pulse-code modulation
Sign in to saveAlso known as PCM, pulse code modulation
digital representation of sampled analog signals
Key facts
- Filename extension
- .L16, .WAV, .AIFF, .AU, .PCM
- Internet media type
- audio/L16, audio/L8, audio/L20, audio/L24
- Type code
- "AIFF" for L16, none
- Magic number
- Varies
- Type of format
- Uncompressed audio
- Contained by
- Audio CD , AES3 , WAV , AIFF , AU , M2TS , VOB , and many others
- Open format
- Yes
- Free format
- Yes
via Wikipedia infobox
Wikidata facts
Show 3 more facts
- Commons category
- Pulse-code modulation
- Stack Exchange tag
- stackoverflow.com/tags/pcm
- file extension
- pcm
via Wikidata · CC0
~19 min read
Article
Pulse-code modulation (PCM) is a method used to digitally represent analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps. Claude Shannon, Bernard Oliver, and John Pierce were inducted into the National Inventors Hall of Fame for their PCM patent granted in 1952.
Linear pulse-code modulation (LPCM) is a specific type of PCM in which the quantization levels are linearly uniform. This is in contrast to PCM encodings in which quantization levels vary as a function of amplitude (as with the A-law algorithm or the μ-law algorithm). Though PCM is a more general term, it is often used to describe data encoded as LPCM.