text: /*
   * MPEG Audio decoder
   * Copyright (c) 2001, 2002 Fabrice Bellard
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * @file
   * MPEG Audio decoder
   */
  
  #include "libavutil/attributes.h"
  #include "libavutil/avassert.h"
  #include "libavutil/channel_layout.h"
  #include "libavutil/float_dsp.h"
  #include "libavutil/libm.h"
  #include "avcodec.h"
  #include "get_bits.h"
  #include "internal.h"
  #include "mathops.h"
  #include "mpegaudiodsp.h"
  
  /*
   * TODO:
   *  - test lsf / mpeg25 extensively.
   */
  
  #include "mpegaudio.h"
  #include "mpegaudiodecheader.h"
  
  #define BACKSTEP_SIZE 512
  #define EXTRABYTES 24
  #define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES
  
  /* layer 3 "granule" */
  typedef struct GranuleDef {
      uint8_t scfsi;
      int part2_3_length;
      int big_values;
      int global_gain;
      int scalefac_compress;
      uint8_t block_type;
      uint8_t switch_point;
      int table_select[3];
      int subblock_gain[3];
      uint8_t scalefac_scale;
      uint8_t count1table_select;
      int region_size[3]; /* number of huffman codes in each region */
      int preflag;
      int short_start, long_end; /* long/short band indexes */
      uint8_t scale_factors[40];
      DECLARE_ALIGNED(16, INTFLOAT, sb_hybrid)[SBLIMIT * 18]; /* 576 samples */
  } GranuleDef;
  
  typedef struct MPADecodeContext {
      MPA_DECODE_HEADER
      uint8_t last_buf[LAST_BUF_SIZE];
      int last_buf_size;
      /* next header (used in free format parsing) */
      uint32_t free_format_next_header;
      GetBitContext gb;
      GetBitContext in_gb;
      DECLARE_ALIGNED(32, MPA_INT, synth_buf)[MPA_MAX_CHANNELS][512 * 2];
      int synth_buf_offset[MPA_MAX_CHANNELS];
      DECLARE_ALIGNED(32, INTFLOAT, sb_samples)[MPA_MAX_CHANNELS][36][SBLIMIT];
      INTFLOAT mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
      GranuleDef granules[2][2]; /* Used in Layer 3 */
      int adu_mode; ///< 0 for standard mp3, 1 for adu formatted mp3
      int dither_state;
      int err_recognition;
      AVCodecContext* avctx;
      MPADSPContext mpadsp;
      AVFloatDSPContext *fdsp;
      AVFrame *frame;
  } MPADecodeContext;
  
  #define HEADER_SIZE 4
  
  #include "mpegaudiodata.h"
  #include "mpegaudiodectab.h"
  
  /* vlc structure for decoding layer 3 huffman tables */
  static VLC huff_vlc[16];
  static VLC_TYPE huff_vlc_tables[
      0 + 128 + 128 + 128 + 130 + 128 + 154 + 166 +
    142 + 204 + 190 + 170 + 542 + 460 + 662 + 414
    ][2];
  static const int huff_vlc_tables_sizes[16] = {
      0,  128,  128,  128,  130,  128,  154,  166,
    142,  204,  190,  170,  542,  460,  662,  414
  };
  static VLC huff_quad_vlc[2];
  static VLC_TYPE  huff_quad_vlc_tables[128+16][2];
  static const int huff_quad_vlc_tables_sizes[2] = { 128, 16 };
  /* computed from band_size_long */
  static uint16_t band_index_long[9][23];
  #include "mpegaudio_tablegen.h"
  /* intensity stereo coef table */
  static INTFLOAT is_table[2][16];
  static INTFLOAT is_table_lsf[2][2][16];
  static INTFLOAT csa_table[8][4];
  
  static int16_t division_tab3[1<<6 ];
  static int16_t division_tab5[1<<8 ];
  static int16_t division_tab9[1<<11];
  
  static int16_t * const division_tabs[4] = {
      division_tab3, division_tab5, NULL, division_tab9
  };
  
  /* lower 2 bits: modulo 3, higher bits: shift */
  static uint16_t scale_factor_modshift[64];
  /* [i][j]:  2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
  static int32_t scale_factor_mult[15][3];
  /* mult table for layer 2 group quantization */
  
  #define SCALE_GEN(v) \
  { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }
  
  static const int32_t scale_factor_mult2[3][3] = {
      SCALE_GEN(4.0 / 3.0), /* 3 steps */
      SCALE_GEN(4.0 / 5.0), /* 5 steps */
      SCALE_GEN(4.0 / 9.0), /* 9 steps */
  };
  
  /**
   * Convert region offsets to region sizes and truncate
   * size to big_values.
   */
  static void region_offset2size(GranuleDef *g)
  {
      int i, k, j = 0;
      g->region_size[2] = 576 / 2;
      for (i = 0; i < 3; i++) {
          k = FFMIN(g->region_size[i], g->big_values);
          g->region_size[i] = k - j;
          j = k;
      }
  }
  
  static void init_short_region(MPADecodeContext *s, GranuleDef *g)
  {
      if (g->block_type == 2) {
          if (s->sample_rate_index != 8)
              g->region_size[0] = (36 / 2);
          else
              g->region_size[0] = (72 / 2);
      } else {
          if (s->sample_rate_index <= 2)
              g->region_size[0] = (36 / 2);
          else if (s->sample_rate_index != 8)
              g->region_size[0] = (54 / 2);
          else
              g->region_size[0] = (108 / 2);
      }
      g->region_size[1] = (576 / 2);
  }
  
  static void init_long_region(MPADecodeContext *s, GranuleDef *g,
                               int ra1, int ra2)
  {
      int l;
      g->region_size[0] = band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
      /* should not overflow */
      l = FFMIN(ra1 + ra2 + 2, 22);
      g->region_size[1] = band_index_long[s->sample_rate_index][      l] >> 1;
  }
  
  static void compute_band_indexes(MPADecodeContext *s, GranuleDef *g)
  {
      if (g->block_type == 2) {
          if (g->switch_point) {
              if(s->sample_rate_index == 8)
                  avpriv_request_sample(s->avctx, "switch point in 8khz");
              /* if switched mode, we handle the 36 first samples as
                  long blocks.  For 8000Hz, we handle the 72 first
                  exponents as long blocks */
              if (s->sample_rate_index <= 2)
                  g->long_end = 8;
              else
                  g->long_end = 6;
  
              g->short_start = 3;
          } else {
              g->long_end    = 0;
              g->short_start = 0;
          }
      } else {
          g->short_start = 13;
          g->long_end    = 22;
      }
  }
  
  /* layer 1 unscaling */
  /* n = number of bits of the mantissa minus 1 */
  static inline int l1_unscale(int n, int mant, int scale_factor)
  {
      int shift, mod;
      int64_t val;
  
      shift   = scale_factor_modshift[scale_factor];
      mod     = shift & 3;
      shift >>= 2;
      val     = MUL64((int)(mant + (-1U << n) + 1), scale_factor_mult[n-1][mod]);
      shift  += n;
      /* NOTE: at this point, 1 <= shift >= 21 + 15 */
      return (int)((val + (1LL << (shift - 1))) >> shift);
  }
  
  static inline int l2_unscale_group(int steps, int mant, int scale_factor)
  {
      int shift, mod, val;
  
      shift   = scale_factor_modshift[scale_factor];
      mod     = shift & 3;
      shift >>= 2;
  
      val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
      /* NOTE: at this point, 0 <= shift <= 21 */
      if (shift > 0)
          val = (val + (1 << (shift - 1))) >> shift;
      return val;
  }
  
  /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
  static inline int l3_unscale(int value, int exponent)
  {
      unsigned int m;
      int e;
  
      e  = table_4_3_exp  [4 * value + (exponent & 3)];
      m  = table_4_3_value[4 * value + (exponent & 3)];
      e -= exponent >> 2;
  #ifdef DEBUG
      if(e < 1)
          av_log(NULL, AV_LOG_WARNING, "l3_unscale: e is %d\n", e);
  #endif
      if (e > 31)
          return 0;
      m = (m + (1 << (e - 1))) >> e;
  
      return m;
  }
  
  static av_cold void decode_init_static(void)
  {
      int i, j, k;
      int offset;
  
      /* scale factors table for layer 1/2 */
      for (i = 0; i < 64; i++) {
          int shift, mod;
          /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
          shift = i / 3;
          mod   = i % 3;
          scale_factor_modshift[i] = mod | (shift << 2);
      }
  
      /* scale factor multiply for layer 1 */
      for (i = 0; i < 15; i++) {
          int n, norm;
          n = i + 2;
          norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
          scale_factor_mult[i][0] = MULLx(norm, FIXR(1.0          * 2.0), FRAC_BITS);
          scale_factor_mult[i][1] = MULLx(norm, FIXR(0.7937005259 * 2.0), FRAC_BITS);
          scale_factor_mult[i][2] = MULLx(norm, FIXR(0.6299605249 * 2.0), FRAC_BITS);
          ff_dlog(NULL, "%d: norm=%x s=%x %x %x\n", i, norm,
                  scale_factor_mult[i][0],
                  scale_factor_mult[i][1],
                  scale_factor_mult[i][2]);
      }
  
      RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));
  
      /* huffman decode tables */
      offset = 0;
      for (i = 1; i < 16; i++) {
          const HuffTable *h = &mpa_huff_tables[i];
          int xsize, x, y;
          uint8_t  tmp_bits [512] = { 0 };
          uint16_t tmp_codes[512] = { 0 };
  
          xsize = h->xsize;
  
          j = 0;
          for (x = 0; x < xsize; x++) {
              for (y = 0; y < xsize; y++) {
                  tmp_bits [(x << 5) | y | ((x&&y)<<4)]= h->bits [j  ];
                  tmp_codes[(x << 5) | y | ((x&&y)<<4)]= h->codes[j++];
              }
          }
  
          /* XXX: fail test */
          huff_vlc[i].table = huff_vlc_tables+offset;
          huff_vlc[i].table_allocated = huff_vlc_tables_sizes[i];
          init_vlc(&huff_vlc[i], 7, 512,
                   tmp_bits, 1, 1, tmp_codes, 2, 2,
                   INIT_VLC_USE_NEW_STATIC);
          offset += huff_vlc_tables_sizes[i];
      }
      av_assert0(offset == FF_ARRAY_ELEMS(huff_vlc_tables));
  
      offset = 0;
      for (i = 0; i < 2; i++) {
          huff_quad_vlc[i].table = huff_quad_vlc_tables+offset;
          huff_quad_vlc[i].table_allocated = huff_quad_vlc_tables_sizes[i];
          init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
                   mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1,
                   INIT_VLC_USE_NEW_STATIC);
          offset += huff_quad_vlc_tables_sizes[i];
      }
      av_assert0(offset == FF_ARRAY_ELEMS(huff_quad_vlc_tables));
  
      for (i = 0; i < 9; i++) {
          k = 0;
          for (j = 0; j < 22; j++) {
              band_index_long[i][j] = k;
              k += band_size_long[i][j];
          }
          band_index_long[i][22] = k;
      }
  
      /* compute n ^ (4/3) and store it in mantissa/exp format */
  
      mpegaudio_tableinit();
  
      for (i = 0; i < 4; i++) {
          if (ff_mpa_quant_bits[i] < 0) {
              for (j = 0; j < (1 << (-ff_mpa_quant_bits[i]+1)); j++) {
                  int val1, val2, val3, steps;
                  int val = j;
                  steps   = ff_mpa_quant_steps[i];
                  val1    = val % steps;
                  val    /= steps;
                  val2    = val % steps;
                  val3    = val / steps;
                  division_tabs[i][j] = val1 + (val2 << 4) + (val3 << 8);
              }
          }
      }
  
  
      for (i = 0; i < 7; i++) {
          float f;
          INTFLOAT v;
          if (i != 6) {
              f = tan((double)i * M_PI / 12.0);
              v = FIXR(f / (1.0 + f));
          } else {
              v = FIXR(1.0);
          }
          is_table[0][    i] = v;
          is_table[1][6 - i] = v;
      }
      /* invalid values */
      for (i = 7; i < 16; i++)
          is_table[0][i] = is_table[1][i] = 0.0;
  
      for (i = 0; i < 16; i++) {
          double f;
          int e, k;
  
          for (j = 0; j < 2; j++) {
              e = -(j + 1) * ((i + 1) >> 1);
              f = exp2(e / 4.0);
              k = i & 1;
              is_table_lsf[j][k ^ 1][i] = FIXR(f);
              is_table_lsf[j][k    ][i] = FIXR(1.0);
              ff_dlog(NULL, "is_table_lsf %d %d: %f %f\n",
                      i, j, (float) is_table_lsf[j][0][i],
                      (float) is_table_lsf[j][1][i]);
          }
      }
  
      for (i = 0; i < 8; i++) {
          double ci, cs, ca;
          ci = ci_table[i];
          cs = 1.0 / sqrt(1.0 + ci * ci);
          ca = cs * ci;
  #if !USE_FLOATS
          csa_table[i][0] = FIXHR(cs/4);
          csa_table[i][1] = FIXHR(ca/4);
          csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
          csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
  #else
          csa_table[i][0] = cs;
          csa_table[i][1] = ca;
          csa_table[i][2] = ca + cs;
          csa_table[i][3] = ca - cs;
  #endif
      }
  }
  
  #if USE_FLOATS
  static av_cold int decode_close(AVCodecContext * avctx)
  {
      MPADecodeContext *s = avctx->priv_data;
      av_freep(&s->fdsp);
  
      return 0;
  }
  #endif
  
  static av_cold int decode_init(AVCodecContext * avctx)
  {
      static int initialized_tables = 0;
      MPADecodeContext *s = avctx->priv_data;
  
      if (!initialized_tables) {
          decode_init_static();
          initialized_tables = 1;
      }
  
      s->avctx = avctx;
  
  #if USE_FLOATS
      s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
      if (!s->fdsp)
          return AVERROR(ENOMEM);
  #endif
  
      ff_mpadsp_init(&s->mpadsp);
  
      if (avctx->request_sample_fmt == OUT_FMT &&
          avctx->codec_id != AV_CODEC_ID_MP3ON4)
          avctx->sample_fmt = OUT_FMT;
      else
          avctx->sample_fmt = OUT_FMT_P;
      s->err_recognition = avctx->err_recognition;
  
      if (avctx->codec_id == AV_CODEC_ID_MP3ADU)
          s->adu_mode = 1;
  
      return 0;
  }
  
  #define C3 FIXHR(0.86602540378443864676/2)
  #define C4 FIXHR(0.70710678118654752439/2) //0.5 / cos(pi*(9)/36)
  #define C5 FIXHR(0.51763809020504152469/2) //0.5 / cos(pi*(5)/36)
  #define C6 FIXHR(1.93185165257813657349/4) //0.5 / cos(pi*(15)/36)
  
  /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
     cases. */
  static void imdct12(INTFLOAT *out, INTFLOAT *in)
  {
      INTFLOAT in0, in1, in2, in3, in4, in5, t1, t2;
  
      in0  = in[0*3];
      in1  = in[1*3] + in[0*3];
      in2  = in[2*3] + in[1*3];
      in3  = in[3*3] + in[2*3];
      in4  = in[4*3] + in[3*3];
      in5  = in[5*3] + in[4*3];
      in5 += in3;
      in3 += in1;
  
      in2  = MULH3(in2, C3, 2);
      in3  = MULH3(in3, C3, 4);
  
      t1   = in0 - in4;
      t2   = MULH3(in1 - in5, C4, 2);
  
      out[ 7] =
      out[10] = t1 + t2;
      out[ 1] =
      out[ 4] = t1 - t2;
  
      in0    += SHR(in4, 1);
      in4     = in0 + in2;
      in5    += 2*in1;
      in1     = MULH3(in5 + in3, C5, 1);
      out[ 8] =
      out[ 9] = in4 + in1;
      out[ 2] =
      out[ 3] = in4 - in1;
  
      in0    -= in2;
      in5     = MULH3(in5 - in3, C6, 2);
      out[ 0] =
      out[ 5] = in0 - in5;
      out[ 6] =
      out[11] = in0 + in5;
  }
  
  /* return the number of decoded frames */
  static int mp_decode_layer1(MPADecodeContext *s)
  {
      int bound, i, v, n, ch, j, mant;
      uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
      uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
  
      if (s->mode == MPA_JSTEREO)
          bound = (s->mode_ext + 1) * 4;
      else
          bound = SBLIMIT;
  
      /* allocation bits */
      for (i = 0; i < bound; i++) {
          for (ch = 0; ch < s->nb_channels; ch++) {
              allocation[ch][i] = get_bits(&s->gb, 4);
          }
      }
      for (i = bound; i < SBLIMIT; i++)
          allocation[0][i] = get_bits(&s->gb, 4);
  
      /* scale factors */
      for (i = 0; i < bound; i++) {
          for (ch = 0; ch < s->nb_channels; ch++) {
              if (allocation[ch][i])
                  scale_factors[ch][i] = get_bits(&s->gb, 6);
          }
      }
      for (i = bound; i < SBLIMIT; i++) {
          if (allocation[0][i]) {
              scale_factors[0][i] = get_bits(&s->gb, 6);
              scale_factors[1][i] = get_bits(&s->gb, 6);
          }
      }
  
      /* compute samples */
      for (j = 0; j < 12; j++) {
          for (i = 0; i < bound; i++) {
              for (ch = 0; ch < s->nb_channels; ch++) {
                  n = allocation[ch][i];
                  if (n) {
                      mant = get_bits(&s->gb, n + 1);
                      v = l1_unscale(n, mant, scale_factors[ch][i]);
                  } else {
                      v = 0;
                  }
                  s->sb_samples[ch][j][i] = v;
              }
          }
          for (i = bound; i < SBLIMIT; i++) {
              n = allocation[0][i];
              if (n) {
                  mant = get_bits(&s->gb, n + 1);
                  v = l1_unscale(n, mant, scale_factors[0][i]);
                  s->sb_samples[0][j][i] = v;
                  v = l1_unscale(n, mant, scale_factors[1][i]);
                  s->sb_samples[1][j][i] = v;
              } else {
                  s->sb_samples[0][j][i] = 0;
                  s->sb_samples[1][j][i] = 0;
              }
          }
      }
      return 12;
  }
  
  static int mp_decode_layer2(MPADecodeContext *s)
  {
      int sblimit; /* number of used subbands */
      const unsigned char *alloc_table;
      int table, bit_alloc_bits, i, j, ch, bound, v;
      unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
      unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
      unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
      int scale, qindex, bits, steps, k, l, m, b;
  
      /* select decoding table */
      table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,
                                     s->sample_rate, s->lsf);
      sblimit     = ff_mpa_sblimit_table[table];
      alloc_table = ff_mpa_alloc_tables[table];
  
      if (s->mode == MPA_JSTEREO)
          bound = (s->mode_ext + 1) * 4;
      else
          bound = sblimit;
  
      ff_dlog(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);
  
      /* sanity check */
      if (bound > sblimit)
          bound = sblimit;
  
      /* parse bit allocation */
      j = 0;
      for (i = 0; i < bound; i++) {
          bit_alloc_bits = alloc_table[j];
          for (ch = 0; ch < s->nb_channels; ch++)
              bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
          j += 1 << bit_alloc_bits;
      }
      for (i = bound; i < sblimit; i++) {
          bit_alloc_bits = alloc_table[j];
          v = get_bits(&s->gb, bit_alloc_bits);
          bit_alloc[0][i] = v;
          bit_alloc[1][i] = v;
          j += 1 << bit_alloc_bits;
      }
  
      /* scale codes */
      for (i = 0; i < sblimit; i++) {
          for (ch = 0; ch < s->nb_channels; ch++) {
              if (bit_alloc[ch][i])
                  scale_code[ch][i] = get_bits(&s->gb, 2);
          }
      }
  
      /* scale factors */
      for (i = 0; i < sblimit; i++) {
          for (ch = 0; ch < s->nb_channels; ch++) {
              if (bit_alloc[ch][i]) {
                  sf = scale_factors[ch][i];
                  switch (scale_code[ch][i]) {
                  default:
                  case 0:
                      sf[0] = get_bits(&s->gb, 6);
                      sf[1] = get_bits(&s->gb, 6);
                      sf[2] = get_bits(&s->gb, 6);
                      break;
                  case 2:
                      sf[0] = get_bits(&s->gb, 6);
                      sf[1] = sf[0];
                      sf[2] = sf[0];
                      break;
                  case 1:
                      sf[0] = get_bits(&s->gb, 6);
                      sf[2] = get_bits(&s->gb, 6);
                      sf[1] = sf[0];
                      break;
                  case 3:
                      sf[0] = get_bits(&s->gb, 6);
                      sf[2] = get_bits(&s->gb, 6);
                      sf[1] = sf[2];
                      break;
                  }
              }
          }
      }
  
      /* samples */
      for (k = 0; k < 3; k++) {
          for (l = 0; l < 12; l += 3) {
              j = 0;
              for (i = 0; i < bound; i++) {
                  bit_alloc_bits = alloc_table[j];
                  for (ch = 0; ch < s->nb_channels; ch++) {
                      b = bit_alloc[ch][i];
                      if (b) {
                          scale = scale_factors[ch][i][k];
                          qindex = alloc_table[j+b];
                          bits = ff_mpa_quant_bits[qindex];
                          if (bits < 0) {
                              int v2;
                              /* 3 values at the same time */
                              v = get_bits(&s->gb, -bits);
                              v2 = division_tabs[qindex][v];
                              steps  = ff_mpa_quant_steps[qindex];
  
                              s->sb_samples[ch][k * 12 + l + 0][i] =
                                  l2_unscale_group(steps,  v2       & 15, scale);
                              s->sb_samples[ch][k * 12 + l + 1][i] =
                                  l2_unscale_group(steps, (v2 >> 4) & 15, scale);
                              s->sb_samples[ch][k * 12 + l + 2][i] =
                                  l2_unscale_group(steps,  v2 >> 8      , scale);
                          } else {
                              for (m = 0; m < 3; m++) {
                                  v = get_bits(&s->gb, bits);
                                  v = l1_unscale(bits - 1, v, scale);
                                  s->sb_samples[ch][k * 12 + l + m][i] = v;
                              }
                          }
                      } else {
                          s->sb_samples[ch][k * 12 + l + 0][i] = 0;
                          s->sb_samples[ch][k * 12 + l + 1][i] = 0;
                          s->sb_samples[ch][k * 12 + l + 2][i] = 0;
                      }
                  }
                  /* next subband in alloc table */
                  j += 1 << bit_alloc_bits;
              }
              /* XXX: find a way to avoid this duplication of code */
              for (i = bound; i < sblimit; i++) {
                  bit_alloc_bits = alloc_table[j];
                  b = bit_alloc[0][i];
                  if (b) {
                      int mant, scale0, scale1;
                      scale0 = scale_factors[0][i][k];
                      scale1 = scale_factors[1][i][k];
                      qindex = alloc_table[j+b];
                      bits = ff_mpa_quant_bits[qindex];
                      if (bits < 0) {
                          /* 3 values at the same time */
                          v = get_bits(&s->gb, -bits);
                          steps = ff_mpa_quant_steps[qindex];
                          mant = v % steps;
                          v = v / steps;
                          s->sb_samples[0][k * 12 + l + 0][i] =
                              l2_unscale_group(steps, mant, scale0);
                          s->sb_samples[1][k * 12 + l + 0][i] =
                              l2_unscale_group(steps, mant, scale1);
                          mant = v % steps;
                          v = v / steps;
                          s->sb_samples[0][k * 12 + l + 1][i] =
                              l2_unscale_group(steps, mant, scale0);
                          s->sb_samples[1][k * 12 + l + 1][i] =
                              l2_unscale_group(steps, mant, scale1);
                          s->sb_samples[0][k * 12 + l + 2][i] =
                              l2_unscale_group(steps, v, scale0);
                          s->sb_samples[1][k * 12 + l + 2][i] =
                              l2_unscale_group(steps, v, scale1);
                      } else {
                          for (m = 0; m < 3; m++) {
                              mant = get_bits(&s->gb, bits);
                              s->sb_samples[0][k * 12 + l + m][i] =
                                  l1_unscale(bits - 1, mant, scale0);
                              s->sb_samples[1][k * 12 + l + m][i] =
                                  l1_unscale(bits - 1, mant, scale1);
                          }
                      }
                  } else {
                      s->sb_samples[0][k * 12 + l + 0][i] = 0;
                      s->sb_samples[0][k * 12 + l + 1][i] = 0;
                      s->sb_samples[0][k * 12 + l + 2][i] = 0;
                      s->sb_samples[1][k * 12 + l + 0][i] = 0;
                      s->sb_samples[1][k * 12 + l + 1][i] = 0;
                      s->sb_samples[1][k * 12 + l + 2][i] = 0;
                  }
                  /* next subband in alloc table */
                  j += 1 << bit_alloc_bits;
              }
              /* fill remaining samples to zero */
              for (i = sblimit; i < SBLIMIT; i++) {
                  for (ch = 0; ch < s->nb_channels; ch++) {
                      s->sb_samples[ch][k * 12 + l + 0][i] = 0;
                      s->sb_samples[ch][k * 12 + l + 1][i] = 0;
                      s->sb_samples[ch][k * 12 + l + 2][i] = 0;
                  }
              }
          }
      }
      return 3 * 12;
  }
  
  #define SPLIT(dst,sf,n)             \
      if (n == 3) {                   \
          int m = (sf * 171) >> 9;    \
          dst   = sf - 3 * m;         \
          sf    = m;                  \
      } else if (n == 4) {            \
          dst  = sf & 3;              \
          sf >>= 2;                   \
      } else if (n == 5) {            \
          int m = (sf * 205) >> 10;   \
          dst   = sf - 5 * m;         \
          sf    = m;                  \
      } else if (n == 6) {            \
          int m = (sf * 171) >> 10;   \
          dst   = sf - 6 * m;         \
          sf    = m;                  \
      } else {                        \
          dst = 0;                    \
      }
  
  static av_always_inline void lsf_sf_expand(int *slen, int sf, int n1, int n2,
                                             int n3)
  {
      SPLIT(slen[3], sf, n3)
      SPLIT(slen[2], sf, n2)
      SPLIT(slen[1], sf, n1)
      slen[0] = sf;
  }
  
  static void exponents_from_scale_factors(MPADecodeContext *s, GranuleDef *g,
                                           int16_t *exponents)
  {
      const uint8_t *bstab, *pretab;
      int len, i, j, k, l, v0, shift, gain, gains[3];
      int16_t *exp_ptr;
  
      exp_ptr = exponents;
      gain    = g->global_gain - 210;
      shift   = g->scalefac_scale + 1;
  
      bstab  = band_size_long[s->sample_rate_index];
      pretab = mpa_pretab[g->preflag];
      for (i = 0; i < g->long_end; i++) {
          v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;
          len = bstab[i];
          for (j = len; j > 0; j--)
              *exp_ptr++ = v0;
      }
  
      if (g->short_start < 13) {
          bstab    = band_size_short[s->sample_rate_index];
          gains[0] = gain - (g->subblock_gain[0] << 3);
          gains[1] = gain - (g->subblock_gain[1] << 3);
          gains[2] = gain - (g->subblock_gain[2] << 3);
          k        = g->long_end;
          for (i = g->short_start; i < 13; i++) {
              len = bstab[i];
              for (l = 0; l < 3; l++) {
                  v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;
                  for (j = len; j > 0; j--)
                      *exp_ptr++ = v0;
              }
          }
      }
  }
  
  /* handle n = 0 too */
  static inline int get_bitsz(GetBitContext *s, int n)
  {
      return n ? get_bits(s, n) : 0;
  }
  
  
  static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos,
                            int *end_pos2)
  {
      if (s->in_gb.buffer && *pos >= s->gb.size_in_bits) {
          s->gb           = s->in_gb;
          s->in_gb.buffer = NULL;
          av_assert2((get_bits_count(&s->gb) & 7) == 0);
          skip_bits_long(&s->gb, *pos - *end_pos);
          *end_pos2 =
          *end_pos  = *end_pos2 + get_bits_count(&s->gb) - *pos;
          *pos      = get_bits_count(&s->gb);
      }
  }
  
  /* Following is a optimized code for
              INTFLOAT v = *src
              if(get_bits1(&s->gb))
                  v = -v;
              *dst = v;
  */
  #if USE_FLOATS
  #define READ_FLIP_SIGN(dst,src)                     \
      v = AV_RN32A(src) ^ (get_bits1(&s->gb) << 31);  \
      AV_WN32A(dst, v);
  #else
  #define READ_FLIP_SIGN(dst,src)     \
      v      = -get_bits1(&s->gb);    \
      *(dst) = (*(src) ^ v) - v;
  #endif
  
  static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
                            int16_t *exponents, int end_pos2)
  {
      int s_index;
      int i;
      int last_pos, bits_left;
      VLC *vlc;
      int end_pos = FFMIN(end_pos2, s->gb.size_in_bits);
  
      /* low frequencies (called big values) */
      s_index = 0;
      for (i = 0; i < 3; i++) {
          int j, k, l, linbits;
          j = g->region_size[i];
          if (j == 0)
              continue;
          /* select vlc table */
          k       = g->table_select[i];
          l       = mpa_huff_data[k][0];
          linbits = mpa_huff_data[k][1];
          vlc     = &huff_vlc[l];
  
          if (!l) {
              memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * 2 * j);
              s_index += 2 * j;
              continue;
          }
  
          /* read huffcode and compute each couple */
          for (; j > 0; j--) {
              int exponent, x, y;
              int v;
              int pos = get_bits_count(&s->gb);
  
              if (pos >= end_pos){
                  switch_buffer(s, &pos, &end_pos, &end_pos2);
                  if (pos >= end_pos)
                      break;
              }
              y = get_vlc2(&s->gb, vlc->table, 7, 3);
  
              if (!y) {
                  g->sb_hybrid[s_index  ] =
                  g->sb_hybrid[s_index+1] = 0;
                  s_index += 2;
                  continue;
              }
  
              exponent= exponents[s_index];
  
              ff_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",
                      i, g->region_size[i] - j, x, y, exponent);
              if (y & 16) {
                  x = y >> 5;
                  y = y & 0x0f;
                  if (x < 15) {
                      READ_FLIP_SIGN(g->sb_hybrid + s_index, RENAME(expval_table)[exponent] + x)
                  } else {
                      x += get_bitsz(&s->gb, linbits);
                      v  = l3_unscale(x, exponent);
                      if (get_bits1(&s->gb))
                          v = -v;
                      g->sb_hybrid[s_index] = v;
                  }
                  if (y < 15) {
                      READ_FLIP_SIGN(g->sb_hybrid + s_index + 1, RENAME(expval_table)[exponent] + y)
                  } else {
                      y += get_bitsz(&s->gb, linbits);
                      v  = l3_unscale(y, exponent);
                      if (get_bits1(&s->gb))
                          v = -v;
                      g->sb_hybrid[s_index+1] = v;
                  }
              } else {
                  x = y >> 5;
                  y = y & 0x0f;
                  x += y;
                  if (x < 15) {
                      READ_FLIP_SIGN(g->sb_hybrid + s_index + !!y, RENAME(expval_table)[exponent] + x)
                  } else {
                      x += get_bitsz(&s->gb, linbits);
                      v  = l3_unscale(x, exponent);
                      if (get_bits1(&s->gb))
                          v = -v;
                      g->sb_hybrid[s_index+!!y] = v;
                  }
                  g->sb_hybrid[s_index + !y] = 0;
              }
              s_index += 2;
          }
      }
  
      /* high frequencies */
      vlc = &huff_quad_vlc[g->count1table_select];
      last_pos = 0;
      while (s_index <= 572) {
          int pos, code;
          pos = get_bits_count(&s->gb);
          if (pos >= end_pos) {
              if (pos > end_pos2 && last_pos) {
                  /* some encoders generate an incorrect size for this
                     part. We must go back into the data */
                  s_index -= 4;
                  skip_bits_long(&s->gb, last_pos - pos);
                  av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
                  if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
                      s_index=0;
                  break;
              }
              switch_buffer(s, &pos, &end_pos, &end_pos2);
              if (pos >= end_pos)
                  break;
          }
          last_pos = pos;
  
          code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);
          ff_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);
          g->sb_hybrid[s_index+0] =
          g->sb_hybrid[s_index+1] =
          g->sb_hybrid[s_index+2] =
          g->sb_hybrid[s_index+3] = 0;
          while (code) {
              static const int idxtab[16] = { 3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0 };
              int v;
              int pos = s_index + idxtab[code];
              code   ^= 8 >> idxtab[code];
              READ_FLIP_SIGN(g->sb_hybrid + pos, RENAME(exp_table)+exponents[pos])
          }
          s_index += 4;
      }
      /* skip extension bits */
      bits_left = end_pos2 - get_bits_count(&s->gb);
      if (bits_left < 0 && (s->err_recognition & (AV_EF_BUFFER|AV_EF_COMPLIANT))) {
          av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
          s_index=0;
      } else if (bits_left > 0 && (s->err_recognition & (AV_EF_BUFFER|AV_EF_AGGRESSIVE))) {
          av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
          s_index = 0;
      }
      memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * (576 - s_index));
      skip_bits_long(&s->gb, bits_left);
  
      i = get_bits_count(&s->gb);
      switch_buffer(s, &i, &end_pos, &end_pos2);
  
      return 0;
  }
  
  /* Reorder short blocks from bitstream order to interleaved order. It
     would be faster to do it in parsing, but the code would be far more
     complicated */
  static void reorder_block(MPADecodeContext *s, GranuleDef *g)
  {
      int i, j, len;
      INTFLOAT *ptr, *dst, *ptr1;
      INTFLOAT tmp[576];
  
      if (g->block_type != 2)
          return;
  
      if (g->switch_point) {
          if (s->sample_rate_index != 8)
              ptr = g->sb_hybrid + 36;
          else
              ptr = g->sb_hybrid + 72;
      } else {
          ptr = g->sb_hybrid;
      }
  
      for (i = g->short_start; i < 13; i++) {
          len  = band_size_short[s->sample_rate_index][i];
          ptr1 = ptr;
          dst  = tmp;
          for (j = len; j > 0; j--) {
              *dst++ = ptr[0*len];
              *dst++ = ptr[1*len];
              *dst++ = ptr[2*len];
              ptr++;
          }
          ptr += 2 * len;
          memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));
      }
  }
  
  #define ISQRT2 FIXR(0.70710678118654752440)
  
  static void compute_stereo(MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)
  {
      int i, j, k, l;
      int sf_max, sf, len, non_zero_found;
      INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;
      int non_zero_found_short[3];
  
      /* intensity stereo */
      if (s->mode_ext & MODE_EXT_I_STEREO) {
          if (!s->lsf) {
              is_tab = is_table;
              sf_max = 7;
          } else {
              is_tab = is_table_lsf[g1->scalefac_compress & 1];
              sf_max = 16;
          }
  
          tab0 = g0->sb_hybrid + 576;
          tab1 = g1->sb_hybrid + 576;
  
          non_zero_found_short[0] = 0;
          non_zero_found_short[1] = 0;
          non_zero_found_short[2] = 0;
          k = (13 - g1->short_start) * 3 + g1->long_end - 3;
          for (i = 12; i >= g1->short_start; i--) {
              /* for last band, use previous scale factor */
              if (i != 11)
                  k -= 3;
              len = band_size_short[s->sample_rate_index][i];
              for (l = 2; l >= 0; l--) {
                  tab0 -= len;
                  tab1 -= len;
                  if (!non_zero_found_short[l]) {
                      /* test if non zero band. if so, stop doing i-stereo */
                      for (j = 0; j < len; j++) {
                          if (tab1[j] != 0) {
                              non_zero_found_short[l] = 1;
                              goto found1;
                          }
                      }
                      sf = g1->scale_factors[k + l];
                      if (sf >= sf_max)
                          goto found1;
  
                      v1 = is_tab[0][sf];
                      v2 = is_tab[1][sf];
                      for (j = 0; j < len; j++) {
                          tmp0    = tab0[j];
                          tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
                          tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
                      }
                  } else {
  found1:
                      if (s->mode_ext & MODE_EXT_MS_STEREO) {
                          /* lower part of the spectrum : do ms stereo
                             if enabled */
                          for (j = 0; j < len; j++) {
                              tmp0    = tab0[j];
                              tmp1    = tab1[j];
                              tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
                              tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
                          }
                      }
                  }
              }
          }
  
          non_zero_found = non_zero_found_short[0] |
                           non_zero_found_short[1] |
                           non_zero_found_short[2];
  
          for (i = g1->long_end - 1;i >= 0;i--) {
              len   = band_size_long[s->sample_rate_index][i];
              tab0 -= len;
              tab1 -= len;
              /* test if non zero band. if so, stop doing i-stereo */
              if (!non_zero_found) {
                  for (j = 0; j < len; j++) {
                      if (tab1[j] != 0) {
                          non_zero_found = 1;
                          goto found2;
                      }
                  }
                  /* for last band, use previous scale factor */
                  k  = (i == 21) ? 20 : i;
                  sf = g1->scale_factors[k];
                  if (sf >= sf_max)
                      goto found2;
                  v1 = is_tab[0][sf];
                  v2 = is_tab[1][sf];
                  for (j = 0; j < len; j++) {
                      tmp0    = tab0[j];
                      tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
                      tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
                  }
              } else {
  found2:
                  if (s->mode_ext & MODE_EXT_MS_STEREO) {
                      /* lower part of the spectrum : do ms stereo
                         if enabled */
                      for (j = 0; j < len; j++) {
                          tmp0    = tab0[j];
                          tmp1    = tab1[j];
                          tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
                          tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
                      }
                  }
              }
          }
      } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
          /* ms stereo ONLY */
          /* NOTE: the 1/sqrt(2) normalization factor is included in the
             global gain */
  #if USE_FLOATS
         s->fdsp->butterflies_float(g0->sb_hybrid, g1->sb_hybrid, 576);
  #else
          tab0 = g0->sb_hybrid;
          tab1 = g1->sb_hybrid;
          for (i = 0; i < 576; i++) {
              tmp0    = tab0[i];
              tmp1    = tab1[i];
              tab0[i] = tmp0 + tmp1;
              tab1[i] = tmp0 - tmp1;
          }
  #endif
      }
  }
  
  #if USE_FLOATS
  #if HAVE_MIPSFPU
  #   include "mips/compute_antialias_float.h"
  #endif /* HAVE_MIPSFPU */
  #else
  #if HAVE_MIPSDSPR1
  #   include "mips/compute_antialias_fixed.h"
  #endif /* HAVE_MIPSDSPR1 */
  #endif /* USE_FLOATS */
  
  #ifndef compute_antialias
  #if USE_FLOATS
  #define AA(j) do {                                                      \
          float tmp0 = ptr[-1-j];                                         \
          float tmp1 = ptr[   j];                                         \
          ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1];    \
          ptr[   j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0];    \
      } while (0)
  #else
  #define AA(j) do {                                              \
          int tmp0 = ptr[-1-j];                                   \
          int tmp1 = ptr[   j];                                   \
          int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]);          \
          ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2]));   \
          ptr[   j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3]));   \
      } while (0)
  #endif
  
  static void compute_antialias(MPADecodeContext *s, GranuleDef *g)
  {
      INTFLOAT *ptr;
      int n, i;
  
      /* we antialias only "long" bands */
      if (g->block_type == 2) {
          if (!g->switch_point)
              return;
          /* XXX: check this for 8000Hz case */
          n = 1;
      } else {
          n = SBLIMIT - 1;
      }
  
      ptr = g->sb_hybrid + 18;
      for (i = n; i > 0; i--) {
          AA(0);
          AA(1);
          AA(2);
          AA(3);
          AA(4);
          AA(5);
          AA(6);
          AA(7);
  
          ptr += 18;
      }
  }
  #endif /* compute_antialias */
  
  static void compute_imdct(MPADecodeContext *s, GranuleDef *g,
                            INTFLOAT *sb_samples, INTFLOAT *mdct_buf)
  {
      INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;
      INTFLOAT out2[12];
      int i, j, mdct_long_end, sblimit;
  
      /* find last non zero block */
      ptr  = g->sb_hybrid + 576;
      ptr1 = g->sb_hybrid + 2 * 18;
      while (ptr >= ptr1) {
          int32_t *p;
          ptr -= 6;
          p    = (int32_t*)ptr;
          if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])
              break;
      }
      sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
  
      if (g->block_type == 2) {
          /* XXX: check for 8000 Hz */
          if (g->switch_point)
              mdct_long_end = 2;
          else
              mdct_long_end = 0;
      } else {
          mdct_long_end = sblimit;
      }
  
      s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,
                                       mdct_long_end, g->switch_point,
                                       g->block_type);
  
      buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);
      ptr = g->sb_hybrid + 18 * mdct_long_end;
  
      for (j = mdct_long_end; j < sblimit; j++) {
          /* select frequency inversion */
          win     = RENAME(ff_mdct_win)[2 + (4  & -(j & 1))];
          out_ptr = sb_samples + j;
  
          for (i = 0; i < 6; i++) {
              *out_ptr = buf[4*i];
              out_ptr += SBLIMIT;
          }
          imdct12(out2, ptr + 0);
          for (i = 0; i < 6; i++) {
              *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*1)];
              buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);
              out_ptr += SBLIMIT;
          }
          imdct12(out2, ptr + 1);
          for (i = 0; i < 6; i++) {
              *out_ptr     = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*2)];
              buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);
              out_ptr += SBLIMIT;
          }
          imdct12(out2, ptr + 2);
          for (i = 0; i < 6; i++) {
              buf[4*(i + 6*0)] = MULH3(out2[i    ], win[i    ], 1) + buf[4*(i + 6*0)];
              buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);
              buf[4*(i + 6*2)] = 0;
          }
          ptr += 18;
          buf += (j&3) != 3 ? 1 : (4*18-3);
      }
      /* zero bands */
      for (j = sblimit; j < SBLIMIT; j++) {
          /* overlap */
          out_ptr = sb_samples + j;
          for (i = 0; i < 18; i++) {
              *out_ptr = buf[4*i];
              buf[4*i]   = 0;
              out_ptr += SBLIMIT;
          }
          buf += (j&3) != 3 ? 1 : (4*18-3);
      }
  }
  
  /* main layer3 decoding function */
  static int mp_decode_layer3(MPADecodeContext *s)
  {
      int nb_granules, main_data_begin;
      int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;
      GranuleDef *g;
      int16_t exponents[576]; //FIXME try INTFLOAT
  
      /* read side info */
      if (s->lsf) {
          main_data_begin = get_bits(&s->gb, 8);
          skip_bits(&s->gb, s->nb_channels);
          nb_granules = 1;
      } else {
          main_data_begin = get_bits(&s->gb, 9);
          if (s->nb_channels == 2)
              skip_bits(&s->gb, 3);
          else
              skip_bits(&s->gb, 5);
          nb_granules = 2;
          for (ch = 0; ch < s->nb_channels; ch++) {
              s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */
              s->granules[ch][1].scfsi = get_bits(&s->gb, 4);
          }
      }
  
      for (gr = 0; gr < nb_granules; gr++) {
          for (ch = 0; ch < s->nb_channels; ch++) {
              ff_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);
              g = &s->granules[ch][gr];
              g->part2_3_length = get_bits(&s->gb, 12);
              g->big_values     = get_bits(&s->gb,  9);
              if (g->big_values > 288) {
                  av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");
                  return AVERROR_INVALIDDATA;
              }
  
              g->global_gain = get_bits(&s->gb, 8);
              /* if MS stereo only is selected, we precompute the
                 1/sqrt(2) renormalization factor */
              if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
                  MODE_EXT_MS_STEREO)
                  g->global_gain -= 2;
              if (s->lsf)
                  g->scalefac_compress = get_bits(&s->gb, 9);
              else
                  g->scalefac_compress = get_bits(&s->gb, 4);
              blocksplit_flag = get_bits1(&s->gb);
              if (blocksplit_flag) {
                  g->block_type = get_bits(&s->gb, 2);
                  if (g->block_type == 0) {
                      av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");
                      return AVERROR_INVALIDDATA;
                  }
                  g->switch_point = get_bits1(&s->gb);
                  for (i = 0; i < 2; i++)
                      g->table_select[i] = get_bits(&s->gb, 5);
                  for (i = 0; i < 3; i++)
                      g->subblock_gain[i] = get_bits(&s->gb, 3);
                  init_short_region(s, g);
              } else {
                  int region_address1, region_address2;
                  g->block_type = 0;
                  g->switch_point = 0;
                  for (i = 0; i < 3; i++)
                      g->table_select[i] = get_bits(&s->gb, 5);
                  /* compute huffman coded region sizes */
                  region_address1 = get_bits(&s->gb, 4);
                  region_address2 = get_bits(&s->gb, 3);
                  ff_dlog(s->avctx, "region1=%d region2=%d\n",
                          region_address1, region_address2);
                  init_long_region(s, g, region_address1, region_address2);
              }
              region_offset2size(g);
              compute_band_indexes(s, g);
  
              g->preflag = 0;
              if (!s->lsf)
                  g->preflag = get_bits1(&s->gb);
              g->scalefac_scale     = get_bits1(&s->gb);
              g->count1table_select = get_bits1(&s->gb);
              ff_dlog(s->avctx, "block_type=%d switch_point=%d\n",
                      g->block_type, g->switch_point);
          }
      }
  
      if (!s->adu_mode) {
          int skip;
          const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
          int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0, EXTRABYTES);
          av_assert1((get_bits_count(&s->gb) & 7) == 0);
          /* now we get bits from the main_data_begin offset */
          ff_dlog(s->avctx, "seekback:%d, lastbuf:%d\n",
                  main_data_begin, s->last_buf_size);
  
          memcpy(s->last_buf + s->last_buf_size, ptr, extrasize);
          s->in_gb = s->gb;
          init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);
  #if !UNCHECKED_BITSTREAM_READER
          s->gb.size_in_bits_plus8 += FFMAX(extrasize, LAST_BUF_SIZE - s->last_buf_size) * 8;
  #endif
          s->last_buf_size <<= 3;
          for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) {
              for (ch = 0; ch < s->nb_channels; ch++) {
                  g = &s->granules[ch][gr];
                  s->last_buf_size += g->part2_3_length;
                  memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));
                  compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
              }
          }
          skip = s->last_buf_size - 8 * main_data_begin;
          if (skip >= s->gb.size_in_bits && s->in_gb.buffer) {
              skip_bits_long(&s->in_gb, skip - s->gb.size_in_bits);
              s->gb           = s->in_gb;
              s->in_gb.buffer = NULL;
          } else {
              skip_bits_long(&s->gb, skip);
          }
      } else {
          gr = 0;
      }
  
      for (; gr < nb_granules; gr++) {
          for (ch = 0; ch < s->nb_channels; ch++) {
              g = &s->granules[ch][gr];
              bits_pos = get_bits_count(&s->gb);
  
              if (!s->lsf) {
                  uint8_t *sc;
                  int slen, slen1, slen2;
  
                  /* MPEG1 scale factors */
                  slen1 = slen_table[0][g->scalefac_compress];
                  slen2 = slen_table[1][g->scalefac_compress];
                  ff_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);
                  if (g->block_type == 2) {
                      n = g->switch_point ? 17 : 18;
                      j = 0;
                      if (slen1) {
                          for (i = 0; i < n; i++)
                              g->scale_factors[j++] = get_bits(&s->gb, slen1);
                      } else {
                          for (i = 0; i < n; i++)
                              g->scale_factors[j++] = 0;
                      }
                      if (slen2) {
                          for (i = 0; i < 18; i++)
                              g->scale_factors[j++] = get_bits(&s->gb, slen2);
                          for (i = 0; i < 3; i++)
                              g->scale_factors[j++] = 0;
                      } else {
                          for (i = 0; i < 21; i++)
                              g->scale_factors[j++] = 0;
                      }
                  } else {
                      sc = s->granules[ch][0].scale_factors;
                      j = 0;
                      for (k = 0; k < 4; k++) {
                          n = k == 0 ? 6 : 5;
                          if ((g->scfsi & (0x8 >> k)) == 0) {
                              slen = (k < 2) ? slen1 : slen2;
                              if (slen) {
                                  for (i = 0; i < n; i++)
                                      g->scale_factors[j++] = get_bits(&s->gb, slen);
                              } else {
                                  for (i = 0; i < n; i++)
                                      g->scale_factors[j++] = 0;
                              }
                          } else {
                              /* simply copy from last granule */
                              for (i = 0; i < n; i++) {
                                  g->scale_factors[j] = sc[j];
                                  j++;
                              }
                          }
                      }
                      g->scale_factors[j++] = 0;
                  }
              } else {
                  int tindex, tindex2, slen[4], sl, sf;
  
                  /* LSF scale factors */
                  if (g->block_type == 2)
                      tindex = g->switch_point ? 2 : 1;
                  else
                      tindex = 0;
  
                  sf = g->scalefac_compress;
                  if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
                      /* intensity stereo case */
                      sf >>= 1;
                      if (sf < 180) {
                          lsf_sf_expand(slen, sf, 6, 6, 0);
                          tindex2 = 3;
                      } else if (sf < 244) {
                          lsf_sf_expand(slen, sf - 180, 4, 4, 0);
                          tindex2 = 4;
                      } else {
                          lsf_sf_expand(slen, sf - 244, 3, 0, 0);
                          tindex2 = 5;
                      }
                  } else {
                      /* normal case */
                      if (sf < 400) {
                          lsf_sf_expand(slen, sf, 5, 4, 4);
                          tindex2 = 0;
                      } else if (sf < 500) {
                          lsf_sf_expand(slen, sf - 400, 5, 4, 0);
                          tindex2 = 1;
                      } else {
                          lsf_sf_expand(slen, sf - 500, 3, 0, 0);
                          tindex2 = 2;
                          g->preflag = 1;
                      }
                  }
  
                  j = 0;
                  for (k = 0; k < 4; k++) {
                      n  = lsf_nsf_table[tindex2][tindex][k];
                      sl = slen[k];
                      if (sl) {
                          for (i = 0; i < n; i++)
                              g->scale_factors[j++] = get_bits(&s->gb, sl);
                      } else {
                          for (i = 0; i < n; i++)
                              g->scale_factors[j++] = 0;
                      }
                  }
                  /* XXX: should compute exact size */
                  for (; j < 40; j++)
                      g->scale_factors[j] = 0;
              }
  
              exponents_from_scale_factors(s, g, exponents);
  
              /* read Huffman coded residue */
              huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
          } /* ch */
  
          if (s->mode == MPA_JSTEREO)
              compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
  
          for (ch = 0; ch < s->nb_channels; ch++) {
              g = &s->granules[ch][gr];
  
              reorder_block(s, g);
              compute_antialias(s, g);
              compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
          }
      } /* gr */
      if (get_bits_count(&s->gb) < 0)
          skip_bits_long(&s->gb, -get_bits_count(&s->gb));
      return nb_granules * 18;
  }
  
  static int mp_decode_frame(MPADecodeContext *s, OUT_INT **samples,
                             const uint8_t *buf, int buf_size)
  {
      int i, nb_frames, ch, ret;
      OUT_INT *samples_ptr;
  
      init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);
  
      /* skip error protection field */
      if (s->error_protection)
          skip_bits(&s->gb, 16);
  
      switch(s->layer) {
      case 1:
          s->avctx->frame_size = 384;
          nb_frames = mp_decode_layer1(s);
          break;
      case 2:
          s->avctx->frame_size = 1152;
          nb_frames = mp_decode_layer2(s);
          break;
      case 3:
          s->avctx->frame_size = s->lsf ? 576 : 1152;
      default:
          nb_frames = mp_decode_layer3(s);
  
          s->last_buf_size=0;
          if (s->in_gb.buffer) {
              align_get_bits(&s->gb);
              i = get_bits_left(&s->gb)>>3;
              if (i >= 0 && i <= BACKSTEP_SIZE) {
                  memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
                  s->last_buf_size=i;
              } else
                  av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);
              s->gb           = s->in_gb;
              s->in_gb.buffer = NULL;
          }
  
          align_get_bits(&s->gb);
          av_assert1((get_bits_count(&s->gb) & 7) == 0);
          i = get_bits_left(&s->gb) >> 3;
  
          if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {
              if (i < 0)
                  av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);
              i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
          }
          av_assert1(i <= buf_size - HEADER_SIZE && i >= 0);
          memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
          s->last_buf_size += i;
      }
  
      if(nb_frames < 0)
          return nb_frames;
  
      /* get output buffer */
      if (!samples) {
          av_assert0(s->frame);
          s->frame->nb_samples = s->avctx->frame_size;
          if ((ret = ff_get_buffer(s->avctx, s->frame, 0)) < 0)
              return ret;
          samples = (OUT_INT **)s->frame->extended_data;
      }
  
      /* apply the synthesis filter */
      for (ch = 0; ch < s->nb_channels; ch++) {
          int sample_stride;
          if (s->avctx->sample_fmt == OUT_FMT_P) {
              samples_ptr   = samples[ch];
              sample_stride = 1;
          } else {
              samples_ptr   = samples[0] + ch;
              sample_stride = s->nb_channels;
          }
          for (i = 0; i < nb_frames; i++) {
              RENAME(ff_mpa_synth_filter)(&s->mpadsp, s->synth_buf[ch],
                                          &(s->synth_buf_offset[ch]),
                                          RENAME(ff_mpa_synth_window),
                                          &s->dither_state, samples_ptr,
                                          sample_stride, s->sb_samples[ch][i]);
              samples_ptr += 32 * sample_stride;
          }
      }
  
      return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
  }
  
  static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,
                          AVPacket *avpkt)
  {
      const uint8_t *buf  = avpkt->data;
      int buf_size        = avpkt->size;
      MPADecodeContext *s = avctx->priv_data;
      uint32_t header;
      int ret;
  
      while(buf_size && !*buf){
          buf++;
          buf_size--;
      }
  
      if (buf_size < HEADER_SIZE)
          return AVERROR_INVALIDDATA;
  
      header = AV_RB32(buf);
      if (header>>8 == AV_RB32("TAG")>>8) {
          av_log(avctx, AV_LOG_DEBUG, "discarding ID3 tag\n");
          return buf_size;
      }
      if (ff_mpa_check_header(header) < 0) {
          av_log(avctx, AV_LOG_ERROR, "Header missing\n");
          return AVERROR_INVALIDDATA;
      }
  
      if (avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {
          /* free format: prepare to compute frame size */
          s->frame_size = -1;
          return AVERROR_INVALIDDATA;
      }
      /* update codec info */
      avctx->channels       = s->nb_channels;
      avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
      if (!avctx->bit_rate)
          avctx->bit_rate = s->bit_rate;
  
      if (s->frame_size <= 0) {
          av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
          return AVERROR_INVALIDDATA;
      } else if (s->frame_size < buf_size) {
          av_log(avctx, AV_LOG_DEBUG, "incorrect frame size - multiple frames in buffer?\n");
          buf_size= s->frame_size;
      }
  
      s->frame = data;
  
      ret = mp_decode_frame(s, NULL, buf, buf_size);
      if (ret >= 0) {
          s->frame->nb_samples = avctx->frame_size;
          *got_frame_ptr       = 1;
          avctx->sample_rate   = s->sample_rate;
          //FIXME maybe move the other codec info stuff from above here too
      } else {
          av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
          /* Only return an error if the bad frame makes up the whole packet or
           * the error is related to buffer management.
           * If there is more data in the packet, just consume the bad frame
           * instead of returning an error, which would discard the whole
           * packet. */
          *got_frame_ptr = 0;
          if (buf_size == avpkt->size || ret != AVERROR_INVALIDDATA)
              return ret;
      }
      s->frame_size = 0;
      return buf_size;
  }
  
  static void mp_flush(MPADecodeContext *ctx)
  {
      memset(ctx->synth_buf, 0, sizeof(ctx->synth_buf));
      memset(ctx->mdct_buf, 0, sizeof(ctx->mdct_buf));
      ctx->last_buf_size = 0;
      ctx->dither_state = 0;
  }
  
  static void flush(AVCodecContext *avctx)
  {
      mp_flush(avctx->priv_data);
  }
  
  #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER
  static int decode_frame_adu(AVCodecContext *avctx, void *data,
                              int *got_frame_ptr, AVPacket *avpkt)
  {
      const uint8_t *buf  = avpkt->data;
      int buf_size        = avpkt->size;
      MPADecodeContext *s = avctx->priv_data;
      uint32_t header;
      int len, ret;
      int av_unused out_size;
  
      len = buf_size;
  
      // Discard too short frames
      if (buf_size < HEADER_SIZE) {
          av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
          return AVERROR_INVALIDDATA;
      }
  
  
      if (len > MPA_MAX_CODED_FRAME_SIZE)
          len = MPA_MAX_CODED_FRAME_SIZE;
  
      // Get header and restore sync word
      header = AV_RB32(buf) | 0xffe00000;
  
      if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
          av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");
          return AVERROR_INVALIDDATA;
      }
  
      avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);
      /* update codec info */
      avctx->sample_rate = s->sample_rate;
      avctx->channels    = s->nb_channels;
      avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
      if (!avctx->bit_rate)
          avctx->bit_rate = s->bit_rate;
  
      s->frame_size = len;
  
      s->frame = data;
  
      ret = mp_decode_frame(s, NULL, buf, buf_size);
      if (ret < 0) {
          av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
          return ret;
      }
  
      *got_frame_ptr = 1;
  
      return buf_size;
  }
  #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */
  
  #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER
  
  /**
   * Context for MP3On4 decoder
   */
  typedef struct MP3On4DecodeContext {
      int frames;                     ///< number of mp3 frames per block (number of mp3 decoder instances)
      int syncword;                   ///< syncword patch
      const uint8_t *coff;            ///< channel offsets in output buffer
      MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance
  } MP3On4DecodeContext;
  
  #include "mpeg4audio.h"
  
  /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
  
  /* number of mp3 decoder instances */
  static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };
  
  /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */
  static const uint8_t chan_offset[8][5] = {
      { 0             },
      { 0             },  // C
      { 0             },  // FLR
      { 2, 0          },  // C FLR
      { 2, 0, 3       },  // C FLR BS
      { 2, 0, 3       },  // C FLR BLRS
      { 2, 0, 4, 3    },  // C FLR BLRS LFE
      { 2, 0, 6, 4, 3 },  // C FLR BLRS BLR LFE
  };
  
  /* mp3on4 channel layouts */
  static const int16_t chan_layout[8] = {
      0,
      AV_CH_LAYOUT_MONO,
      AV_CH_LAYOUT_STEREO,
      AV_CH_LAYOUT_SURROUND,
      AV_CH_LAYOUT_4POINT0,
      AV_CH_LAYOUT_5POINT0,
      AV_CH_LAYOUT_5POINT1,
      AV_CH_LAYOUT_7POINT1
  };
  
  static av_cold int decode_close_mp3on4(AVCodecContext * avctx)
  {
      MP3On4DecodeContext *s = avctx->priv_data;
      int i;
  
      for (i = 0; i < s->frames; i++)
          av_freep(&s->mp3decctx[i]);
  
      return 0;
  }
  
  
  static av_cold int decode_init_mp3on4(AVCodecContext * avctx)
  {
      MP3On4DecodeContext *s = avctx->priv_data;
      MPEG4AudioConfig cfg;
      int i;
  
      if ((avctx->extradata_size < 2) || !avctx->extradata) {
          av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
          return AVERROR_INVALIDDATA;
      }
  
      avpriv_mpeg4audio_get_config(&cfg, avctx->extradata,
                                   avctx->extradata_size * 8, 1);
      if (!cfg.chan_config || cfg.chan_config > 7) {
          av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
          return AVERROR_INVALIDDATA;
      }
      s->frames             = mp3Frames[cfg.chan_config];
      s->coff               = chan_offset[cfg.chan_config];
      avctx->channels       = ff_mpeg4audio_channels[cfg.chan_config];
      avctx->channel_layout = chan_layout[cfg.chan_config];
  
      if (cfg.sample_rate < 16000)
          s->syncword = 0xffe00000;
      else
          s->syncword = 0xfff00000;
  
      /* Init the first mp3 decoder in standard way, so that all tables get builded
       * We replace avctx->priv_data with the context of the first decoder so that
       * decode_init() does not have to be changed.
       * Other decoders will be initialized here copying data from the first context
       */
      // Allocate zeroed memory for the first decoder context
      s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
      if (!s->mp3decctx[0])
          goto alloc_fail;
      // Put decoder context in place to make init_decode() happy
      avctx->priv_data = s->mp3decctx[0];
      decode_init(avctx);
      // Restore mp3on4 context pointer
      avctx->priv_data = s;
      s->mp3decctx[0]->adu_mode = 1; // Set adu mode
  
      /* Create a separate codec/context for each frame (first is already ok).
       * Each frame is 1 or 2 channels - up to 5 frames allowed
       */
      for (i = 1; i < s->frames; i++) {
          s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
          if (!s->mp3decctx[i])
              goto alloc_fail;
          s->mp3decctx[i]->adu_mode = 1;
          s->mp3decctx[i]->avctx = avctx;
          s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;
          s->mp3decctx[i]->fdsp = s->mp3decctx[0]->fdsp;
      }
  
      return 0;
  alloc_fail:
      decode_close_mp3on4(avctx);
      return AVERROR(ENOMEM);
  }
  
  
  static void flush_mp3on4(AVCodecContext *avctx)
  {
      int i;
      MP3On4DecodeContext *s = avctx->priv_data;
  
      for (i = 0; i < s->frames; i++)
          mp_flush(s->mp3decctx[i]);
  }
  
  
  static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,
                                 int *got_frame_ptr, AVPacket *avpkt)
  {
      AVFrame *frame         = data;
      const uint8_t *buf     = avpkt->data;
      int buf_size           = avpkt->size;
      MP3On4DecodeContext *s = avctx->priv_data;
      MPADecodeContext *m;
      int fsize, len = buf_size, out_size = 0;
      uint32_t header;
      OUT_INT **out_samples;
      OUT_INT *outptr[2];
      int fr, ch, ret;
  
      /* get output buffer */
      frame->nb_samples = MPA_FRAME_SIZE;
      if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
          return ret;
      out_samples = (OUT_INT **)frame->extended_data;
  
      // Discard too short frames
      if (buf_size < HEADER_SIZE)
          return AVERROR_INVALIDDATA;
  
      avctx->bit_rate = 0;
  
      ch = 0;
      for (fr = 0; fr < s->frames; fr++) {
          fsize = AV_RB16(buf) >> 4;
          fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);
          m     = s->mp3decctx[fr];
          av_assert1(m);
  
          if (fsize < HEADER_SIZE) {
              av_log(avctx, AV_LOG_ERROR, "Frame size smaller than header size\n");
              return AVERROR_INVALIDDATA;
          }
          header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header
  
          if (ff_mpa_check_header(header) < 0) {
              av_log(avctx, AV_LOG_ERROR, "Bad header, discard block\n");
              return AVERROR_INVALIDDATA;
          }
  
          avpriv_mpegaudio_decode_header((MPADecodeHeader *)m, header);
  
          if (ch + m->nb_channels > avctx->channels ||
              s->coff[fr] + m->nb_channels > avctx->channels) {
              av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "
                                          "channel count\n");
              return AVERROR_INVALIDDATA;
          }
          ch += m->nb_channels;
  
          outptr[0] = out_samples[s->coff[fr]];
          if (m->nb_channels > 1)
              outptr[1] = out_samples[s->coff[fr] + 1];
  
          if ((ret = mp_decode_frame(m, outptr, buf, fsize)) < 0) {
              av_log(avctx, AV_LOG_ERROR, "failed to decode channel %d\n", ch);
              memset(outptr[0], 0, MPA_FRAME_SIZE*sizeof(OUT_INT));
              if (m->nb_channels > 1)
                  memset(outptr[1], 0, MPA_FRAME_SIZE*sizeof(OUT_INT));
              ret = m->nb_channels * MPA_FRAME_SIZE*sizeof(OUT_INT);
          }
  
          out_size += ret;
          buf      += fsize;
          len      -= fsize;
  
          avctx->bit_rate += m->bit_rate;
      }
      if (ch != avctx->channels) {
          av_log(avctx, AV_LOG_ERROR, "failed to decode all channels\n");
          return AVERROR_INVALIDDATA;
      }
  
      /* update codec info */
      avctx->sample_rate = s->mp3decctx[0]->sample_rate;
  
      frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));
      *got_frame_ptr    = 1;
  
      return buf_size;
  }
  #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */
  