MPEG-1's known weaknesses:
    * an audio compression system 
limited to two channels (stereo.)
    * 
no standardized support for interlaced video with poor compression when used for interlaced video
    * only one standardized "profile" (Constrained Parameters
Bitstream) which was unsuited for higher resolution video. MPEG-1 could
support 4k video but there was no easy way to encode video for higher
resolutions, and identify hardware capable of supporting it, as the
limitations of such hardware were not defined.
    * Support for only one color space, 
4:2:0.
[링크 : 
http://en.wikipedia.org/wiki/Mpeg2]
MPEG-2 part 1 ~ 11
Part  1 H.222.0
Part  2 H.262
Part  3 MPEG-2 BC - backwards compatible with MPEG-1 Audio
Part  4 - conformance testing
Part  5 - software simulation
Part  6 DSM-CC (Digital Storage Media Command and Control)
Part  7 MPEG-2 NBC (Audio - Non-Backwards Compatible with MPEG-1 Audio) / AAC
Part  8 - drop
Part  9 
Part 10 DSM-CC
Part 11 IPMP (Intellectual Property Management and Protection)
Audio encoding
 MPEG-2 also introduces new audio encoding methods. These are:[12]
 MPEG-2 BC (backward compatible with MPEG-1 audio formats)[6][5][9]
     * low bitrate encoding with halved sampling rate (
MPEG-1 Layer 1/2/3 LSF)
     * multichannel encoding with up to 
5.1 channels
 MPEG-2 NBC (Non-Backward Compatible)[6][5]
     * MPEG-2 
AAC
     * multichannel encoding with up to 
48 channels
[링크 : 
http://en.wikipedia.org/wiki/Mpeg2]
MPEG-4 part 1 ~ 27
Part  1 System
Part  2 Visual
Part  3 Audio
Part  4 Conformance testing
Part  5 Reference software
Part  6 DMIF (Delivery Multimedia Integration Framework)
Part  7 
Part  8 over IP
Part  9 Reference hardware description
Part 10 AVC (H.264)
Part 11 
Part 12 3gp (iso base media file format)
Part 13 IPMP
Part 14 mp4
Part 15 AVC (Advanced Video Coding)
Part 16 AFX (Animation Framework eXtension)
Part 17 
Part 18 
Part 19 
Part 20 
Part 21 
Part 22 
Part 23 
Part 24 
Part 25 
Part 26 
Part 27