[FFmpeg-soc] [soc]: r4936 - in amr: amr-ffmpeg.diff amrnbdec.c

[cmcq]

Author: cmcq
Date: Tue Aug  4 02:32:31 2009
New Revision: 4936

Log:
Split AGC into two functions to get and apply the energy
This will allow emphasis to be done in-place, but the functions should also
be useful elsewhere

Modified:
   amr/amr-ffmpeg.diff
   amr/amrnbdec.c

Modified: amr/amr-ffmpeg.diff
==============================================================================
--- amr/amr-ffmpeg.diff	Tue Aug  4 01:17:45 2009	(r4935)
+++ amr/amr-ffmpeg.diff	Tue Aug  4 02:32:31 2009	(r4936)
@@ -160,45 +160,65 @@ Index: libavcodec/acelp_vectors.c
  #include "acelp_vectors.h"
  
  const uint8_t ff_fc_2pulses_9bits_track1[16] =
-@@ -155,3 +156,14 @@
+@@ -155,3 +156,25 @@
          out[i] = weight_coeff_a * in_a[i]
                 + weight_coeff_b * in_b[i];
  }
 +
-+void ff_apply_gain_ctrl(float *v_out, const float *v_ref, const float *v_in,
-+                        const int length)
++float ff_energyf(const float *v, int length)
 +{
++    float sum = 0;
 +    int i;
-+    float scalefactor = ff_dot_productf(v_in, v_in, length);
++
++    for (i = 0; i < length; i++)
++        sum += v[i] * v[i];
++
++    return sum;
++}
++
++void ff_set_energyf(float *v_out, const float *v_in, float energy,
++                    const int length)
++{
++    int i;
++    float scalefactor = ff_energyf(v_in, length);
 +    if (scalefactor)
-+        scalefactor = sqrt(ff_dot_productf(v_ref, v_ref, length) / scalefactor);
++        scalefactor = sqrt(energy / scalefactor);
 +    for (i = 0; i < length; i++)
-+        v_out[i] = scalefactor * v_in[i];
++        v_out[i] = v_in[i] * scalefactor;
 +}
 Index: libavcodec/acelp_vectors.h
 ===================================================================
 --- libavcodec/acelp_vectors.h	(revision 19574)
 +++ libavcodec/acelp_vectors.h	(working copy)
-@@ -164,4 +164,22 @@
+@@ -164,4 +164,31 @@
  void ff_weighted_vector_sumf(float *out, const float *in_a, const float *in_b,
                               float weight_coeff_a, float weight_coeff_b, int length);
  
 +/**
-+ * Apply adaptive gain control by gain scaling.
++ * returns the energy
++ * @param in input data array
++ * @param length number of elements
++ *
++ * @return energy = sum of squares
++ */
++float ff_energyf(const float *in, int length);
++
++/**
++ * Set the energy of a vector by scaling
 + *
 + * @param v_out output vector
-+ * @param v_in gain-controlled vector
-+ * @param v_ref vector to control gain of
++ * @param v_in vector to set energy of
++ * @param energy new energy
 + * @param length vectors length
 + *
-+ * @note If v_in is zero (or its energy underflows), the output is zero.
-+ *       This is the behavior of the AMR reference decoder. The QCELP
++ * @note If v is zero (or its energy underflows), the output is zero.
++ *       This is the behavior of AGC in the AMR reference decoder. The QCELP
 + *       reference decoder seems to have undefined behavior.
 + *
 + * TIA/EIA/IS-733 2.4.8.3-2/3/4/5, 2.4.8.6
 + * 3GPP TS 26.090 6.1 (6)
 + */
-+void ff_apply_gain_ctrl(float *v_out, const float *v_ref, const float *v_in,
-+                        const int length);
++void ff_set_energyf(float *v_out, const float *v_in, float energy,
++                    const int length);
 +
  #endif /* AVCODEC_ACELP_VECTORS_H */

Modified: amr/amrnbdec.c
==============================================================================
--- amr/amrnbdec.c	Tue Aug  4 01:17:45 2009	(r4935)
+++ amr/amrnbdec.c	Tue Aug  4 02:32:31 2009	(r4936)
@@ -913,6 +913,7 @@ static int synthesis(AMRContext *p, floa
     // emphasize pitch vector contribution
     if (p->pitch_gain[4] > 0.5 && !overflow) {
         float exc_emph[AMR_SUBFRAME_SIZE]; // FIXME: unnecessary tmp buffer
+        float energy = ff_energyf(excitation, AMR_SUBFRAME_SIZE);
         float pitch_factor = (p->cur_frame_mode == MODE_122 ? 0.25 : 0.5)
             * FFMIN(p->pitch_gain[4],
                     p->cur_frame_mode == MODE_122 ? 1.0 : SHARP_MAX)
@@ -921,8 +922,7 @@ static int synthesis(AMRContext *p, floa
         for (i = 0; i < AMR_SUBFRAME_SIZE; i++)
             exc_emph[i] = excitation[i] + pitch_factor * p->pitch_vector[i];
 
-        ff_apply_gain_ctrl(excitation, excitation, exc_emph,
-                           AMR_SUBFRAME_SIZE);
+        ff_set_energyf(excitation, exc_emph, energy, AMR_SUBFRAME_SIZE);
     }
 
     ff_celp_lp_synthesis_filterf(samples, lpc, excitation, AMR_SUBFRAME_SIZE,