951             return AVERROR_INVALIDDATA;
01952         }
01953         ch += m->nb_channels;
01954 
01955         if ((ret = mp_decode_frame(m, outptr, buf, fsize)) < 0)
01956             return ret;
01957 
01958         out_size += ret;
01959         buf      += fsize;
01960         len      -= fsize;
01961 
01962         if (s->frames > 1) {
01963             n = m->avctx->frame_size*m->nb_channels;
01964             /* interleave output data */
01965             bp = out_samples + s->coff[fr];
01966             if (m->nb_channels == 1) {
01967                 for (j = 0; j < n; j++) {
01968                     *bp = s->decoded_buf[j];
01969                     bp += avctx->channels;
01970                 }
01971             } else {
01972                 for (j = 0; j < n; j++) {
01973                     bp[0] = s->decoded_buf[j++];
01974                     bp[1] = s->decoded_buf[j];
01975                     bp   += avctx->channels;
01976                 }
01977             }
01978         }
01979         avctx->bit_rate += m->bit_rate;
01980     }
01981 
01982     /* update codec info */
01983     avctx->sample_rate = s->mp3decctx[0]->sample_rate;
01984 
01985     s->frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));
01986     *got_frame_ptr   = 1;
01987     *(AVFrame *)data = *s->frame;
01988 
01989     return buf_size;
01990 }
01991 #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */
01992 
01993 #if !CONFIG_FLOAT
01994 #if CONFIG_MP1_DECODER
01995 AVCodec ff_mp1_decoder = {
01996     .name           = "mp1",
01997     .type           = AVMEDIA_TYPE_AUDIO,
01998     .id             = CODEC_ID_MP1,
01999     .priv_data_size = sizeof(MPADecodeContext),
02000     .init           = decode_init,
02001     .decode         = decode_frame,
02002 #if FF_API_PARSE_FRAME
02003     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02004 #else
02005     .capabilities   = CODEC_CAP_DR1,
02006 #endif
02007     .flush          = flush,
02008     .long_name      = NULL_IF_CONFIG_SMALL("MP1 (MPEG audio layer 1)"),
02009 };
02010 #endif
02011 #if CONFIG_MP2_DECODER
02012 AVCodec ff_mp2_decoder = {
02013     .name           = "mp2",
02014     .type           = AVMEDIA_TYPE_AUDIO,
02015     .id             = CODEC_ID_MP2,
02016     .priv_data_size = sizeof(MPADecodeContext),
02017     .init           = decode_init,
02018     .decode         = decode_frame,
02019 #if FF_API_PARSE_FRAME
02020     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02021 #else
02022     .capabilities   = CODEC_CAP_DR1,
02023 #endif
02024     .flush          = flush,
02025     .long_name      = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
02026 };
02027 #endif
02028 #if CONFIG_MP3_DECODER
02029 AVCodec ff_mp3_decoder = {
02030     .name           = "mp3",
02031     .type           = AVMEDIA_TYPE_AUDIO,
02032     .id             = CODEC_ID_MP3,
02033     .priv_data_size = sizeof(MPADecodeContext),
02034     .init           = decode_init,
02035     .decode         = decode_frame,
02036 #if FF_API_PARSE_FRAME
02037     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02038 #else
02039     .capabilities   = CODEC_CAP_DR1,
02040 #endif
02041     .flush          = flush,
02042     .long_name      = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
02043 };
02044 #endif
02045 #if CONFIG_MP3ADU_DECODER
02046 AVCodec ff_mp3adu_decoder = {
02047     .name           = "mp3adu",
02048     .type           = AVMEDIA_TYPE_AUDIO,
02049     .id             = CODEC_ID_MP3ADU,
02050     .priv_data_size = sizeof(MPADecodeContext),
02051     .init           = decode_init,
02052     .decode         = decode_frame_adu,
02053 #if FF_API_PARSE_FRAME
02054     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02055 #else
02056     .capabilities   = CODEC_CAP_DR1,
02057 #endif
02058     .flush          = flush,
02059     .long_name      = NULL_IF_CONFIG_SMALL("ADU (Application Data Unit) MP3 (MPEG audio layer 3)"),
02060 };
02061 #endif
02062 #if CONFIG_MP3ON4_DECODER
02063 AVCodec ff_mp3on4_decoder = {
02064     .name           = "mp3on4",
02065     .type           = AVMEDIA_TYPE_AUDIO,
02066     .id             = CODEC_ID_MP3ON4,
02067     .priv_data_size = sizeof(MP3On4DecodeContext),
02068     .init           = decode_init_mp3on4,
02069     .close          = decode_close_mp3on4,
02070     .decode         = decode_frame_mp3on4,
02071     .capabilities   = CODEC_CAP_DR1,
02072     .flush          = flush_mp3on4,
02073     .long_name      = NULL_IF_CONFIG_SMALL("MP3onMP4"),
02074 };
02075 #endif
02076 #endif