libavcodec/wma.c - nest-android-app/ffmpeg - Git at Google

 /*
  * 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 "internal.h"
 #include "sinewin.h"
 #include "wma.h"
 #include "wma_common.h"
 #include "wma_freqs.h"
 #include "wmadata.h"

 /* XXX: use same run/length optimization as mpeg decoders */
 // FIXME maybe split decode / encode or pass flag
 static av_cold int 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));
     if (!run_table || !level_table || !flevel_table || !int_table) {
         av_freep(&run_table);
         av_freep(&level_table);
         av_freep(&flevel_table);
         av_freep(&int_table);
         return AVERROR(ENOMEM);
     }
     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);

     return 0;
 }

 av_cold int ff_wma_init(AVCodecContext *avctx, int flags2)
 {
     WMACodecContext *s = avctx->priv_data;
     int i, ret;
     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;


     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;
     }
     ff_dlog(s->avctx, "flags2=0x%x\n", flags2);
     ff_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%"PRId64" block_align=%d\n",
             s->version, avctx->channels, avctx->sample_rate, (int64_t)avctx->bit_rate,
             avctx->block_align);
     ff_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
             bps, bps1, high_freq, s->byte_offset_bits);
     ff_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
             ff_tlog(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++)
                 ff_tlog(s->avctx, " %d", s->exponent_high_bands[k][j]);
             ff_tlog(s->avctx, "\n");
 #endif /* 0 */
         }
     }

 #ifdef TRACE
     {
         int i, j;
         for (i = 0; i < s->nb_block_sizes; i++) {
             ff_tlog(s->avctx, "%5d: n=%2d:",
                     s->frame_len >> i,
                     s->exponent_sizes[i]);
             for (j = 0; j < s->exponent_sizes[i]; j++)
                 ff_tlog(s->avctx, " %d", s->exponent_bands[i][j]);
             ff_tlog(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 */
     }

     s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
     if (!s->fdsp)
         return AVERROR(ENOMEM);

     /* 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];
     ret = init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
                         &s->int_table[0], s->coef_vlcs[0]);
     if (ret < 0)
         return ret;

     return init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
                          &s->int_table[1], s->coef_vlcs[1]);
 }

 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]);
     }
     av_freep(&s->fdsp);

     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 & 0x80000000);
         } 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 (%d > %d) in spectral RLE, ignoring\n",
                offset,
                num_coefs
               );
         return -1;
     }

     return 0;
 }
	/*
	* 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 "internal.h"
	#include "sinewin.h"
	#include "wma.h"
	#include "wma_common.h"
	#include "wma_freqs.h"
	#include "wmadata.h"

	/* XXX: use same run/length optimization as mpeg decoders */
	// FIXME maybe split decode / encode or pass flag
	static av_cold int 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));
	if (!run_table \|\| !level_table \|\| !flevel_table \|\| !int_table) {
	av_freep(&run_table);
	av_freep(&level_table);
	av_freep(&flevel_table);
	av_freep(&int_table);
	return AVERROR(ENOMEM);
	}
	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);

	return 0;
	}

	av_cold int ff_wma_init(AVCodecContext *avctx, int flags2)
	{
	WMACodecContext *s = avctx->priv_data;
	int i, ret;
	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;


	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;
	}
	ff_dlog(s->avctx, "flags2=0x%x\n", flags2);
	ff_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%"PRId64" block_align=%d\n",
	s->version, avctx->channels, avctx->sample_rate, (int64_t)avctx->bit_rate,
	avctx->block_align);
	ff_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
	bps, bps1, high_freq, s->byte_offset_bits);
	ff_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
	ff_tlog(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++)
	ff_tlog(s->avctx, " %d", s->exponent_high_bands[k][j]);
	ff_tlog(s->avctx, "\n");
	#endif /* 0 */
	}
	}

	#ifdef TRACE
	{
	int i, j;
	for (i = 0; i < s->nb_block_sizes; i++) {
	ff_tlog(s->avctx, "%5d: n=%2d:",
	s->frame_len >> i,
	s->exponent_sizes[i]);
	for (j = 0; j < s->exponent_sizes[i]; j++)
	ff_tlog(s->avctx, " %d", s->exponent_bands[i][j]);
	ff_tlog(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 */
	}

	s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
	if (!s->fdsp)
	return AVERROR(ENOMEM);

	/* 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];
	ret = init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
	&s->int_table[0], s->coef_vlcs[0]);
	if (ret < 0)
	return ret;

	return init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
	&s->int_table[1], s->coef_vlcs[1]);
	}

	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]);
	}
	av_freep(&s->fdsp);

	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 & 0x80000000);
	} 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 (%d > %d) in spectral RLE, ignoring\n",
	offset,
	num_coefs
	);
	return -1;
	}

	return 0;
	}