Part 3 of the
MPEG-2 standard (formally known as ISO/IEC 13818-3, also known as MPEG-2 Audio or MPEG-2 BC) defines audio coding:
*
MPEG Multichannel
__NOTOC__
MPEG Multichannel is an extension to the MPEG-1 Layer II sound, audio compression specification, as defined in the MPEG-2 Audio standard (International Organization for Standardization, ISO/International Electrotechnical Commission, IE ...
- It enhances
MPEG-1
MPEG-1 is a standard for lossy compression of video and audio. It is designed to compress VHS-quality raw digital video and CD audio down to about 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively) without excessive quality loss, making ...
's audio by allowing the coding of audio programs with more than two
channels, up to 5.1 multichannel. This method is backwards-compatible (also known as MPEG-2 BC
), allowing MPEG-1 audio decoders to decode the two main stereo components of the presentation.
* MPEG-2 Part 3 also defined additional bit rates and sample rates for
MPEG-1 Audio Layer I
MPEG-1 Audio Layer I, commonly abbreviated to MP1, is one of three audio formats included in the MPEG-1 standard. It is a deliberately simplified version of MPEG-1 Audio Layer II (MP2), created for applications where lower compression efficiency ...
,
MPEG-1 Audio Layer II
MPEG-1 Audio Layer II or MPEG-2 Audio Layer II (MP2, sometimes incorrectly called Musicam or MUSICAM) is a lossy audio compression format defined by ISO/IEC 11172-3 alongside MPEG-1 Audio Layer I and MPEG-1 Audio Layer III (MP3). While MP3 is m ...
and
MPEG-1 Audio Layer III
MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Origin ...
(the first version of
MP3
MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Origin ...
).
[Predrag Supurovic]
MPEG Audio Frame Header
Retrieved on 2009-07-11
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-2
Advanced Audio Coding
Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves higher sound quality than MP3 encoders at the same bit rate.
AAC has been stan ...
with support for multichannel encoding (up to 48 channels).
Overview
MPEG-2 Part 3 introduced new audio encoding methods compared to MPEG-1 Part 3:
MPEG-2 BC (backward compatible with MPEG-1 audio formats)
* low bitrate encoding with halved sampling rate (MPEG-1 Layer
1/
2/
3 LSF - "Low Sampling Frequencies")
* multichannel encoding with up to 5.1 channels
References
{{MPEG
#03