MPEG, the Moving Picture Experts Group, is a working group formed under ISO and IEC in 1988 to develop standards for the coded representation of digital audio and video. Over more than three decades it produced the family of specifications that underpin most digital video and compressed audio in the world. Its first two standards, MPEG-1 and MPEG-2, established the core techniques and the institutional model that the group followed thereafter.
MPEG-1 was published as ISO/IEC 11172, “Information technology - Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s.” Its parts cover systems, video, and audio; the video part is ISO/IEC 11172-2, whose ISO catalogue record carries a first edition dated 1993. MPEG-1 targeted the bitrate of CD-ROM and was designed for applications such as Video CD. Its audio part, ISO/IEC 11172-3, defined the three audio layers, the third of which became known to the world as MP3.
MPEG-2 followed as ISO/IEC 13818, “Information technology - Generic coding of moving pictures and associated audio information,” developed jointly with the ITU-T, where the video part appears as ITU-T Recommendation H.262. The ITU catalogue confirms H.262 was produced through joint activity with ISO and IEC and is technically identical to ISO/IEC 13818-2. MPEG-2 extended MPEG-1 with support for interlaced video, higher resolutions, and broadcast-quality bitrates, and it became the coding standard for DVD-Video, digital television, and early digital broadcasting around the world.
The video coding model these standards share is built on motion-compensated prediction and the discrete cosine transform. Rather than coding each frame independently, the encoder exploits temporal redundancy by predicting much of a frame from earlier (and, for B-frames, later) reference frames using motion vectors, then coding only the residual differences with a DCT-based scheme conceptually similar to JPEG. This combination of temporal and spatial compression is what makes full-motion video small enough to store and transmit, and it is the foundation on which later codecs such as H.264 build.
Beyond the codecs themselves, MPEG defined container and systems layers that multiplex audio, video, and timing information into a single stream, distinguishing the transport stream used for broadcasting from the program stream used for storage. The group went on to produce MPEG-4 (including the widely used AVC video codec), audio standards such as AAC, and metadata and systems specifications, but MPEG-1 and MPEG-2 remain the bedrock, having defined how the world stores and broadcasts digital moving pictures.