Table of Contents

• Introduction to std::chrono
• Calculating the Duration of Video Files
• Calculating the Duration of Audio Files
• Conclusion

Introduction to std::chrono

The std::chrono library, introduced in C++11, provides a set of utilities for handling time-related operations. It offers high-resolution clocks and a type-safe representation of time durations.

To calculate the duration of video and audio files, we can utilize the std::chrono::duration class, which represents a duration of time with a specified precision. We can combine this with the std::chrono::steady_clock, which is a monotonic clock that ticks at a constant rate.

Calculating the Duration of Video Files

To calculate the duration of a video file, we need to read its metadata, which usually includes the total number of frames and the frame rate. With this information, we can calculate the duration using the following steps:

1. Read the total number of frames from the video file’s metadata.
2. Read the frame rate from the video file’s metadata.
3. Calculate the duration in seconds by dividing the total number of frames by the frame rate.

Here’s an example code snippet that demonstrates how to calculate the duration of a video file using std::chrono in C++:

#include <iostream>
#include <chrono>

int main() {
    int totalFrames = 1000;
    double frameRate = 30.0;

    double durationInSec = totalFrames / frameRate;

    std::chrono::duration<double> duration(durationInSec);

    std::cout << "Video duration: " << duration.count() << " seconds" << std::endl;

    return 0;
}

Calculating the Duration of Audio Files

Similar to video files, calculating the duration of audio files requires reading the metadata. The metadata usually includes the sample rate and the total number of samples. We can calculate the duration using the following steps:

1. Read the total number of samples from the audio file’s metadata.
2. Read the sample rate from the audio file’s metadata.
3. Calculate the duration in seconds by dividing the total number of samples by the sample rate.

Here’s an example code snippet that demonstrates how to calculate the duration of an audio file using std::chrono in C++:

#include <iostream>
#include <chrono>

int main() {
    int totalSamples = 44100;
    int sampleRate = 44100;

    double durationInSec = static_cast<double>(totalSamples) / sampleRate;

    std::chrono::duration<double> duration(durationInSec);

    std::cout << "Audio duration: " << duration.count() << " seconds" << std::endl;

    return 0;
}

Conclusion

In this blog post, we explored how to use the std::chrono library in C++ to calculate the duration of video and audio files accurately. By leveraging the provided utilities, we can easily handle time-related operations and calculate precise durations.