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Appendix 6 Media Formats
A6.1 Moive formats
High resolution movie programs will meet a lot of difficulties in both storage and transferring.
The only solution is digital compression of signals.
HDTV video usually adopts many coding formats such as MPEG2-TS, WMV-HD and H.264.
The most common one is MPEG2-TS Code Standard HDTV program. These video files are
usually video stream files with suffixes of ‘.tp, .ts, .mpg’. H.264 has an advantage of excellent
structure originating from MPEG-4. It also has a technical advantage of 2-3 times higher than
MPEG-2 digital compression rate and 1.5 times higher than that of MPEG-4. Based on that, it
is greatly inclined to replace MPEF-2/4 code standard. Microsoft-dominant WMV-HD,
however, becomes the most familiar coding mode among recent 1080p programs on the internet,
as a result of its extremely high compression ratio and perfect support to PC platform. Usually
its suffix is “.wmv.”
H.264
On May, 2003, ITU and ISO MPEG (International Organization for Standardization’s Moving
Picture Experts Group) together issued an H.264 video compression standard. It is formally
named as MPEG-4 AVC
(
Advanced Video Coding
)
, which is the chapter 10 of MPEG-4.
H.264 has been authorized as one of the video formats of Blue Ray DVD and HD-DVD by DVD
Forum and Blue Ray Disk Association. Now Japan adopts H.264 coding stream for its ISDB-T
Digital Broadcast, while many satellite TV like BskyB, DirecTV, Dish Network, Euro1080, Sat1
HD also adopt H.264 format.
Technically speaking, H.264 represents the most advanced video compression technique in the
video digital processing field. It is able to provide high quality image transmission in the
condition of low bandwidth (within 2M). According to the data analysis, H.264 averagely saves
64% transmission bandwidth compared with its previous MPEG2 in the same video quality.
H.264 technique also has strong fault-tolerance and better support to network transmission. It
introduces a coding format system apply to IP packet.
WMV9/WMV-HD/VC-1
WMV (Windows Media Video) format, upgrades and extends from Windows Media centered ASF
(Advanced Stream Format). WMV is a kind of coding format, through which multi-media
information like audio, video, image and control command script transfer in the form of network
data packet to realize the issuance of stream style multi-media contents. WMV has a great
advantage of low bit rate, which is suitable to network transmission.
WMV9 supports VBR coding, which is short for Variable Bit Rate. Still picture and motive
picture of movie have different requirements of the Compression Sample Rate. It will affect the
movie quality if you always keep the fixed bit rate. With the great popularization of WMV9 by