|  | /* | 
|  | *  Copyright (c) 2017 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. | 
|  | */ | 
|  |  | 
|  | #ifndef MODULES_AUDIO_MIXER_SINE_WAVE_GENERATOR_H_ | 
|  | #define MODULES_AUDIO_MIXER_SINE_WAVE_GENERATOR_H_ | 
|  |  | 
|  | #include <stdint.h> | 
|  |  | 
|  | #include "api/audio/audio_frame.h" | 
|  | #include "rtc_base/checks.h" | 
|  |  | 
|  | namespace webrtc { | 
|  |  | 
|  | class SineWaveGenerator { | 
|  | public: | 
|  | SineWaveGenerator(float wave_frequency_hz, int16_t amplitude) | 
|  | : wave_frequency_hz_(wave_frequency_hz), amplitude_(amplitude) { | 
|  | RTC_DCHECK_GT(wave_frequency_hz, 0); | 
|  | } | 
|  |  | 
|  | // Produces appropriate output based on frame->num_channels_, | 
|  | // frame->sample_rate_hz_. | 
|  | void GenerateNextFrame(AudioFrame* frame); | 
|  |  | 
|  | private: | 
|  | float phase_ = 0.f; | 
|  | const float wave_frequency_hz_; | 
|  | const int16_t amplitude_; | 
|  | }; | 
|  |  | 
|  | }  // namespace webrtc | 
|  |  | 
|  | #endif  // MODULES_AUDIO_MIXER_SINE_WAVE_GENERATOR_H_ |