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lpc: use levinson for the first pass of multipass cholesky

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Levinson is faster, and cholesky is only needed if we want to apply different
weights to different samples, which doesn't happen on the first pass.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This commit is contained in:
Loren Merritt 2013-06-16 00:53:47 +00:00 committed by Luca Barbato
parent b545179fdf
commit c93ccf5a4c
1 changed files with 16 additions and 13 deletions
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29
libavcodec/lpc.c
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@ -176,7 +176,7 @@ int ff_lpc_calc_coefs(LPCContext *s,
double autoc[MAX_LPC_ORDER+1];
double ref[MAX_LPC_ORDER];
double lpc[MAX_LPC_ORDER][MAX_LPC_ORDER];
int i, j, pass;
int i, j, pass = 0;
int opt_order;
assert(max_order >= MIN_LPC_ORDER && max_order <= MAX_LPC_ORDER &&
@ -189,7 +189,7 @@ int ff_lpc_calc_coefs(LPCContext *s,
ff_lpc_init(s, blocksize, max_order, lpc_type);
}
if (lpc_type == FF_LPC_TYPE_LEVINSON) {
if (lpc_type == FF_LPC_TYPE_LEVINSON || (lpc_type == FF_LPC_TYPE_CHOLESKY && lpc_passes > 1)) {
s->lpc_apply_welch_window(samples, blocksize, s->windowed_samples);
s->lpc_compute_autocorr(s->windowed_samples, blocksize, max_order, autoc);
@ -198,13 +198,20 @@ int ff_lpc_calc_coefs(LPCContext *s,
for(i=0; i<max_order; i++)
ref[i] = fabs(lpc[i][i]);
} else if (lpc_type == FF_LPC_TYPE_CHOLESKY) {
pass++;
}
if (lpc_type == FF_LPC_TYPE_CHOLESKY) {
LLSModel m[2];
LOCAL_ALIGNED(32, double, var, [FFALIGN(MAX_LPC_ORDER+1,4)]);
double av_uninit(weight);
memset(var, 0, FFALIGN(MAX_LPC_ORDER+1,4)*sizeof(*var));
for(pass=0; pass<lpc_passes; pass++){
for(j=0; j<max_order; j++)
m[0].coeff[max_order-1][j] = -lpc[max_order-1][j];
for(; pass<lpc_passes; pass++){
avpriv_init_lls(&m[pass&1], max_order);
weight=0;
@ -259,15 +266,11 @@ av_cold int ff_lpc_init(LPCContext *s, int blocksize, int max_order,
s->max_order = max_order;
s->lpc_type = lpc_type;
if (lpc_type == FF_LPC_TYPE_LEVINSON) {
s->windowed_buffer = av_mallocz((blocksize + 2 + FFALIGN(max_order, 4)) *
sizeof(*s->windowed_samples));
if (!s->windowed_buffer)
return AVERROR(ENOMEM);
s->windowed_samples = s->windowed_buffer + FFALIGN(max_order, 4);
} else {
s->windowed_samples = NULL;
}
s->windowed_buffer = av_mallocz((blocksize + 2 + FFALIGN(max_order, 4)) *
sizeof(*s->windowed_samples));
if (!s->windowed_buffer)
return AVERROR(ENOMEM);
s->windowed_samples = s->windowed_buffer + FFALIGN(max_order, 4);
s->lpc_apply_welch_window = lpc_apply_welch_window_c;
s->lpc_compute_autocorr = lpc_compute_autocorr_c;