BioListener_demo.cpp

This is an example of how to use the Yobe BioListener.

 
 
#include "util/demo_utils.hpp"
 
#include "cpp/yobe_create_listener.hpp"
#include "cpp/yobe_lib_util.hpp"
 
#include <fstream>
#include <iostream>
#include <vector>
 
constexpr auto ENV_VAR_LICENSE = "YOBE_LICENSE";
 
std::vector<double> YobeProcessing(const std::string& license, std::vector<double> input_buffer);
 
std::ofstream log_stream;
 
int main(int argc, char* argv[]) {
    if (argc != 2) {
        std::cout << "cpp demo requires a .wav file as input.\n";
    } else {
        // Just printing out the setting the Yobe engine expects
        std::cout << "Just checking to see if the Yobe parameters match the audio file.\n";
        std::cout << "Expected sampling rate: " << Yobe::Info::SamplingRate() << '\n';
        std::cout << "Expected buffer size in seconds: " << Yobe::Info::AudioBufferTime() << '\n';
        std::cout << "Number expected input channels: " << Yobe::Info::InputChannels() << '\n';
        std::cout << "Number expected output channels: " << Yobe::Info::OutputChannels() << "\n\n";
 
        const std::string file_path(argv[1]);
 
        // Preparing input buffer by reading the audio file
        const auto input_buffer = DemoUtil::ReadAudioFile(file_path);
 
        std::cout << '\n';
 
        // All the Yobe processing happens in this function
        const auto processed_audio = YobeProcessing(std::getenv(ENV_VAR_LICENSE), input_buffer);
 
        // Writing the processed data to a .wav file
        DemoUtil::WriteAudioFile(file_path, processed_audio);
    }
 
    return 0;
}
 
std::vector<double> YobeProcessing(const std::string& license, std::vector<double> input_buffer) {
    // Create a new BioListener instance.
    auto bio_listener = Yobe::Create::NewBioListener();
 
    // Set up a logging callback.
    log_stream.open("yobe_bio_listener_demo.log");
    Yobe::Info::RegisterCallback([](const char* mess) { log_stream << mess << '\n'; });
 
    // Initialize the Yobe engine with the provided license.
    auto init_status = bio_listener->Init(license.c_str());
    if (init_status != Yobe::Status::YOBE_OK) {
        std::cout << "YOBE_Init returned: " << Yobe::Info::StdError(init_status) << '\n';
    }
 
    // Determine the size of the input buffer required for YOBE_ProcessBuffer.
    const auto input_size = Yobe::Info::InputBufferSize();
 
    // Prepare an output buffer for collecting the output from the Yobe engine.
    std::vector<double> output_buffer;
 
    // Determine the size of the output buffer required for YOBE_ProcessBuffer.
    const auto output_size = Yobe::Info::OutputBufferSize();
 
    // Pre-allocate a buffer that will be returned with processed data in it.
    std::vector<double> scratch_buffer(output_size);
 
    auto status = Yobe::Status::YOBE_UNKNOWN;
    uint32_t out_buffer_size = 0;
    const auto total_input_samples = input_buffer.size();
 
    std::cout << "Yobe engine has started processing.\n";
 
    // Process the audio buffer one chunk at a time.
    for (size_t input_index = 0; input_index < total_input_samples; input_index += input_size) {
        // If the last buffer is too small, pad it with zeros to avoid losing information.
        if (input_index + input_size > total_input_samples) {
            std::vector<double> pad_buffer(input_index + input_size - total_input_samples, 0.0);
            input_buffer.insert(input_buffer.end(), pad_buffer.begin(), pad_buffer.end());
        }
 
        // Reset the output buffer size.
        out_buffer_size = output_size;
 
        // Process the current chunk of audio.
        status = bio_listener->ProcessBuffer(&input_buffer[input_index], scratch_buffer.data(), input_size,
                                             &out_buffer_size);
        log_stream << "Yobe::ProcessBuffer: " << Yobe::Info::StdError(status) << "\n";
 
        // Check the status to ensure that the audio was processed.
        if (status != Yobe::Status::YOBE_OK && status != Yobe::Status::NEEDS_MORE_DATA) {
            std::cout << "ProcessBuffer returned: " << Yobe::Info::StdError(status) << '\n';
        } else if (out_buffer_size != 0) {
            // Collect the processed audio data into the output buffer.
            output_buffer.insert(output_buffer.end(), scratch_buffer.begin(), scratch_buffer.end());
        }
    }
 
    // Clean up and deinitialize the Yobe engine.
    auto deinit_status = bio_listener->Deinit();
 
    if (deinit_status != Yobe::Status::YOBE_STOPPED) {
        std::cout << "There was an error when deinitializing the Yobe engine.\n";
    }
 
    std::cout << "Yobe engine has finished processing.\n";
 
    // Close the log stream.
    log_stream.close();
 
    return output_buffer;
}