This post will be a short exploration of some of the mathematical and digital concepts involved in sampling, which I might attempt to explore further in later posts.
The process of digitizing analog signals (sound, light, etc) and re-outputting those signals as analog again.
- Digital Audio Signal Processing p. 63 – 95 – Udo Zölzer
- How Analog-to-Digital Conversion Works – Gabriel Torres
- The Data Conversion Handbook – Edited by Walt Kester
The Nyquist-Shannon Theorem
The Nyquist-Shannon Theorem states that you must sample at least 2x as often as the highest frequency you want to capture.
- Certain Topics in Telegraph Transmission Theory – H. Nyquist
- Communication in the Presence of Noise – C. Shannon
- Sampling Theory for Digital Audio – D. Larvy
A mathematical function which transforms between time or space domain and frequency domain. In audio this can be used to visualize sound into graphs and find the specific frequency of sounds, typically using FFT (fast fourier transforms) and Spectrograph technology.
- The Fourier Transform – University of British Columbia
- An Interactive Guide to the Fourier Transform – BetterExplained.com
A zero crossing is a frame of audio where the waveform where it has zero amplitude, it’s not rising to it’s peak or falling to it’s trough.
- Zero Crossing Points – Oh Drat Digital