From a3896c63775e82d2d06766db682e816872a8c0e1 Mon Sep 17 00:00:00 2001 From: Vitor Sessak Date: Thu, 24 Jul 2008 04:05:41 +0000 Subject: [PATCH] Rename pred() to eval_lpc_coeffs() and add a doxy comment Originally committed as revision 14361 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/ra288.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/libavcodec/ra288.c b/libavcodec/ra288.c index 946820cf56..228125825d 100644 --- a/libavcodec/ra288.c +++ b/libavcodec/ra288.c @@ -97,7 +97,13 @@ static void colmult(float *tgt, const float *m1, const float *m2, int n) *(tgt++) = (*(m1++)) * (*(m2++)); } -static int pred(const float *in, float *tgt, int n) +/** + * Converts autocorrelation coefficients to LPC coefficients using the + * Levinson-Durbin algorithm. See blocks 37 and 50 of the G.728 specification. + * + * @return 1 if success, 0 if fail + */ +static int eval_lpc_coeffs(const float *in, float *tgt, int n) { int x, y; double f0, f1, f2; @@ -189,7 +195,7 @@ static void update(Real288_internal *glob) do_hybrid_window(36, 40, 35, buffer1, temp1, glob->st1a, glob->st1b, syn_window); - if (pred(temp1, glob->st1, 36)) + if (eval_lpc_coeffs(temp1, glob->st1, 36)) colmult(glob->pr1, glob->st1, table1a, 36); memcpy(buffer2 , glob->history + 4, 4*sizeof(*buffer2)); @@ -198,7 +204,7 @@ static void update(Real288_internal *glob) do_hybrid_window(10, 8, 20, buffer2, temp2, glob->st2a, glob->st2b, gain_window); - if (pred(temp2, glob->st2, 10)) + if (eval_lpc_coeffs(temp2, glob->st2, 10)) colmult(glob->pr2, glob->st2, table2a, 10); }