cook.c

Fixptcook[1].tar.gz, 固点运算的rm格式音频编解码源代码

static void categorize(COOKContext *q, int* quant_index_table,
                       int* category, int* category_index){
    int exp_idx, bias, tmpbias, bits_left, num_bits, index, v, i, j;
    int exp_index2[102];
    int exp_index1[102];

    int tmp_categorize_array1[128];
    int tmp_categorize_array1_idx=0;
    int tmp_categorize_array2[128];
    int tmp_categorize_array2_idx=0;
    int category_index_size=0;

    bits_left =  q->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(NULL, 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_array1,0,128*sizeof(int));
    memset(&tmp_categorize_array2,0,128*sizeof(int));

    bias=-32;

    /* Estimate bias. */
    for (i=32 ; i>0 ; i=i/2){
        num_bits = 0;
        index = 0;
        for (j=q->total_subbands ; j>0 ; j--){
            exp_idx = (i - quant_index_table[index] + bias) / 2;
            if (exp_idx<0){
                exp_idx=0;
            } else if(exp_idx >7) {
                exp_idx=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<q->total_subbands ; i++) {
        exp_idx = (bias - quant_index_table[i]) / 2;
        if (exp_idx<0) {
            exp_idx=0;
        } else if(exp_idx >7) {
            exp_idx=7;
        }
        num_bits += expbits_tab[exp_idx];
        exp_index1[i] = exp_idx;
        exp_index2[i] = exp_idx;
    }
    tmpbias = bias = num_bits;

    for (j = 1 ; j < q->numvector_size ; j++) {
        if (tmpbias + bias > 2*bits_left) {  /* ---> */
            int max = -999999;
            index=-1;
            for (i=0 ; i<q->total_subbands ; i++){
                if (exp_index1[i] < 7) {
                    v = (-2*exp_index1[i]) - quant_index_table[i] - 32;
                    if ( v >= max) {
                        max = v;
                        index = i;
                    }
                }
            }
            if(index==-1)break;
            tmp_categorize_array1[tmp_categorize_array1_idx++] = index;
            tmpbias -= expbits_tab[exp_index1[index]] -
                       expbits_tab[exp_index1[index]+1];
            ++exp_index1[index];
        } else {  /* <--- */
            int min = 999999;
            index=-1;
            for (i=0 ; i<q->total_subbands ; i++){
                if(exp_index2[i] > 0){
                    v = (-2*exp_index2[i])-quant_index_table[i];
                    if ( v < min) {
                        min = v;
                        index = i;
                    }
                }
            }
            if(index == -1)break;
            tmp_categorize_array2[tmp_categorize_array2_idx++] = index;
            tmpbias -= expbits_tab[exp_index2[index]] -
                       expbits_tab[exp_index2[index]-1];
            --exp_index2[index];
        }
    }

    for(i=0 ; i<q->total_subbands ; i++)
        category[i] = exp_index2[i];

    /* Concatenate the two arrays. */
    for(i=tmp_categorize_array2_idx-1 ; i >= 0; i--)
        category_index[category_index_size++] =  tmp_categorize_array2[i];

    for(i=0;i<tmp_categorize_array1_idx;i++)
        category_index[category_index_size++ ] =  tmp_categorize_array1[i];

    /* FIXME: mc_sich_ra8_20.rm triggers this, not sure with what we
       should fill the remaining bytes. */
    for(i=category_index_size;i<q->numvector_size;i++)
        category_index[i]=0;

}


/**
 * 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 void inline expand_category(COOKContext *q, int* category,
                                   int* category_index){
    int i;
    for(i=0 ; i<q->num_vectors ; i++){
        ++category[category_index[i]];
    }
}

/**
 * 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, int category, int* subband_coef_index,
                       int* subband_coef_sign) {
    int i,j;
    int vlc, vd ,tmp, result;
    int ub;
    int cb;

    vd = vd_tab[category];
    result = 0;
    for(i=0 ; i<vpr_tab[category] ; i++){
        ub = get_bits_count(&q->gb);
        vlc = get_vlc2(&q->gb, q->sqvh[category].table, q->sqvh[category].bits, 3);
        cb = get_bits_count(&q->gb);
        if (q->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) < q->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, int* category,
                           int *quant_index_table, REAL_T *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<q->total_subbands ; band++){
        index = category[band];
        if(category[band] < 7){
            if(unpack_SQVH(q, category[band], subband_coef_index, subband_coef_sign)){
                index=7;
                for(j=0 ; j<q->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));
        }
        scalar_dequant_math(q, index, quant_index_table[band],
                            subband_coef_index, subband_coef_sign,
                            &mlt_buffer[band * 20]);
    }

    if(q->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_buffer1       pointer to left channel mlt coefficients
 * @param mlt_buffer2       pointer to right channel mlt coefficients
 */

static void mono_decode(COOKContext *q, REAL_T *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, quant_index_table);
    q->num_vectors = get_bits(&q->gb,q->log2_numvector_size);
    categorize(q, quant_index_table, category, category_index);
    expand_category(q, category, category_index);
    decode_vectors(q, category, quant_index_table, mlt_buffer);
}


/**
 * 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, REAL_T *inbuffer,
                      cook_gains *gains_ptr, REAL_T *previous_buffer)
{
    REAL_T *buffer0 = q->mono_mdct_output;
    REAL_T *buffer1 = q->mono_mdct_output + q->samples_per_channel;
    int gain_size_factor = q->samples_per_channel/8;
    int i;

    imlt_math(q, inbuffer, gains_ptr->previous[0], previous_buffer);

    /* Apply gain profile */
    for (i = 0; i < 8; i++) {
        if (gains_ptr->now[i] || gains_ptr->now[i + 1])
            interpolate_math(q, &buffer1[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, int* decouple_tab){
    int length, i;

    if(get_bits1(&q->gb)) {
        if(cplband[q->js_subband_start] > cplband[q->subbands-1]) return;

        length = cplband[q->subbands-1] - cplband[q->js_subband_start] + 1;
        for (i=0 ; i<length ; i++) {
            decouple_tab[cplband[q->js_subband_start] + i] = get_vlc2(&q->gb, q->ccpl.table, q->ccpl.bits, 2);
        }
        return;
    }

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

    length = cplband[q->subbands-1] - cplband[q->js_subband_start] + 1;
    for (i=0 ; i<length ; i++) {
       decouple_tab[cplband[q->js_subband_start] + i] = get_bits(&q->gb, q->js_vlc_bits);
    }
    return;
}


/**
 * 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, REAL_T *mlt_buffer1,
                         REAL_T *mlt_buffer2) {
    int i,j;
    int decouple_tab[SUBBAND_SIZE];
    REAL_T decode_buffer[1060];
    int idx;

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