Using Audio Manager APIs to play DTMF tone in a voice call.

Please follow the below steps to play a DTMF tone in an active voice call. Note that only Rx direction is supported now.

### 1. Get the Audio Factory and Audio Manager instances ###

auto &audioFactory = AudioFactory::getInstance();
auto audioManager = audioFactory.getAudioManager();

### 2. Wait for the Audio subsystem to be initialized and ready ###

bool isReady = audioManager->isSubsystemReady();
if(!isReady) {
    std::cout << "Audio subsystem is not ready, waiting for it to be ready " << std::endl;
    std::future<bool> f = audioManager->onSubsystemReady();
    isReady = f.get();
}

### 3. Exit the application, if SDK is unable to initialize Audio subsystem ###

if(isReady) {
    std::cout << " *** Audio subsystem is Ready *** " << std::endl;
} else {
    std::cout << " *** ERROR - Unable to initialize Audio subsystem " << std::endl;
    return 1;
}

### 4. Create an audio Stream (to be associated with Voice call session) ###

// Implement a response function to get the request status
void createStreamCallback(std::shared_ptr<IAudioStream> &stream, ErrorCode error) {
    if (error != ErrorCode::SUCCESS) {
        std::cout << "createStream() failed with error" << static_cast<int>(error) << std::endl;
        return;
    }
    std::cout << "createStream() succeeded." << std::endl;
    audioVoiceStream = std::dynamic_pointer_cast<IAudioVoiceStream>(stream);
}
// Create a voice stream with required configuration
status = audioManager->createStream(config, createStreamCallback);

### 5. Start the Voice call session ###

// Implement a response function to get the request status
void startAudioCallback(ErrorCode error)
{
    if (error != ErrorCode::SUCCESS) {
        std::cout << "startAudio() failed with error " << static_cast<int>(error) << std::endl;
        return;
    }
    std::cout << "startAudio() succeeded." << std::endl;
}
// Start the Voice call session
status = audioVoiceStream->startAudio(startAudioCallback);

### 6. Play a DTMF tone ###

// Implement a response function to get the request status
void playDtmfCallback(ErrorCode error)
{
    if (error != ErrorCode::SUCCESS) {
        std::cout << "playDtmfTone() failed with error" << static_cast<int>(error) << std::endl;
        return;
    }
    std::cout << "playDtmfTone() succeeded." << std::endl;
}
// Play the DTMF tone with required configuration
status = audioVoiceStream->playDtmfTone(dtmfTone, duration, gain, playDtmfCallback);

### 7. Stop the Voice call session ###

// Implement a response function to get the request status
void stopAudioCallback(ErrorCode error)
{
    if (error != ErrorCode::SUCCESS) {
        std::cout << "stopAudio() failed with error " << static_cast<int>(error) << std::endl;
        return;
    }
    std::cout << "stopAudio() succeeded." << std::endl;
}
// Stop the Voice call session, which was started earlier
status = audioVoiceStream->stopAudio(stopAudioCallback);

8. Delete the audio stream associated with the Voice call session

// Implement a response function to get the request status
void deleteStreamCallback(ErrorCode error) {
    if (error != ErrorCode::SUCCESS) {
        std::cout << "deleteStream() failed with error" << static_cast<int>(error) << std::endl;
        return;
    }
    std::cout << "deleteStream() succeeded." << std::endl;
    audioVoiceStream->reset();
}
//Delete the Audio Stream
status = audioManager->deleteStream(std::dynamic_pointer_cast<IAudioStream>(audioVoiceStream),
                                deleteStreamCallback);