PCM - Analog to digital conversion

The video by Sunny explains Pulse Code Modulation (PCM), a method for converting analog signals to digital signals through three main steps: sampling, quantizing, and encoding.

Steps of Pulse Code Modulation

1. Sampling: This step involves taking a sufficient number of samples from the continuous analog signal to represent it accurately. The sample rate, measured in Hertz (Hz), indicates how many times per second the signal is sampled. For example:
   • Telephone: 8 kHz (8000 samples/second)
   • Voice over IP: 16 kHz
   • Audio CD/MP3: 44 kHz
   • Blu-ray Disc: up to 1 MHz
2. Quantizing: This process converts the discrete time signal into a finite set of values, which can be represented in binary. The bit depth determines how many levels can be represented:
   • 8-bit: 256 levels
   • 16-bit: 65,536 levels
   • 24-bit: approximately 16.8 million levels
   The quantizing process rounds the amplitude of each sample to match one of these levels.
3. Encoding: In this final step, the quantized samples are converted into binary numbers. Each sample corresponds to a specific bit value, resulting in a long stream of zeros and ones that represent the original analog data.

The video emphasizes that while PCM may seem complex, it is a straightforward process of converting analog signals into digital formats.

Main Speaker

• Sunny