Resampling question

General JUCE discussion
1

Hello! I’m completely stuck with the JUCE interpolators (
Before that I used libsamplerate.
I need to resample the buffer of floats from sound file’s samplerate to DAW session’s sample rate.
So I have the source buffer (loaded from the reader):
juce::AudioBuffer<float> *buffer = new juce::AudioBuffer<float>;
If the buffer’s samplerate != session’s samplerate I need to resample.
My steps are.

  1. Define the resamling ratio:
    float ratio = (float) samplerate / session_samplerate;
  2. Calculate the output frames (samples) count for each channels:
    size_t output_frames_count = ratio * length_in_samples;
    length_in_samples is the length of the source buffer, in samples, for the any of the channels.
  3. I define the new buffer to write resampled data:
    juce::AudioBuffer<float> * output_buffer = new juce::AudioBuffer <float> (channels, output_frames_count);
  4. Then I process:
 for (int i = 0; i < channels; i++)
      {
       juce::LinearInterpolator interpolator;

        int result = interpolator.process (ratio,
                                            buffer->getReadPointer(i),
                                            output_buffer->getWritePointer(i),
                                            output_frames_count);
}
  1. It works, but It makes samples high-pitched (in my test I resample 44100 to 48000, and 16000 to 44100 or 48000). How to fix it?
2

Juce’s interpolators define ratio as “the number of input samples to use for each output sample”, whereas your ratio is the inverse of this.

3

Thank you! But it crashes ( Now I decided to use speex resampler instead…