PeerStreamer

/*

 * COOK compatible decoder

 * Copyright (c) 2003 Sascha Sommer

 * Copyright (c) 2005 Benjamin Larsson

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * Cook compatible decoder. Bastardization of the G.722.1 standard.

 * This decoder handles RealNetworks, RealAudio G2 data.

 * Cook is identified by the codec name cook in RM files.

 *

 * To use this decoder, a calling application must supply the extradata

 * bytes provided from the RM container; 8+ bytes for mono streams and

 * 16+ for stereo streams (maybe more).

 *

 * Codec technicalities (all this assume a buffer length of 1024):

 * Cook works with several different techniques to achieve its compression.

 * In the timedomain the buffer is divided into 8 pieces and quantized. If

 * two neighboring pieces have different quantization index a smooth

 * quantization curve is used to get a smooth overlap between the different

 * pieces.

 * To get to the transformdomain Cook uses a modulated lapped transform.

 * The transform domain has 50 subbands with 20 elements each. This

 * means only a maximum of 50*20=1000 coefficients are used out of the 1024

 * available.

 */

#include <math.h>

#include <stddef.h>

#include <stdio.h>

#include "libavutil/lfg.h"

#include "libavutil/random_seed.h"

#include "avcodec.h"

#include "get_bits.h"

#include "dsputil.h"

#include "bytestream.h"

#include "fft.h"

#include "libavutil/audioconvert.h"

#include "sinewin.h"

#include "cookdata.h"

/* the different Cook versions */

#define MONO            0x1000001

#define STEREO          0x1000002

#define JOINT_STEREO    0x1000003

#define MC_COOK         0x2000000   //multichannel Cook, not supported

#define SUBBAND_SIZE    20

#define MAX_SUBPACKETS   5

//#define COOKDEBUG

typedef struct {

    int *now;

    int *previous;

} cook_gains;

typedef struct {

    int                 ch_idx;

    int                 size;

    int                 num_channels;

    int                 cookversion;

    int                 samples_per_frame;

    int                 subbands;

    int                 js_subband_start;

    int                 js_vlc_bits;

    int                 samples_per_channel;

    int                 log2_numvector_size;

    unsigned int        channel_mask;

    VLC                 ccpl;                 ///< channel coupling

    int                 joint_stereo;

    int                 bits_per_subpacket;

    int                 bits_per_subpdiv;

    int                 total_subbands;

    int                 numvector_size;       ///< 1 << log2_numvector_size;

    float               mono_previous_buffer1[1024];

    float               mono_previous_buffer2[1024];

    /** gain buffers */

    cook_gains          gains1;

    cook_gains          gains2;

    int                 gain_1[9];

    int                 gain_2[9];

    int                 gain_3[9];

    int                 gain_4[9];

} COOKSubpacket;

typedef struct cook {

    /*

     * The following 5 functions provide the lowlevel arithmetic on

     * the internal audio buffers.

     */

    void (* scalar_dequant)(struct cook *q, int index, int quant_index,

                            int* subband_coef_index, int* subband_coef_sign,

                            float* mlt_p);

    void (* decouple) (struct cook *q,

                       COOKSubpacket *p,

                       int subband,

                       float f1, float f2,

                       float *decode_buffer,

                       float *mlt_buffer1, float *mlt_buffer2);

    void (* imlt_window) (struct cook *q, float *buffer1,

                          cook_gains *gains_ptr, float *previous_buffer);

    void (* interpolate) (struct cook *q, float* buffer,

                          int gain_index, int gain_index_next);

    void (* saturate_output) (struct cook *q, int chan, int16_t *out);

    AVCodecContext*     avctx;

    GetBitContext       gb;

    /* stream data */

    int                 nb_channels;

    int                 bit_rate;

    int                 sample_rate;

    int                 num_vectors;

    int                 samples_per_channel;

    /* states */

    AVLFG               random_state;

    /* transform data */

    FFTContext          mdct_ctx;

    float*              mlt_window;

    /* VLC data */

    VLC                 envelope_quant_index[13];

    VLC                 sqvh[7];          //scalar quantization

    /* generatable tables and related variables */

    int                 gain_size_factor;

    float               gain_table[23];

    /* data buffers */

    uint8_t*            decoded_bytes_buffer;

    DECLARE_ALIGNED(16, float,mono_mdct_output)[2048];

    float               decode_buffer_1[1024];

    float               decode_buffer_2[1024];

    float               decode_buffer_0[1060]; /* static allocation for joint decode */

    const float         *cplscales[5];

    int                 num_subpackets;

    COOKSubpacket       subpacket[MAX_SUBPACKETS];

} COOKContext;

static float     pow2tab[127];

static float rootpow2tab[127];

/* debug functions */

#ifdef COOKDEBUG

static void dump_float_table(float* table, int size, int delimiter) {

    int i=0;

    av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i);

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

        av_log(NULL, AV_LOG_ERROR, "%5.1f, ", table[i]);

        if ((i+1)%delimiter == 0) av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i+1);

    }

}

static void dump_int_table(int* table, int size, int delimiter) {

    int i=0;

    av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i);

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

        av_log(NULL, AV_LOG_ERROR, "%d, ", table[i]);

        if ((i+1)%delimiter == 0) av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i+1);

    }

}

static void dump_short_table(short* table, int size, int delimiter) {

    int i=0;

    av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i);

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

        av_log(NULL, AV_LOG_ERROR, "%d, ", table[i]);

        if ((i+1)%delimiter == 0) av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i+1);

    }

}

#endif

/*************** init functions ***************/

/* table generator */

static av_cold void init_pow2table(void){

    int i;

    for (i=-63 ; i<64 ; i++){

            pow2tab[63+i]=     pow(2, i);

        rootpow2tab[63+i]=sqrt(pow(2, i));

    }

}

/* table generator */

static av_cold void init_gain_table(COOKContext *q) {

    int i;

    q->gain_size_factor = q->samples_per_channel/8;

    for (i=0 ; i<23 ; i++) {

        q->gain_table[i] = pow(pow2tab[i+52] ,

                               (1.0/(double)q->gain_size_factor));

    }

}

static av_cold int init_cook_vlc_tables(COOKContext *q) {

    int i, result;

    result = 0;

    for (i=0 ; i<13 ; i++) {

        result |= init_vlc (&q->envelope_quant_index[i], 9, 24,

            envelope_quant_index_huffbits[i], 1, 1,

            envelope_quant_index_huffcodes[i], 2, 2, 0);

    }

    av_log(q->avctx,AV_LOG_DEBUG,"sqvh VLC init\n");

    for (i=0 ; i<7 ; i++) {

        result |= init_vlc (&q->sqvh[i], vhvlcsize_tab[i], vhsize_tab[i],

            cvh_huffbits[i], 1, 1,

            cvh_huffcodes[i], 2, 2, 0);

    }

    for(i=0;i<q->num_subpackets;i++){

        if (q->subpacket[i].joint_stereo==1){

            result |= init_vlc (&q->subpacket[i].ccpl, 6, (1<<q->subpacket[i].js_vlc_bits)-1,

                ccpl_huffbits[q->subpacket[i].js_vlc_bits-2], 1, 1,

                ccpl_huffcodes[q->subpacket[i].js_vlc_bits-2], 2, 2, 0);

            av_log(q->avctx,AV_LOG_DEBUG,"subpacket %i Joint-stereo VLC used.\n",i);

        }

    }

    av_log(q->avctx,AV_LOG_DEBUG,"VLC tables initialized.\n");

    return result;

}

static av_cold int init_cook_mlt(COOKContext *q) {

    int j;

    int mlt_size = q->samples_per_channel;

    if ((q->mlt_window = av_malloc(sizeof(float)*mlt_size)) == 0)

      return -1;

    /* Initialize the MLT window: simple sine window. */

    ff_sine_window_init(q->mlt_window, mlt_size);

    for(j=0 ; j<mlt_size ; j++)

        q->mlt_window[j] *= sqrt(2.0 / q->samples_per_channel);

    /* Initialize the MDCT. */

    if (ff_mdct_init(&q->mdct_ctx, av_log2(mlt_size)+1, 1, 1.0)) {

      av_free(q->mlt_window);

      return -1;

    }

    av_log(q->avctx,AV_LOG_DEBUG,"MDCT initialized, order = %d.\n",

           av_log2(mlt_size)+1);

    return 0;

}

static const float *maybe_reformat_buffer32 (COOKContext *q, const float *ptr, int n)

{

    if (1)

        return ptr;

}

static av_cold void init_cplscales_table (COOKContext *q) {

    int i;

    for (i=0;i<5;i++)

        q->cplscales[i] = maybe_reformat_buffer32 (q, cplscales[i], (1<<(i+2))-1);

}

/*************** init functions end ***********/

#define DECODE_BYTES_PAD1(bytes) (3 - ((bytes)+3) % 4)

#define DECODE_BYTES_PAD2(bytes) ((bytes) % 4 + DECODE_BYTES_PAD1(2 * (bytes)))

/**

 * Cook indata decoding, every 32 bits are XORed with 0x37c511f2.

 * Why? No idea, some checksum/error detection method maybe.

 *

 * Out buffer size: extra bytes are needed to cope with

 * padding/misalignment.

 * Subpackets passed to the decoder can contain two, consecutive

 * half-subpackets, of identical but arbitrary size.

 *          1234 1234 1234 1234  extraA extraB

 * Case 1:  AAAA BBBB              0      0

 * Case 2:  AAAA ABBB BB--         3      3

 * Case 3:  AAAA AABB BBBB         2      2

 * Case 4:  AAAA AAAB BBBB BB--    1      5

 *

 * Nice way to waste CPU cycles.

 *

 * @param inbuffer  pointer to byte array of indata

 * @param out       pointer to byte array of outdata

 * @param bytes     number of bytes

 */

static inline int decode_bytes(const uint8_t* inbuffer, uint8_t* out, int bytes){

    int i, off;

    uint32_t c;

    const uint32_t* buf;

    uint32_t* obuf = (uint32_t*) out;

    /* FIXME: 64 bit platforms would be able to do 64 bits at a time.

     * I'm too lazy though, should be something like

     * for(i=0 ; i<bitamount/64 ; i++)

     *     (int64_t)out[i] = 0x37c511f237c511f2^av_be2ne64(int64_t)in[i]);

     * Buffer alignment needs to be checked. */

    off = (intptr_t)inbuffer & 3;

    buf = (const uint32_t*) (inbuffer - off);

    c = av_be2ne32((0x37c511f2 >> (off*8)) | (0x37c511f2 << (32-(off*8))));

    bytes += 3 + off;

    for (i = 0; i < bytes/4; i++)

        obuf[i] = c ^ buf[i];

    return off;

}

/**

 * Cook uninit

 */

static av_cold int cook_decode_close(AVCodecContext *avctx)

{

    int i;

    COOKContext *q = avctx->priv_data;

    av_log(avctx,AV_LOG_DEBUG, "Deallocating memory.\n");

    /* Free allocated memory buffers. */

    av_free(q->mlt_window);

    av_free(q->decoded_bytes_buffer);

    /* Free the transform. */

    ff_mdct_end(&q->mdct_ctx);

    /* Free the VLC tables. */

    for (i=0 ; i<13 ; i++) {

        free_vlc(&q->envelope_quant_index[i]);

    }

    for (i=0 ; i<7 ; i++) {

        free_vlc(&q->sqvh[i]);

    }

    for (i=0 ; i<q->num_subpackets ; i++) {

        free_vlc(&q->subpacket[i].ccpl);

    }

    av_log(avctx,AV_LOG_DEBUG,"Memory deallocated.\n");

    return 0;

}

/**

 * Fill the gain array for the timedomain quantization.

 *

 * @param gb          pointer to the GetBitContext

 * @param gaininfo[9] array of gain indexes

 */

static void decode_gain_info(GetBitContext *gb, int *gaininfo)

{

    int i, n;

    while (get_bits1(gb)) {}

    n = get_bits_count(gb) - 1;     //amount of elements*2 to update

    i = 0;

    while (n--) {

        int index = get_bits(gb, 3);

        int gain = get_bits1(gb) ? get_bits(gb, 4) - 7 : -1;

        while (i <= index) gaininfo[i++] = gain;

    }

    while (i <= 8) gaininfo[i++] = 0;

}

/**

 * Create the quant index table needed for the envelope.

 *

 * @param q                 pointer to the COOKContext

 * @param quant_index_table pointer to the array

 */

static void decode_envelope(COOKContext *q, COOKSubpacket *p, int* quant_index_table) {

    int i,j, vlc_index;

    quant_index_table[0]= get_bits(&q->gb,6) - 6;       //This is used later in categorize

    for (i=1 ; i < p->total_subbands ; i++){

        vlc_index=i;

        if (i >= p->js_subband_start * 2) {

            vlc_index-=p->js_subband_start;

        } else {

            vlc_index/=2;

            if(vlc_index < 1) vlc_index = 1;

        }

        if (vlc_index>13) vlc_index = 13;           //the VLC tables >13 are identical to No. 13

        j = get_vlc2(&q->gb, q->envelope_quant_index[vlc_index-1].table,

                     q->envelope_quant_index[vlc_index-1].bits,2);

        quant_index_table[i] = quant_index_table[i-1] + j - 12;    //differential encoding

    }

}

/**

 * Calculate the category and category_index vector.

 *

 * @param q                     pointer to the COOKContext

 * @param quant_index_table     pointer to the array

 * @param category              pointer to the category array

 * @param category_index        pointer to the category_index array

 */

static void categorize(COOKContext *q, COOKSubpacket *p, int* quant_index_table,

                       int* category, int* category_index){

    int exp_idx, bias, tmpbias1, tmpbias2, bits_left, num_bits, index, v, i, j;

    int exp_index2[102];

    int exp_index1[102];

    int tmp_categorize_array[128*2];

    int tmp_categorize_array1_idx=p->numvector_size;

    int tmp_categorize_array2_idx=p->numvector_size;

    bits_left =  p->bits_per_subpacket - get_bits_count(&q->gb);

    if(bits_left > q->samples_per_channel) {

        bits_left = q->samples_per_channel +

                    ((bits_left - q->samples_per_channel)*5)/8;

        //av_log(q->avctx, AV_LOG_ERROR, "bits_left = %d\n",bits_left);

    }

    memset(&exp_index1,0,102*sizeof(int));

    memset(&exp_index2,0,102*sizeof(int));

    memset(&tmp_categorize_array,0,128*2*sizeof(int));

    bias=-32;

    /* Estimate bias. */

    for (i=32 ; i>0 ; i=i/2){

        num_bits = 0;

        index = 0;

        for (j=p->total_subbands ; j>0 ; j--){

            exp_idx = av_clip((i - quant_index_table[index] + bias) / 2, 0, 7);

            index++;

            num_bits+=expbits_tab[exp_idx];

        }

        if(num_bits >= bits_left - 32){

            bias+=i;

        }

    }

    /* Calculate total number of bits. */

    num_bits=0;

    for (i=0 ; i<p->total_subbands ; i++) {

        exp_idx = av_clip((bias - quant_index_table[i]) / 2, 0, 7);

        num_bits += expbits_tab[exp_idx];

        exp_index1[i] = exp_idx;

        exp_index2[i] = exp_idx;

    }

    tmpbias1 = tmpbias2 = num_bits;

    for (j = 1 ; j < p->numvector_size ; j++) {

        if (tmpbias1 + tmpbias2 > 2*bits_left) {  /* ---> */

            int max = -999999;

            index=-1;

            for (i=0 ; i<p->total_subbands ; i++){

                if (exp_index1[i] < 7) {

                    v = (-2*exp_index1[i]) - quant_index_table[i] + bias;

                    if ( v >= max) {

                        max = v;

                        index = i;

                    }

                }

            }

            if(index==-1)break;

            tmp_categorize_array[tmp_categorize_array1_idx++] = index;

            tmpbias1 -= expbits_tab[exp_index1[index]] -

                        expbits_tab[exp_index1[index]+1];

            ++exp_index1[index];

        } else {  /* <--- */

            int min = 999999;

            index=-1;

            for (i=0 ; i<p->total_subbands ; i++){

                if(exp_index2[i] > 0){

                    v = (-2*exp_index2[i])-quant_index_table[i]+bias;

                    if ( v < min) {

                        min = v;

                        index = i;

                    }

                }

            }

            if(index == -1)break;

            tmp_categorize_array[--tmp_categorize_array2_idx] = index;

            tmpbias2 -= expbits_tab[exp_index2[index]] -

                        expbits_tab[exp_index2[index]-1];

            --exp_index2[index];

        }

    }

    for(i=0 ; i<p->total_subbands ; i++)

        category[i] = exp_index2[i];

    for(i=0 ; i<p->numvector_size-1 ; i++)

        category_index[i] = tmp_categorize_array[tmp_categorize_array2_idx++];

}

/**

 * Expand the category vector.

 *

 * @param q                     pointer to the COOKContext

 * @param category              pointer to the category array

 * @param category_index        pointer to the category_index array

 */

static inline void expand_category(COOKContext *q, int* category,

                                   int* category_index){

    int i;

    for(i=0 ; i<q->num_vectors ; i++){

        ++category[category_index[i]];

    }

}

/**

 * The real requantization of the mltcoefs

 *

 * @param q                     pointer to the COOKContext

 * @param index                 index

 * @param quant_index           quantisation index

 * @param subband_coef_index    array of indexes to quant_centroid_tab

 * @param subband_coef_sign     signs of coefficients

 * @param mlt_p                 pointer into the mlt buffer

 */

static void scalar_dequant_float(COOKContext *q, int index, int quant_index,

                           int* subband_coef_index, int* subband_coef_sign,

                           float* mlt_p){

    int i;

    float f1;

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

        if (subband_coef_index[i]) {

            f1 = quant_centroid_tab[index][subband_coef_index[i]];

            if (subband_coef_sign[i]) f1 = -f1;

        } else {

            /* noise coding if subband_coef_index[i] == 0 */

            f1 = dither_tab[index];

            if (av_lfg_get(&q->random_state) < 0x80000000) f1 = -f1;

        }

        mlt_p[i] = f1 * rootpow2tab[quant_index+63];

    }

}

/**

 * Unpack the subband_coef_index and subband_coef_sign vectors.

 *

 * @param q                     pointer to the COOKContext

 * @param category              pointer to the category array

 * @param subband_coef_index    array of indexes to quant_centroid_tab

 * @param subband_coef_sign     signs of coefficients

 */

static int unpack_SQVH(COOKContext *q, COOKSubpacket *p, int category, int* subband_coef_index,

                       int* subband_coef_sign) {

    int i,j;

    int vlc, vd ,tmp, result;

    vd = vd_tab[category];

    result = 0;

    for(i=0 ; i<vpr_tab[category] ; i++){

        vlc = get_vlc2(&q->gb, q->sqvh[category].table, q->sqvh[category].bits, 3);

        if (p->bits_per_subpacket < get_bits_count(&q->gb)){

            vlc = 0;

            result = 1;

        }

        for(j=vd-1 ; j>=0 ; j--){

            tmp = (vlc * invradix_tab[category])/0x100000;

            subband_coef_index[vd*i+j] = vlc - tmp * (kmax_tab[category]+1);

            vlc = tmp;

        }

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

            if (subband_coef_index[i*vd + j]) {

                if(get_bits_count(&q->gb) < p->bits_per_subpacket){

                    subband_coef_sign[i*vd+j] = get_bits1(&q->gb);

                } else {

                    result=1;

                    subband_coef_sign[i*vd+j]=0;

                }

            } else {

                subband_coef_sign[i*vd+j]=0;

            }

        }

    }

    return result;

}

/**

 * Fill the mlt_buffer with mlt coefficients.

 *

 * @param q                 pointer to the COOKContext

 * @param category          pointer to the category array

 * @param quant_index_table pointer to the array

 * @param mlt_buffer        pointer to mlt coefficients

 */

static void decode_vectors(COOKContext* q, COOKSubpacket* p, int* category,

                           int *quant_index_table, float* mlt_buffer){

    /* A zero in this table means that the subband coefficient is

       random noise coded. */

    int subband_coef_index[SUBBAND_SIZE];

    /* A zero in this table means that the subband coefficient is a

       positive multiplicator. */

    int subband_coef_sign[SUBBAND_SIZE];

    int band, j;

    int index=0;

    for(band=0 ; band<p->total_subbands ; band++){

        index = category[band];

        if(category[band] < 7){

            if(unpack_SQVH(q, p, category[band], subband_coef_index, subband_coef_sign)){

                index=7;

                for(j=0 ; j<p->total_subbands ; j++) category[band+j]=7;

            }

        }

        if(index>=7) {

            memset(subband_coef_index, 0, sizeof(subband_coef_index));

            memset(subband_coef_sign, 0, sizeof(subband_coef_sign));

        }

        q->scalar_dequant(q, index, quant_index_table[band],

                          subband_coef_index, subband_coef_sign,

                          &mlt_buffer[band * SUBBAND_SIZE]);

    }

    if(p->total_subbands*SUBBAND_SIZE >= q->samples_per_channel){

        return;

    } /* FIXME: should this be removed, or moved into loop above? */

}

/**

 * function for decoding mono data

 *

 * @param q                 pointer to the COOKContext

 * @param mlt_buffer        pointer to mlt coefficients

 */

static void mono_decode(COOKContext *q, COOKSubpacket *p, float* mlt_buffer) {

    int category_index[128];

    int quant_index_table[102];

    int category[128];

    memset(&category, 0, 128*sizeof(int));

    memset(&category_index, 0, 128*sizeof(int));

    decode_envelope(q, p, quant_index_table);

    q->num_vectors = get_bits(&q->gb,p->log2_numvector_size);

    categorize(q, p, quant_index_table, category, category_index);

    expand_category(q, category, category_index);

    decode_vectors(q, p, category, quant_index_table, mlt_buffer);

}

/**

 * the actual requantization of the timedomain samples

 *

 * @param q                 pointer to the COOKContext

 * @param buffer            pointer to the timedomain buffer

 * @param gain_index        index for the block multiplier

 * @param gain_index_next   index for the next block multiplier

 */

static void interpolate_float(COOKContext *q, float* buffer,

                        int gain_index, int gain_index_next){

    int i;

    float fc1, fc2;

    fc1 = pow2tab[gain_index+63];

    if(gain_index == gain_index_next){              //static gain

        for(i=0 ; i<q->gain_size_factor ; i++){

            buffer[i]*=fc1;

        }

        return;

    } else {                                        //smooth gain

        fc2 = q->gain_table[11 + (gain_index_next-gain_index)];

        for(i=0 ; i<q->gain_size_factor ; i++){

            buffer[i]*=fc1;

            fc1*=fc2;

        }

        return;

    }

}

/**

 * Apply transform window, overlap buffers.

 *

 * @param q                 pointer to the COOKContext

 * @param inbuffer          pointer to the mltcoefficients

 * @param gains_ptr         current and previous gains

 * @param previous_buffer   pointer to the previous buffer to be used for overlapping

 */

static void imlt_window_float (COOKContext *q, float *inbuffer,

                               cook_gains *gains_ptr, float *previous_buffer)

{

    const float fc = pow2tab[gains_ptr->previous[0] + 63];

    int i;

    /* The weird thing here, is that the two halves of the time domain

     * buffer are swapped. Also, the newest data, that we save away for

     * next frame, has the wrong sign. Hence the subtraction below.

     * Almost sounds like a complex conjugate/reverse data/FFT effect.

     */

    /* Apply window and overlap */

    for(i = 0; i < q->samples_per_channel; i++){

        inbuffer[i] = inbuffer[i] * fc * q->mlt_window[i] -

          previous_buffer[i] * q->mlt_window[q->samples_per_channel - 1 - i];

    }

}

/**

 * The modulated lapped transform, this takes transform coefficients

 * and transforms them into timedomain samples.

 * Apply transform window, overlap buffers, apply gain profile

 * and buffer management.

 *

 * @param q                 pointer to the COOKContext

 * @param inbuffer          pointer to the mltcoefficients

 * @param gains_ptr         current and previous gains

 * @param previous_buffer   pointer to the previous buffer to be used for overlapping

 */

static void imlt_gain(COOKContext *q, float *inbuffer,

                      cook_gains *gains_ptr, float* previous_buffer)

{

    float *buffer0 = q->mono_mdct_output;

    float *buffer1 = q->mono_mdct_output + q->samples_per_channel;

    int i;

    /* Inverse modified discrete cosine transform */

    q->mdct_ctx.imdct_calc(&q->mdct_ctx, q->mono_mdct_output, inbuffer);

    q->imlt_window (q, buffer1, gains_ptr, previous_buffer);

    /* Apply gain profile */

    for (i = 0; i < 8; i++) {

        if (gains_ptr->now[i] || gains_ptr->now[i + 1])

            q->interpolate(q, &buffer1[q->gain_size_factor * i],

                           gains_ptr->now[i], gains_ptr->now[i + 1]);

    }

    /* Save away the current to be previous block. */

    memcpy(previous_buffer, buffer0, sizeof(float)*q->samples_per_channel);

}

/**

 * function for getting the jointstereo coupling information

 *

 * @param q                 pointer to the COOKContext

 * @param decouple_tab      decoupling array

 *

 */

static void decouple_info(COOKContext *q, COOKSubpacket *p, int* decouple_tab){

    int length, i;

    if(get_bits1(&q->gb)) {

        if(cplband[p->js_subband_start] > cplband[p->subbands-1]) return;

        length = cplband[p->subbands-1] - cplband[p->js_subband_start] + 1;

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

            decouple_tab[cplband[p->js_subband_start] + i] = get_vlc2(&q->gb, p->ccpl.table, p->ccpl.bits, 2);

        }

        return;

    }

    if(cplband[p->js_subband_start] > cplband[p->subbands-1]) return;

    length = cplband[p->subbands-1] - cplband[p->js_subband_start] + 1;

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

       decouple_tab[cplband[p->js_subband_start] + i] = get_bits(&q->gb, p->js_vlc_bits);

    }

    return;

}

/*

 * function decouples a pair of signals from a single signal via multiplication.

 *

 * @param q                 pointer to the COOKContext

 * @param subband           index of the current subband

 * @param f1                multiplier for channel 1 extraction

 * @param f2                multiplier for channel 2 extraction

 * @param decode_buffer     input buffer

 * @param mlt_buffer1       pointer to left channel mlt coefficients

 * @param mlt_buffer2       pointer to right channel mlt coefficients

 */

static void decouple_float (COOKContext *q,

                            COOKSubpacket *p,

                            int subband,

                            float f1, float f2,

                            float *decode_buffer,

                            float *mlt_buffer1, float *mlt_buffer2)

{

    int j, tmp_idx;

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

        tmp_idx = ((p->js_subband_start + subband)*SUBBAND_SIZE)+j;

        mlt_buffer1[SUBBAND_SIZE*subband + j] = f1 * decode_buffer[tmp_idx];

        mlt_buffer2[SUBBAND_SIZE*subband + j] = f2 * decode_buffer[tmp_idx];

    }

}

/**

 * function for decoding joint stereo data

 *

 * @param q                 pointer to the COOKContext

 * @param mlt_buffer1       pointer to left channel mlt coefficients

 * @param mlt_buffer2       pointer to right channel mlt coefficients

 */

static void joint_decode(COOKContext *q, COOKSubpacket *p, float* mlt_buffer1,

                         float* mlt_buffer2) {

    int i,j;

    int decouple_tab[SUBBAND_SIZE];

    float *decode_buffer = q->decode_buffer_0;

    int idx, cpl_tmp;

    float f1,f2;

    const float* cplscale;

    memset(decouple_tab, 0, sizeof(decouple_tab));

    memset(decode_buffer, 0, sizeof(decode_buffer));

    /* Make sure the buffers are zeroed out. */

    memset(mlt_buffer1,0, 1024*sizeof(float));

    memset(mlt_buffer2,0, 1024*sizeof(float));

    decouple_info(q, p, decouple_tab);

    mono_decode(q, p, decode_buffer);

    /* The two channels are stored interleaved in decode_buffer. */

    for (i=0 ; i<p->js_subband_start ; i++) {

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

            mlt_buffer1[i*20+j] = decode_buffer[i*40+j];

            mlt_buffer2[i*20+j] = decode_buffer[i*40+20+j];

        }

    }

    /* When we reach js_subband_start (the higher frequencies)

       the coefficients are stored in a coupling scheme. */

    idx = (1 << p->js_vlc_bits) - 1;

    for (i=p->js_subband_start ; i<p->subbands ; i++) {

        cpl_tmp = cplband[i];

        idx -=decouple_tab[cpl_tmp];

        cplscale = q->cplscales[p->js_vlc_bits-2];  //choose decoupler table

        f1 = cplscale[decouple_tab[cpl_tmp]];

        f2 = cplscale[idx-1];

        q->decouple (q, p, i, f1, f2, decode_buffer, mlt_buffer1, mlt_buffer2);

        idx = (1 << p->js_vlc_bits) - 1;

    }

}

/**

 * First part of subpacket decoding:

 *  decode raw stream bytes and read gain info.

 *

 * @param q                 pointer to the COOKContext

 * @param inbuffer          pointer to raw stream data

 * @param gains_ptr         array of current/prev gain pointers

 */

static inline void

decode_bytes_and_gain(COOKContext *q, COOKSubpacket *p, const uint8_t *inbuffer,

                      cook_gains *gains_ptr)

{

    int offset;

    offset = decode_bytes(inbuffer, q->decoded_bytes_buffer,

                          p->bits_per_subpacket/8);

    init_get_bits(&q->gb, q->decoded_bytes_buffer + offset,

                  p->bits_per_subpacket);

    decode_gain_info(&q->gb, gains_ptr->now);

    /* Swap current and previous gains */

    FFSWAP(int *, gains_ptr->now, gains_ptr->previous);

}

 /**

 * Saturate the output signal to signed 16bit integers.

 *

 * @param q                 pointer to the COOKContext

 * @param chan              channel to saturate

 * @param out               pointer to the output vector

 */

static void

saturate_output_float (COOKContext *q, int chan, int16_t *out)

{

    int j;

    float *output = q->mono_mdct_output + q->samples_per_channel;

    /* Clip and convert floats to 16 bits.

     */

    for (j = 0; j < q->samples_per_channel; j++) {

        out[chan + q->nb_channels * j] =

          av_clip_int16(lrintf(output[j]));

    }

}

/**

 * Final part of subpacket decoding:

 *  Apply modulated lapped transform, gain compensation,

 *  clip and convert to integer.

 *

 * @param q                 pointer to the COOKContext

 * @param decode_buffer     pointer to the mlt coefficients

 * @param gains_ptr         array of current/prev gain pointers

 * @param previous_buffer   pointer to the previous buffer to be used for overlapping

 * @param out               pointer to the output buffer

 * @param chan              0: left or single channel, 1: right channel

 */

static inline void

mlt_compensate_output(COOKContext *q, float *decode_buffer,

                      cook_gains *gains_ptr, float *previous_buffer,

                      int16_t *out, int chan)

{

    imlt_gain(q, decode_buffer, gains_ptr, previous_buffer);

    q->saturate_output (q, chan, out);

}

/**

 * Cook subpacket decoding. This function returns one decoded subpacket,

 * usually 1024 samples per channel.

 *

 * @param q                 pointer to the COOKContext

 * @param inbuffer          pointer to the inbuffer

 * @param outbuffer         pointer to the outbuffer

 */

static void decode_subpacket(COOKContext *q, COOKSubpacket* p, const uint8_t *inbuffer, int16_t *outbuffer) {

    int sub_packet_size = p->size;

    /* packet dump */

//    for (i=0 ; i<sub_packet_size ; i++) {

//        av_log(q->avctx, AV_LOG_ERROR, "%02x", inbuffer[i]);

//    }

//    av_log(q->avctx, AV_LOG_ERROR, "\n");

    memset(q->decode_buffer_1,0,sizeof(q->decode_buffer_1));

    decode_bytes_and_gain(q, p, inbuffer, &p->gains1);

    if (p->joint_stereo) {

        joint_decode(q, p, q->decode_buffer_1, q->decode_buffer_2);

    } else {

        mono_decode(q, p, q->decode_buffer_1);

        if (p->num_channels == 2) {

            decode_bytes_and_gain(q, p, inbuffer + sub_packet_size/2, &p->gains2);

            mono_decode(q, p, q->decode_buffer_2);

        }

    }

    mlt_compensate_output(q, q->decode_buffer_1, &p->gains1,

                          p->mono_previous_buffer1, outbuffer, p->ch_idx);

    if (p->num_channels == 2) {

        if (p->joint_stereo) {

            mlt_compensate_output(q, q->decode_buffer_2, &p->gains1,

                                  p->mono_previous_buffer2, outbuffer, p->ch_idx + 1);

         } else {

            mlt_compensate_output(q, q->decode_buffer_2, &p->gains2,

                                  p->mono_previous_buffer2, outbuffer, p->ch_idx + 1);

         }

     }

}

/**

 * Cook frame decoding

 *

 * @param avctx     pointer to the AVCodecContext

 */

static int cook_decode_frame(AVCodecContext *avctx,

            void *data, int *data_size,

            AVPacket *avpkt) {

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    COOKContext *q = avctx->priv_data;

    int i;

    int offset = 0;

    int chidx = 0;

    if (buf_size < avctx->block_align)

        return buf_size;

    /* estimate subpacket sizes */

    q->subpacket[0].size = avctx->block_align;

    for(i=1;i<q->num_subpackets;i++){

        q->subpacket[i].size = 2 * buf[avctx->block_align - q->num_subpackets + i];

        q->subpacket[0].size -= q->subpacket[i].size + 1;

        if (q->subpacket[0].size < 0) {

            av_log(avctx,AV_LOG_DEBUG,"frame subpacket size total > avctx->block_align!\n");

            return -1;

        }

    }

    /* decode supbackets */

    *data_size = 0;

    for(i=0;i<q->num_subpackets;i++){

        q->subpacket[i].bits_per_subpacket = (q->subpacket[i].size*8)>>q->subpacket[i].bits_per_subpdiv;

        q->subpacket[i].ch_idx = chidx;

        av_log(avctx,AV_LOG_DEBUG,"subpacket[%i] size %i js %i %i block_align %i\n",i,q->subpacket[i].size,q->subpacket[i].joint_stereo,offset,avctx->block_align);

        decode_subpacket(q, &q->subpacket[i], buf + offset, (int16_t*)data);

        offset += q->subpacket[i].size;

        chidx += q->subpacket[i].num_channels;

        av_log(avctx,AV_LOG_DEBUG,"subpacket[%i] %i %i\n",i,q->subpacket[i].size * 8,get_bits_count(&q->gb));

    }

    *data_size = sizeof(int16_t) * q->nb_channels * q->samples_per_channel;

    /* Discard the first two frames: no valid audio. */

    if (avctx->frame_number < 2) *data_size = 0;

    return avctx->block_align;

}

#ifdef COOKDEBUG

static void dump_cook_context(COOKContext *q)

{

    //int i=0;

#define PRINT(a,b) av_log(q->avctx,AV_LOG_ERROR," %s = %d\n", a, b);

    av_log(q->avctx,AV_LOG_ERROR,"COOKextradata\n");

    av_log(q->avctx,AV_LOG_ERROR,"cookversion=%x\n",q->subpacket[0].cookversion);

    if (q->subpacket[0].cookversion > STEREO) {

        PRINT("js_subband_start",q->subpacket[0].js_subband_start);

        PRINT("js_vlc_bits",q->subpacket[0].js_vlc_bits);

    }

    av_log(q->avctx,AV_LOG_ERROR,"COOKContext\n");

    PRINT("nb_channels",q->nb_channels);

    PRINT("bit_rate",q->bit_rate);

    PRINT("sample_rate",q->sample_rate);

    PRINT("samples_per_channel",q->subpacket[0].samples_per_channel);

    PRINT("samples_per_frame",q->subpacket[0].samples_per_frame);

    PRINT("subbands",q->subpacket[0].subbands);

    PRINT("random_state",q->random_state);

    PRINT("js_subband_start",q->subpacket[0].js_subband_start);

    PRINT("log2_numvector_size",q->subpacket[0].log2_numvector_size);

    PRINT("numvector_size",q->subpacket[0].numvector_size);

    PRINT("total_subbands",q->subpacket[0].total_subbands);

}

#endif

static av_cold int cook_count_channels(unsigned int mask){

    int i;

    int channels = 0;

    for(i = 0;i<32;i++){

        if(mask & (1<<i))

            ++channels;

    }

    return channels;

}

/**

 * Cook initialization

 *

 * @param avctx     pointer to the AVCodecContext

 */

static av_cold int cook_decode_init(AVCodecContext *avctx)

{

    COOKContext *q = avctx->priv_data;

    const uint8_t *edata_ptr = avctx->extradata;

    const uint8_t *edata_ptr_end = edata_ptr + avctx->extradata_size;

    int extradata_size = avctx->extradata_size;

    int s = 0;

    unsigned int channel_mask = 0;

    q->avctx = avctx;

    /* Take care of the codec specific extradata. */

    if (extradata_size <= 0) {

        av_log(avctx,AV_LOG_ERROR,"Necessary extradata missing!\n");

        return -1;

    }

    av_log(avctx,AV_LOG_DEBUG,"codecdata_length=%d\n",avctx->extradata_size);

    /* Take data from the AVCodecContext (RM container). */

    q->sample_rate = avctx->sample_rate;

    q->nb_channels = avctx->channels;

    q->bit_rate = avctx->bit_rate;

    /* Initialize RNG. */

    av_lfg_init(&q->random_state, 0);

    while(edata_ptr < edata_ptr_end){

        /* 8 for mono, 16 for stereo, ? for multichannel

           Swap to right endianness so we don't need to care later on. */

        if (extradata_size >= 8){

            q->subpacket[s].cookversion = bytestream_get_be32(&edata_ptr);

            q->subpacket[s].samples_per_frame =  bytestream_get_be16(&edata_ptr);

            q->subpacket[s].subbands = bytestream_get_be16(&edata_ptr);

            extradata_size -= 8;

        }

        if (avctx->extradata_size >= 8){

            bytestream_get_be32(&edata_ptr);    //Unknown unused

            q->subpacket[s].js_subband_start = bytestream_get_be16(&edata_ptr);

            q->subpacket[s].js_vlc_bits = bytestream_get_be16(&edata_ptr);

            extradata_size -= 8;

        }

        /* Initialize extradata related variables. */

        q->subpacket[s].samples_per_channel = q->subpacket[s].samples_per_frame / q->nb_channels;

        q->subpacket[s].bits_per_subpacket = avctx->block_align * 8;

        /* Initialize default data states. */

        q->subpacket[s].log2_numvector_size = 5;

        q->subpacket[s].total_subbands = q->subpacket[s].subbands;

        q->subpacket[s].num_channels = 1;

        /* Initialize version-dependent variables */

        av_log(avctx,AV_LOG_DEBUG,"subpacket[%i].cookversion=%x\n",s,q->subpacket[s].cookversion);

        q->subpacket[s].joint_stereo = 0;

        switch (q->subpacket[s].cookversion) {

            case MONO:

                if (q->nb_channels != 1) {

                    av_log_ask_for_sample(avctx, "Container channels != 1.!\n");

                    return -1;

                }

                av_log(avctx,AV_LOG_DEBUG,"MONO\n");

                break;

            case STEREO:

                if (q->nb_channels != 1) {

                    q->subpacket[s].bits_per_subpdiv = 1;

                    q->subpacket[s].num_channels = 2;

                }

                av_log(avctx,AV_LOG_DEBUG,"STEREO\n");

                break;

            case JOINT_STEREO:

                if (q->nb_channels != 2) {

                    av_log_ask_for_sample(avctx, "Container channels != 2.\n");

                    return -1;

                }

                av_log(avctx,AV_LOG_DEBUG,"JOINT_STEREO\n");

                if (avctx->extradata_size >= 16){

                    q->subpacket[s].total_subbands = q->subpacket[s].subbands + q->subpacket[s].js_subband_start;

                    q->subpacket[s].joint_stereo = 1;

                    q->subpacket[s].num_channels = 2;

                }

                if (q->subpacket[s].samples_per_channel > 256) {

                    q->subpacket[s].log2_numvector_size  = 6;

                }

                if (q->subpacket[s].samples_per_channel > 512) {

                    q->subpacket[s].log2_numvector_size  = 7;

                }

                break;

            case MC_COOK:

                av_log(avctx,AV_LOG_DEBUG,"MULTI_CHANNEL\n");

                if(extradata_size >= 4)

                    channel_mask |= q->subpacket[s].channel_mask = bytestream_get_be32(&edata_ptr);

                if(cook_count_channels(q->subpacket[s].channel_mask) > 1){

                    q->subpacket[s].total_subbands = q->subpacket[s].subbands + q->subpacket[s].js_subband_start;

                    q->subpacket[s].joint_stereo = 1;

                    q->subpacket[s].num_channels = 2;

                    q->subpacket[s].samples_per_channel = q->subpacket[s].samples_per_frame >> 1;

                    if (q->subpacket[s].samples_per_channel > 256) {

                        q->subpacket[s].log2_numvector_size  = 6;

                    }

                    if (q->subpacket[s].samples_per_channel > 512) {

                        q->subpacket[s].log2_numvector_size  = 7;

                    }

                }else

                    q->subpacket[s].samples_per_channel = q->subpacket[s].samples_per_frame;

                break;

            default:

                av_log_ask_for_sample(avctx, "Unknown Cook version.\n");

                return -1;

                break;

        }

        if(s > 1 && q->subpacket[s].samples_per_channel != q->samples_per_channel) {

            av_log(avctx,AV_LOG_ERROR,"different number of samples per channel!\n");

            return -1;

        } else

            q->samples_per_channel = q->subpacket[0].samples_per_channel;

        /* Initialize variable relations */

        q->subpacket[s].numvector_size = (1 << q->subpacket[s].log2_numvector_size);

        /* Try to catch some obviously faulty streams, othervise it might be exploitable */

        if (q->subpacket[s].total_subbands > 53) {

            av_log_ask_for_sample(avctx, "total_subbands > 53\n");

            return -1;

        }

        if ((q->subpacket[s].js_vlc_bits > 6) || (q->subpacket[s].js_vlc_bits < 0)) {

            av_log(avctx,AV_LOG_ERROR,"js_vlc_bits = %d, only >= 0 and <= 6 allowed!\n",q->subpacket[s].js_vlc_bits);

            return -1;

        }

        if (q->subpacket[s].subbands > 50) {

            av_log_ask_for_sample(avctx, "subbands > 50\n");

            return -1;

        }

        q->subpacket[s].gains1.now      = q->subpacket[s].gain_1;

        q->subpacket[s].gains1.previous = q->subpacket[s].gain_2;

        q->subpacket[s].gains2.now      = q->subpacket[s].gain_3;

        q->subpacket[s].gains2.previous = q->subpacket[s].gain_4;

        q->num_subpackets++;

        s++;

        if (s > MAX_SUBPACKETS) {

            av_log_ask_for_sample(avctx, "Too many subpackets > 5\n");

            return -1;

        }

    }

    /* Generate tables */

    init_pow2table();

    init_gain_table(q);

    init_cplscales_table(q);

    if (init_cook_vlc_tables(q) != 0)

        return -1;

    if(avctx->block_align >= UINT_MAX/2)

        return -1;

    /* Pad the databuffer with:

       DECODE_BYTES_PAD1 or DECODE_BYTES_PAD2 for decode_bytes(),

       FF_INPUT_BUFFER_PADDING_SIZE, for the bitstreamreader. */

        q->decoded_bytes_buffer =

          av_mallocz(avctx->block_align

                     + DECODE_BYTES_PAD1(avctx->block_align)

                     + FF_INPUT_BUFFER_PADDING_SIZE);

    if (q->decoded_bytes_buffer == NULL)

        return -1;

    /* Initialize transform. */

    if ( init_cook_mlt(q) != 0 )

        return -1;

    /* Initialize COOK signal arithmetic handling */

    if (1) {

        q->scalar_dequant  = scalar_dequant_float;

        q->decouple        = decouple_float;

        q->imlt_window     = imlt_window_float;

        q->interpolate     = interpolate_float;

        q->saturate_output = saturate_output_float;

    }

    /* Try to catch some obviously faulty streams, othervise it might be exploitable */

    if ((q->samples_per_channel == 256) || (q->samples_per_channel == 512) || (q->samples_per_channel == 1024)) {

    } else {

        av_log(avctx,AV_LOG_ERROR,"unknown amount of samples_per_channel = %d, report sample!\n",q->samples_per_channel);

        return -1;

    }

    avctx->sample_fmt = AV_SAMPLE_FMT_S16;

    if (channel_mask)

        avctx->channel_layout = channel_mask;

    else

        avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;

#ifdef COOKDEBUG

    dump_cook_context(q);

#endif

    return 0;

}

AVCodec ff_cook_decoder =

{

    .name = "cook",

    .type = AVMEDIA_TYPE_AUDIO,

    .id = CODEC_ID_COOK,

    .priv_data_size = sizeof(COOKContext),

    .init = cook_decode_init,