PeerStreamer

/*

 * 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 "avcodec.h"

#include "wma.h"

#undef NDEBUG

#include <assert.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_shorts(WMACodecContext *s, const char *name, const short *tab, int n)

{

    int i;

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

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

        if ((i & 7) == 0)

            tprintf(s->avctx, "%4d: ", i);

        tprintf(s->avctx, " %5d.0", tab[i]);

        if ((i & 7) == 7)

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

    }

}

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

{

    int i;

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

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

        if ((i & 7) == 0)

            tprintf(s->avctx, "%4d: ", i);

        tprintf(s->avctx, " %8.*f", prec, tab[i]);

        if ((i & 7) == 7)

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

    }

    if ((i & 7) != 0)

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

}

#endif

static int wma_decode_init(AVCodecContext * avctx)

{

    WMACodecContext *s = avctx->priv_data;

    int i, flags2;

    uint8_t *extradata;

    s->avctx = avctx;

    /* extract flag infos */

    flags2 = 0;

    extradata = avctx->extradata;

    if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {

        flags2 = AV_RL16(extradata+2);

    } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {

        flags2 = AV_RL16(extradata+4);

    }

// for(i=0; i<avctx->extradata_size; i++)

//     av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);

    s->use_exp_vlc = flags2 & 0x0001;

    s->use_bit_reservoir = flags2 & 0x0002;

    s->use_variable_block_len = flags2 & 0x0004;

    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);

    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_S16;

    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 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;

    }

#if 0

    for(i=1;i<20;i++) {

        float v, r1, r2;

        v = 5.0 / i;

        r1 = pow_m1_4(s, v);

        r2 = pow(v,-0.25);

        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);

    }

#endif

}

/**

 * 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->dsp.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->dsp.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->dsp.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->dsp.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;

#ifdef TRACE

    tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);

#endif

    /* 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;

    }

    /* 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->nb_channels == 2) {

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

    }

    v = 0;

    for(ch = 0; ch < s->nb_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(;;) {

        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->nb_channels; ch++)

        nb_coefs[ch] = n;

    /* complex coding */

    if (s->use_noise_coding) {

        for(ch = 0; ch < s->nb_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->nb_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->nb_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->nb_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->nb_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->nb_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;

                        tprintf(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->nb_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

    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]) {

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

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

            s->channel_coded[0] = 1;

        }

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

    }

next:

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

        int n4, index;

        n4 = s->block_len / 2;

        if(s->channel_coded[ch]){

            ff_imdct_calc(&s->mdct_ctx[bsize], 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, int16_t *samples)

{

    int ret, n, ch, incr;

    const float *output[MAX_CHANNELS];

#ifdef TRACE

    tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);

#endif

    /* 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;

    }

    /* convert frame to integer */

    n = s->frame_len;

    incr = s->nb_channels;

    for (ch = 0; ch < MAX_CHANNELS; ch++)

        output[ch] = s->frame_out[ch];

    s->dsp.float_to_int16_interleave(samples, output, n, incr);

    for (ch = 0; ch < incr; ch++) {

        /* prepare for next block */

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

    }

#ifdef TRACE

    dump_shorts(s, "samples", samples, n * s->nb_channels);

#endif

    return 0;

}

static int wma_decode_superframe(AVCodecContext *avctx,

                                 void *data, int *data_size,

                                 AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    WMACodecContext *s = avctx->priv_data;

    int nb_frames, bit_offset, i, pos, len;

    uint8_t *q;

    int16_t *samples;

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

    if(buf_size==0){

        s->last_superframe_len = 0;

        return 0;

    }

    if (buf_size < s->block_align)

        return 0;

    buf_size = s->block_align;

    samples = data;

    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) - 1;

        if((nb_frames+1) * s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){

            av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");

            goto fail;

        }

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

        if (s->last_superframe_len > 0) {

            //        printf("skip=%d\n", s->last_bitoffset);

            /* 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);

            }

            /* XXX: bit_offset bits into last frame */

            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);

            /* 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) < 0)

                goto fail;

            samples += s->nb_channels * s->frame_len;

        }

        /* read each frame starting from bit_offset */

        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;

        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_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) < 0)

                goto fail;

            samples += s->nb_channels * 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 {

        if(s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){

            av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");

            goto fail;

        }

        /* single frame decode */

        if (wma_decode_frame(s, samples) < 0)

            goto fail;

        samples += s->nb_channels * s->frame_len;

    }

//av_log(NULL, AV_LOG_ERROR, "%d %d %d %d outbytes:%d eaten:%d\n", s->frame_len_bits, s->block_len_bits, s->frame_len, s->block_len,        (int8_t *)samples - (int8_t *)data, s->block_align);

    *data_size = (int8_t *)samples - (int8_t *)data;

    return s->block_align;

 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;

}