void mdct_sub(double sb_sample[2][3][18][SBLIMIT],
double (*mdct_freq)[2][samp_per_frame2],
side_info_t *side_info)
{
double (*mdct_enc)[2][32][18] = (double (*)[2][32][18]) mdct_freq;
int ch,gr,band,k,j;
gr_info *cod_info;
double mdct_in[36];
double bu,bd;
for(gr=0; gr<2; gr++)
for(ch=config.wave.channels; ch--; )
{
cod_info = (gr_info*) &(side_info->gr[gr].ch[ch]) ;
/* Compensate for inversion in the analysis filter */
for(band=32; band--; )
for(k=18; k--; )
if((band&1) && (k&1))
sb_sample[ch][gr+1][k][band] *= -1.0;
/* Perform imdct of 18 previous subband samples + 18 current subband samples */
for(band=32; band--; )
{
for(k=18; k--; )
{
mdct_in[k] = sb_sample[ch][ gr ][k][band];
mdct_in[k+18] = sb_sample[ch][gr+1][k][band];
}
mdct(mdct_in,&mdct_enc[gr][ch][band][0]);
}
/* Perform aliasing reduction butterfly*/
for(band=31; band--; )
for(k=8; k--; )
{
bu = mdct_enc[gr][ch][band][17-k] * cs[k] + mdct_enc[gr][ch][band+1][k] * ca[k];
bd = mdct_enc[gr][ch][band+1][k] * cs[k] - mdct_enc[gr][ch][band][17-k] * ca[k];
mdct_enc[gr][ch][band][17-k] = bu;
mdct_enc[gr][ch][band+1][k] = bd;
}
}
/* Save latest granule's subband samples to be used in the next mdct call */
for(ch=config.wave.channels ;ch--; )
for(j=18; j--; )
for(band=32; band--; )
sb_sample[ch][0][j][band] = sb_sample[ch][2][j][band];
}
/* only works for LTP -> no overlapping, no short blocks */
void filter_bank_ltp(fb_info *fb, uint8_t window_sequence, uint8_t window_shape,
uint8_t window_shape_prev, real_t *in_data, real_t *out_mdct,
uint8_t object_type, uint16_t frame_len)
{
int16_t i;
ALIGN real_t windowed_buf[2*1024] = {0};
const real_t *window_long = NULL;
const real_t *window_long_prev = NULL;
const real_t *window_short = NULL;
const real_t *window_short_prev = NULL;
uint16_t nlong = frame_len;
uint16_t nshort = frame_len/8;
uint16_t nflat_ls = (nlong-nshort)/2;
assert(window_sequence != EIGHT_SHORT_SEQUENCE);
#ifdef LD_DEC
if (object_type == LD)
{
window_long = fb->ld_window[window_shape];
window_long_prev = fb->ld_window[window_shape_prev];
} else {
#endif
window_long = fb->long_window[window_shape];
window_long_prev = fb->long_window[window_shape_prev];
window_short = fb->short_window[window_shape];
window_short_prev = fb->short_window[window_shape_prev];
#ifdef LD_DEC
}
#endif
switch(window_sequence)
{
case ONLY_LONG_SEQUENCE:
for (i = nlong-1; i >= 0; i--)
{
windowed_buf[i] = MUL_F(in_data[i], window_long_prev[i]);
windowed_buf[i+nlong] = MUL_F(in_data[i+nlong], window_long[nlong-1-i]);
}
mdct(fb, windowed_buf, out_mdct, 2*nlong);
break;
case LONG_START_SEQUENCE:
for (i = 0; i < nlong; i++)
windowed_buf[i] = MUL_F(in_data[i], window_long_prev[i]);
for (i = 0; i < nflat_ls; i++)
windowed_buf[i+nlong] = in_data[i+nlong];
for (i = 0; i < nshort; i++)
windowed_buf[i+nlong+nflat_ls] = MUL_F(in_data[i+nlong+nflat_ls], window_short[nshort-1-i]);
for (i = 0; i < nflat_ls; i++)
windowed_buf[i+nlong+nflat_ls+nshort] = 0;
mdct(fb, windowed_buf, out_mdct, 2*nlong);
break;
case LONG_STOP_SEQUENCE:
for (i = 0; i < nflat_ls; i++)
windowed_buf[i] = 0;
for (i = 0; i < nshort; i++)
windowed_buf[i+nflat_ls] = MUL_F(in_data[i+nflat_ls], window_short_prev[i]);
for (i = 0; i < nflat_ls; i++)
windowed_buf[i+nflat_ls+nshort] = in_data[i+nflat_ls+nshort];
for (i = 0; i < nlong; i++)
windowed_buf[i+nlong] = MUL_F(in_data[i+nlong], window_long[nlong-1-i]);
mdct(fb, windowed_buf, out_mdct, 2*nlong);
break;
}
}
