How to find highest volume level of a WAV file using C++

Question

I want to get the value of the highest volume level of a WAV-file by using C++ (library libsndfile)? Any suggestions on how to do it?

Answer 1

You can simply find the highest single sample value (Peak) among the absolute values of the samples in the sample buffer(s). This takes the general form:

t_sample PeakAmplitude(const t_sample* const buffer, const size_t& count) {
  t_sample highest(0);
  for (size_t idx(0); idx < count; ++idx) {
    // or fabs if fp
    highest = std::max(highest, abs(buffer[idx]));
  }
  return highest;
}

To get averages, you can use RMS functions. Illustration:

t_sample RMSAmplitude(const t_sample* const buffer, const size_t& count) {
  t_sample s2(0);
  for (size_t idx(0); idx < count; ++idx) {
    // mind your sample types and ranges
    s2 += buffer[idx] * buffer[idx];
  }
  return sqrt(s2 / static_cast<double>(count));
}

RMS calculations are closer to human perception than Peak.

To go even deeper into human perception, you can employ Weighing Filters.