MPEG-1 Audio Layer II

What Does MPEG-1 Audio Layer II Mean?

MPEG-1 Audio Layer II (MP2) is an audio file format that uses the MPEG Audio Layer-2 compression standard defined by ISO/IEC 11172-3 to reduce the size of the file. It is a lossy format, which was replaced by MP3 because MP3 required a lower bit rate to achieve the same quality. However, MP2 is still predominantly used in broadcasting because it has higher error resilience than MP3 and sounds better at higher bit rates of 256 kbps and above.


MPEG-1 Audio Layer II is also known as MPEG-2 Audio Layer II.

Techopedia Explains MPEG-1 Audio Layer II

The MP2 format is the predecessor of the widely known MP3 format for audio compression. It is a sub-band audio encoder, so the compression is done in the time domain with a low-delay filter bank. As a comparison, MP3 uses a transform audio encoder with a hybrid filter bank that compresses the frequency domain after a hybrid or double transformation is done in the time domain.

As the predecessor to MP3, MP2 is the core algorithm used in MP3 and all psychoacoustical characteristics as well as frame format structures of MP3 are derived from the MP2 algorithms and format.

MP2 has the following characteristics:

  • Sampling rates: 32, 44.1 and 48 kHz
  • Bit rates: 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320 and 384 kbps

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Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…