2. CMS Content Updating
In this chapter, you will learn:
o Define what is “digital video”
o Identify the various video format and their
characteristics
o Describe the advantages and disadvantages of
the various formats across platforms.
o Define what is “digital audio”
o Identify the various sound formats and its
characteristics
3. Video
Video is stream of data composed of
discrete frames, usually including both
audio and pictures
o US TV Signal = 30 fps
o European stations = 15 fps
o Movies = 24 fps
4. Video
Analog Video
o It is the representation of information by
variable physical quantities such as the size
of electrical voltages.
5. Video
• Digital Video
o is a sheet of dots, called pixels, each holding
colour value.
6. Video
Video File Format
File Platform Purpose
Extension
.MOV Mac, Win Mac’s * Once the movie is
QuickTime compressed, the
Video viewer must have the
.AVI Mac, Win Microsoft’s same compressor to
Audio Video play it back.
Interleaved
7. Video
Video File Format
File Platform Purpose
Extension
.MPEG Mac, Win, MPEG Video * Once the movie is
Unix Mac may compressed, the
have problem viewer must have the
with the audio same compressor to
track play it back.
8. Video
Video File Format
File Platform Purpose
Extension
.ASF Mac, Win Microsoft Both .RM and .ASF
streaming compression is
format intended to produce
a low data rate :
may discard data as well as
compress it, which is
important for streaming
used for distribution only
9. Video
Video File Format
File Platform Purpose
Extension
.RM Mac, Win, Used by Both .RM and .ASF
Unix RealNetworks compression is
streaming intended to produce
a low data rate :
may discard data as well as
compress it, which is
important for streaming
used for distribution only
10. Video
Cross Platform
Dynamic Data Exchange (DDE)
o allows data to be transmitted between client
and a server
o Hot link and/or cold link
11. Video
Cross Platform
Object Linking and Embedding (OLE)
o Lets you embed or link data objects created
in different OS app
o An embedded object becomes a part of the
file into which it is pasted
o A linked object is changed automatically in
when the original file is updated
12. Video Compression
Lossless compression
o The simplest form of digital video compression
takes advantage of spatial redundancy – i.e
areas of single picture that are the same.
Lossy Compression
o information is removed permanently.
13. Video Compression
Advantages of compression
o smaller amount of storage is needed
o compression allows highly miniaturized
equipment for consumer and professionals
o compression reduces the bandwidth needed
o allows faster-than-real-time transfer between
media.
