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Move scale factor computation to its own function. Patch by Kenan 

Gillet.

Originally committed as revision 18345 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Kenan Gillet 2009-04-07 01:39:17 +00:00 committed by Reynaldo H. Verdejo Pinochet
parent 38d5647a63
commit 809e07c618
1 changed files with 24 additions and 8 deletions
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32
libavcodec/qcelpdec.c
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@ -412,18 +412,39 @@ static void compute_svector(QCELPContext *q, const float *gain,
}
/**
* Apply generic gain control.
* Compute the gain control
*
* @param v_out output vector
* @param v_in gain-controlled vector
* @param v_ref vector to control gain of
*
* @return gain control
*
* FIXME: If v_ref is a zero vector, it energy is zero
* and the behavior of the gain control is
* undefined in the specs.
*
* TIA/EIA/IS-733 2.4.8.3-2/3/4/5, 2.4.8.6
*/
static float compute_gain_ctrl(const float *v_ref, const float *v_in, const int len)
{
float scalefactor = ff_dot_productf(v_in, v_in, len);
if(scalefactor)
scalefactor = sqrt(ff_dot_productf(v_ref, v_ref, len) / scalefactor);
else
ff_log_missing_feature(NULL, "Zero energy for gain control", 1);
return scalefactor;
}
/**
* Apply generic gain control.
*
* @param v_out output vector
* @param v_in gain-controlled vector
* @param v_ref vector to control gain of
*
* TIA/EIA/IS-733 2.4.8.3, 2.4.8.6
*/
static void apply_gain_ctrl(float *v_out, const float *v_ref,
const float *v_in)
{
@ -432,12 +453,7 @@ static void apply_gain_ctrl(float *v_out, const float *v_ref,
for(i=0, j=0; i<4; i++)
{
scalefactor = ff_dot_productf(v_in + j, v_in + j, 40);
if(scalefactor)
scalefactor = sqrt(ff_dot_productf(v_ref + j, v_ref + j, 40)
/ scalefactor);
else
ff_log_missing_feature(NULL, "Zero energy for gain control", 1);
scalefactor = compute_gain_ctrl(v_ref + j, v_in + j, 40);
for(len=j+40; j<len; j++)
v_out[j] = scalefactor * v_in[j];
}