In recent years, coroutines have become a popular feature in modern programming languages like C++20. Coroutines provide a convenient way to write asynchronous code that is more readable and easier to maintain. One exciting application of coroutines is in audio processing, where real-time processing is required. In this blog post, we will explore how coroutines can be used for audio processing in C++.

What are Coroutines?

Coroutines can be viewed as a generalization of functions. They allow us to suspend and resume their execution at specific points, enabling asynchronous programming. Instead of blocking the execution flow, coroutines can “pause” and pass control back to the caller without losing their state. This makes coroutines perfect for handling audio processing tasks that require real-time and non-blocking operations.

Coroutine-based Audio Processing

To implement audio processing with coroutines, we need a library that supports coroutines, such as Boost.Asio or Boost.Beast. These libraries provide the necessary utilities to write coroutine-based code.

Let’s look at an example of how to write a coroutine-based audio processing function using Boost.Asio:

#include <boost/asio.hpp>
#include <iostream>

// Coroutine-based audio processing function
boost::asio::awaitable<void> processAudio()
{
  // Initialize audio device
  // ...

  while (true)
  {
    // Read audio input
    // ...

    // Process audio data
    // ...

    // Write audio output
    // ...

    // Suspend coroutine until the next audio buffer is available
    co_await boost::asio::deadline_timer(boost::asio::this_coro::executor, boost::asio::chrono::milliseconds(10));
  }
}

int main()
{
  boost::asio::io_context ioContext;

  // Start the coroutine
  boost::asio::spawn(ioContext, processAudio);

  // Run the I/O context
  ioContext.run();

  return 0;
}

In this example, we define a coroutine function processAudio() that reads audio input, processes the data, and writes audio output. By using the co_await keyword, we can suspend the coroutine and resume it later when the next audio buffer is available. This allows us to perform other tasks in the meantime without blocking the audio processing.

Conclusion

Coroutines provide a powerful mechanism for implementing audio processing in C++. By leveraging coroutines and libraries like Boost.Asio, we can write non-blocking and efficient code for real-time audio processing applications. This enables us to handle audio input/output, apply real-time effects, and perform other audio processing tasks seamlessly.

#coroutines #audio-processing