Data Compression


Survey Formats


Compression Methods

Data Formats


Audio Data

MPEG-1 Audio

MPEG-1 Layer I to III

Sampling and Bit Rate

Variable Bit Rates

Principle of the coding


Acoustic Model

Entropy Coding

Encoding (Diagram)

Image Data

Video Data




Sampling and Bit Rate

Equivalent to the common audio systems three different sampling rates are defined: 32, 44.1 and 48 kHz. They correspond with the audio sources radio (FM), CD and DAT.

Bit rates (data transfer rates) may be selected in a wide range. The internal header specification of MPEG allows the usage of the following rates:

IndexLayer ILayer IILayer III
0free formatfree formatfree format
132 kbit/s32 kbit/s32 kbit/s
264 kbit/s48 kbit/s40 kbit/s
396 kbit/s56 kbit/s48 kbit/s
4128 kbit/s64 kbit/s56 kbit/s
5160 kbit/s80 kbit/s64 kbit/s
6192 kbit/s96 kbit/s80 kbit/s
7224 kbit/s112 kbit/s96 kbit/s
8256 kbit/s128 kbit/s112 kbit/s
9288 kbit/s160 kbit/s128 kbit/s
10320 kbit/s192 kbit/s160 kbit/s
11352 kbit/s224 kbit/s192 kbit/s
12384 kbit/s256 kbit/s224 kbit/s
13416 kbit/s320 kbit/s256 kbit/s
14448 kbit/s384 kbit/s320 kbit/s

According to the specification there are some restrictions regarding the combination of bit rates and operation mode, which concern Layer II.

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MPEG-1 Audio MPEG-1 Layer I to III Variable Bit Rates