/*
  * WMA compatible decoder

  * Copyright (c) 2002 The FFmpeg Project

  *

  * 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

  * WMA compatible decoder.

  * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.

  * WMA v1 is identified by audio format 0x160 in Microsoft media files

  * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.
  *
  * To use this decoder, a calling application must supply the extra data
  * bytes provided with the WMA data. These are the extra, codec-specific

  * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes
  * to the decoder using the extradata[_size] fields in AVCodecContext. There

  * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.

  */
 

 #include "libavutil/attributes.h"

 #include "avcodec.h"

 #include "internal.h"

 #include "wma.h"

 #define EXPVLCBITS 8

 #define EXPMAX     ((19 + EXPVLCBITS - 1) / EXPVLCBITS)

 
 #define HGAINVLCBITS 9

 #define HGAINMAX     ((13 + HGAINVLCBITS - 1) / HGAINVLCBITS)

 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);

 #ifdef TRACE

 static void dump_floats(WMACodecContext *s, const char *name,
                         int prec, const float *tab, int n)

 {
     int i;
 

     ff_tlog(s->avctx, "%s[%d]:\n", name, n);

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

         if ((i & 7) == 0)

             ff_tlog(s->avctx, "%4d: ", i);
         ff_tlog(s->avctx, " %8.*f", prec, tab[i]);

         if ((i & 7) == 7)

             ff_tlog(s->avctx, "\n");

     }
     if ((i & 7) != 0)

         ff_tlog(s->avctx, "\n");

 }

 #endif /* TRACE */

 static av_cold int wma_decode_init(AVCodecContext *avctx)

 {

     WMACodecContext *s = avctx->priv_data;

     int i, flags2;

     uint8_t *extradata;

     if (!avctx->block_align) {
         av_log(avctx, AV_LOG_ERROR, "block_align is not set\n");
         return AVERROR(EINVAL);
     }
 

     s->avctx = avctx;
 

     /* extract flag infos */

     flags2    = 0;

     extradata = avctx->extradata;

     if (avctx->codec->id == AV_CODEC_ID_WMAV1 && avctx->extradata_size >= 4)
         flags2 = AV_RL16(extradata + 2);
     else if (avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 6)
         flags2 = AV_RL16(extradata + 4);

     s->use_exp_vlc            = flags2 & 0x0001;
     s->use_bit_reservoir      = flags2 & 0x0002;

     s->use_variable_block_len = flags2 & 0x0004;
 

     if (avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 8){
         if (AV_RL16(extradata+4)==0xd && s->use_variable_block_len){

             av_log(avctx, AV_LOG_WARNING, "Disabling use_variable_block_len, if this fails contact the ffmpeg developers and send us the file\n");
             s->use_variable_block_len= 0; // this fixes issue1503
         }
     }
 

     for (i=0; i<MAX_CHANNELS; i++)
         s->max_exponent[i] = 1.0;
 

     if (ff_wma_init(avctx, flags2) < 0)

         return -1;

 
     /* init MDCT */

     for (i = 0; i < s->nb_block_sizes; i++)

         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0 / 32768.0);

     if (s->use_noise_coding) {

         init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
                  ff_wma_hgain_huffbits, 1, 1,
                  ff_wma_hgain_huffcodes, 2, 2, 0);

     }
 

     if (s->use_exp_vlc)
         init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), // FIXME move out of context

                  ff_aac_scalefactor_bits, 1, 1,
                  ff_aac_scalefactor_code, 4, 4, 0);

     else

         wma_lsp_to_curve_init(s, s->frame_len);
 

     avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;

     return 0;
 }
 

 /**
  * compute x^-0.25 with an exponent and mantissa table. We use linear
  * interpolation to reduce the mantissa table size at a small speed
  * expense (linear interpolation approximately doubles the number of
  * bits of precision).
  */

 static inline float pow_m1_4(WMACodecContext *s, float x)

 {
     union {
         float f;
         unsigned int v;
     } u, t;
     unsigned int e, m;
     float a, b;
 
     u.f = x;

     e   =  u.v >>  23;
     m   = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);

     /* build interpolation scale: 1 <= t < 2. */
     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);

     a   = s->lsp_pow_m_table1[m];
     b   = s->lsp_pow_m_table2[m];

     return s->lsp_pow_e_table[e] * (a + b * t.f);
 }
 

 static av_cold void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)

 {

     float wdel, a, b;
     int i, e, m;
 
     wdel = M_PI / frame_len;

     for (i = 0; i < frame_len; i++)

         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 
     /* tables for x^-0.25 computation */

     for (i = 0; i < 256; i++) {
         e                     = i - 126;

         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
     }
 
     /* NOTE: these two tables are needed to avoid two operations in

      * pow_m1_4 */

     b = 1.0;

     for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
         m                      = (1 << LSP_POW_BITS) + i;
         a                      = (float) m * (0.5 / (1 << LSP_POW_BITS));
         a                      = pow(a, -0.25);

         s->lsp_pow_m_table1[i] = 2 * a - b;
         s->lsp_pow_m_table2[i] = b - a;

         b                      = a;

     }
 }
 

 /**
  * NOTE: We use the same code as Vorbis here
  * @todo optimize it further with SSE/3Dnow
  */

 static void wma_lsp_to_curve(WMACodecContext *s, float *out, float *val_max_ptr,

                              int n, float *lsp)
 {
     int i, j;
     float p, q, w, v, val_max;
 
     val_max = 0;

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

         p = 0.5f;
         q = 0.5f;
         w = s->lsp_cos_table[i];

         for (j = 1; j < NB_LSP_COEFS; j += 2) {

             q *= w - lsp[j - 1];
             p *= w - lsp[j];
         }
         p *= p * (2.0f - w);
         q *= q * (2.0f + w);

         v  = p + q;
         v  = pow_m1_4(s, v);

         if (v > val_max)
             val_max = v;
         out[i] = v;
     }
     *val_max_ptr = val_max;
 }
 

 /**
  * decode exponents coded with LSP coefficients (same idea as Vorbis)
  */

 static void decode_exp_lsp(WMACodecContext *s, int ch)

 {
     float lsp_coefs[NB_LSP_COEFS];
     int val, i;
 

     for (i = 0; i < NB_LSP_COEFS; i++) {

         if (i == 0 || i >= 8)
             val = get_bits(&s->gb, 3);
         else
             val = get_bits(&s->gb, 4);

         lsp_coefs[i] = ff_wma_lsp_codebook[i][val];

     }
 
     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
                      s->block_len, lsp_coefs);
 }
 

 /** pow(10, i / 16.0) for i in -60..95 */

 static const float pow_tab[] = {

     1.7782794100389e-04, 2.0535250264571e-04,
     2.3713737056617e-04, 2.7384196342644e-04,
     3.1622776601684e-04, 3.6517412725484e-04,
     4.2169650342858e-04, 4.8696752516586e-04,
     5.6234132519035e-04, 6.4938163157621e-04,
     7.4989420933246e-04, 8.6596432336006e-04,
     1.0000000000000e-03, 1.1547819846895e-03,
     1.3335214321633e-03, 1.5399265260595e-03,
     1.7782794100389e-03, 2.0535250264571e-03,
     2.3713737056617e-03, 2.7384196342644e-03,
     3.1622776601684e-03, 3.6517412725484e-03,
     4.2169650342858e-03, 4.8696752516586e-03,
     5.6234132519035e-03, 6.4938163157621e-03,
     7.4989420933246e-03, 8.6596432336006e-03,
     1.0000000000000e-02, 1.1547819846895e-02,
     1.3335214321633e-02, 1.5399265260595e-02,
     1.7782794100389e-02, 2.0535250264571e-02,
     2.3713737056617e-02, 2.7384196342644e-02,
     3.1622776601684e-02, 3.6517412725484e-02,
     4.2169650342858e-02, 4.8696752516586e-02,
     5.6234132519035e-02, 6.4938163157621e-02,
     7.4989420933246e-02, 8.6596432336007e-02,
     1.0000000000000e-01, 1.1547819846895e-01,
     1.3335214321633e-01, 1.5399265260595e-01,
     1.7782794100389e-01, 2.0535250264571e-01,
     2.3713737056617e-01, 2.7384196342644e-01,
     3.1622776601684e-01, 3.6517412725484e-01,
     4.2169650342858e-01, 4.8696752516586e-01,
     5.6234132519035e-01, 6.4938163157621e-01,
     7.4989420933246e-01, 8.6596432336007e-01,
     1.0000000000000e+00, 1.1547819846895e+00,
     1.3335214321633e+00, 1.5399265260595e+00,
     1.7782794100389e+00, 2.0535250264571e+00,
     2.3713737056617e+00, 2.7384196342644e+00,
     3.1622776601684e+00, 3.6517412725484e+00,
     4.2169650342858e+00, 4.8696752516586e+00,
     5.6234132519035e+00, 6.4938163157621e+00,
     7.4989420933246e+00, 8.6596432336007e+00,
     1.0000000000000e+01, 1.1547819846895e+01,
     1.3335214321633e+01, 1.5399265260595e+01,
     1.7782794100389e+01, 2.0535250264571e+01,
     2.3713737056617e+01, 2.7384196342644e+01,
     3.1622776601684e+01, 3.6517412725484e+01,
     4.2169650342858e+01, 4.8696752516586e+01,
     5.6234132519035e+01, 6.4938163157621e+01,
     7.4989420933246e+01, 8.6596432336007e+01,
     1.0000000000000e+02, 1.1547819846895e+02,
     1.3335214321633e+02, 1.5399265260595e+02,
     1.7782794100389e+02, 2.0535250264571e+02,
     2.3713737056617e+02, 2.7384196342644e+02,
     3.1622776601684e+02, 3.6517412725484e+02,
     4.2169650342858e+02, 4.8696752516586e+02,
     5.6234132519035e+02, 6.4938163157621e+02,
     7.4989420933246e+02, 8.6596432336007e+02,
     1.0000000000000e+03, 1.1547819846895e+03,
     1.3335214321633e+03, 1.5399265260595e+03,
     1.7782794100389e+03, 2.0535250264571e+03,
     2.3713737056617e+03, 2.7384196342644e+03,
     3.1622776601684e+03, 3.6517412725484e+03,
     4.2169650342858e+03, 4.8696752516586e+03,
     5.6234132519035e+03, 6.4938163157621e+03,
     7.4989420933246e+03, 8.6596432336007e+03,
     1.0000000000000e+04, 1.1547819846895e+04,
     1.3335214321633e+04, 1.5399265260595e+04,

     1.7782794100389e+04, 2.0535250264571e+04,
     2.3713737056617e+04, 2.7384196342644e+04,
     3.1622776601684e+04, 3.6517412725484e+04,
     4.2169650342858e+04, 4.8696752516586e+04,

     5.6234132519035e+04, 6.4938163157621e+04,
     7.4989420933246e+04, 8.6596432336007e+04,
     1.0000000000000e+05, 1.1547819846895e+05,
     1.3335214321633e+05, 1.5399265260595e+05,
     1.7782794100389e+05, 2.0535250264571e+05,
     2.3713737056617e+05, 2.7384196342644e+05,
     3.1622776601684e+05, 3.6517412725484e+05,
     4.2169650342858e+05, 4.8696752516586e+05,
     5.6234132519035e+05, 6.4938163157621e+05,
     7.4989420933246e+05, 8.6596432336007e+05,

 };
 

 /**
  * decode exponents coded with VLC codes
  */

 static int decode_exp_vlc(WMACodecContext *s, int ch)

 {
     int last_exp, n, code;

     const uint16_t *ptr;

     float v, max_scale;
     uint32_t *q, *q_end, iv;

     const float *ptab = pow_tab + 60;

     const uint32_t *iptab = (const uint32_t *) ptab;

     ptr       = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
     q         = (uint32_t *) s->exponents[ch];
     q_end     = q + s->block_len;

     max_scale = 0;
     if (s->version == 1) {

         last_exp  = get_bits(&s->gb, 5) + 10;
         v         = ptab[last_exp];
         iv        = iptab[last_exp];

         max_scale = v;

         n         = *ptr++;

         switch (n & 3) do {
         case 0: *q++ = iv;
         case 3: *q++ = iv;
         case 2: *q++ = iv;
         case 1: *q++ = iv;
         } while ((n -= 4) > 0);

     } else

         last_exp = 36;
 

     while (q < q_end) {

         code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);

         if (code < 0) {

             av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");

             return -1;

         }

         /* NOTE: this offset is the same as MPEG4 AAC ! */
         last_exp += code - 60;

         if ((unsigned) last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {

             av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
                    last_exp);

             return -1;

         }

         v  = ptab[last_exp];

         iv = iptab[last_exp];

         if (v > max_scale)
             max_scale = v;
         n = *ptr++;

         switch (n & 3) do {
         case 0: *q++ = iv;
         case 3: *q++ = iv;
         case 2: *q++ = iv;
         case 1: *q++ = iv;
         } while ((n -= 4) > 0);

     }
     s->max_exponent[ch] = max_scale;
     return 0;
 }
 

 /**
  * Apply MDCT window and add into output.
  *
  * We ensure that when the windows overlap their squared sum
  * is always 1 (MDCT reconstruction rule).
  */
 static void wma_window(WMACodecContext *s, float *out)
 {
     float *in = s->output;
     int block_len, bsize, n;
 
     /* left part */
     if (s->block_len_bits <= s->prev_block_len_bits) {
         block_len = s->block_len;

         bsize     = s->frame_len_bits - s->block_len_bits;

         s->fdsp->vector_fmul_add(out, in, s->windows[bsize],

                                 out, block_len);

     } else {
         block_len = 1 << s->prev_block_len_bits;

         n         = (s->block_len - block_len) / 2;
         bsize     = s->frame_len_bits - s->prev_block_len_bits;

         s->fdsp->vector_fmul_add(out + n, in + n, s->windows[bsize],

                                 out + n, block_len);

         memcpy(out + n + block_len, in + n + block_len, n * sizeof(float));

     }
 
     out += s->block_len;

     in  += s->block_len;

 
     /* right part */
     if (s->block_len_bits <= s->next_block_len_bits) {
         block_len = s->block_len;

         bsize     = s->frame_len_bits - s->block_len_bits;

         s->fdsp->vector_fmul_reverse(out, in, s->windows[bsize], block_len);

     } else {
         block_len = 1 << s->next_block_len_bits;

         n         = (s->block_len - block_len) / 2;
         bsize     = s->frame_len_bits - s->next_block_len_bits;

         memcpy(out, in, n * sizeof(float));

         s->fdsp->vector_fmul_reverse(out + n, in + n, s->windows[bsize],

                                     block_len);

         memset(out + n + block_len, 0, n * sizeof(float));

     }
 }
 

 /**
  * @return 0 if OK. 1 if last block of frame. return -1 if
  * unrecorrable error.
  */

 static int wma_decode_block(WMACodecContext *s)

 {

     int n, v, a, ch, bsize;

     int coef_nb_bits, total_gain;

     int nb_coefs[MAX_CHANNELS];
     float mdct_norm;

     FFTContext *mdct;

 #ifdef TRACE

     ff_tlog(s->avctx, "***decode_block: %d:%d\n",

             s->frame_count - 1, s->block_num);
 #endif /* TRACE */

 
     /* compute current block length */
     if (s->use_variable_block_len) {
         n = av_log2(s->nb_block_sizes - 1) + 1;

         if (s->reset_block_lengths) {
             s->reset_block_lengths = 0;

             v                      = get_bits(&s->gb, n);
             if (v >= s->nb_block_sizes) {
                 av_log(s->avctx, AV_LOG_ERROR,
                        "prev_block_len_bits %d out of range\n",
                        s->frame_len_bits - v);

                 return -1;

             }

             s->prev_block_len_bits = s->frame_len_bits - v;

             v                      = get_bits(&s->gb, n);
             if (v >= s->nb_block_sizes) {
                 av_log(s->avctx, AV_LOG_ERROR,
                        "block_len_bits %d out of range\n",
                        s->frame_len_bits - v);

                 return -1;

             }

             s->block_len_bits = s->frame_len_bits - v;
         } else {
             /* update block lengths */
             s->prev_block_len_bits = s->block_len_bits;

             s->block_len_bits      = s->next_block_len_bits;

         }
         v = get_bits(&s->gb, n);

         if (v >= s->nb_block_sizes) {
             av_log(s->avctx, AV_LOG_ERROR,
                    "next_block_len_bits %d out of range\n",
                    s->frame_len_bits - v);

             return -1;

         }

         s->next_block_len_bits = s->frame_len_bits - v;
     } else {
         /* fixed block len */
         s->next_block_len_bits = s->frame_len_bits;
         s->prev_block_len_bits = s->frame_len_bits;

         s->block_len_bits      = s->frame_len_bits;

     }
 

     if (s->frame_len_bits - s->block_len_bits >= s->nb_block_sizes){
         av_log(s->avctx, AV_LOG_ERROR, "block_len_bits not initialized to a valid value\n");
         return -1;
     }
 

     /* now check if the block length is coherent with the frame length */
     s->block_len = 1 << s->block_len_bits;

     if ((s->block_pos + s->block_len) > s->frame_len) {

         av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");

         return -1;

     }

     if (s->avctx->channels == 2)

         s->ms_stereo = get_bits1(&s->gb);

     v = 0;

     for (ch = 0; ch < s->avctx->channels; ch++) {
         a                    = get_bits1(&s->gb);

         s->channel_coded[ch] = a;

         v                   |= a;

     }

 
     bsize = s->frame_len_bits - s->block_len_bits;
 

     /* if no channel coded, no need to go further */
     /* XXX: fix potential framing problems */
     if (!v)
         goto next;
 
     /* read total gain and extract corresponding number of bits for

      * coef escape coding */

     total_gain = 1;

     for (;;) {

         if (get_bits_left(&s->gb) < 7) {
             av_log(s->avctx, AV_LOG_ERROR, "total_gain overread\n");
             return AVERROR_INVALIDDATA;
         }

         a           = get_bits(&s->gb, 7);

         total_gain += a;
         if (a != 127)
             break;
     }

     coef_nb_bits = ff_wma_total_gain_to_bits(total_gain);

 
     /* compute number of coefficients */
     n = s->coefs_end[bsize] - s->coefs_start;

     for (ch = 0; ch < s->avctx->channels; ch++)

         nb_coefs[ch] = n;
 
     /* complex coding */
     if (s->use_noise_coding) {

         for (ch = 0; ch < s->avctx->channels; ch++) {

             if (s->channel_coded[ch]) {
                 int i, n, a;
                 n = s->exponent_high_sizes[bsize];

                 for (i = 0; i < n; i++) {
                     a                         = get_bits1(&s->gb);

                     s->high_band_coded[ch][i] = a;
                     /* if noise coding, the coefficients are not transmitted */
                     if (a)
                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
                 }
             }
         }

         for (ch = 0; ch < s->avctx->channels; ch++) {

             if (s->channel_coded[ch]) {
                 int i, n, val, code;
 

                 n   = s->exponent_high_sizes[bsize];
                 val = (int) 0x80000000;
                 for (i = 0; i < n; i++) {

                     if (s->high_band_coded[ch][i]) {

                         if (val == (int) 0x80000000) {

                             val = get_bits(&s->gb, 7) - 19;
                         } else {

                             code = get_vlc2(&s->gb, s->hgain_vlc.table,
                                             HGAINVLCBITS, HGAINMAX);
                             if (code < 0) {
                                 av_log(s->avctx, AV_LOG_ERROR,
                                        "hgain vlc invalid\n");

                                 return -1;

                             }

                             val += code - 18;
                         }
                         s->high_band_values[ch][i] = val;
                     }
                 }
             }
         }
     }

     /* exponents can be reused in short blocks. */

     if ((s->block_len_bits == s->frame_len_bits) || get_bits1(&s->gb)) {
         for (ch = 0; ch < s->avctx->channels; ch++) {

             if (s->channel_coded[ch]) {
                 if (s->use_exp_vlc) {
                     if (decode_exp_vlc(s, ch) < 0)
                         return -1;
                 } else {
                     decode_exp_lsp(s, ch);
                 }

                 s->exponents_bsize[ch] = bsize;

             }
         }
     }
 
     /* parse spectral coefficients : just RLE encoding */

     for (ch = 0; ch < s->avctx->channels; ch++) {

         if (s->channel_coded[ch]) {

             int tindex;

             WMACoef *ptr = &s->coefs1[ch][0];

 
             /* special VLC tables are used for ms stereo because

              * there is potentially less energy there */

             tindex = (ch == 1 && s->ms_stereo);

             memset(ptr, 0, s->block_len * sizeof(WMACoef));

             ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],

                                     s->level_table[tindex], s->run_table[tindex],
                                     0, ptr, 0, nb_coefs[ch],
                                     s->block_len, s->frame_len_bits, coef_nb_bits);

         }

         if (s->version == 1 && s->avctx->channels >= 2)

             align_get_bits(&s->gb);
     }

     /* normalize */
     {
         int n4 = s->block_len / 2;

         mdct_norm = 1.0 / (float) n4;
         if (s->version == 1)

             mdct_norm *= sqrt(n4);
     }
 
     /* finally compute the MDCT coefficients */

     for (ch = 0; ch < s->avctx->channels; ch++) {

         if (s->channel_coded[ch]) {

             WMACoef *coefs1;

             float *coefs, *exponents, mult, mult1, noise;
             int i, j, n, n1, last_high_band, esize;

             float exp_power[HIGH_BAND_MAX_SIZE];
 

             coefs1    = s->coefs1[ch];

             exponents = s->exponents[ch];

             esize     = s->exponents_bsize[ch];
             mult      = pow(10, total_gain * 0.05) / s->max_exponent[ch];
             mult     *= mdct_norm;
             coefs     = s->coefs[ch];

             if (s->use_noise_coding) {
                 mult1 = mult;
                 /* very low freqs : noise */

                 for (i = 0; i < s->coefs_start; i++) {

                     *coefs++ = s->noise_table[s->noise_index] *

                                exponents[i << bsize >> esize] * mult1;
                     s->noise_index = (s->noise_index + 1) &
                                      (NOISE_TAB_SIZE - 1);

                 }

                 n1 = s->exponent_high_sizes[bsize];
 
                 /* compute power of high bands */

                 exponents = s->exponents[ch] +

                             (s->high_band_start[bsize] << bsize >> esize);

                 last_high_band = 0; /* avoid warning */

                 for (j = 0; j < n1; j++) {

                     n = s->exponent_high_bands[s->frame_len_bits -

                                                s->block_len_bits][j];

                     if (s->high_band_coded[ch][j]) {
                         float e2, v;
                         e2 = 0;

                         for (i = 0; i < n; i++) {
                             v   = exponents[i << bsize >> esize];

                             e2 += v * v;
                         }

                         exp_power[j]   = e2 / n;

                         last_high_band = j;

                         ff_tlog(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);

                     }

                     exponents += n << bsize >> esize;

                 }
 
                 /* main freqs and high freqs */

                 exponents = s->exponents[ch] + (s->coefs_start << bsize >> esize);
                 for (j = -1; j < n1; j++) {
                     if (j < 0)
                         n = s->high_band_start[bsize] - s->coefs_start;
                     else

                         n = s->exponent_high_bands[s->frame_len_bits -

                                                    s->block_len_bits][j];

                     if (j >= 0 && s->high_band_coded[ch][j]) {
                         /* use noise with specified power */
                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);

                         /* XXX: use a table */

                         mult1  = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
                         mult1  = mult1 / (s->max_exponent[ch] * s->noise_mult);

                         mult1 *= mdct_norm;

                         for (i = 0; i < n; i++) {
                             noise          = s->noise_table[s->noise_index];

                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);

                             *coefs++       = noise * exponents[i << bsize >> esize] * mult1;

                         }

                         exponents += n << bsize >> esize;

                     } else {
                         /* coded values + small noise */

                         for (i = 0; i < n; i++) {
                             noise          = s->noise_table[s->noise_index];

                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);

                             *coefs++       = ((*coefs1++) + noise) *
                                              exponents[i << bsize >> esize] * mult;

                         }

                         exponents += n << bsize >> esize;

                     }
                 }
 
                 /* very high freqs : noise */

                 n     = s->block_len - s->coefs_end[bsize];

                 mult1 = mult * exponents[(-(1 << bsize)) >> esize];

                 for (i = 0; i < n; i++) {
                     *coefs++       = s->noise_table[s->noise_index] * mult1;

                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
                 }
             } else {
                 /* XXX: optimize more */

                 for (i = 0; i < s->coefs_start; i++)

                     *coefs++ = 0.0;
                 n = nb_coefs[ch];

                 for (i = 0; i < n; i++)
                     *coefs++ = coefs1[i] * exponents[i << bsize >> esize] * mult;

                 n = s->block_len - s->coefs_end[bsize];

                 for (i = 0; i < n; i++)

                     *coefs++ = 0.0;
             }
         }
     }
 

 #ifdef TRACE

     for (ch = 0; ch < s->avctx->channels; ch++) {

         if (s->channel_coded[ch]) {

             dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
             dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);

         }
     }

 #endif /* TRACE */

     if (s->ms_stereo && s->channel_coded[1]) {
         /* nominal case for ms stereo: we do it before mdct */
         /* no need to optimize this case because it should almost

          * never happen */

         if (!s->channel_coded[0]) {

             ff_tlog(s->avctx, "rare ms-stereo case happened\n");

             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
             s->channel_coded[0] = 1;
         }

         s->fdsp->butterflies_float(s->coefs[0], s->coefs[1], s->block_len);

     }
 

 next:

     mdct = &s->mdct_ctx[bsize];
 

     for (ch = 0; ch < s->avctx->channels; ch++) {

         int n4, index;

         n4 = s->block_len / 2;

         if (s->channel_coded[ch])

             mdct->imdct_calc(mdct, s->output, s->coefs[ch]);

         else if (!(s->ms_stereo && ch == 1))

             memset(s->output, 0, sizeof(s->output));
 
         /* multiply by the window and add in the frame */
         index = (s->frame_len / 2) + s->block_pos - n4;
         wma_window(s, &s->frame_out[ch][index]);

     }

     /* update block number */
     s->block_num++;
     s->block_pos += s->block_len;
     if (s->block_pos >= s->frame_len)
         return 1;
     else
         return 0;
 }
 
 /* decode a frame of frame_len samples */

 static int wma_decode_frame(WMACodecContext *s, float **samples,
                             int samples_offset)

 {

     int ret, ch;

 #ifdef TRACE

     ff_tlog(s->avctx, "***decode_frame: %d size=%d\n",

             s->frame_count++, s->frame_len);
 #endif /* TRACE */

 
     /* read each block */
     s->block_num = 0;
     s->block_pos = 0;

     for (;;) {

         ret = wma_decode_block(s);

         if (ret < 0)

             return -1;
         if (ret)
             break;
     }
 

     for (ch = 0; ch < s->avctx->channels; ch++) {

         /* copy current block to output */
         memcpy(samples[ch] + samples_offset, s->frame_out[ch],
                s->frame_len * sizeof(*s->frame_out[ch]));

         /* prepare for next block */

         memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
                 s->frame_len * sizeof(*s->frame_out[ch]));

 #ifdef TRACE

         dump_floats(s, "samples", 6, samples[ch] + samples_offset,
                     s->frame_len);
 #endif /* TRACE */

     }
 

     return 0;
 }
 

 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
                                  int *got_frame_ptr, AVPacket *avpkt)

 {

     AVFrame *frame = data;

     const uint8_t *buf = avpkt->data;

     int buf_size       = avpkt->size;

     WMACodecContext *s = avctx->priv_data;

     int nb_frames, bit_offset, i, pos, len, ret;

     uint8_t *q;

     float **samples;
     int samples_offset;

     ff_tlog(avctx, "***decode_superframe:\n");

     if (buf_size == 0) {

         s->last_superframe_len = 0;
         return 0;
     }

     if (buf_size < avctx->block_align) {

         av_log(avctx, AV_LOG_ERROR,
                "Input packet size too small (%d < %d)\n",

                buf_size, avctx->block_align);

         return AVERROR_INVALIDDATA;
     }

     if (avctx->block_align)

         buf_size = avctx->block_align;

     init_get_bits(&s->gb, buf, buf_size * 8);

     if (s->use_bit_reservoir) {
         /* read super frame header */

         skip_bits(&s->gb, 4); /* super frame index */

         nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);

         if (nb_frames <= 0) {

             int is_error = nb_frames < 0 || get_bits_left(&s->gb) <= 8;
             av_log(avctx, is_error ? AV_LOG_ERROR : AV_LOG_WARNING,
                    "nb_frames is %d bits left %d\n",

                    nb_frames, get_bits_left(&s->gb));

             if (is_error)
                 return AVERROR_INVALIDDATA;
 
             if ((s->last_superframe_len + buf_size - 1) >
                 MAX_CODED_SUPERFRAME_SIZE)
                 goto fail;
 
             q   = s->last_superframe + s->last_superframe_len;
             len = buf_size - 1;
             while (len > 0) {
                 *q++ = get_bits (&s->gb, 8);
                 len --;
             }

             memset(q, 0, AV_INPUT_BUFFER_PADDING_SIZE);

 
             s->last_superframe_len += 8*buf_size - 8;
 //             s->reset_block_lengths = 1; //XXX is this needed ?
             *got_frame_ptr = 0;
             return buf_size;

         }

     } else

         nb_frames = 1;

     /* get output buffer */

     frame->nb_samples = nb_frames * s->frame_len;

     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

         return ret;

     samples        = (float **) frame->extended_data;

     samples_offset = 0;

     if (s->use_bit_reservoir) {

         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);

         if (bit_offset > get_bits_left(&s->gb)) {
             av_log(avctx, AV_LOG_ERROR,
                    "Invalid last frame bit offset %d > buf size %d (%d)\n",
                    bit_offset, get_bits_left(&s->gb), buf_size);
             goto fail;
         }

 
         if (s->last_superframe_len > 0) {
             /* add bit_offset bits to last frame */

             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >

                 MAX_CODED_SUPERFRAME_SIZE)

                 goto fail;

             q   = s->last_superframe + s->last_superframe_len;

             len = bit_offset;

             while (len > 7) {

                 *q++ = (get_bits) (&s->gb, 8);

                 len -= 8;
             }

             if (len > 0)
                 *q++ = (get_bits) (&s->gb, len) << (8 - len);

             memset(q, 0, AV_INPUT_BUFFER_PADDING_SIZE);

             /* XXX: bit_offset bits into last frame */

             init_get_bits(&s->gb, s->last_superframe,
                           s->last_superframe_len * 8 + bit_offset);

             /* skip unused bits */
             if (s->last_bitoffset > 0)
                 skip_bits(&s->gb, s->last_bitoffset);
             /* this frame is stored in the last superframe and in the

              * current one */

             if (wma_decode_frame(s, samples, samples_offset) < 0)

                 goto fail;

             samples_offset += s->frame_len;

             nb_frames--;

         }
 
         /* read each frame starting from bit_offset */
         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;

         if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)

             return AVERROR_INVALIDDATA;

         init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3)) * 8);

         len = pos & 7;
         if (len > 0)
             skip_bits(&s->gb, len);

         s->reset_block_lengths = 1;

         for (i = 0; i < nb_frames; i++) {

             if (wma_decode_frame(s, samples, samples_offset) < 0)

                 goto fail;

             samples_offset += s->frame_len;

         }
 
         /* we copy the end of the frame in the last frame buffer */

         pos               = get_bits_count(&s->gb) +
                             ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);

         s->last_bitoffset = pos & 7;

         pos             >>= 3;
         len               = buf_size - pos;

         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {

             av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);

             goto fail;

         }
         s->last_superframe_len = len;
         memcpy(s->last_superframe, buf + pos, len);
     } else {
         /* single frame decode */

         if (wma_decode_frame(s, samples, samples_offset) < 0)

             goto fail;

         samples_offset += s->frame_len;

     }

     ff_dlog(s->avctx, "%d %d %d %d outbytes:%"PTRDIFF_SPECIFIER" eaten:%d\n",

             s->frame_len_bits, s->block_len_bits, s->frame_len, s->block_len,

             (int8_t *) samples - (int8_t *) data, avctx->block_align);

     *got_frame_ptr = 1;

     return buf_size;

 
 fail:

     /* when error, we reset the bit reservoir */
     s->last_superframe_len = 0;
     return -1;

 }
 

 static av_cold void flush(AVCodecContext *avctx)
 {
     WMACodecContext *s = avctx->priv_data;
 

     s->last_bitoffset      =
     s->last_superframe_len = 0;

 }
 

 #if CONFIG_WMAV1_DECODER

 AVCodec ff_wmav1_decoder = {
     .name           = "wmav1",

     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_WMAV1,

     .priv_data_size = sizeof(WMACodecContext),
     .init           = wma_decode_init,
     .close          = ff_wma_end,
     .decode         = wma_decode_superframe,
     .flush          = flush,

     .capabilities   = AV_CODEC_CAP_DR1,

     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                       AV_SAMPLE_FMT_NONE },

 };

 #endif
 #if CONFIG_WMAV2_DECODER

 AVCodec ff_wmav2_decoder = {
     .name           = "wmav2",

     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_WMAV2,

     .priv_data_size = sizeof(WMACodecContext),
     .init           = wma_decode_init,
     .close          = ff_wma_end,
     .decode         = wma_decode_superframe,
     .flush          = flush,

     .capabilities   = AV_CODEC_CAP_DR1,

     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                       AV_SAMPLE_FMT_NONE },

 };

 #endif