Codec Central - MPEG Codecs



	Introduction \| Choosing a Technology \| Index of Codecs \| Index of Architectures In-Depth Articles \| Sample Movies \| Glossary of Digital Video Terms

MPEG-1

Note: To view this movie, you will need QuickTime 2.5 or later, the QuickTime Netscape plug-in, and the QuickTime MPEG Extension. All of these are available for free download from Apple.

MPEG-1: 320x240, 30fps, 170KBps

General Information

Overview
MPEG-1 provides excellent image quality at CD-ROM data rates. One of the most popular uses of MPEG-1 is the VCD, or "white book" video CD. MPEG includes both audio and video compression.

The biggest problem with MPEG is that it has high requirements for playback. Either a dedicated MPEG decoder card must be installed, or a high-end CPU is required for software-only playback. Because of this limitation, MPEG has not gained wide acceptance in consumer titles.

MPEG-2 is a related standard. It is used by DVD-Video and several broadcasting applications. MPEG-2 provides excellent fullscreen NTSC quality. However, playback is even more difficult than MPEG-1. There are no software-only playback solutions, and the hardware required to play MPEG-2 movies is quite expensive and rare at this point.

MPEG may be embedded in several other formats, including QuickTime. The example on this page is a QuickTime movie which includes an MPEG track.

Architectures Supported

QuickTime

Pros, Cons & Tips

Pros

Excellent image quality

Cons

Very high playback requirements
Majority of installed base not capable of viewing MPEG
Licensing fees (typically US $0.04 - $0.40 per unit) are required to distribute MPEG-2 video. There may also be fees for MPEG-1; there is some uncertainty regarding this.
Not well-suited to WWW video (the upcoming MPEG-4 standard will address this)

Ideal source material	Video
Supported bit depths	24 bit
Compression time	Very slow (software), realtime (hardware)
Temporal compression?	Yes
Special features	-
Encoder requirements	Commercial encoder software and/or hardware
Decoder requirements	MPEG decoder card, or 120+ Mhz PowerMac or 166+ Mhz Pentium
Encoder availability	Commercially available from several companies
Decoder availability	Wide range of MPEG-1 software & hardware decoders
Algorithm	Discrete Cosine Transform (DCT) with Motion Prediction based on H.261
Manufacturer	Many

If you have any comments or tips & tricks to share about MPEG, please contact us at info@terran-int.com.