1 /* 2 * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_DTMF_TONE_GENERATOR_H_ 12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_DTMF_TONE_GENERATOR_H_ 13 14 15 #include "webrtc/base/constructormagic.h" 16 #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h" 17 #include "webrtc/typedefs.h" 18 19 namespace webrtc { 20 21 // This class provides a generator for DTMF tones. 22 class DtmfToneGenerator { 23 public: 24 enum ReturnCodes { 25 kNotInitialized = -1, 26 kParameterError = -2, 27 }; 28 29 DtmfToneGenerator(); 30 virtual ~DtmfToneGenerator() {} 31 virtual int Init(int fs, int event, int attenuation); 32 virtual void Reset(); 33 virtual int Generate(size_t num_samples, AudioMultiVector* output); 34 virtual bool initialized() const; 35 36 private: 37 static const int kCoeff1[4][16]; // 1st oscillator model coefficient table. 38 static const int kCoeff2[4][16]; // 2nd oscillator model coefficient table. 39 static const int kInitValue1[4][16]; // Initialization for 1st oscillator. 40 static const int kInitValue2[4][16]; // Initialization for 2nd oscillator. 41 static const int kAmplitude[37]; // Amplitude for 0 through -36 dBm0. 42 static const int16_t kAmpMultiplier = 23171; // 3 dB attenuation (in Q15). 43 44 bool initialized_; // True if generator is initialized properly. 45 int coeff1_; // 1st oscillator coefficient for this event. 46 int coeff2_; // 2nd oscillator coefficient for this event. 47 int amplitude_; // Amplitude for this event. 48 int16_t sample_history1_[2]; // Last 2 samples for the 1st oscillator. 49 int16_t sample_history2_[2]; // Last 2 samples for the 2nd oscillator. 50 51 RTC_DISALLOW_COPY_AND_ASSIGN(DtmfToneGenerator); 52 }; 53 54 } // namespace webrtc 55 #endif // WEBRTC_MODULES_AUDIO_CODING_NETEQ_DTMF_TONE_GENERATOR_H_ 56
