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Linear Pulse Code Modulation

What Does Linear Pulse Code Modulation Mean?

Linear pulse code modulation (LPCM) is a method for 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 being the log of the amplitudes. This means that the values are linearly quantized, thus approximating a very large set of possible values with a relatively small set of values that may be integers or even discrete symbols.


LPCM is also used as a collective reference to audio formats that occur as a result of using this encoding method. Pulse code modulation (PCM), a more general method of encoding, is often used to describe LPCM. LPCM is capable of very high throughput.

Techopedia Explains Linear Pulse Code Modulation

The sampled audio signals in LPCM are represented by one of a fixed number of values in the PCM. LPCM audio is coded using a combination of values such as:

  • Resolution or sample sizes
  • Frequency of sample rate
  • Signed or unsigned numbers
  • Number of channels, such as monaural, stereo, quadraphonic, 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 a 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.


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