Commit some functions that are used by both SIPR and AMR.

Based on AMR SoC code by Robert Swain and Colin McQuillan.

Originally committed as revision 20392 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 22 insertions, 0 deletions

diff --git a/libavcodec/acelp_vectors.c b/libavcodec/acelp_vectors.c
index 5443006718..2d9aa1ad79 100644
--- a/libavcodec/acelp_vectors.c
+++ b/libavcodec/acelp_vectors.c
@@ -23,6 +23,7 @@
 #include <inttypes.h>
 #include "avcodec.h"
 #include "acelp_vectors.h"
+#include "celp_math.h"
 
 const uint8_t ff_fc_2pulses_9bits_track1[16] =
 {
@@ -155,3 +156,24 @@ void ff_weighted_vector_sumf(float *out, const float *in_a, const float *in_b,
         out[i] = weight_coeff_a * in_a[i]
                + weight_coeff_b * in_b[i];
 }
+
+void ff_adaptative_gain_control(float *buf_out, float speech_energ,
+                                int size, float alpha, float *gain_mem)
+{
+    int i;
+    float postfilter_energ = ff_dot_productf(buf_out, buf_out, size);
+    float gain_scale_factor = 1.0;
+    float mem = *gain_mem;
+
+    if (postfilter_energ)
+        gain_scale_factor = sqrt(speech_energ / postfilter_energ);
+
+    gain_scale_factor *= 1.0 - alpha;
+
+    for (i = 0; i < size; i++) {
+        mem = alpha * mem + gain_scale_factor;
+        buf_out[i] *= mem;
+    }
+
+    *gain_mem = mem;
+}