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 video CDs, digital cable/satellite TV and digital audio broadcasting (DAB) practical.

MPEG-1 has become a widely compatible lossy audio/video format, and is used in a large number of products and technologies. Perhaps the best-known part of the MPEG-1 standard is the first version of the MP3 audio format it introduced.

The MPEG-1 standard is published as ISO/IEC 11172, titled Information technology—Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mbit/s.

The standard consists of the following five Parts:

1. Systems (defining a format for storage and synchronization of video, audio, and other data together in a single file—later dubbed the MPEG program stream to distinguish it from the MPEG transport stream format introduced as an alternative in MPEG-2).
2. Video (compressed video content)
3. Audio (compressed audio content), including MP3 and MP2
4. Conformance testing (testing the correctness of implementations of the standard)
5. Reference software (example software showing how to encode and decode according to the standard)