What is linear pulse code modulation?
Linear pulse code modulation (LPCM) is a method of digitally encoding uncompressed audio information, where audio waveforms are represented by a sequence of amplitude values from a sample on a linear scale in which the values are proportional to the amplitudes as opposed to the log of the amplitudes. This means that the values are quantized linearly, thereby approximating a very large set of possible values with a relatively small set of values, which can be integers or even discrete symbols.
LPCM is also used as a collective reference on audio formats that occur as a result of using this encoding method. Pulse Code Modulation (PCM), a more general method of coding, is often used to describe LPCM. LPCM is capable of very high throughput.
The sampled audio signals in LPCM are represented by one of a fixed number of values in the PCM. LPCM audio is encoded with a combination of values, e.g.
- resolution or sample size
- Frequency of the sampling rate
- Signed or unsigned numbers
- Number of channels, e.g. B. mono, stereo, quadrophone or interleaving
- byte order
Formats that use LPCM data include AES3, Au file format, raw audio, WAV, AC3 (Dolby Digital), MPEG audio, and audio interchange file format (AIFF). LPCM is also part of the DVD (1995) and Blue-Ray (2006) sound and video recording standards and is defined as part of a number of other digital video and audio storage formats.