-/**
+/*
* LPC utility code
* Copyright (c) 2006 Justin Ruggles <justin.ruggles@gmail.com>
*
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavutil/common.h"
#include "libavutil/lls.h"
#define LPC_USE_DOUBLE
double w;
double c;
- assert(!(len&1)); //the optimization in r11881 does not support odd len
- //if someone wants odd len extend the change in r11881
+ /* The optimization in commit fa4ed8c does not support odd len.
+ * If someone wants odd len extend that change. */
+ assert(!(len & 1));
n2 = (len >> 1);
c = 2.0 / (len - 1.0);
/**
* Calculate LPC coefficients for multiple orders
*
- * @param use_lpc LPC method for determining coefficients
- * 0 = LPC with fixed pre-defined coeffs
- * 1 = LPC with coeffs determined by Levinson-Durbin recursion
- * 2+ = LPC with coeffs determined by Cholesky factorization using (use_lpc-1) passes.
+ * @param lpc_type LPC method for determining coefficients,
+ * see #FFLPCType for details
*/
int ff_lpc_calc_coefs(LPCContext *s,
const int32_t *samples, int blocksize, int min_order,
}
if (lpc_type == FF_LPC_TYPE_LEVINSON) {
- double *windowed_samples = s->windowed_samples + max_order;
-
- s->lpc_apply_welch_window(samples, blocksize, windowed_samples);
+ s->lpc_apply_welch_window(samples, blocksize, s->windowed_samples);
- s->lpc_compute_autocorr(windowed_samples, blocksize, max_order, autoc);
+ s->lpc_compute_autocorr(s->windowed_samples, blocksize, max_order, autoc);
compute_lpc_coefs(autoc, max_order, &lpc[0][0], MAX_LPC_ORDER, 0, 1);
s->lpc_type = lpc_type;
if (lpc_type == FF_LPC_TYPE_LEVINSON) {
- s->windowed_samples = av_mallocz((blocksize + max_order + 2) *
- sizeof(*s->windowed_samples));
- if (!s->windowed_samples)
+ 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;
}
av_cold void ff_lpc_end(LPCContext *s)
{
- av_freep(&s->windowed_samples);
+ av_freep(&s->windowed_buffer);
}