In audio processing, dynamic range compression is a technique used to reduce the difference between the loudest and softest parts of an audio signal. It helps to even out the volume levels, resulting in a more balanced sound. In this blog post, we will explore how to implement dynamic range compression in C++.

What is Dynamic Range Compression?

Dynamic range compression works by reducing the gain of the audio signal when it exceeds a certain threshold. This threshold can be set to a fixed value or adjusted dynamically based on the input signal. The compression ratio determines how much the gain is reduced when the signal exceeds the threshold.

Steps to Implement Dynamic Range Compression

Step 1: Include Required Libraries

#include <iostream>
#include <cmath>

Step 2: Define the Compression Parameters

// Compression threshold in decibels (dB)
const double compressionThreshold = -20.0;

// Compression ratio
const double compressionRatio = 2.0;

Step 3: Implement the Compression Function

double compressSignal(double inputSignal)
{
    // Convert the input signal to decibels (dB)
    double inputSignal_dB = 20 * std::log10(std::abs(inputSignal));

    // Check if the signal exceeds the compression threshold
    if (inputSignal_dB > compressionThreshold)
    {
        // Calculate the compression gain reduction
        double gainReduction = (inputSignal_dB - compressionThreshold) / compressionRatio;

        // Apply the gain reduction to the signal
        double compressedSignal = inputSignal * std::pow(10, (-gainReduction / 20));
        return compressedSignal;
    }

    return inputSignal;
}

Step 4: Test the Compression Function

int main()
{
    // Test the compression function
    double inputSignal = 0.5;  // Sample input signal

    double compressedSignal = compressSignal(inputSignal);

    std::cout << "Input Signal: " << inputSignal << std::endl;
    std::cout << "Compressed Signal: " << compressedSignal << std::endl;

    return 0;
}

Conclusion

Dynamic range compression is a valuable technique in audio processing to control the volume levels of an audio signal. By applying this technique, we can achieve a more balanced and consistent sound experience. In this blog post, we implemented dynamic range compression in C++ using a simple compression function. You can further extend this implementation to handle audio files or real-time audio streaming.

#programming #audio #compression #C++