/*
  * WMA compatible codec

  * Copyright (c) 2002-2007 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
  */
 

 #include "libavutil/attributes.h"

 #include "avcodec.h"

 #include "sinewin.h"

 #include "wma.h"

 #include "wma_common.h"

 #include "wma_freqs.h"

 #include "wmadata.h"
 
 #undef NDEBUG
 #include <assert.h>
 
 /* XXX: use same run/length optimization as mpeg decoders */

 // FIXME maybe split decode / encode or pass flag

 static av_cold void init_coef_vlc(VLC *vlc, uint16_t **prun_table,
                                   float **plevel_table, uint16_t **pint_table,
                                   const CoefVLCTable *vlc_table)

 {

     int n                        = vlc_table->n;

     const uint8_t  *table_bits   = vlc_table->huffbits;
     const uint32_t *table_codes  = vlc_table->huffcodes;

     const uint16_t *levels_table = vlc_table->levels;
     uint16_t *run_table, *level_table, *int_table;

     float *flevel_table;

     int i, l, j, k, level;
 
     init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
 

     run_table    = av_malloc_array(n, sizeof(uint16_t));
     level_table  = av_malloc_array(n, sizeof(uint16_t));
     flevel_table = av_malloc_array(n, sizeof(*flevel_table));
     int_table    = av_malloc_array(n, sizeof(uint16_t));

     i            = 2;
     level        = 1;
     k            = 0;

     while (i < n) {

         int_table[k] = i;

         l            = levels_table[k++];

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

             run_table[i]    = j;
             level_table[i]  = level;
             flevel_table[i] = level;

             i++;
         }
         level++;
     }

     *prun_table   = run_table;

     *plevel_table = flevel_table;

     *pint_table   = int_table;

     av_free(level_table);

 }
 

 av_cold int ff_wma_init(AVCodecContext *avctx, int flags2)

 {

     WMACodecContext *s = avctx->priv_data;

     int i;
     float bps1, high_freq;
     volatile float bps;
     int sample_rate1;
     int coef_vlc_table;
 

     if (avctx->sample_rate <= 0 || avctx->sample_rate > 50000 ||
         avctx->channels    <= 0 || avctx->channels    > 2     ||
         avctx->bit_rate    <= 0)

         return -1;
 

     ff_fmt_convert_init(&s->fmt_conv, avctx);

     avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);

     if (avctx->codec->id == AV_CODEC_ID_WMAV1)

         s->version = 1;

     else

         s->version = 2;
 
     /* compute MDCT block size */

     s->frame_len_bits = ff_wma_get_frame_len_bits(avctx->sample_rate,
                                                   s->version, 0);

     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;

     s->frame_len = 1 << s->frame_len_bits;
     if (s->use_variable_block_len) {
         int nb_max, nb;
         nb = ((flags2 >> 3) & 3) + 1;

         if ((avctx->bit_rate / avctx->channels) >= 32000)

             nb += 2;
         nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
         if (nb > nb_max)
             nb = nb_max;
         s->nb_block_sizes = nb + 1;

     } else

         s->nb_block_sizes = 1;
 

     /* init rate dependent parameters */

     s->use_noise_coding = 1;

     high_freq           = avctx->sample_rate * 0.5;

 
     /* if version 2, then the rates are normalized */

     sample_rate1 = avctx->sample_rate;

     if (s->version == 2) {

         if (sample_rate1 >= 44100)

             sample_rate1 = 44100;

         else if (sample_rate1 >= 22050)

             sample_rate1 = 22050;

         else if (sample_rate1 >= 16000)

             sample_rate1 = 16000;

         else if (sample_rate1 >= 11025)

             sample_rate1 = 11025;

         else if (sample_rate1 >= 8000)

             sample_rate1 = 8000;
     }
 

     bps                 = (float) avctx->bit_rate /
                           (float) (avctx->channels * avctx->sample_rate);
     s->byte_offset_bits = av_log2((int) (bps * s->frame_len / 8.0 + 0.5)) + 2;

     if (s->byte_offset_bits + 3 > MIN_CACHE_BITS) {
         av_log(avctx, AV_LOG_ERROR, "byte_offset_bits %d is too large\n", s->byte_offset_bits);
         return AVERROR_PATCHWELCOME;
     }

 
     /* compute high frequency value and choose if noise coding should

      * be activated */

     bps1 = bps;

     if (avctx->channels == 2)

         bps1 = bps * 1.6;
     if (sample_rate1 == 44100) {

         if (bps1 >= 0.61)

             s->use_noise_coding = 0;

         else

             high_freq = high_freq * 0.4;
     } else if (sample_rate1 == 22050) {

         if (bps1 >= 1.16)

             s->use_noise_coding = 0;

         else if (bps1 >= 0.72)

             high_freq = high_freq * 0.7;

         else

             high_freq = high_freq * 0.6;
     } else if (sample_rate1 == 16000) {

         if (bps > 0.5)

             high_freq = high_freq * 0.5;

         else

             high_freq = high_freq * 0.3;

     } else if (sample_rate1 == 11025)

         high_freq = high_freq * 0.7;

     else if (sample_rate1 == 8000) {
         if (bps <= 0.625)

             high_freq = high_freq * 0.5;

         else if (bps > 0.75)

             s->use_noise_coding = 0;

         else

             high_freq = high_freq * 0.65;
     } else {

         if (bps >= 0.8)

             high_freq = high_freq * 0.75;

         else if (bps >= 0.6)

             high_freq = high_freq * 0.6;

         else

             high_freq = high_freq * 0.5;
     }

     av_dlog(s->avctx, "flags2=0x%x\n", flags2);
     av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",

             s->version, avctx->channels, avctx->sample_rate, avctx->bit_rate,
             avctx->block_align);

     av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",

             bps, bps1, high_freq, s->byte_offset_bits);

     av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",

             s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);

 
     /* compute the scale factor band sizes for each MDCT block size */
     {
         int a, b, pos, lpos, k, block_len, i, j, n;
         const uint8_t *table;
 

         if (s->version == 1)

             s->coefs_start = 3;

         else

             s->coefs_start = 0;

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

             block_len = s->frame_len >> k;
 
             if (s->version == 1) {
                 lpos = 0;

                 for (i = 0; i < 25; i++) {

                     a   = ff_wma_critical_freqs[i];
                     b   = avctx->sample_rate;

                     pos = ((block_len * 2 * a) + (b >> 1)) / b;

                     if (pos > block_len)
                         pos = block_len;
                     s->exponent_bands[0][i] = pos - lpos;
                     if (pos >= block_len) {
                         i++;
                         break;
                     }
                     lpos = pos;
                 }
                 s->exponent_sizes[0] = i;
             } else {
                 /* hardcoded tables */
                 table = NULL;

                 a     = s->frame_len_bits - BLOCK_MIN_BITS - k;

                 if (a < 3) {

                     if (avctx->sample_rate >= 44100)

                         table = exponent_band_44100[a];

                     else if (avctx->sample_rate >= 32000)

                         table = exponent_band_32000[a];

                     else if (avctx->sample_rate >= 22050)

                         table = exponent_band_22050[a];
                 }
                 if (table) {
                     n = *table++;

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

                         s->exponent_bands[k][i] = table[i];
                     s->exponent_sizes[k] = n;
                 } else {

                     j    = 0;

                     lpos = 0;

                     for (i = 0; i < 25; i++) {

                         a     = ff_wma_critical_freqs[i];
                         b     = avctx->sample_rate;
                         pos   = ((block_len * 2 * a) + (b << 1)) / (4 * b);

                         pos <<= 2;
                         if (pos > block_len)
                             pos = block_len;
                         if (pos > lpos)
                             s->exponent_bands[k][j++] = pos - lpos;
                         if (pos >= block_len)
                             break;
                         lpos = pos;
                     }
                     s->exponent_sizes[k] = j;
                 }
             }
 
             /* max number of coefs */
             s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
             /* high freq computation */

             s->high_band_start[k] = (int) ((block_len * 2 * high_freq) /
                                            avctx->sample_rate + 0.5);
             n   = s->exponent_sizes[k];
             j   = 0;

             pos = 0;

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

                 int start, end;
                 start = pos;

                 pos  += s->exponent_bands[k][i];
                 end   = pos;

                 if (start < s->high_band_start[k])
                     start = s->high_band_start[k];
                 if (end > s->coefs_end[k])
                     end = s->coefs_end[k];
                 if (end > start)
                     s->exponent_high_bands[k][j++] = end - start;
             }
             s->exponent_high_sizes[k] = j;
 #if 0

             tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",

                     s->frame_len >> k,
                     s->coefs_end[k],
                     s->high_band_start[k],
                     s->exponent_high_sizes[k]);
             for (j = 0; j < s->exponent_high_sizes[k]; j++)

                 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
             tprintf(s->avctx, "\n");

 #endif /* 0 */

         }
     }
 
 #ifdef TRACE
     {
         int i, j;

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

             tprintf(s->avctx, "%5d: n=%2d:",

                     s->frame_len >> i,
                     s->exponent_sizes[i]);
             for (j = 0; j < s->exponent_sizes[i]; j++)

                 tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
             tprintf(s->avctx, "\n");

         }
     }

 #endif /* TRACE */

     /* init MDCT windows : simple sine window */

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

         ff_init_ff_sine_windows(s->frame_len_bits - i);

         s->windows[i] = ff_sine_windows[s->frame_len_bits - i];

     }
 
     s->reset_block_lengths = 1;
 
     if (s->use_noise_coding) {
         /* init the noise generator */

         if (s->use_exp_vlc)

             s->noise_mult = 0.02;

         else

             s->noise_mult = 0.04;
 
 #ifdef TRACE

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

             s->noise_table[i] = 1.0 * s->noise_mult;
 #else
         {
             unsigned int seed;
             float norm;
             seed = 1;

             norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * s->noise_mult;

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

                 seed              = seed * 314159 + 1;
                 s->noise_table[i] = (float) ((int) seed) * norm;

             }
         }

 #endif /* TRACE */

     }
 
     /* choose the VLC tables for the coefficients */
     coef_vlc_table = 2;

     if (avctx->sample_rate >= 32000) {

         if (bps1 < 0.72)

             coef_vlc_table = 0;

         else if (bps1 < 1.16)

             coef_vlc_table = 1;
     }

     s->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
     s->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
     init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
                   &s->int_table[0], s->coef_vlcs[0]);
     init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
                   &s->int_table[1], s->coef_vlcs[1]);

 
     return 0;
 }
 

 int ff_wma_total_gain_to_bits(int total_gain)
 {

     if (total_gain < 15)
         return 13;
     else if (total_gain < 32)
         return 12;
     else if (total_gain < 40)
         return 11;
     else if (total_gain < 45)
         return 10;
     else
         return  9;

 }
 
 int ff_wma_end(AVCodecContext *avctx)
 {

     WMACodecContext *s = avctx->priv_data;

     int i;
 

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

         ff_mdct_end(&s->mdct_ctx[i]);
 

     if (s->use_exp_vlc)

         ff_free_vlc(&s->exp_vlc);

     if (s->use_noise_coding)

         ff_free_vlc(&s->hgain_vlc);

     for (i = 0; i < 2; i++) {

         ff_free_vlc(&s->coef_vlc[i]);

         av_freep(&s->run_table[i]);
         av_freep(&s->level_table[i]);
         av_freep(&s->int_table[i]);

     }
 
     return 0;
 }

 
 /**

  * Decode an uncompressed coefficient.

  * @param gb GetBitContext

  * @return the decoded coefficient
  */

 unsigned int ff_wma_get_large_val(GetBitContext *gb)

 {
     /** consumes up to 34 bits */
     int n_bits = 8;
     /** decode length */
     if (get_bits1(gb)) {
         n_bits += 8;
         if (get_bits1(gb)) {
             n_bits += 8;

             if (get_bits1(gb))

                 n_bits += 7;
         }
     }
     return get_bits_long(gb, n_bits);
 }
 
 /**

  * Decode run level compressed coefficients.
  * @param avctx codec context
  * @param gb bitstream reader context
  * @param vlc vlc table for get_vlc2
  * @param level_table level codes
  * @param run_table run codes
  * @param version 0 for wma1,2 1 for wmapro
  * @param ptr output buffer
  * @param offset offset in the output buffer
  * @param num_coefs number of input coefficents
  * @param block_len input buffer length (2^n)
  * @param frame_len_bits number of bits for escaped run codes
  * @param coef_nb_bits number of bits for escaped level codes
  * @return 0 on success, -1 otherwise
  */

 int ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb,
                             VLC *vlc, const float *level_table,
                             const uint16_t *run_table, int version,
                             WMACoef *ptr, int offset, int num_coefs,
                             int block_len, int frame_len_bits,

                             int coef_nb_bits)
 {

     int code, level, sign;

     const uint32_t *ilvl = (const uint32_t *) level_table;
     uint32_t *iptr = (uint32_t *) ptr;

     const unsigned int coef_mask = block_len - 1;
     for (; offset < num_coefs; offset++) {

         code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);

         if (code > 1) {
             /** normal code */

             offset                  += run_table[code];
             sign                     = get_bits1(gb) - 1;
             iptr[offset & coef_mask] = ilvl[code] ^ sign << 31;

         } else if (code == 1) {

             /** EOB */

             break;

         } else {

             /** escape */

             if (!version) {

                 level = get_bits(gb, coef_nb_bits);

                 /** NOTE: this is rather suboptimal. reading

                  *  block_len_bits would be better */

                 offset += get_bits(gb, frame_len_bits);

             } else {
                 level = ff_wma_get_large_val(gb);
                 /** escape decode */
                 if (get_bits1(gb)) {
                     if (get_bits1(gb)) {
                         if (get_bits1(gb)) {

                             av_log(avctx, AV_LOG_ERROR,
                                    "broken escape sequence\n");

                             return -1;
                         } else

                             offset += get_bits(gb, frame_len_bits) + 4;

                     } else

                         offset += get_bits(gb, 2) + 1;
                 }

             }

             sign                    = get_bits1(gb) - 1;
             ptr[offset & coef_mask] = (level ^ sign) - sign;

         }
     }

     /** NOTE: EOB can be omitted */
     if (offset > num_coefs) {
         av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
         return -1;
     }
 

     return 0;
 }