The existing function ff_lpc_calc_coefs does this, but doesn't
return the reflection coefficients, only the lpc coefficients.
---
libavcodec/lpc.c | 18 ++++++++++++++++++
libavcodec/lpc.h | 3 +++
2 files changed, 21 insertions(+)
diff --git a/libavcodec/lpc.c b/libavcodec/lpc.c
index 126dbc1..a4e4121 100644
--- a/libavcodec/lpc.c
+++ b/libavcodec/lpc.c
@@ -148,6 +148,24 @@ static int estimate_best_order(double *ref, int min_order,
int max_order)
return est;
}
+int ff_lpc_calc_refl_coefs(LPCContext *s,
+ const int32_t *samples, int order, float *refl)
+{
+ double autoc[MAX_LPC_ORDER+1];
+ double lpc[MAX_LPC_ORDER][MAX_LPC_ORDER];
+ int i;
+
+ s->lpc_apply_welch_window(samples, s->blocksize, s->windowed_samples);
+
+ s->lpc_compute_autocorr(s->windowed_samples, s->blocksize, order, autoc);
+
+ compute_lpc_coefs(autoc, order, &lpc[0][0], MAX_LPC_ORDER, 0, 1);
+
+ for (i = 0; i < order; i++)
+ refl[i] = lpc[i][i];
+ return order;
+}
+
/**
* Calculate LPC coefficients for multiple orders
*
diff --git a/libavcodec/lpc.h b/libavcodec/lpc.h
index cbee46f..6174c48 100644
--- a/libavcodec/lpc.h
+++ b/libavcodec/lpc.h
@@ -92,6 +92,9 @@ int ff_lpc_calc_coefs(LPCContext *s,
enum FFLPCType lpc_type, int lpc_passes,
int omethod, int max_shift, int zero_shift);
+int ff_lpc_calc_refl_coefs(LPCContext *s,
+ const int32_t *samples, int order, float *refl);
+
/**
* Initialize LPCContext.
*/
--
1.7.9.4
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