MPEG-1

From AudioLexic

MPEG-1 defines a group of Audio and Video (AV) coding and compression standards agreed upon by MPEG (Moving Picture Experts Group). MPEG-1 video is used by the Video CD (VCD) format and less commonly by the DVD-Video format. The quality at standard VCD resolution and bitrate is near the quality and performance of a VHS tape. MPEG-1, Audio Layer 3 is the popular audio format known as MP3. As cheaper and more powerful consumer decoding hardware became available, more advanced formats such as MPEG-2 and MPEG-4 were developed. These newer formats are more complex and require more powerful hardware, but the formats also achieve greater coding efficiency, i.e., quality per bitrate.

MPEG-1 consists of several parts or steps, as follows:

1. Synchronization and multiplexing of video and audio (MPEG-1 Program Stream).
2. Compression codec for non-interlaced video signals.
3. Compression codec for perceptual coding of audio signals. The standard defines three "layers," or levels of complexity, of MPEG audio coding.
   1. MP1 or MPEG-1 Part 3 Layer 1 (MPEG-1 Audio Layer I)
   2. MP2 or MPEG-1 Part 3 Layer 2 (MPEG-1 Audio Layer II)
   3. MP3 or MPEG-1 Part 3 Layer 3 (MPEG-1 Audio Layer III)
4. Procedures for testing conformance.
5. Reference software.

Reference: ISO/IEC JTC1/SC29/WG11 (June 1996)

[edit] History

Developments in video conferencing techniques and standards such as H.261 in the late 1980s formed the bases of the MPEG-1 standard in the early 1990s[1]. The Moving Picture Experts Group (MPEG) investigated how to store compressed video on a CD-ROM, which led to the development of the MPEG-1 standard. More history at MP3 History.

[edit] MPEG-1 video

MPEG-1 video was originally designed with a goal of achieving acceptable video quality at 1.5M bit/second data rates and 352x240 (29.97 frame per second) / 352x288 (25 frame per second) resolution. While MPEG-1 applications are often low resolution and low bitrate, the standard allows any resolution less than 4095x4095. Nevertheless, most implementations were designed with the Constrained Parameter Bitstream specification in mind.

At present MPEG-1 is the most compatible format in the MPEG family; it is playable in almost all computers and VCD/DVD players.

One big disadvantage of MPEG-1 video is that it supports only progressive pictures. This deficiency helped prompt development of the more advanced MPEG-2.

[edit] See also

Related standards:

• MPEG-2
• MPEG-1 Audio Layer II
• MPEG-1 Audio Layer III
• JPEG
• JBIG
• AAC

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