View Full Version : Changing Frequency/Pitch of Audio from SD Card

04-02-2016, 10:29 PM

I am currently working on a sampler project that involves the task of adjusting the frequency/pitch of audio from an SD card. Ultimately, this sampler is meant to have 4 separate channels. I am currently in possession of a Teensy 3.2 and two Teensy Audio Adapters. I am also currently able to play the sound files from the SD card and am aware of certain predefined methods and functions that allow for the adjusting of the volume and playback of the sounds.

However, I am confused on where to start in order to be able to change the frequency of these sound files. I could not find any preexisting methods or functions to adjust the frequency (please point me in the right direction if such does exist). I am assuming that I must read in the audio from the SD card first and then be able to manipulate the sound files. I have started looking into the wav2sketch program that converts the .wav files to data arrays. However, I would like to be able to read in and convert these sound files to malleable data internally in my program directly from the SD card (not externally first through the wav2sketch program and then sending my files into the code).

Is such a feat possible? Am I headed down a rabbit hole and are there preexisting methods or functions that allow for the adjusting of the frequency of audio?

I am willing to provide more detail if needed. Thank you in advance for your time.