Audio effects enhance the listening experience by modifying the sound properties. One popular audio effect is the flanger, which creates a sweeping “jet plane” or “whooshing” sound. In this blog post, we will explore how to implement flangers in C++.

What is a Flanger?

A flanger is an audio effect that creates a series of delayed and modulated copies of the original audio signal. It works by mixing the original signal with a delayed version of itself, producing a comb filtering effect. The delayed signal is modulated by an LFO (Low Frequency Oscillator), which introduces variations in the delay over time.

Setting up the Project

Before we dive into the implementation details, let’s set up our C++ project. We will use a popular library called PortAudio for audio input/output. Install PortAudio on your system and set up a new C++ project, including the necessary headers and library dependencies.

Implementing the Flanger Effect

To implement the flanger effect, follow these steps:

1. Read audio data from a source file or microphone input using PortAudio.
2. Apply a varying delay to the audio signal using an LFO.
3. Mix the delayed signal with the original signal.
4. Write the processed audio data to an output file or play it back using PortAudio.

Let’s take a closer look at each step:

Step 1: Reading Audio Data

To read audio data from a source file or microphone input, use the appropriate functions provided by PortAudio. These functions will give you access to the audio buffer containing the raw audio samples.

// Code to read audio data using PortAudio

Step 2: Applying Varying Delay

To create the flanger effect, we need to apply a varying delay to the audio signal. This is achieved by using an LFO to modulate the delay time. The LFO generates a waveform that controls the amount of delay at a given time.

// Code to apply varying delay using an LFO

Step 3: Mixing Delayed Signal

After applying the varying delay, we need to mix the delayed audio signal with the original signal. This can be done by adding the two signals together or using other mixing techniques.

// Code to mix the delayed audio signal with the original signal

Step 4: Writing Processed Audio Data

Finally, you can write the processed audio data to an output file or play it back using PortAudio. The choice depends on your specific needs and project requirements.

// Code to write processed audio data to an output file or play it back

Conclusion

By implementing flangers in C++ using PortAudio, you can add interesting and dynamic audio effects to your applications. Experiment with different settings and parameters to achieve unique and immersive audio experiences. Happy coding!

#audioeffects #flangers