Part 3 of theMPEG-2 standard (formally known asISO/IEC 13818-3, also known asMPEG-2 Audio orMPEG-2 BC) defines audio coding:

• MPEG Multichannel - It enhancesMPEG-1's audio by allowing the coding of audio programs with more than twochannels, up to 5.1 multichannel. This method is backwards-compatible (also known as MPEG-2 BC^[1][2][3][4]), allowing MPEG-1 audio decoders to decode the two main stereo components of the presentation.^[5]
• MPEG-2 Part 3 also defined additional bit rates and sample rates forMPEG-1 Audio Layer I,MPEG-1 Audio Layer II andMPEG-1 Audio Layer III (the first version ofMP3).^[6]

The MPEG-2 Part 3 should not be confused with MPEG-2 Part 7: AAC a.k.a. MPEG-2 NBC (Non-Backward Compatible) - the MPEG-2Advanced Audio Coding with support for multichannel encoding (up to 48 channels).^[1][2]

MPEG-2 Part 3 introduced new audio encoding methods compared to MPEG-1 Part 3:^[7] MPEG-2 BC (backward compatible with MPEG-1 audio formats)^[1][2][5]

• low bitrate encoding with halved sampling rate (MPEG-1 Layer1/2/3 LSF - "Low Sampling Frequencies")
• multichannel encoding with up to 5.1 channels

• MPEG-2

• CS1 maint: multiple names: authors list