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 "get_bits.h"
00030 #include "mathops.h"
00031 #include "mpegaudiodsp.h"
00032 
00033 /*
00034  * TODO:
00035  *  - test lsf / mpeg25 extensively.
00036  */
00037 
00038 #include "mpegaudio.h"
00039 #include "mpegaudiodecheader.h"
00040 
00041 #define BACKSTEP_SIZE 512
00042 #define EXTRABYTES 24
00043 #define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES
00044 
00045 /* layer 3 "granule" */
00046 typedef struct GranuleDef {
00047     uint8_t scfsi;
00048     int part2_3_length;
00049     int big_values;
00050     int global_gain;
00051     int scalefac_compress;
00052     uint8_t block_type;
00053     uint8_t switch_point;
00054     int table_select[3];
00055     int subblock_gain[3];
00056     uint8_t scalefac_scale;
00057     uint8_t count1table_select;
00058     int region_size[3]; /* number of huffman codes in each region */
00059     int preflag;
00060     int short_start, long_end; /* long/short band indexes */
00061     uint8_t scale_factors[40];
00062     DECLARE_ALIGNED(16, INTFLOAT, sb_hybrid)[SBLIMIT * 18]; /* 576 samples */
00063 } GranuleDef;
00064 
00065 typedef struct MPADecodeContext {
00066     MPA_DECODE_HEADER
00067     uint8_t last_buf[LAST_BUF_SIZE];
00068     int last_buf_size;
00069     /* next header (used in free format parsing) */
00070     uint32_t free_format_next_header;
00071     GetBitContext gb;
00072     GetBitContext in_gb;
00073     DECLARE_ALIGNED(32, MPA_INT, synth_buf)[MPA_MAX_CHANNELS][512 * 2];
00074     int synth_buf_offset[MPA_MAX_CHANNELS];
00075     DECLARE_ALIGNED(32, INTFLOAT, sb_samples)[MPA_MAX_CHANNELS][36][SBLIMIT];
00076     INTFLOAT mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
00077     GranuleDef granules[2][2]; /* Used in Layer 3 */
00078     int adu_mode; 
00079     int dither_state;
00080     int err_recognition;
00081     AVCodecContext* avctx;
00082     MPADSPContext mpadsp;
00083     AVFrame frame;
00084 } MPADecodeContext;
00085 
00086 #if CONFIG_FLOAT
00087 #   define SHR(a,b)       ((a)*(1.0f/(1<<(b))))
00088 #   define FIXR_OLD(a)    ((int)((a) * FRAC_ONE + 0.5))
00089 #   define FIXR(x)        ((float)(x))
00090 #   define FIXHR(x)       ((float)(x))
00091 #   define MULH3(x, y, s) ((s)*(y)*(x))
00092 #   define MULLx(x, y, s) ((y)*(x))
00093 #   define RENAME(a) a ## _float
00094 #   define OUT_FMT AV_SAMPLE_FMT_FLT
00095 #else
00096 #   define SHR(a,b)       ((a)>>(b))
00097 /* WARNING: only correct for positive numbers */
00098 #   define FIXR_OLD(a)    ((int)((a) * FRAC_ONE + 0.5))
00099 #   define FIXR(a)        ((int)((a) * FRAC_ONE + 0.5))
00100 #   define FIXHR(a)       ((int)((a) * (1LL<<32) + 0.5))
00101 #   define MULH3(x, y, s) MULH((s)*(x), y)
00102 #   define MULLx(x, y, s) MULL(x,y,s)
00103 #   define RENAME(a)      a ## _fixed
00104 #   define OUT_FMT AV_SAMPLE_FMT_S16
00105 #endif
00106 
00107 /****************/
00108 
00109 #define HEADER_SIZE 4
00110 
00111 #include "mpegaudiodata.h"
00112 #include "mpegaudiodectab.h"
00113 
00114 /* vlc structure for decoding layer 3 huffman tables */
00115 static VLC huff_vlc[16];
00116 static VLC_TYPE huff_vlc_tables[
00117     0 + 128 + 128 + 128 + 130 + 128 + 154 + 166 +
00118   142 + 204 + 190 + 170 + 542 + 460 + 662 + 414
00119   ][2];
00120 static const int huff_vlc_tables_sizes[16] = {
00121     0,  128,  128,  128,  130,  128,  154,  166,
00122   142,  204,  190,  170,  542,  460,  662,  414
00123 };
00124 static VLC huff_quad_vlc[2];
00125 static VLC_TYPE  huff_quad_vlc_tables[128+16][2];
00126 static const int huff_quad_vlc_tables_sizes[2] = { 128, 16 };
00127 /* computed from band_size_long */
00128 static uint16_t band_index_long[9][23];
00129 #include "mpegaudio_tablegen.h"
00130 /* intensity stereo coef table */
00131 static INTFLOAT is_table[2][16];
00132 static INTFLOAT is_table_lsf[2][2][16];
00133 static INTFLOAT csa_table[8][4];
00134 
00135 static int16_t division_tab3[1<<6 ];
00136 static int16_t division_tab5[1<<8 ];
00137 static int16_t division_tab9[1<<11];
00138 
00139 static int16_t * const division_tabs[4] = {
00140     division_tab3, division_tab5, NULL, division_tab9
00141 };
00142 
00143 /* lower 2 bits: modulo 3, higher bits: shift */
00144 static uint16_t scale_factor_modshift[64];
00145 /* [i][j]:  2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
00146 static int32_t scale_factor_mult[15][3];
00147 /* mult table for layer 2 group quantization */
00148 
00149 #define SCALE_GEN(v) \
00150 { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }
00151 
00152 static const int32_t scale_factor_mult2[3][3] = {
00153     SCALE_GEN(4.0 / 3.0), /* 3 steps */
00154     SCALE_GEN(4.0 / 5.0), /* 5 steps */
00155     SCALE_GEN(4.0 / 9.0), /* 9 steps */
00156 };
00157 
00162 static void ff_region_offset2size(GranuleDef *g)
00163 {
00164     int i, k, j = 0;
00165     g->region_size[2] = 576 / 2;
00166     for (i = 0; i < 3; i++) {
00167         k = FFMIN(g->region_size[i], g->big_values);
00168         g->region_size[i] = k - j;
00169         j = k;
00170     }
00171 }
00172 
00173 static void ff_init_short_region(MPADecodeContext *s, GranuleDef *g)
00174 {
00175     if (g->block_type == 2)
00176         g->region_size[0] = (36 / 2);
00177     else {
00178         if (s->sample_rate_index <= 2)
00179             g->region_size[0] = (36 / 2);
00180         else if (s->sample_rate_index != 8)
00181             g->region_size[0] = (54 / 2);
00182         else
00183             g->region_size[0] = (108 / 2);
00184     }
00185     g->region_size[1] = (576 / 2);
00186 }
00187 
00188 static void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2)
00189 {
00190     int l;
00191     g->region_size[0] = band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
00192     /* should not overflow */
00193     l = FFMIN(ra1 + ra2 + 2, 22);
00194     g->region_size[1] = band_index_long[s->sample_rate_index][      l] >> 1;
00195 }
00196 
00197 static void ff_compute_band_indexes(MPADecodeContext *s, GranuleDef *g)
00198 {
00199     if (g->block_type == 2) {
00200         if (g->switch_point) {
00201             /* if switched mode, we handle the 36 first samples as
00202                 long blocks.  For 8000Hz, we handle the 48 first
00203                 exponents as long blocks (XXX: check this!) */
00204             if (s->sample_rate_index <= 2)
00205                 g->long_end = 8;
00206             else if (s->sample_rate_index != 8)
00207                 g->long_end = 6;
00208             else
00209                 g->long_end = 4; /* 8000 Hz */
00210 
00211             g->short_start = 3;
00212         } else {
00213             g->long_end    = 0;
00214             g->short_start = 0;
00215         }
00216     } else {
00217         g->short_start = 13;
00218         g->long_end    = 22;
00219     }
00220 }
00221 
00222 /* layer 1 unscaling */
00223 /* n = number of bits of the mantissa minus 1 */
00224 static inline int l1_unscale(int n, int mant, int scale_factor)
00225 {
00226     int shift, mod;
00227     int64_t val;
00228 
00229     shift   = scale_factor_modshift[scale_factor];
00230     mod     = shift & 3;
00231     shift >>= 2;
00232     val     = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
00233     shift  += n;
00234     /* NOTE: at this point, 1 <= shift >= 21 + 15 */
00235     return (int)((val + (1LL << (shift - 1))) >> shift);
00236 }
00237 
00238 static inline int l2_unscale_group(int steps, int mant, int scale_factor)
00239 {
00240     int shift, mod, val;
00241 
00242     shift   = scale_factor_modshift[scale_factor];
00243     mod     = shift & 3;
00244     shift >>= 2;
00245 
00246     val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
00247     /* NOTE: at this point, 0 <= shift <= 21 */
00248     if (shift > 0)
00249         val = (val + (1 << (shift - 1))) >> shift;
00250     return val;
00251 }
00252 
00253 /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
00254 static inline int l3_unscale(int value, int exponent)
00255 {
00256     unsigned int m;
00257     int e;
00258 
00259     e  = table_4_3_exp  [4 * value + (exponent & 3)];
00260     m  = table_4_3_value[4 * value + (exponent & 3)];
00261     e -= exponent >> 2;
00262     assert(e >= 1);
00263     if (e > 31)
00264         return 0;
00265     m = (m + (1 << (e - 1))) >> e;
00266 
00267     return m;
00268 }
00269 
00270 static av_cold void decode_init_static(void)
00271 {
00272     int i, j, k;
00273     int offset;
00274 
00275     /* scale factors table for layer 1/2 */
00276     for (i = 0; i < 64; i++) {
00277         int shift, mod;
00278         /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
00279         shift = i / 3;
00280         mod   = i % 3;
00281         scale_factor_modshift[i] = mod | (shift << 2);
00282     }
00283 
00284     /* scale factor multiply for layer 1 */
00285     for (i = 0; i < 15; i++) {
00286         int n, norm;
00287         n = i + 2;
00288         norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
00289         scale_factor_mult[i][0] = MULLx(norm, FIXR(1.0          * 2.0), FRAC_BITS);
00290         scale_factor_mult[i][1] = MULLx(norm, FIXR(0.7937005259 * 2.0), FRAC_BITS);
00291         scale_factor_mult[i][2] = MULLx(norm, FIXR(0.6299605249 * 2.0), FRAC_BITS);
00292         av_dlog(NULL, "%d: norm=%x s=%x %x %x\n", i, norm,
00293                 scale_factor_mult[i][0],
00294                 scale_factor_mult[i][1],
00295                 scale_factor_mult[i][2]);
00296     }
00297 
00298     RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));
00299 
00300     /* huffman decode tables */
00301     offset = 0;
00302     for (i = 1; i < 16; i++) {
00303         const HuffTable *h = &mpa_huff_tables[i];
00304         int xsize, x, y;
00305         uint8_t  tmp_bits [512];
00306         uint16_t tmp_codes[512];
00307 
00308         memset(tmp_bits , 0, sizeof(tmp_bits ));
00309         memset(tmp_codes, 0, sizeof(tmp_codes));
00310 
00311         xsize = h->xsize;
00312 
00313         j = 0;
00314         for (x = 0; x < xsize; x++) {
00315             for (y = 0; y < xsize; y++) {
00316                 tmp_bits [(x << 5) | y | ((x&&y)<<4)]= h->bits [j  ];
00317                 tmp_codes[(x << 5) | y | ((x&&y)<<4)]= h->codes[j++];
00318             }
00319         }
00320 
00321         /* XXX: fail test */
00322         huff_vlc[i].table = huff_vlc_tables+offset;
00323         huff_vlc[i].table_allocated = huff_vlc_tables_sizes[i];
00324         init_vlc(&huff_vlc[i], 7, 512,
00325                  tmp_bits, 1, 1, tmp_codes, 2, 2,
00326                  INIT_VLC_USE_NEW_STATIC);
00327         offset += huff_vlc_tables_sizes[i];
00328     }
00329     assert(offset == FF_ARRAY_ELEMS(huff_vlc_tables));
00330 
00331     offset = 0;
00332     for (i = 0; i < 2; i++) {
00333         huff_quad_vlc[i].table = huff_quad_vlc_tables+offset;
00334         huff_quad_vlc[i].table_allocated = huff_quad_vlc_tables_sizes[i];
00335         init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
00336                  mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1,
00337                  INIT_VLC_USE_NEW_STATIC);
00338         offset += huff_quad_vlc_tables_sizes[i];
00339     }
00340     assert(offset == FF_ARRAY_ELEMS(huff_quad_vlc_tables));
00341 
00342     for (i = 0; i < 9; i++) {
00343         k = 0;
00344         for (j = 0; j < 22; j++) {
00345             band_index_long[i][j] = k;
00346             k += band_size_long[i][j];
00347         }
00348         band_index_long[i][22] = k;
00349     }
00350 
00351     /* compute n ^ (4/3) and store it in mantissa/exp format */
00352 
00353     mpegaudio_tableinit();
00354 
00355     for (i = 0; i < 4; i++) {
00356         if (ff_mpa_quant_bits[i] < 0) {
00357             for (j = 0; j < (1 << (-ff_mpa_quant_bits[i]+1)); j++) {
00358                 int val1, val2, val3, steps;
00359                 int val = j;
00360                 steps   = ff_mpa_quant_steps[i];
00361                 val1    = val % steps;
00362                 val    /= steps;
00363                 val2    = val % steps;
00364                 val3    = val / steps;
00365                 division_tabs[i][j] = val1 + (val2 << 4) + (val3 << 8);
00366             }
00367         }
00368     }
00369 
00370 
00371     for (i = 0; i < 7; i++) {
00372         float f;
00373         INTFLOAT v;
00374         if (i != 6) {
00375             f = tan((double)i * M_PI / 12.0);
00376             v = FIXR(f / (1.0 + f));
00377         } else {
00378             v = FIXR(1.0);
00379         }
00380         is_table[0][    i] = v;
00381         is_table[1][6 - i] = v;
00382     }
00383     /* invalid values */
00384     for (i = 7; i < 16; i++)
00385         is_table[0][i] = is_table[1][i] = 0.0;
00386 
00387     for (i = 0; i < 16; i++) {
00388         double f;
00389         int e, k;
00390 
00391         for (j = 0; j < 2; j++) {
00392             e = -(j + 1) * ((i + 1) >> 1);
00393             f = pow(2.0, e / 4.0);
00394             k = i & 1;
00395             is_table_lsf[j][k ^ 1][i] = FIXR(f);
00396             is_table_lsf[j][k    ][i] = FIXR(1.0);
00397             av_dlog(NULL, "is_table_lsf %d %d: %f %f\n",
00398                     i, j, (float) is_table_lsf[j][0][i],
00399                     (float) is_table_lsf[j][1][i]);
00400         }
00401     }
00402 
00403     for (i = 0; i < 8; i++) {
00404         float ci, cs, ca;
00405         ci = ci_table[i];
00406         cs = 1.0 / sqrt(1.0 + ci * ci);
00407         ca = cs * ci;
00408 #if !CONFIG_FLOAT
00409         csa_table[i][0] = FIXHR(cs/4);
00410         csa_table[i][1] = FIXHR(ca/4);
00411         csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
00412         csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
00413 #else
00414         csa_table[i][0] = cs;
00415         csa_table[i][1] = ca;
00416         csa_table[i][2] = ca + cs;
00417         csa_table[i][3] = ca - cs;
00418 #endif
00419     }
00420 }
00421 
00422 static av_cold int decode_init(AVCodecContext * avctx)
00423 {
00424     static int initialized_tables = 0;
00425     MPADecodeContext *s = avctx->priv_data;
00426 
00427     if (!initialized_tables) {
00428         decode_init_static();
00429         initialized_tables = 1;
00430     }
00431 
00432     s->avctx = avctx;
00433 
00434     ff_mpadsp_init(&s->mpadsp);
00435 
00436     avctx->sample_fmt= OUT_FMT;
00437     s->err_recognition = avctx->err_recognition;
00438 
00439     if (avctx->codec_id == CODEC_ID_MP3ADU)
00440         s->adu_mode = 1;
00441 
00442     avcodec_get_frame_defaults(&s->frame);
00443     avctx->coded_frame = &s->frame;
00444 
00445     return 0;
00446 }
00447 
00448 #define C3 FIXHR(0.86602540378443864676/2)
00449 #define C4 FIXHR(0.70710678118654752439/2) //0.5 / cos(pi*(9)/36)
00450 #define C5 FIXHR(0.51763809020504152469/2) //0.5 / cos(pi*(5)/36)
00451 #define C6 FIXHR(1.93185165257813657349/4) //0.5 / cos(pi*(15)/36)
00452 
00453 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
00454    cases. */
00455 static void imdct12(INTFLOAT *out, INTFLOAT *in)
00456 {
00457     INTFLOAT in0, in1, in2, in3, in4, in5, t1, t2;
00458 
00459     in0  = in[0*3];
00460     in1  = in[1*3] + in[0*3];
00461     in2  = in[2*3] + in[1*3];
00462     in3  = in[3*3] + in[2*3];
00463     in4  = in[4*3] + in[3*3];
00464     in5  = in[5*3] + in[4*3];
00465     in5 += in3;
00466     in3 += in1;
00467 
00468     in2  = MULH3(in2, C3, 2);
00469     in3  = MULH3(in3, C3, 4);
00470 
00471     t1   = in0 - in4;
00472     t2   = MULH3(in1 - in5, C4, 2);
00473 
00474     out[ 7] =
00475     out[10] = t1 + t2;
00476     out[ 1] =
00477     out[ 4] = t1 - t2;
00478 
00479     in0    += SHR(in4, 1);
00480     in4     = in0 + in2;
00481     in5    += 2*in1;
00482     in1     = MULH3(in5 + in3, C5, 1);
00483     out[ 8] =
00484     out[ 9] = in4 + in1;
00485     out[ 2] =
00486     out[ 3] = in4 - in1;
00487 
00488     in0    -= in2;
00489     in5     = MULH3(in5 - in3, C6, 2);
00490     out[ 0] =
00491     out[ 5] = in0 - in5;
00492     out[ 6] =
00493     out[11] = in0 + in5;
00494 }
00495 
00496 /* return the number of decoded frames */
00497 static int mp_decode_layer1(MPADecodeContext *s)
00498 {
00499     int bound, i, v, n, ch, j, mant;
00500     uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
00501     uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
00502 
00503     if (s->mode == MPA_JSTEREO)
00504         bound = (s->mode_ext + 1) * 4;
00505     else
00506         bound = SBLIMIT;
00507 
00508     /* allocation bits */
00509     for (i = 0; i < bound; i++) {
00510         for (ch = 0; ch < s->nb_channels; ch++) {
00511             allocation[ch][i] = get_bits(&s->gb, 4);
00512         }
00513     }
00514     for (i = bound; i < SBLIMIT; i++)
00515         allocation[0][i] = get_bits(&s->gb, 4);
00516 
00517     /* scale factors */
00518     for (i = 0; i < bound; i++) {
00519         for (ch = 0; ch < s->nb_channels; ch++) {
00520             if (allocation[ch][i])
00521                 scale_factors[ch][i] = get_bits(&s->gb, 6);
00522         }
00523     }
00524     for (i = bound; i < SBLIMIT; i++) {
00525         if (allocation[0][i]) {
00526             scale_factors[0][i] = get_bits(&s->gb, 6);
00527             scale_factors[1][i] = get_bits(&s->gb, 6);
00528         }
00529     }
00530 
00531     /* compute samples */
00532     for (j = 0; j < 12; j++) {
00533         for (i = 0; i < bound; i++) {
00534             for (ch = 0; ch < s->nb_channels; ch++) {
00535                 n = allocation[ch][i];
00536                 if (n) {
00537                     mant = get_bits(&s->gb, n + 1);
00538                     v = l1_unscale(n, mant, scale_factors[ch][i]);
00539                 } else {
00540                     v = 0;
00541                 }
00542                 s->sb_samples[ch][j][i] = v;
00543             }
00544         }
00545         for (i = bound; i < SBLIMIT; i++) {
00546             n = allocation[0][i];
00547             if (n) {
00548                 mant = get_bits(&s->gb, n + 1);
00549                 v = l1_unscale(n, mant, scale_factors[0][i]);
00550                 s->sb_samples[0][j][i] = v;
00551                 v = l1_unscale(n, mant, scale_factors[1][i]);
00552                 s->sb_samples[1][j][i] = v;
00553             } else {
00554                 s->sb_samples[0][j][i] = 0;
00555                 s->sb_samples[1][j][i] = 0;
00556             }
00557         }
00558     }
00559     return 12;
00560 }
00561 
00562 static int mp_decode_layer2(MPADecodeContext *s)
00563 {
00564     int sblimit; /* number of used subbands */
00565     const unsigned char *alloc_table;
00566     int table, bit_alloc_bits, i, j, ch, bound, v;
00567     unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
00568     unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
00569     unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
00570     int scale, qindex, bits, steps, k, l, m, b;
00571 
00572     /* select decoding table */
00573     table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,
00574                                    s->sample_rate, s->lsf);
00575     sblimit     = ff_mpa_sblimit_table[table];
00576     alloc_table = ff_mpa_alloc_tables[table];
00577 
00578     if (s->mode == MPA_JSTEREO)
00579         bound = (s->mode_ext + 1) * 4;
00580     else
00581         bound = sblimit;
00582 
00583     av_dlog(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);
00584 
00585     /* sanity check */
00586     if (bound > sblimit)
00587         bound = sblimit;
00588 
00589     /* parse bit allocation */
00590     j = 0;
00591     for (i = 0; i < bound; i++) {
00592         bit_alloc_bits = alloc_table[j];
00593         for (ch = 0; ch < s->nb_channels; ch++)
00594             bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
00595         j += 1 << bit_alloc_bits;
00596     }
00597     for (i = bound; i < sblimit; i++) {
00598         bit_alloc_bits = alloc_table[j];
00599         v = get_bits(&s->gb, bit_alloc_bits);
00600         bit_alloc[0][i] = v;
00601         bit_alloc[1][i] = v;
00602         j += 1 << bit_alloc_bits;
00603     }
00604 
00605     /* scale codes */
00606     for (i = 0; i < sblimit; i++) {
00607         for (ch = 0; ch < s->nb_channels; ch++) {
00608             if (bit_alloc[ch][i])
00609                 scale_code[ch][i] = get_bits(&s->gb, 2);
00610         }
00611     }
00612 
00613     /* scale factors */
00614     for (i = 0; i < sblimit; i++) {
00615         for (ch = 0; ch < s->nb_channels; ch++) {
00616             if (bit_alloc[ch][i]) {
00617                 sf = scale_factors[ch][i];
00618                 switch (scale_code[ch][i]) {
00619                 default:
00620                 case 0:
00621                     sf[0] = get_bits(&s->gb, 6);
00622                     sf[1] = get_bits(&s->gb, 6);
00623                     sf[2] = get_bits(&s->gb, 6);
00624                     break;
00625                 case 2:
00626                     sf[0] = get_bits(&s->gb, 6);
00627                     sf[1] = sf[0];
00628                     sf[2] = sf[0];
00629                     break;
00630                 case 1:
00631                     sf[0] = get_bits(&s->gb, 6);
00632                     sf[2] = get_bits(&s->gb, 6);
00633                     sf[1] = sf[0];
00634                     break;
00635                 case 3:
00636                     sf[0] = get_bits(&s->gb, 6);
00637                     sf[2] = get_bits(&s->gb, 6);
00638                     sf[1] = sf[2];
00639                     break;
00640                 }
00641             }
00642         }
00643     }
00644 
00645     /* samples */
00646     for (k = 0; k < 3; k++) {
00647         for (l = 0; l < 12; l += 3) {
00648             j = 0;
00649             for (i = 0; i < bound; i++) {
00650                 bit_alloc_bits = alloc_table[j];
00651                 for (ch = 0; ch < s->nb_channels; ch++) {
00652                     b = bit_alloc[ch][i];
00653                     if (b) {
00654                         scale = scale_factors[ch][i][k];
00655                         qindex = alloc_table[j+b];
00656                         bits = ff_mpa_quant_bits[qindex];
00657                         if (bits < 0) {
00658                             int v2;
00659                             /* 3 values at the same time */
00660                             v = get_bits(&s->gb, -bits);
00661                             v2 = division_tabs[qindex][v];
00662                             steps  = ff_mpa_quant_steps[qindex];
00663 
00664                             s->sb_samples[ch][k * 12 + l + 0][i] =
00665                                 l2_unscale_group(steps,  v2       & 15, scale);
00666                             s->sb_samples[ch][k * 12 + l + 1][i] =
00667                                 l2_unscale_group(steps, (v2 >> 4) & 15, scale);
00668                             s->sb_samples[ch][k * 12 + l + 2][i] =
00669                                 l2_unscale_group(steps,  v2 >> 8      , scale);
00670                         } else {
00671                             for (m = 0; m < 3; m++) {
00672                                 v = get_bits(&s->gb, bits);
00673                                 v = l1_unscale(bits - 1, v, scale);
00674                                 s->sb_samples[ch][k * 12 + l + m][i] = v;
00675                             }
00676                         }
00677                     } else {
00678                         s->sb_samples[ch][k * 12 + l + 0][i] = 0;
00679                         s->sb_samples[ch][k * 12 + l + 1][i] = 0;
00680                         s->sb_samples[ch][k * 12 + l + 2][i] = 0;
00681                     }
00682                 }
00683                 /* next subband in alloc table */
00684                 j += 1 << bit_alloc_bits;
00685             }
00686             /* XXX: find a way to avoid this duplication of code */
00687             for (i = bound; i < sblimit; i++) {
00688                 bit_alloc_bits = alloc_table[j];
00689                 b = bit_alloc[0][i];
00690                 if (b) {
00691                     int mant, scale0, scale1;
00692                     scale0 = scale_factors[0][i][k];
00693                     scale1 = scale_factors[1][i][k];
00694                     qindex = alloc_table[j+b];
00695                     bits = ff_mpa_quant_bits[qindex];
00696                     if (bits < 0) {
00697                         /* 3 values at the same time */
00698                         v = get_bits(&s->gb, -bits);
00699                         steps = ff_mpa_quant_steps[qindex];
00700                         mant = v % steps;
00701                         v = v / steps;
00702                         s->sb_samples[0][k * 12 + l + 0][i] =
00703                             l2_unscale_group(steps, mant, scale0);
00704                         s->sb_samples[1][k * 12 + l + 0][i] =
00705                             l2_unscale_group(steps, mant, scale1);
00706                         mant = v % steps;
00707                         v = v / steps;
00708                         s->sb_samples[0][k * 12 + l + 1][i] =
00709                             l2_unscale_group(steps, mant, scale0);
00710                         s->sb_samples[1][k * 12 + l + 1][i] =
00711                             l2_unscale_group(steps, mant, scale1);
00712                         s->sb_samples[0][k * 12 + l + 2][i] =
00713                             l2_unscale_group(steps, v, scale0);
00714                         s->sb_samples[1][k * 12 + l + 2][i] =
00715                             l2_unscale_group(steps, v, scale1);
00716                     } else {
00717                         for (m = 0; m < 3; m++) {
00718                             mant = get_bits(&s->gb, bits);
00719                             s->sb_samples[0][k * 12 + l + m][i] =
00720                                 l1_unscale(bits - 1, mant, scale0);
00721                             s->sb_samples[1][k * 12 + l + m][i] =
00722                                 l1_unscale(bits - 1, mant, scale1);
00723                         }
00724                     }
00725                 } else {
00726                     s->sb_samples[0][k * 12 + l + 0][i] = 0;
00727                     s->sb_samples[0][k * 12 + l + 1][i] = 0;
00728                     s->sb_samples[0][k * 12 + l + 2][i] = 0;
00729                     s->sb_samples[1][k * 12 + l + 0][i] = 0;
00730                     s->sb_samples[1][k * 12 + l + 1][i] = 0;
00731                     s->sb_samples[1][k * 12 + l + 2][i] = 0;
00732                 }
00733                 /* next subband in alloc table */
00734                 j += 1 << bit_alloc_bits;
00735             }
00736             /* fill remaining samples to zero */
00737             for (i = sblimit; i < SBLIMIT; i++) {
00738                 for (ch = 0; ch < s->nb_channels; ch++) {
00739                     s->sb_samples[ch][k * 12 + l + 0][i] = 0;
00740                     s->sb_samples[ch][k * 12 + l + 1][i] = 0;
00741                     s->sb_samples[ch][k * 12 + l + 2][i] = 0;
00742                 }
00743             }
00744         }
00745     }
00746     return 3 * 12;
00747 }
00748 
00749 #define SPLIT(dst,sf,n)             \
00750     if (n == 3) {                   \
00751         int m = (sf * 171) >> 9;    \
00752         dst   = sf - 3 * m;         \
00753         sf    = m;                  \
00754     } else if (n == 4) {            \
00755         dst  = sf & 3;              \
00756         sf >>= 2;                   \
00757     } else if (n == 5) {            \
00758         int m = (sf * 205) >> 10;   \
00759         dst   = sf - 5 * m;         \
00760         sf    = m;                  \
00761     } else if (n == 6) {            \
00762         int m = (sf * 171) >> 10;   \
00763         dst   = sf - 6 * m;         \
00764         sf    = m;                  \
00765     } else {                        \
00766         dst = 0;                    \
00767     }
00768 
00769 static av_always_inline void lsf_sf_expand(int *slen, int sf, int n1, int n2,
00770                                            int n3)
00771 {
00772     SPLIT(slen[3], sf, n3)
00773     SPLIT(slen[2], sf, n2)
00774     SPLIT(slen[1], sf, n1)
00775     slen[0] = sf;
00776 }
00777 
00778 static void exponents_from_scale_factors(MPADecodeContext *s, GranuleDef *g,
00779                                          int16_t *exponents)
00780 {
00781     const uint8_t *bstab, *pretab;
00782     int len, i, j, k, l, v0, shift, gain, gains[3];
00783     int16_t *exp_ptr;
00784 
00785     exp_ptr = exponents;
00786     gain    = g->global_gain - 210;
00787     shift   = g->scalefac_scale + 1;
00788 
00789     bstab  = band_size_long[s->sample_rate_index];
00790     pretab = mpa_pretab[g->preflag];
00791     for (i = 0; i < g->long_end; i++) {
00792         v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;
00793         len = bstab[i];
00794         for (j = len; j > 0; j--)
00795             *exp_ptr++ = v0;
00796     }
00797 
00798     if (g->short_start < 13) {
00799         bstab    = band_size_short[s->sample_rate_index];
00800         gains[0] = gain - (g->subblock_gain[0] << 3);
00801         gains[1] = gain - (g->subblock_gain[1] << 3);
00802         gains[2] = gain - (g->subblock_gain[2] << 3);
00803         k        = g->long_end;
00804         for (i = g->short_start; i < 13; i++) {
00805             len = bstab[i];
00806             for (l = 0; l < 3; l++) {
00807                 v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;
00808                 for (j = len; j > 0; j--)
00809                     *exp_ptr++ = v0;
00810             }
00811         }
00812     }
00813 }
00814 
00815 /* handle n = 0 too */
00816 static inline int get_bitsz(GetBitContext *s, int n)
00817 {
00818     return n ? get_bits(s, n) : 0;
00819 }
00820 
00821 
00822 static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos,
00823                           int *end_pos2)
00824 {
00825     if (s->in_gb.buffer && *pos >= s->gb.size_in_bits) {
00826         s->gb           = s->in_gb;
00827         s->in_gb.buffer = NULL;
00828         assert((get_bits_count(&s->gb) & 7) == 0);
00829         skip_bits_long(&s->gb, *pos - *end_pos);
00830         *end_pos2 =
00831         *end_pos  = *end_pos2 + get_bits_count(&s->gb) - *pos;
00832         *pos      = get_bits_count(&s->gb);
00833     }
00834 }
00835 
00836 /* Following is a optimized code for
00837             INTFLOAT v = *src
00838             if(get_bits1(&s->gb))
00839                 v = -v;
00840             *dst = v;
00841 */
00842 #if CONFIG_FLOAT
00843 #define READ_FLIP_SIGN(dst,src)                     \
00844     v = AV_RN32A(src) ^ (get_bits1(&s->gb) << 31);  \
00845     AV_WN32A(dst, v);
00846 #else
00847 #define READ_FLIP_SIGN(dst,src)     \
00848     v      = -get_bits1(&s->gb);    \
00849     *(dst) = (*(src) ^ v) - v;
00850 #endif
00851 
00852 static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
00853                           int16_t *exponents, int end_pos2)
00854 {
00855     int s_index;
00856     int i;
00857     int last_pos, bits_left;
00858     VLC *vlc;
00859     int end_pos = FFMIN(end_pos2, s->gb.size_in_bits);
00860 
00861     /* low frequencies (called big values) */
00862     s_index = 0;
00863     for (i = 0; i < 3; i++) {
00864         int j, k, l, linbits;
00865         j = g->region_size[i];
00866         if (j == 0)
00867             continue;
00868         /* select vlc table */
00869         k       = g->table_select[i];
00870         l       = mpa_huff_data[k][0];
00871         linbits = mpa_huff_data[k][1];
00872         vlc     = &huff_vlc[l];
00873 
00874         if (!l) {
00875             memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * 2 * j);
00876             s_index += 2 * j;
00877             continue;
00878         }
00879 
00880         /* read huffcode and compute each couple */
00881         for (; j > 0; j--) {
00882             int exponent, x, y;
00883             int v;
00884             int pos = get_bits_count(&s->gb);
00885 
00886             if (pos >= end_pos){
00887 //                av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);
00888                 switch_buffer(s, &pos, &end_pos, &end_pos2);
00889 //                av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);
00890                 if (pos >= end_pos)
00891                     break;
00892             }
00893             y = get_vlc2(&s->gb, vlc->table, 7, 3);
00894 
00895             if (!y) {
00896                 g->sb_hybrid[s_index  ] =
00897                 g->sb_hybrid[s_index+1] = 0;
00898                 s_index += 2;
00899                 continue;
00900             }
00901 
00902             exponent= exponents[s_index];
00903 
00904             av_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",
00905                     i, g->region_size[i] - j, x, y, exponent);
00906             if (y & 16) {
00907                 x = y >> 5;
00908                 y = y & 0x0f;
00909                 if (x < 15) {
00910                     READ_FLIP_SIGN(g->sb_hybrid + s_index, RENAME(expval_table)[exponent] + x)
00911                 } else {
00912                     x += get_bitsz(&s->gb, linbits);
00913                     v  = l3_unscale(x, exponent);
00914                     if (get_bits1(&s->gb))
00915                         v = -v;
00916                     g->sb_hybrid[s_index] = v;
00917                 }
00918                 if (y < 15) {
00919                     READ_FLIP_SIGN(g->sb_hybrid + s_index + 1, RENAME(expval_table)[exponent] + y)
00920                 } else {
00921                     y += get_bitsz(&s->gb, linbits);
00922                     v  = l3_unscale(y, exponent);
00923                     if (get_bits1(&s->gb))
00924                         v = -v;
00925                     g->sb_hybrid[s_index+1] = v;
00926                 }
00927             } else {
00928                 x = y >> 5;
00929                 y = y & 0x0f;
00930                 x += y;
00931                 if (x < 15) {
00932                     READ_FLIP_SIGN(g->sb_hybrid + s_index + !!y, RENAME(expval_table)[exponent] + x)
00933                 } else {
00934                     x += get_bitsz(&s->gb, linbits);
00935                     v  = l3_unscale(x, exponent);
00936                     if (get_bits1(&s->gb))
00937                         v = -v;
00938                     g->sb_hybrid[s_index+!!y] = v;
00939                 }
00940                 g->sb_hybrid[s_index + !y] = 0;
00941             }
00942             s_index += 2;
00943         }
00944     }
00945 
00946     /* high frequencies */
00947     vlc = &huff_quad_vlc[g->count1table_select];
00948     last_pos = 0;
00949     while (s_index <= 572) {
00950         int pos, code;
00951         pos = get_bits_count(&s->gb);
00952         if (pos >= end_pos) {
00953             if (pos > end_pos2 && last_pos) {
00954                 /* some encoders generate an incorrect size for this
00955                    part. We must go back into the data */
00956                 s_index -= 4;
00957                 skip_bits_long(&s->gb, last_pos - pos);
00958                 av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
00959                 if(s->err_recognition & AV_EF_BITSTREAM)
00960                     s_index=0;
00961                 break;
00962             }
00963 //                av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);
00964             switch_buffer(s, &pos, &end_pos, &end_pos2);
00965 //                av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);
00966             if (pos >= end_pos)
00967                 break;
00968         }
00969         last_pos = pos;
00970 
00971         code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);
00972         av_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);
00973         g->sb_hybrid[s_index+0] =
00974         g->sb_hybrid[s_index+1] =
00975         g->sb_hybrid[s_index+2] =
00976         g->sb_hybrid[s_index+3] = 0;
00977         while (code) {
00978             static const int idxtab[16] = { 3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0 };
00979             int v;
00980             int pos = s_index + idxtab[code];
00981             code   ^= 8 >> idxtab[code];
00982             READ_FLIP_SIGN(g->sb_hybrid + pos, RENAME(exp_table)+exponents[pos])
00983         }
00984         s_index += 4;
00985     }
00986     /* skip extension bits */
00987     bits_left = end_pos2 - get_bits_count(&s->gb);
00988 //av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s->in_gb.buffer);
00989     if (bits_left < 0 && (s->err_recognition & AV_EF_BUFFER)) {
00990         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
00991         s_index=0;
00992     } else if (bits_left > 0 && (s->err_recognition & AV_EF_BUFFER)) {
00993         av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
00994         s_index = 0;
00995     }
00996     memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * (576 - s_index));
00997     skip_bits_long(&s->gb, bits_left);
00998 
00999     i = get_bits_count(&s->gb);
01000     switch_buffer(s, &i, &end_pos, &end_pos2);
01001 
01002     return 0;
01003 }
01004 
01005 /* Reorder short blocks from bitstream order to interleaved order. It
01006    would be faster to do it in parsing, but the code would be far more
01007    complicated */
01008 static void reorder_block(MPADecodeContext *s, GranuleDef *g)
01009 {
01010     int i, j, len;
01011     INTFLOAT *ptr, *dst, *ptr1;
01012     INTFLOAT tmp[576];
01013 
01014     if (g->block_type != 2)
01015         return;
01016 
01017     if (g->switch_point) {
01018         if (s->sample_rate_index != 8)
01019             ptr = g->sb_hybrid + 36;
01020         else
01021             ptr = g->sb_hybrid + 48;
01022     } else {
01023         ptr = g->sb_hybrid;
01024     }
01025 
01026     for (i = g->short_start; i < 13; i++) {
01027         len  = band_size_short[s->sample_rate_index][i];
01028         ptr1 = ptr;
01029         dst  = tmp;
01030         for (j = len; j > 0; j--) {
01031             *dst++ = ptr[0*len];
01032             *dst++ = ptr[1*len];
01033             *dst++ = ptr[2*len];
01034             ptr++;
01035         }
01036         ptr += 2 * len;
01037         memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));
01038     }
01039 }
01040 
01041 #define ISQRT2 FIXR(0.70710678118654752440)
01042 
01043 static void compute_stereo(MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)
01044 {
01045     int i, j, k, l;
01046     int sf_max, sf, len, non_zero_found;
01047     INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;
01048     int non_zero_found_short[3];
01049 
01050     /* intensity stereo */
01051     if (s->mode_ext & MODE_EXT_I_STEREO) {
01052         if (!s->lsf) {
01053             is_tab = is_table;
01054             sf_max = 7;
01055         } else {
01056             is_tab = is_table_lsf[g1->scalefac_compress & 1];
01057             sf_max = 16;
01058         }
01059 
01060         tab0 = g0->sb_hybrid + 576;
01061         tab1 = g1->sb_hybrid + 576;
01062 
01063         non_zero_found_short[0] = 0;
01064         non_zero_found_short[1] = 0;
01065         non_zero_found_short[2] = 0;
01066         k = (13 - g1->short_start) * 3 + g1->long_end - 3;
01067         for (i = 12; i >= g1->short_start; i--) {
01068             /* for last band, use previous scale factor */
01069             if (i != 11)
01070                 k -= 3;
01071             len = band_size_short[s->sample_rate_index][i];
01072             for (l = 2; l >= 0; l--) {
01073                 tab0 -= len;
01074                 tab1 -= len;
01075                 if (!non_zero_found_short[l]) {
01076                     /* test if non zero band. if so, stop doing i-stereo */
01077                     for (j = 0; j < len; j++) {
01078                         if (tab1[j] != 0) {
01079                             non_zero_found_short[l] = 1;
01080                             goto found1;
01081                         }
01082                     }
01083                     sf = g1->scale_factors[k + l];
01084                     if (sf >= sf_max)
01085                         goto found1;
01086 
01087                     v1 = is_tab[0][sf];
01088                     v2 = is_tab[1][sf];
01089                     for (j = 0; j < len; j++) {
01090                         tmp0    = tab0[j];
01091                         tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
01092                         tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
01093                     }
01094                 } else {
01095 found1:
01096                     if (s->mode_ext & MODE_EXT_MS_STEREO) {
01097                         /* lower part of the spectrum : do ms stereo
01098                            if enabled */
01099                         for (j = 0; j < len; j++) {
01100                             tmp0    = tab0[j];
01101                             tmp1    = tab1[j];
01102                             tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
01103                             tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
01104                         }
01105                     }
01106                 }
01107             }
01108         }
01109 
01110         non_zero_found = non_zero_found_short[0] |
01111                          non_zero_found_short[1] |
01112                          non_zero_found_short[2];
01113 
01114         for (i = g1->long_end - 1;i >= 0;i--) {
01115             len   = band_size_long[s->sample_rate_index][i];
01116             tab0 -= len;
01117             tab1 -= len;
01118             /* test if non zero band. if so, stop doing i-stereo */
01119             if (!non_zero_found) {
01120                 for (j = 0; j < len; j++) {
01121                     if (tab1[j] != 0) {
01122                         non_zero_found = 1;
01123                         goto found2;
01124                     }
01125                 }
01126                 /* for last band, use previous scale factor */
01127                 k  = (i == 21) ? 20 : i;
01128                 sf = g1->scale_factors[k];
01129                 if (sf >= sf_max)
01130                     goto found2;
01131                 v1 = is_tab[0][sf];
01132                 v2 = is_tab[1][sf];
01133                 for (j = 0; j < len; j++) {
01134                     tmp0    = tab0[j];
01135                     tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
01136                     tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
01137                 }
01138             } else {
01139 found2:
01140                 if (s->mode_ext & MODE_EXT_MS_STEREO) {
01141                     /* lower part of the spectrum : do ms stereo
01142                        if enabled */
01143                     for (j = 0; j < len; j++) {
01144                         tmp0    = tab0[j];
01145                         tmp1    = tab1[j];
01146                         tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
01147                         tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
01148                     }
01149                 }
01150             }
01151         }
01152     } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
01153         /* ms stereo ONLY */
01154         /* NOTE: the 1/sqrt(2) normalization factor is included in the
01155            global gain */
01156         tab0 = g0->sb_hybrid;
01157         tab1 = g1->sb_hybrid;
01158         for (i = 0; i < 576; i++) {
01159             tmp0    = tab0[i];
01160             tmp1    = tab1[i];
01161             tab0[i] = tmp0 + tmp1;
01162             tab1[i] = tmp0 - tmp1;
01163         }
01164     }
01165 }
01166 
01167 #if CONFIG_FLOAT
01168 #define AA(j) do {                                                      \
01169         float tmp0 = ptr[-1-j];                                         \
01170         float tmp1 = ptr[   j];                                         \
01171         ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1];    \
01172         ptr[   j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0];    \
01173     } while (0)
01174 #else
01175 #define AA(j) do {                                              \
01176         int tmp0 = ptr[-1-j];                                   \
01177         int tmp1 = ptr[   j];                                   \
01178         int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]);          \
01179         ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2]));   \
01180         ptr[   j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3]));   \
01181     } while (0)
01182 #endif
01183 
01184 static void compute_antialias(MPADecodeContext *s, GranuleDef *g)
01185 {
01186     INTFLOAT *ptr;
01187     int n, i;
01188 
01189     /* we antialias only "long" bands */
01190     if (g->block_type == 2) {
01191         if (!g->switch_point)
01192             return;
01193         /* XXX: check this for 8000Hz case */
01194         n = 1;
01195     } else {
01196         n = SBLIMIT - 1;
01197     }
01198 
01199     ptr = g->sb_hybrid + 18;
01200     for (i = n; i > 0; i--) {
01201         AA(0);
01202         AA(1);
01203         AA(2);
01204         AA(3);
01205         AA(4);
01206         AA(5);
01207         AA(6);
01208         AA(7);
01209 
01210         ptr += 18;
01211     }
01212 }
01213 
01214 static void compute_imdct(MPADecodeContext *s, GranuleDef *g,
01215                           INTFLOAT *sb_samples, INTFLOAT *mdct_buf)
01216 {
01217     INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;
01218     INTFLOAT out2[12];
01219     int i, j, mdct_long_end, sblimit;
01220 
01221     /* find last non zero block */
01222     ptr  = g->sb_hybrid + 576;
01223     ptr1 = g->sb_hybrid + 2 * 18;
01224     while (ptr >= ptr1) {
01225         int32_t *p;
01226         ptr -= 6;
01227         p    = (int32_t*)ptr;
01228         if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])
01229             break;
01230     }
01231     sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
01232 
01233     if (g->block_type == 2) {
01234         /* XXX: check for 8000 Hz */
01235         if (g->switch_point)
01236             mdct_long_end = 2;
01237         else
01238             mdct_long_end = 0;
01239     } else {
01240         mdct_long_end = sblimit;
01241     }
01242 
01243     s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,
01244                                      mdct_long_end, g->switch_point,
01245                                      g->block_type);
01246 
01247     buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);
01248     ptr = g->sb_hybrid + 18 * mdct_long_end;
01249 
01250     for (j = mdct_long_end; j < sblimit; j++) {
01251         /* select frequency inversion */
01252         win     = RENAME(ff_mdct_win)[2 + (4  & -(j & 1))];
01253         out_ptr = sb_samples + j;
01254 
01255         for (i = 0; i < 6; i++) {
01256             *out_ptr = buf[4*i];
01257             out_ptr += SBLIMIT;
01258         }
01259         imdct12(out2, ptr + 0);
01260         for (i = 0; i < 6; i++) {
01261             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*1)];
01262             buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);
01263             out_ptr += SBLIMIT;
01264         }
01265         imdct12(out2, ptr + 1);
01266         for (i = 0; i < 6; i++) {
01267             *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*2)];
01268             buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);
01269             out_ptr += SBLIMIT;
01270         }
01271         imdct12(out2, ptr + 2);
01272         for (i = 0; i < 6; i++) {
01273             buf[4*(i + 6*0)] = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*0)];
01274             buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);
01275             buf[4*(i + 6*2)] = 0;
01276         }
01277         ptr += 18;
01278         buf += (j&3) != 3 ? 1 : (4*18-3);
01279     }
01280     /* zero bands */
01281     for (j = sblimit; j < SBLIMIT; j++) {
01282         /* overlap */
01283         out_ptr = sb_samples + j;
01284         for (i = 0; i < 18; i++) {
01285             *out_ptr = buf[4*i];
01286             buf[4*i]   = 0;
01287             out_ptr += SBLIMIT;
01288         }
01289         buf += (j&3) != 3 ? 1 : (4*18-3);
01290     }
01291 }
01292 
01293 /* main layer3 decoding function */
01294 static int mp_decode_layer3(MPADecodeContext *s)
01295 {
01296     int nb_granules, main_data_begin;
01297     int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;
01298     GranuleDef *g;
01299     int16_t exponents[576]; //FIXME try INTFLOAT
01300 
01301     /* read side info */
01302     if (s->lsf) {
01303         main_data_begin = get_bits(&s->gb, 8);
01304         skip_bits(&s->gb, s->nb_channels);
01305         nb_granules = 1;
01306     } else {
01307         main_data_begin = get_bits(&s->gb, 9);
01308         if (s->nb_channels == 2)
01309             skip_bits(&s->gb, 3);
01310         else
01311             skip_bits(&s->gb, 5);
01312         nb_granules = 2;
01313         for (ch = 0; ch < s->nb_channels; ch++) {
01314             s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */
01315             s->granules[ch][1].scfsi = get_bits(&s->gb, 4);
01316         }
01317     }
01318 
01319     for (gr = 0; gr < nb_granules; gr++) {
01320         for (ch = 0; ch < s->nb_channels; ch++) {
01321             av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);
01322             g = &s->granules[ch][gr];
01323             g->part2_3_length = get_bits(&s->gb, 12);
01324             g->big_values     = get_bits(&s->gb,  9);
01325             if (g->big_values > 288) {
01326                 av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");
01327                 return AVERROR_INVALIDDATA;
01328             }
01329 
01330             g->global_gain = get_bits(&s->gb, 8);
01331             /* if MS stereo only is selected, we precompute the
01332                1/sqrt(2) renormalization factor */
01333             if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
01334                 MODE_EXT_MS_STEREO)
01335                 g->global_gain -= 2;
01336             if (s->lsf)
01337                 g->scalefac_compress = get_bits(&s->gb, 9);
01338             else
01339                 g->scalefac_compress = get_bits(&s->gb, 4);
01340             blocksplit_flag = get_bits1(&s->gb);
01341             if (blocksplit_flag) {
01342                 g->block_type = get_bits(&s->gb, 2);
01343                 if (g->block_type == 0) {
01344                     av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");
01345                     return AVERROR_INVALIDDATA;
01346                 }
01347                 g->switch_point = get_bits1(&s->gb);
01348                 for (i = 0; i < 2; i++)
01349                     g->table_select[i] = get_bits(&s->gb, 5);
01350                 for (i = 0; i < 3; i++)
01351                     g->subblock_gain[i] = get_bits(&s->gb, 3);
01352                 ff_init_short_region(s, g);
01353             } else {
01354                 int region_address1, region_address2;
01355                 g->block_type = 0;
01356                 g->switch_point = 0;
01357                 for (i = 0; i < 3; i++)
01358                     g->table_select[i] = get_bits(&s->gb, 5);
01359                 /* compute huffman coded region sizes */
01360                 region_address1 = get_bits(&s->gb, 4);
01361                 region_address2 = get_bits(&s->gb, 3);
01362                 av_dlog(s->avctx, "region1=%d region2=%d\n",
01363                         region_address1, region_address2);
01364                 ff_init_long_region(s, g, region_address1, region_address2);
01365             }
01366             ff_region_offset2size(g);
01367             ff_compute_band_indexes(s, g);
01368 
01369             g->preflag = 0;
01370             if (!s->lsf)
01371                 g->preflag = get_bits1(&s->gb);
01372             g->scalefac_scale     = get_bits1(&s->gb);
01373             g->count1table_select = get_bits1(&s->gb);
01374             av_dlog(s->avctx, "block_type=%d switch_point=%d\n",
01375                     g->block_type, g->switch_point);
01376         }
01377     }
01378 
01379     if (!s->adu_mode) {
01380         int skip;
01381         const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
01382         int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0,
01383                                 FFMAX(0, LAST_BUF_SIZE - s->last_buf_size));
01384         assert((get_bits_count(&s->gb) & 7) == 0);
01385         /* now we get bits from the main_data_begin offset */
01386         av_dlog(s->avctx, "seekback: %d\n", main_data_begin);
01387     //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);
01388 
01389         memcpy(s->last_buf + s->last_buf_size, ptr, extrasize);
01390         s->in_gb = s->gb;
01391         init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);
01392 #if !UNCHECKED_BITSTREAM_READER
01393         s->gb.size_in_bits_plus8 += extrasize * 8;
01394 #endif
01395         s->last_buf_size <<= 3;
01396         for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) {
01397             for (ch = 0; ch < s->nb_channels; ch++) {
01398                 g = &s->granules[ch][gr];
01399                 s->last_buf_size += g->part2_3_length;
01400                 memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));
01401             }
01402         }
01403         skip = s->last_buf_size - 8 * main_data_begin;
01404         if (skip >= s->gb.size_in_bits && s->in_gb.buffer) {
01405             skip_bits_long(&s->in_gb, skip - s->gb.size_in_bits);
01406             s->gb           = s->in_gb;
01407             s->in_gb.buffer = NULL;
01408         } else {
01409             skip_bits_long(&s->gb, skip);
01410         }
01411     } else {
01412         gr = 0;
01413     }
01414 
01415     for (; gr < nb_granules; gr++) {
01416         for (ch = 0; ch < s->nb_channels; ch++) {
01417             g = &s->granules[ch][gr];
01418             bits_pos = get_bits_count(&s->gb);
01419 
01420             if (!s->lsf) {
01421                 uint8_t *sc;
01422                 int slen, slen1, slen2;
01423 
01424                 /* MPEG1 scale factors */
01425                 slen1 = slen_table[0][g->scalefac_compress];
01426                 slen2 = slen_table[1][g->scalefac_compress];
01427                 av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);
01428                 if (g->block_type == 2) {
01429                     n = g->switch_point ? 17 : 18;
01430                     j = 0;
01431                     if (slen1) {
01432                         for (i = 0; i < n; i++)
01433                             g->scale_factors[j++] = get_bits(&s->gb, slen1);
01434                     } else {
01435                         for (i = 0; i < n; i++)
01436                             g->scale_factors[j++] = 0;
01437                     }
01438                     if (slen2) {
01439                         for (i = 0; i < 18; i++)
01440                             g->scale_factors[j++] = get_bits(&s->gb, slen2);
01441                         for (i = 0; i < 3; i++)
01442                             g->scale_factors[j++] = 0;
01443                     } else {
01444                         for (i = 0; i < 21; i++)
01445                             g->scale_factors[j++] = 0;
01446                     }
01447                 } else {
01448                     sc = s->granules[ch][0].scale_factors;
01449                     j = 0;
01450                     for (k = 0; k < 4; k++) {
01451                         n = k == 0 ? 6 : 5;
01452                         if ((g->scfsi & (0x8 >> k)) == 0) {
01453                             slen = (k < 2) ? slen1 : slen2;
01454                             if (slen) {
01455                                 for (i = 0; i < n; i++)
01456                                     g->scale_factors[j++] = get_bits(&s->gb, slen);
01457                             } else {
01458                                 for (i = 0; i < n; i++)
01459                                     g->scale_factors[j++] = 0;
01460                             }
01461                         } else {
01462                             /* simply copy from last granule */
01463                             for (i = 0; i < n; i++) {
01464                                 g->scale_factors[j] = sc[j];
01465                                 j++;
01466                             }
01467                         }
01468                     }
01469                     g->scale_factors[j++] = 0;
01470                 }
01471             } else {
01472                 int tindex, tindex2, slen[4], sl, sf;
01473 
01474                 /* LSF scale factors */
01475                 if (g->block_type == 2)
01476                     tindex = g->switch_point ? 2 : 1;
01477                 else
01478                     tindex = 0;
01479 
01480                 sf = g->scalefac_compress;
01481                 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
01482                     /* intensity stereo case */
01483                     sf >>= 1;
01484                     if (sf < 180) {
01485                         lsf_sf_expand(slen, sf, 6, 6, 0);
01486                         tindex2 = 3;
01487                     } else if (sf < 244) {
01488                         lsf_sf_expand(slen, sf - 180, 4, 4, 0);
01489                         tindex2 = 4;
01490                     } else {
01491                         lsf_sf_expand(slen, sf - 244, 3, 0, 0);
01492                         tindex2 = 5;
01493                     }
01494                 } else {
01495                     /* normal case */
01496                     if (sf < 400) {
01497                         lsf_sf_expand(slen, sf, 5, 4, 4);
01498                         tindex2 = 0;
01499                     } else if (sf < 500) {
01500                         lsf_sf_expand(slen, sf - 400, 5, 4, 0);
01501                         tindex2 = 1;
01502                     } else {
01503                         lsf_sf_expand(slen, sf - 500, 3, 0, 0);
01504                         tindex2 = 2;
01505                         g->preflag = 1;
01506                     }
01507                 }
01508 
01509                 j = 0;
01510                 for (k = 0; k < 4; k++) {
01511                     n  = lsf_nsf_table[tindex2][tindex][k];
01512                     sl = slen[k];
01513                     if (sl) {
01514                         for (i = 0; i < n; i++)
01515                             g->scale_factors[j++] = get_bits(&s->gb, sl);
01516                     } else {
01517                         for (i = 0; i < n; i++)
01518                             g->scale_factors[j++] = 0;
01519                     }
01520                 }
01521                 /* XXX: should compute exact size */
01522                 for (; j < 40; j++)
01523                     g->scale_factors[j] = 0;
01524             }
01525 
01526             exponents_from_scale_factors(s, g, exponents);
01527 
01528             /* read Huffman coded residue */
01529             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
01530         } /* ch */
01531 
01532         if (s->nb_channels == 2)
01533             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
01534 
01535         for (ch = 0; ch < s->nb_channels; ch++) {
01536             g = &s->granules[ch][gr];
01537 
01538             reorder_block(s, g);
01539             compute_antialias(s, g);
01540             compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
01541         }
01542     } /* gr */
01543     if (get_bits_count(&s->gb) < 0)
01544         skip_bits_long(&s->gb, -get_bits_count(&s->gb));
01545     return nb_granules * 18;
01546 }
01547 
01548 static int mp_decode_frame(MPADecodeContext *s, OUT_INT *samples,
01549                            const uint8_t *buf, int buf_size)
01550 {
01551     int i, nb_frames, ch, ret;
01552     OUT_INT *samples_ptr;
01553 
01554     init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);
01555 
01556     /* skip error protection field */
01557     if (s->error_protection)
01558         skip_bits(&s->gb, 16);
01559 
01560     switch(s->layer) {
01561     case 1:
01562         s->avctx->frame_size = 384;
01563         nb_frames = mp_decode_layer1(s);
01564         break;
01565     case 2:
01566         s->avctx->frame_size = 1152;
01567         nb_frames = mp_decode_layer2(s);
01568         break;
01569     case 3:
01570         s->avctx->frame_size = s->lsf ? 576 : 1152;
01571     default:
01572         nb_frames = mp_decode_layer3(s);
01573 
01574         if (nb_frames < 0)
01575             return nb_frames;
01576 
01577         s->last_buf_size=0;
01578         if (s->in_gb.buffer) {
01579             align_get_bits(&s->gb);
01580             i = get_bits_left(&s->gb)>>3;
01581             if (i >= 0 && i <= BACKSTEP_SIZE) {
01582                 memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
01583                 s->last_buf_size=i;
01584             } else
01585                 av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);
01586             s->gb           = s->in_gb;
01587             s->in_gb.buffer = NULL;
01588         }
01589 
01590         align_get_bits(&s->gb);
01591         assert((get_bits_count(&s->gb) & 7) == 0);
01592         i = get_bits_left(&s->gb) >> 3;
01593 
01594         if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {
01595             if (i < 0)
01596                 av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);
01597             i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
01598         }
01599         assert(i <= buf_size - HEADER_SIZE && i >= 0);
01600         memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
01601         s->last_buf_size += i;
01602     }
01603 
01604     /* get output buffer */
01605     if (!samples) {
01606         s->frame.nb_samples = s->avctx->frame_size;
01607         if ((ret = s->avctx->get_buffer(s->avctx, &s->frame)) < 0) {
01608             av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
01609             return ret;
01610         }
01611         samples = (OUT_INT *)s->frame.data[0];
01612     }
01613 
01614     /* apply the synthesis filter */
01615     for (ch = 0; ch < s->nb_channels; ch++) {
01616         samples_ptr = samples + ch;
01617         for (i = 0; i < nb_frames; i++) {
01618             RENAME(ff_mpa_synth_filter)(
01619                          &s->mpadsp,
01620                          s->synth_buf[ch], &(s->synth_buf_offset[ch]),
01621                          RENAME(ff_mpa_synth_window), &s->dither_state,
01622                          samples_ptr, s->nb_channels,
01623                          s->sb_samples[ch][i]);
01624             samples_ptr += 32 * s->nb_channels;
01625         }
01626     }
01627 
01628     return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
01629 }
01630 
01631 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,
01632                         AVPacket *avpkt)
01633 {
01634     const uint8_t *buf  = avpkt->data;
01635     int buf_size        = avpkt->size;
01636     MPADecodeContext *s = avctx->priv_data;
01637     uint32_t header;
01638     int ret;
01639 
01640     if (buf_size < HEADER_SIZE)
01641         return AVERROR_INVALIDDATA;
01642 
01643     header = AV_RB32(buf);
01644     if (ff_mpa_check_header(header) < 0) {
01645         av_log(avctx, AV_LOG_ERROR, "Header missing\n");
01646         return AVERROR_INVALIDDATA;
01647     }
01648 
01649     if (avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {
01650         /* free format: prepare to compute frame size */
01651         s->frame_size = -1;
01652         return AVERROR_INVALIDDATA;
01653     }
01654     /* update codec info */
01655     avctx->channels       = s->nb_channels;
01656     avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
01657     if (!avctx->bit_rate)
01658         avctx->bit_rate = s->bit_rate;
01659     avctx->sub_id = s->layer;
01660 
01661     if (s->frame_size <= 0 || s->frame_size > buf_size) {
01662         av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
01663         return AVERROR_INVALIDDATA;
01664     } else if (s->frame_size < buf_size) {
01665         av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");
01666         buf_size= s->frame_size;
01667     }
01668 
01669     ret = mp_decode_frame(s, NULL, buf, buf_size);
01670     if (ret >= 0) {
01671         *got_frame_ptr   = 1;
01672         *(AVFrame *)data = s->frame;
01673         avctx->sample_rate = s->sample_rate;
01674         //FIXME maybe move the other codec info stuff from above here too
01675     } else {
01676         av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
01677         /* Only return an error if the bad frame makes up the whole packet or
01678          * the error is related to buffer management.
01679          * If there is more data in the packet, just consume the bad frame
01680          * instead of returning an error, which would discard the whole
01681          * packet. */
01682         *got_frame_ptr = 0;
01683         if (buf_size == avpkt->size || ret != AVERROR_INVALIDDATA)
01684             return ret;
01685     }
01686     s->frame_size = 0;
01687     return buf_size;
01688 }
01689 
01690 static void flush(AVCodecContext *avctx)
01691 {
01692     MPADecodeContext *s = avctx->priv_data;
01693     memset(s->synth_buf, 0, sizeof(s->synth_buf));
01694     s->last_buf_size = 0;
01695 }
01696 
01697 #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER
01698 static int decode_frame_adu(AVCodecContext *avctx, void *data,
01699                             int *got_frame_ptr, AVPacket *avpkt)
01700 {
01701     const uint8_t *buf  = avpkt->data;
01702     int buf_size        = avpkt->size;
01703     MPADecodeContext *s = avctx->priv_data;
01704     uint32_t header;
01705     int len, out_size, ret = 0;
01706 
01707     len = buf_size;
01708 
01709     // Discard too short frames
01710     if (buf_size < HEADER_SIZE) {
01711         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
01712         return AVERROR_INVALIDDATA;
01713     }
01714 
01715 
01716     if (len > MPA_MAX_CODED_FRAME_SIZE)
01717         len = MPA_MAX_CODED_FRAME_SIZE;
01718 
01719     // Get header and restore sync word
01720     header = AV_RB32(buf) | 0xffe00000;
01721 
01722     if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
01723         av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");
01724         return AVERROR_INVALIDDATA;
01725     }
01726 
01727     avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);
01728     /* update codec info */
01729     avctx->sample_rate = s->sample_rate;
01730     avctx->channels    = s->nb_channels;
01731     if (!avctx->bit_rate)
01732         avctx->bit_rate = s->bit_rate;
01733     avctx->sub_id = s->layer;
01734 
01735     s->frame_size = len;
01736 
01737 #if FF_API_PARSE_FRAME
01738     if (avctx->parse_only)
01739         out_size = buf_size;
01740     else
01741 #endif
01742     ret = mp_decode_frame(s, NULL, buf, buf_size);
01743     if (ret < 0) {
01744         av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
01745         return ret;
01746     }
01747 
01748     *got_frame_ptr   = 1;
01749     *(AVFrame *)data = s->frame;
01750 
01751     return buf_size;
01752 }
01753 #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */
01754 
01755 #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER
01756 
01760 typedef struct MP3On4DecodeContext {
01761     AVFrame *frame;
01762     int frames;                     
01763     int syncword;                   
01764     const uint8_t *coff;            
01765     MPADecodeContext *mp3decctx[5]; 
01766     OUT_INT *decoded_buf;           
01767 } MP3On4DecodeContext;
01768 
01769 #include "mpeg4audio.h"
01770 
01771 /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
01772 
01773 /* number of mp3 decoder instances */
01774 static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };
01775 
01776 /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */
01777 static const uint8_t chan_offset[8][5] = {
01778     { 0             },
01779     { 0             },  // C
01780     { 0             },  // FLR
01781     { 2, 0          },  // C FLR
01782     { 2, 0, 3       },  // C FLR BS
01783     { 2, 0, 3       },  // C FLR BLRS
01784     { 2, 0, 4, 3    },  // C FLR BLRS LFE
01785     { 2, 0, 6, 4, 3 },  // C FLR BLRS BLR LFE
01786 };
01787 
01788 /* mp3on4 channel layouts */
01789 static const int16_t chan_layout[8] = {
01790     0,
01791     AV_CH_LAYOUT_MONO,
01792     AV_CH_LAYOUT_STEREO,
01793     AV_CH_LAYOUT_SURROUND,
01794     AV_CH_LAYOUT_4POINT0,
01795     AV_CH_LAYOUT_5POINT0,
01796     AV_CH_LAYOUT_5POINT1,
01797     AV_CH_LAYOUT_7POINT1
01798 };
01799 
01800 static av_cold int decode_close_mp3on4(AVCodecContext * avctx)
01801 {
01802     MP3On4DecodeContext *s = avctx->priv_data;
01803     int i;
01804 
01805     for (i = 0; i < s->frames; i++)
01806         av_free(s->mp3decctx[i]);
01807 
01808     av_freep(&s->decoded_buf);
01809 
01810     return 0;
01811 }
01812 
01813 
01814 static int decode_init_mp3on4(AVCodecContext * avctx)
01815 {
01816     MP3On4DecodeContext *s = avctx->priv_data;
01817     MPEG4AudioConfig cfg;
01818     int i;
01819 
01820     if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {
01821         av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
01822         return AVERROR_INVALIDDATA;
01823     }
01824 
01825     avpriv_mpeg4audio_get_config(&cfg, avctx->extradata,
01826                                  avctx->extradata_size * 8, 1);
01827     if (!cfg.chan_config || cfg.chan_config > 7) {
01828         av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
01829         return AVERROR_INVALIDDATA;
01830     }
01831     s->frames             = mp3Frames[cfg.chan_config];
01832     s->coff               = chan_offset[cfg.chan_config];
01833     avctx->channels       = ff_mpeg4audio_channels[cfg.chan_config];
01834     avctx->channel_layout = chan_layout[cfg.chan_config];
01835 
01836     if (cfg.sample_rate < 16000)
01837         s->syncword = 0xffe00000;
01838     else
01839         s->syncword = 0xfff00000;
01840 
01841     /* Init the first mp3 decoder in standard way, so that all tables get builded
01842      * We replace avctx->priv_data with the context of the first decoder so that
01843      * decode_init() does not have to be changed.
01844      * Other decoders will be initialized here copying data from the first context
01845      */
01846     // Allocate zeroed memory for the first decoder context
01847     s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
01848     if (!s->mp3decctx[0])
01849         goto alloc_fail;
01850     // Put decoder context in place to make init_decode() happy
01851     avctx->priv_data = s->mp3decctx[0];
01852     decode_init(avctx);
01853     s->frame = avctx->coded_frame;
01854     // Restore mp3on4 context pointer
01855     avctx->priv_data = s;
01856     s->mp3decctx[0]->adu_mode = 1; // Set adu mode
01857 
01858     /* Create a separate codec/context for each frame (first is already ok).
01859      * Each frame is 1 or 2 channels - up to 5 frames allowed
01860      */
01861     for (i = 1; i < s->frames; i++) {
01862         s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
01863         if (!s->mp3decctx[i])
01864             goto alloc_fail;
01865         s->mp3decctx[i]->adu_mode = 1;
01866         s->mp3decctx[i]->avctx = avctx;
01867         s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;
01868     }
01869 
01870     /* Allocate buffer for multi-channel output if needed */
01871     if (s->frames > 1) {
01872         s->decoded_buf = av_malloc(MPA_FRAME_SIZE * MPA_MAX_CHANNELS *
01873                                    sizeof(*s->decoded_buf));
01874         if (!s->decoded_buf)
01875             goto alloc_fail;
01876     }
01877 
01878     return 0;
01879 alloc_fail:
01880     decode_close_mp3on4(avctx);
01881     return AVERROR(ENOMEM);
01882 }
01883 
01884 
01885 static void flush_mp3on4(AVCodecContext *avctx)
01886 {
01887     int i;
01888     MP3On4DecodeContext *s = avctx->priv_data;
01889 
01890     for (i = 0; i < s->frames; i++) {
01891         MPADecodeContext *m = s->mp3decctx[i];
01892         memset(m->synth_buf, 0, sizeof(m->synth_buf));
01893         m->last_buf_size = 0;
01894     }
01895 }
01896 
01897 
01898 static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,
01899                                int *got_frame_ptr, AVPacket *avpkt)
01900 {
01901     const uint8_t *buf     = avpkt->data;
01902     int buf_size           = avpkt->size;
01903     MP3On4DecodeContext *s = avctx->priv_data;
01904     MPADecodeContext *m;
01905     int fsize, len = buf_size, out_size = 0;
01906     uint32_t header;
01907     OUT_INT *out_samples;
01908     OUT_INT *outptr, *bp;
01909     int fr, j, n, ch, ret;
01910 
01911     /* get output buffer */
01912     s->frame->nb_samples = MPA_FRAME_SIZE;
01913     if ((ret = avctx->get_buffer(avctx, s->frame)) < 0) {
01914         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
01915         return ret;
01916     }
01917     out_samples = (OUT_INT *)s->frame->data[0];
01918 
01919     // Discard too short frames
01920     if (buf_size < HEADER_SIZE)
01921         return AVERROR_INVALIDDATA;
01922 
01923     // If only one decoder interleave is not needed
01924     outptr = s->frames == 1 ? out_samples : s->decoded_buf;
01925 
01926     avctx->bit_rate = 0;
01927 
01928     ch = 0;
01929     for (fr = 0; fr < s->frames; fr++) {
01930         fsize = AV_RB16(buf) >> 4;
01931         fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);
01932         m     = s->mp3decctx[fr];
01933         assert(m != NULL);
01934 
01935         if (fsize < HEADER_SIZE) {
01936             av_log(avctx, AV_LOG_ERROR, "Frame size smaller than header size\n");
01937             return AVERROR_INVALIDDATA;
01938         }
01939         header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header
01940 
01941         if (ff_mpa_check_header(header) < 0) // Bad header, discard block
01942             break;
01943 
01944         avpriv_mpegaudio_decode_header((MPADecodeHeader *)m, header);
01945 
01946         if (ch + m->nb_channels > avctx->channels ||
01947             s->coff[fr] + m->nb_channels > avctx->channels) {
01948             av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "
01949                                         "channel count\n");
01950             return AVERROR_INVALIDDATA;
01951         }
01952         ch += m->nb_channels;
01953 
01954         if ((ret = mp_decode_frame(m, outptr, buf, fsize)) < 0)
01955             return ret;
01956 
01957         out_size += ret;
01958         buf      += fsize;
01959         len      -= fsize;
01960 
01961         if (s->frames > 1) {
01962             n = m->avctx->frame_size*m->nb_channels;
01963             /* interleave output data */
01964             bp = out_samples + s->coff[fr];
01965             if (m->nb_channels == 1) {
01966                 for (j = 0; j < n; j++) {
01967                     *bp = s->decoded_buf[j];
01968                     bp += avctx->channels;
01969                 }
01970             } else {
01971                 for (j = 0; j < n; j++) {
01972                     bp[0] = s->decoded_buf[j++];
01973                     bp[1] = s->decoded_buf[j];
01974                     bp   += avctx->channels;
01975                 }
01976             }
01977         }
01978         avctx->bit_rate += m->bit_rate;
01979     }
01980 
01981     /* update codec info */
01982     avctx->sample_rate = s->mp3decctx[0]->sample_rate;
01983 
01984     s->frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));
01985     *got_frame_ptr   = 1;
01986     *(AVFrame *)data = *s->frame;
01987 
01988     return buf_size;
01989 }
01990 #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */
01991 
01992 #if !CONFIG_FLOAT
01993 #if CONFIG_MP1_DECODER
01994 AVCodec ff_mp1_decoder = {
01995     .name           = "mp1",
01996     .type           = AVMEDIA_TYPE_AUDIO,
01997     .id             = CODEC_ID_MP1,
01998     .priv_data_size = sizeof(MPADecodeContext),
01999     .init           = decode_init,
02000     .decode         = decode_frame,
02001 #if FF_API_PARSE_FRAME
02002     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02003 #else
02004     .capabilities   = CODEC_CAP_DR1,
02005 #endif
02006     .flush          = flush,
02007     .long_name      = NULL_IF_CONFIG_SMALL("MP1 (MPEG audio layer 1)"),
02008 };
02009 #endif
02010 #if CONFIG_MP2_DECODER
02011 AVCodec ff_mp2_decoder = {
02012     .name           = "mp2",
02013     .type           = AVMEDIA_TYPE_AUDIO,
02014     .id             = CODEC_ID_MP2,
02015     .priv_data_size = sizeof(MPADecodeContext),
02016     .init           = decode_init,
02017     .decode         = decode_frame,
02018 #if FF_API_PARSE_FRAME
02019     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02020 #else
02021     .capabilities   = CODEC_CAP_DR1,
02022 #endif
02023     .flush          = flush,
02024     .long_name      = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
02025 };
02026 #endif
02027 #if CONFIG_MP3_DECODER
02028 AVCodec ff_mp3_decoder = {
02029     .name           = "mp3",
02030     .type           = AVMEDIA_TYPE_AUDIO,
02031     .id             = CODEC_ID_MP3,
02032     .priv_data_size = sizeof(MPADecodeContext),
02033     .init           = decode_init,
02034     .decode         = decode_frame,
02035 #if FF_API_PARSE_FRAME
02036     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02037 #else
02038     .capabilities   = CODEC_CAP_DR1,
02039 #endif
02040     .flush          = flush,
02041     .long_name      = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
02042 };
02043 #endif
02044 #if CONFIG_MP3ADU_DECODER
02045 AVCodec ff_mp3adu_decoder = {
02046     .name           = "mp3adu",
02047     .type           = AVMEDIA_TYPE_AUDIO,
02048     .id             = CODEC_ID_MP3ADU,
02049     .priv_data_size = sizeof(MPADecodeContext),
02050     .init           = decode_init,
02051     .decode         = decode_frame_adu,
02052 #if FF_API_PARSE_FRAME
02053     .capabilities   = CODEC_CAP_PARSE_ONLY | CODEC_CAP_DR1,
02054 #else
02055     .capabilities   = CODEC_CAP_DR1,
02056 #endif
02057     .flush          = flush,
02058     .long_name      = NULL_IF_CONFIG_SMALL("ADU (Application Data Unit) MP3 (MPEG audio layer 3)"),
02059 };
02060 #endif
02061 #if CONFIG_MP3ON4_DECODER
02062 AVCodec ff_mp3on4_decoder = {
02063     .name           = "mp3on4",
02064     .type           = AVMEDIA_TYPE_AUDIO,
02065     .id             = CODEC_ID_MP3ON4,
02066     .priv_data_size = sizeof(MP3On4DecodeContext),
02067     .init           = decode_init_mp3on4,
02068     .close          = decode_close_mp3on4,
02069     .decode         = decode_frame_mp3on4,
02070     .capabilities   = CODEC_CAP_DR1,
02071     .flush          = flush_mp3on4,
02072     .long_name      = NULL_IF_CONFIG_SMALL("MP3onMP4"),
02073 };
02074 #endif
02075 #endif