Fix bug in DTMF generation where events with level > 36 would be ignored.

webrtc/modules/audio_coding/neteq/dtmf_tone_generator.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 70 matching lines @@
       13323, 15021, 15708, 15708, 15708, 15708},
     { 8207, 7490, 8207, 8979, 7490, 8207, 8979, 7490, 8207, 8979, 7490, 8979,
       9801, 9801, 9801, 9801},
     { 4249, 3853, 4249, 4685, 3853, 4249, 4685, 3853, 4249, 4685, 3853, 4685,
       5164, 5164, 5164, 5164},
     { 2851, 2582, 2851, 3148, 2582, 2851, 3148, 2582, 2851, 3148, 2582, 3148,
       3476, 3476, 3476, 3476} };
 
 // Amplitude multipliers for volume values 0 through 36, corresponding to
 // 0 dBm0 through -36 dBm0. Values are in Q14.
 const int DtmfToneGenerator::kAmplitude[37] = {

[hlundin-webrtc, 2016/10/11 09:08:36]

You will have to extend this array with values for the newly accepted
attenuations. Or, scrap the array and calculate the amplitude each time.

[the sun, 2016/10/11 09:44:53]

Done.

     16141, 14386, 12821, 11427, 10184, 9077, 8090, 7210, 6426, 5727, 5104, 4549,
     4054, 3614, 3221, 2870, 2558, 2280, 2032, 1811, 1614, 1439, 1282, 1143,
     1018, 908, 809, 721, 643, 573, 510, 455, 405, 361, 322, 287, 256 };
 
 // Constructor.
 DtmfToneGenerator::DtmfToneGenerator()
     : initialized_(false),
       coeff1_(0),
       coeff2_(0),
       amplitude_(0) {
@@ skipping 15 matching lines @@
     fs_index = 3;
   } else {
     assert(false);
     fs_index = 1;  // Default to 8000 Hz.
   }
 
   if (event < 0 || event > 15) {
     return kParameterError;  // Invalid event number.
   }
 
-  if (attenuation < 0 || attenuation > 36) {
+  if (attenuation < 0 || attenuation > 63) {
     return kParameterError;  // Invalid attenuation.
   }
 
   // Look up oscillator coefficient for low and high frequencies.
   coeff1_ = kCoeff1[fs_index][event];
   coeff2_ = kCoeff2[fs_index][event];
   // Look up amplitude multiplier.
   amplitude_ = kAmplitude[attenuation];
   // Initialize sample history.
   sample_history1_[0] = kInitValue1[fs_index][event];
@@ skipping 49 matching lines @@
   }
 
   return static_cast<int>(num_samples);
 }
 
 bool DtmfToneGenerator::initialized() const {
   return initialized_;
 }
 
 }  // namespace webrtc