/**
* Backward synthesis filter. Find the LPC coefficients from past speech data.
*/
static void backward_filter(RA288Context *ractx)
{
float temp1[37]; // RTMP in the spec
float temp2[11]; // GPTPMP in the spec
do_hybrid_window(36, 40, 35, ractx->sp_block+1, temp1, ractx->sp_hist,
ractx->sp_rec, syn_window);
if (!eval_lpc_coeffs(temp1, ractx->sp_lpc, 36))
colmult(ractx->sp_lpc, ractx->sp_lpc, syn_bw_tab, 36);
do_hybrid_window(10, 8, 20, ractx->gain_block+2, temp2, ractx->gain_hist,
ractx->gain_rec, gain_window);
if (!eval_lpc_coeffs(temp2, ractx->gain_lpc, 10))
colmult(ractx->gain_lpc, ractx->gain_lpc, gain_bw_tab, 10);
}
/**
* Backward synthesis filter, find the LPC coefficients from past speech data.
*/
static void backward_filter(float *hist, float *rec, const float *window,
float *lpc, const float *tab,
int order, int n, int non_rec, int move_size)
{
float temp[order+1];
do_hybrid_window(order, n, non_rec, temp, hist, rec, window);
if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1))
apply_window(lpc, lpc, tab, order);
memmove(hist, hist + n, move_size*sizeof(*hist));
}
/**
* Backward synthesis filter, find the LPC coefficients from past speech data.
*/
static void backward_filter(RA288Context *ractx,
float *hist, float *rec, const float *window,
float *lpc, const float *tab,
int order, int n, int non_rec, int move_size)
{
float temp[MAX_BACKWARD_FILTER_ORDER+1];
do_hybrid_window(ractx, order, n, non_rec, temp, hist, rec, window);
if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1))
ractx->fdsp->vector_fmul(lpc, lpc, tab, FFALIGN(order, 16));
memmove(hist, hist + n, move_size*sizeof(*hist));
}
/**
* Backward synthesis filter, find the LPC coefficients from past speech data.
*/
static void backward_filter(float *hist, float *rec, const float *window,
float *lpc, const float *tab,
int order, int n, int non_rec, int move_size)
{
#if __STDC_VERSION__ >= 199901L
float temp[order+1];
#else
float *temp = _alloca((order + 1) * sizeof(float));
#endif
do_hybrid_window(order, n, non_rec, temp, hist, rec, window);
if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1))
apply_window(lpc, lpc, tab, order);
memmove(hist, hist + n, move_size*sizeof(*hist));
}
/**
* Backward synthesis filter, find the LPC coefficients from past speech data.
*/
static void backward_filter(float *hist, float *rec, const float *window,
float *lpc, const float *tab,
int order, int n, int non_rec, int move_size)
{
#ifndef _MSC_VER
float temp[order+1];
#else
float *temp = av_malloc_items(order + 1, float);
#endif
do_hybrid_window(order, n, non_rec, temp, hist, rec, window);
if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1))
apply_window(lpc, lpc, tab, order);
memmove(hist, hist + n, move_size*sizeof(*hist));
#ifdef _MSC_VER
av_free(temp);
#endif
}