ffmpeg roll of source to mar 9 version...

patched-ffmpeg-mt/libavcodec/acelp_pitch_delay.c

 /*
  * gain code, gain pitch and pitch delay decoding
  *
  * Copyright (c) 2008 Vladimir Voroshilov
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
@@ skipping 110 matching lines @@
 }
 
 float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy,
                             float *prediction_error, float energy_mean,
                             const float *pred_table)
 {
     // Equations 66-69:
     // ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector)
     // Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)).
     float val = fixed_gain_factor *
-        exp2f(log2f(10.0) * 0.05 *
+        exp2f(M_LOG2_10 * 0.05 *
               (ff_dot_productf(pred_table, prediction_error, 4) +
                energy_mean)) /
         sqrtf(fixed_mean_energy);
 
     // update quantified prediction error energy history
     memmove(&prediction_error[0], &prediction_error[1],
             3 * sizeof(prediction_error[0]));
     prediction_error[3] = 20.0 * log10f(fixed_gain_factor);
 
     return val;
@@ skipping 35 matching lines @@
                 pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN,
                                            PITCH_DELAY_MAX - 19);
             } else
                 pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
                                            PITCH_DELAY_MAX - 9);
         }
     }
     *lag_int  = pitch_index * 10923 >> 15;
     *lag_frac = pitch_index - 3 * *lag_int - 1;
 }