...MPEG-1 Architecture & Compressions
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[edit] Overview
MPEG-1 was the first ISO standard architecture for encoding audio and video (1992). Although its frame size was limited to 352x240 at 30fps for NTSC, its visual and audio quality was stunning. Here is a link to an example of an MPEG-1 video file that is indeed impressive:
MPEG-1 30-second Digital Movie File
Within the International Organization for Standardization (ISO), a working group was established in the late 1990s. Known as the “Moving Pictures Experts Group”, they defined an “area of work” intended to develop international standards for...
- compression,
- de-compression,
- processing, and
- coded representation
...of moving pictures, audio, and their combination, in order to satisfy a wide variety of applications.
The MPEG Working Group developed MPEG-1, followed by MPEG-2. As of 2000, they released the specification for MPEG-4, an international, standardized media architecture:
Although unrelated to media architectures and the playout of audio or video content, the MPEG Working Group is also working on standards for metadata and tracking the life cycles of intellectual content through the MPEG-7 and MPEG-21 areas of work:
Although MPEG-1's successor, MPEG-2, offered greater quality at full-screen display, MPEG-1 became the preferred format for the Video CDs that are most popular in the Asian and Southeast Asian areas of the world. The playback devices simply take the smaller sized MPEG-1 file and double it up to become full screen (standard definition). MPEG-1 was also used frequently in the early days of interactive CD-ROM titles when digital video files were needed.
Today, it is true that an MPEG-1 file can be successfully interpreted and decoded by any major media player, including QuickTime, Real, WindowsMedia, and VLC Player, to name a few. That can't be said of most other media architectures or file formats.
[edit] MPEG-1 Started It All
- Quoted from an article entitled The MPEG Video Standards-from 1 to 21, authored by Larry Bouthillier, February 18, 2004, copyrighted to StreamingMedia.com.
- "In development for years, MPEG1 became an official standard for encoding audio and video in 1992. The simplest of the MPEG standards, it describes a way to encode audio and video data streams, along with a way to decode them. MPEG1 may seem like an almost quaint spec in these days of super-codecs like WM9, RealVideo9, and MPEG4 -- but don't count it out. You can play it on just about any computer or operating system, and it doesn't take any special software or a lot of CPU horsepower to decode. And it's a sure bet that in ten years, you'll still be able to open and play those MPEG1 files in your archive."
- "The default size for an MPEG1 video is 352x240 at 30fps for NTSC (352x288 at 25fps for PAL sources). These were designed to give the correct 4:3 aspect ratio when displayed on the rectangular pixels of TV screens. For a computer-based viewing audience, 320x240 square pixels gives the same aspect ratio. Good up to about 1.5Mbps, MPEG1 delivers roughly VHS quality at 30 frames per second. You can scale up or down in size or bitrate, but from 1.2-1.5Mbps is the sweet spot where you'll get the most bang for your bitrate buck."
[edit] MP3 is Not MPEG-3
- Quoted from an article entitled The MPEG Video Standards-from 1 to 21, authored by Larry Bouthillier, February 18, 2004, copyrighted to StreamingMedia.com.
- "It's the magical ability to squeeze the 1.4Mbps audio stream from a standard audio CD down to a sweet-sounding 128kbps that has made MP3 the de facto standard for digital music distribution. You can find MP3 support in every major media player on every computer platform, and dozens of consumer electronic devices can play MP3s. It's as close to a universal format for audio as you'll find."
- "MP3 is actually part of the MPEG1 standard. The audio portion of the MPEG1 spec contains three different compression schemes called layers. Of the three, Layer 3 provides the greatest audio quality and the greatest compression. At 8kbps, MP3 will sound like a phone call – intelligible, but nothing you'd ever call high-fidelity. Good-quality music starts at about 96kbps, but generally you'll want 128 or 160kbps to get "CD quality" reproduction."
- For a more in depth review of the MP3 standard, reference the article from the Wikipedia entitled MP3.
[edit] Resources
- MPEG-1 Article from the Wikipedia
- http://en.wikipedia.org/wiki/MPEG-1
- MPEG Architecture (1 ,2 , MP3, 4, 7, 21)(authoring by Media Solutions, University of Utah)
- http://stream.uen.org/medsol/digvid/html/2B_mediaarchmpeg1.html
- MPEG Industry Forum
- http://www.m4if.org/
- MPEG Home Page (Motion Pictures Experts Group)
- http://www.chiariglione.org/mpeg/
- MPEG Video Standards - from 1 to 21, article by Larry Bouthillier, 18 Feb 2004
- http://www.streamingmedia.com/article.asp?id=8569&page=1&c=7
- MPEG-1, Overview of the Standard
- http://www.chiariglione.org/mpeg/standards/mpeg-1/mpeg-1.htm
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