Part 2 of 2 of Kenan Gillet's 'make ff_qcelp_lspf2lpc

more general' changeset. This one relocates the QCELP
especific code to the qcelpdec.* files.

Originally committed as revision 17800 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 2 insertions, 41 deletions

diff --git a/libavcodec/qcelp_lsp.c b/libavcodec/qcelp_lsp.c
index 7f920f5f1d..af8e7c98f6 100644
--- a/libavcodec/qcelp_lsp.c
+++ b/libavcodec/qcelp_lsp.c
@@ -30,15 +30,6 @@
 #include "libavutil/mathematics.h"
 
 /**
- * initial coefficient to perform bandwidth expansion on LPC
- *
- * @note: 0.9883 looks like an approximation of 253/256.
- *
- * TIA/EIA/IS-733 2.4.3.3.6 6
- */
-#define QCELP_BANDWITH_EXPANSION_COEFF 0.9883
-
-/**
  * Computes the Pa / (1 + z(-1)) or Qa / (1 - z(-1)) coefficients
  * needed for LSP to LPC conversion.
  * We only need to calculate the 6 first elements of the polynomial.
@@ -84,37 +75,7 @@ void ff_celp_lspf2lpc(const double *lspf, float *lpc)
         double paf = pa[i+1] + pa[i];
         double qaf = qa[i+1] - qa[i];
 
-        lpc[i  ] = 0.5 * (paf+qaf);
-        lpc[9-i] = 0.5 * (paf-qaf);
-    }
-}
-
-/**
- * Reconstructs LPC coefficients from the line spectral pair frequencies
- * and performs bandwidth expansion.
- *
- * @param lspf line spectral pair frequencies
- * @param lpc linear predictive coding coefficients
- *
- * @note: bandwith_expansion_coeff could be precalculated into a table
- *        but it seems to be slower on x86
- *
- * TIA/EIA/IS-733 2.4.3.3.5
- */
-void ff_qcelp_lspf2lpc(const float *lspf, float *lpc)
-{
-    double lsf[10];
-    double bandwith_expansion_coeff = QCELP_BANDWITH_EXPANSION_COEFF;
-    int   i;
-
-    for (i=0; i<10; i++)
-        lsf[i] = cos(M_PI * lspf[i]);
-
-    ff_celp_lspf2lpc(lsf, lpc);
-
-    for (i=0; i<10; i++)
-    {
-        lpc[i] *= bandwith_expansion_coeff;
-        bandwith_expansion_coeff *= QCELP_BANDWITH_EXPANSION_COEFF;
+        lpc[i  ] = 0.5*(paf+qaf);
+        lpc[9-i] = 0.5*(paf-qaf);
     }
 }