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Title: Digital Media Technology : Real World Applications


1
Digital Media Technology Real World Applications
  • June Bicknese

2
Table of contents
  • 1. Digital media technology in media production
  • 2. Overview of digital technology and a media
    server
  • 3. A case study on a production company
  • - digital technologies applied to kiosk
    system architecture

3
Digital Technology Media Production
  • 1. Traditional media production and its
    shortcomings
  • - Inconvenience of an analog and linear
    videotape
  • - Continuous demand for expanding video tape
    storage space
  • - Retrieval of a videotape from a tape library
  • 2. Advantage of using digital techniques
  • - Digital tapes are non-linear.
  • - For storing a digital video, various
    compression algorithms are used.
  • - Retrieval is easy, if used with a server.
  • 3. Current status of migrating from analog
    to digital
  • - Commercial playback loops
  • - Analog/digital editing system such as Avid

4
Video Server Technology
  • Processing
  • Editing
  • Compressing Encoding

Analog
Digital
  • Storage
  • Archive
  • Retrieval

Analog
Digital
Output
Media Server
Input
Network
5
Getting an input
  • Analog input
  • 1) Analog structure Luminance(Brightness)
    Chrominance(Color)
  • gt Frame like a picture
  • gt Series frames as moving images
  • gt A VHS tape
  • 2) Digitizing a VHS video
  • gt Import the analog tape into a digitizing
    software
  • gt Digitizing software makes the
    analog input into the digital format
  • gt Transfer the digitized data into an
    editor
  • Digital input directly transferred into an
    editor

Frame
0111011101101110100101010001110011
gt
Frame
lt Streams of bits gt instructions to recreate
an analog video
6
Video Processing
  • Editing
  • - Software-specific
  • - Popular software Avid Xpress, Avid
    Composer, Windows Media Encoder, Quicktime Pro
  • Compressing
  • - The method that makes the digital media
    small enough to fit through the network

7
Video Compression
  • Why do we need compression?
  • Successive video images have redundant and
    repeated images. So, compression makes the
    repeated images be encapsulated in such a way
    that nearly every piece of redundant content
    should be expressed once.
  • Since there are some limitations that human can
    perceive in visual and auditory systems, digital
    compression can take advantage of this fact.

8
Two types of compression method
  • (1) Lossless compression
  • Data can be compressed and decompressed without
    losing any of the original data so that the
    decompressed data matches the original data
    exactly.
  • (2) Lossy compression
  • Data is lost during the compression process and
    cannot be recovered during the decompression. The
    amount of how much data is lost is depending on
    what kind of compression scheme is applied to the
    data.
  • Ex) streaming media

9
Processing- Encoding
  • Encoding
  • - The way to put the digital media in the
    correct format so that the media can be
    downloaded or streamed via network

10
Storage
  • What is the ideal disk storage?
  • Reliable
  • Available
  • Scalable
  • Fault tolerant

11
RAID Popularity
  • Disk storage capacity , cost
  • Fault tolerance multiple disk drives appear as a
    single storage system. If one of them fails,
    other remaining drives can continue to operate
    without compromise.
  • Easy replacement The failed drive can be
    replaced without seriously degrading ongoing
    operations.

12
Common Levels of RAID
  • RAID 1 Data mirroring

Disk Mirroring
Disk 0
0011
0102
0032
0011
0102
0032
Disk 1
0011
0102
0032
13
Common Levels of RAID
 
  • RAID 3 Striped array Parity

        Byte Striping     Parity Drive      
Disk 0
2
3
0
 
Disk 1
1
2
1
2113
3210
0123
Disk 2
1
1
2
Disk 3
3
0
3
Parity
P3
P2
P1
14
Common Levels of RAID
 
  • RAID 5 Striped array Distributed parity

        Block Striping     Rotating Parity
       
Disk 0
2110
P3
0123
Disk 1
P5
3200
3210
2113
3210
0123
3200
0110
Disk 2
2102
0110
2113
Disk 3
3000
P4
P1
Disk 4
1110
3200
P2
15
Digital Archiving
  • Problem of current analog tape library
  • continuous tape expansion -gt more space needed
  • constant management by tracking all the videos
  • time-wasting retrieval of a video clip
  • Digital media archive
  • effective compression -gt store videos in
    smaller storage space
  • frequently used data can be stored at
    fast-accessible storage
  • seldom-used data can be at less expensive
    storage
  • disk storage and backup -gt multiple copies
    available
  • proper network setup -gt retrieve data fast

16
Playing a video over Internet
  • Web server vs. Video server
  • Retrieving a video with a metafile
  • Streaming vs. Downloading
  • Playing a video on a client browser

17
Web server vs. Video server
  • Using a web server only
  • If you need small amount of video or audio
    clips to be played over the network, your web
    server doesnt need to have a separate video
    server. Your web server can accommodate the basic
    functions of a video server.
  • Combining a web server and a video server
  • If we are considering media production and
    distribution of the output over the network, we
    definitely need a video server that has higher
    quality digital services than the web server.

18
Retrieving a video with a metafile
  • Windows Media Metafile
  • (1) contains the location of the media file
  • (2) references the media file for playing its
    video over the network
  • Why do we need a metafile?
  • (1) Guide a browser what to do with the
    requested video link
  • metafile will properly link to the media
    file and the video will be played accordingly.
  • (2) Instructs Windows Media Player to go the
    location and play the media file accordingly.
  • (3) Great way to combine a web server and a
    video server

19
Retrieving a video with a metafile
  • Creating a Windows Media Metafile
  • ltASX version 3.0gt
  • ltENTRYgt
  • ltRef href mms//MediaServer/MyVideo.wmv /gt
  • lt/ENTRYgt
  • lt/ASXgt
  • (a) ASX defines the enclosed script as being part
    of a Windows media
  • metafile.
  • (b) ENTRY specifies the digital media
  • (c) Ref href specifies the URL of the media.
  • (d) MMS is the Windows Media Streaming protocol.

20
Retrieving a video with a metafile
  • The name convention The name of a metafile
    corresponds to its media file.
  • Ex) Media file MyVideo.wmv, Metafile
    MyVideo.wvx
  • Adding the metafile on a web page
  • ltHTMLgt
  • ltHEADgt
  • ltTITLEgtEasiest way to play a media on a
    weblt/TITLEgt
  • lt/HEADgt
  • ltBODYgt
  • ltA HREF http//WebServer/MyVideo.wvx gtMy
    videolt/Agt
  • lt/BODYgt
  • lt/HTMLgt

21
Streaming vs. Downloading
  • Downloading copying a file over a network.
  • (1) Time wait for an entire file to be
    transmitted
  • (2) Memory space to store the downloaded file.

Media file
........
gt
gt
Server
Client
The media file is divided into multiple packets
to be delivered over network
Original media file
Packets of the media file are delivered to its
destination
22
Streaming vs. Downloading
  • Streaming delivering a file over a network and
    playing the file instantly.
  • (1) As soon as enough data are buffered, the
    video starts to play.
  • (2) After playing, the file is not stored in
    memory.
  • So, no extra memory space is necessary.

........
Media file
Server
Client

gt
gt
Upon the request of the media file, the file is
streamed by sending data bit rate-by-bit rate.
The media file is compressed and encoded into a
certain bit rate. It is stored at a server.
Original media file
23
Streaming vs. Downloading
  • Intelligent streaming
  • It dynamically adjusts the bit rate of
    streaming video as the network bandwidth changes.
    It is beneficial for a video to be streamed via
    networks with different bandwidth over the
    Internet. However, the quality of the video may
    be downgraded.

Server
Client
Media file
........
Server
Client
Original media file
Server
Client
Encode the media file with different bit rates
Send the encoded file based on the network
bandwidth
24
Streaming vs. Downloading
  • Advantage of streaming over downloading
  • ? Real-time playback
  • ? Significantly reduced waiting time
  • ? Only small portion of memory space for
    buffering
  • ? Cancellation of playback at any time
  • ? Same control options such as play, stop,
    pause, fast-forward, and rewind.
  • Disadvantage of streaming over downloading
  • ? Limitation of continuous playback for higher
    bandwidth than the bit rate
  • ? Possibility of unpredictable long buffering
    time -gt discontinuous playback
  • ? In case of intelligent streaming, the video
    quality is not as good as its original file.

25
Playing a video on a client browser
  • A media player on a client side decompresses the
    transmitted data and converts the digital
    instructions into analog video or audio form.
  • Different ways to use a media player
  • ? A link from a web page to a Media Player
    outside the browser
  • - Audio or video will be played outside the
    browser.
  • - This scheme enables the end user to
    continue to surf with the browser while
    listening/watching the streaming clip.

0111011101101110
gt
Frame
1101110001110100
lt Streams of bits gt
lt Analog video gt
26
Playing a video on a client browser
  • Different ways to use a media player (continued)
  • ? embedding a media player in a web page using
    OBJECT tags
  • - This method enables you to integrate the
    design of the player with that of your page.
  • - You can also customize the playback
    control buttons.
  • In order to embed the player, add an OBJECT
    element for the Windows Media ActiveX control
    like the following example
  • ltBODYgt
  • ltOBJECT ID Player width 250 height250
  • CLASSID CLSID6BF52A52-394A-11d3-B153-00C04F
    79F116 gt
  • lt/OBJECTgt
  • lt/BODYgt
  • (More details are in the article Adding
    Windows Media to Web Pages in msdn )

Windows Media Player 7.0 Class ID
27
Playing a video on a client browser
Widows Media Player
Embedded Media Player
Media Players original functions
Embedded and controlled functions
28
Network architecture for digital media
  • Network requirements for media delivery
  • The network should be able to deliver multi-media
    in a time-sensitive manner.
  • Packet switching vs. Circuit switching
  • In packet switching, although data can tolerate
    delays in delivery, audio and video cannot
    tolerate time delays.
  • gt fast packet switching allows control
    parameters that specify the importance of in-time
    delivery in a network header.
  • gt Multimedia protocols such as RTP or RTSP
  • In circuit switching, once virtual circuit is set
    up, it is remained until the end of usage and the
    virtual circuit guarantees fast delivery.
  • Ethernet and ATM are a good match
  • Ethernet is used inside the building for data
    traffic among personal workstation or desktop
  • ATM is used for backbone network.
  • Most of all, Ethernet and ATM are good setup for
    both of the Internet and multimedia that have to
    share the links.

29
Case study of a media production company
  • Current status of digital media usage
  • In production area, digital media technology has
    been used mostly for video editing and commercial
    playback. A video server is not used for the
    production.
  • The closest of using digital technology is the
    kiosk systems. Kiosk systems are using essential
    digital media technology. So, kiosk system can be
    a good example of the current applications for
    digital technology.

30
Overview of Kiosk systems
  • Kiosks are located at the First Union Center.
    They are used to help the sports fans and
    audiences get information about the facilities
    and events. Kiosk touch screens are especially
    popular during a sports game intermission. During
    the intermission, people can see the major
    highlights that just happened during the game.

Main Concourse
Luxury Suites
Lexus Club
31
The major applications of a kiosk
  • The overall interface design is done in
    Macromedia Flash movie

MS SQL
Adobe Illustrator
Adobe Photoshop
32
The major applications of a kiosk
  • SMS (Systems Management Server) check the
    status of all the kiosk systems and allows us to
    remotely trouble-shoot all the kiosk systems.
  • Advantage Rebooting each kiosk
  • can be done remotely at one
  • workstation rather than doing
  • each computer
  • at its location.
  • Disadvantage For remote
  • trouble-shooting, the only
  • function is to turn on and
  • off a kiosk.

Luxury Suites
S M S
Main Concourse
Lexus Club
33
The major applications of a kiosk
  • symantec pcAnywhere remotely access the server
    and update the contents of the server, and to
    transfer files to the server.
  • Advantage we can remotely access the server
    machines rather than we have to physically go to
    each server and update contents.
  • Disadvantage Once a user accesses the server
    with the authorized user name and password, it
    lets a user allow any changes the user can make
    in the server.

First Union Spectrum
First Union Center
pc Anywhere
Web Server
Video Server
34
Video Server- Video Server Architecture
  • Main functions of the media server storage of
    videos and streaming

Compressed digital video input
? Stores the input in order in primary disk
array. ? Retrieve the requested video file in
real time. ? Stream the video ? Transmit the
video file
Windows Media Player requests for the media file
with the metafile.
Streaming
Downloading
lt Windows Media Server gt
35
Video Server- Getting a new input
  • Video inputs game highlights or concert footage
  • 30 seconds to 1 minute 30 seconds
    long
  • Process of getting a new video file
  • ? Shoot videos with the analog camera
  • ? Transfer the videos as composite or component
    inputs into
  • Avid Xpress
  • ? A component input separates analog video
    signal into three different elements of red,
    green, and blue(RGB) and uses three different
    cables, so that they produce better image
    quality.
  • ? A composite input combines all of three
    elements and use one cable so that it is easier
    to import the input but has less image quality.

36
Video Server- Getting a new input
  • ? Digitize the analog inputs
  • ? Compress the video with 2-to-1 compression
    algorithm and save it as motion-JPEG

0111011101101110100101010001110011
gt
Frame
lt Streams of bits gt
Higher compression Less space More artifacts
Lower compression More space Better looking
2 to 1 3 to 1 .. 20 to 1
ltAvid Xpress Compression Algorithmgt
37
Video Server- Getting a new input
  • Motion JPEG
  • ? JPEG is a standard for compressing and
    storing digital images. Motion-JPEG extends this
    standard by supporting videos.
  • ? In motion-JPEG, each frame in the video
    is stored with the JPEG format, and compresses
    each video field separately, returning the
    resulting JPEG bit streams consecutively in a
    single frame.

Frame 1
JPEG 1
01110111011011
Frame 3
Frame 2
Frame 2
0111011101101110 1001010100010100 1010100011
JPEG 2
Frame 1
10100101010001
Frame 3
JPEG 3
ltAnalog Moving Imagesgt
01001010100011
ltMotion-JPEGgt
ltCompressed into a series of JPEGsgt
38
Video Server- Getting a new input
  • Avid Xpress for digitizing and
    compressing

Frame 1
JPEG 1
01110111011011
Frame 3
Frame 2
JPEG 2
Frame 2
Transfer into Avid Xpress
10100101010001
Frame 1
Frame 3
JPEG 3
01001010100011
ltAnalog Moving Imagesgt
(1) Digitizing (2) Compression into a series of
JPEGs with 2-to-1 compression
011101110110111010010 101000101001010100011
ltMotion-JPEGgt
39
Video Server- Getting a new input
  • ? The motion-JPEC file is changed into
    .omfi file. The file is exported from Avid Xpress
    and imported into Windows Media Cleaner.
  • OMFI file as a universal compressed
    file format
  • ? Motion-JPEG has no universal
    decoding algorithm standard. This means that a
    motion-JPEG file may produce different results on
    different applications. In video imaging,
    transporting a compressed video in its native
    compression format between different applications
    may require common denominator.
  • ? For this reason, omfi is used as the
    interchange of digital media data between
    different platforms or applications. OMFI means
    Open Media Framework Interchange, a registered
    trademark of Avid Technology, Inc. It is a
    standard format of the interchange of digital
    media data among heterogeneous platforms.

40
Video Server- Getting a new input
  • ? In the Windows Media Cleaner, encode it
    as a Windows Media file
  • Windows Media Cleaner for encoding

01110111011011101001010100010100101010001101101110
10010101000101101110100101010001011011101001010100
011000101101110100101010....
Encoding for media streaming
ltOMFI Filegt
ltWindows Media Filegt
41
Video Server- Getting a new input
  • ? Save the digital video clip as a media
    file(.wmv) and create its metafile(.wvx) in a
    notepad.
  • ltASX version 3.0gt
  • ltEntrygt
  • ltRef Href Path /gt
  • lt/Entrygt
  • lt/ASXgt
  • ? Transfer the metafile(.wvx) into the web
    server and media file(.wmv) into the media server

Metafile
Video Editing Station
Web Server
Video Server
Media file
42
Video Server-uploading video during game
  • During the game, if there is a memorable moments,
    the highlight is uploaded into the video server
    so that audience can see it again during the
    intermission. This uploading is almost like
    real-time updating, but it takes about 5 minutes
    after the actual event.
  • ? All games are recorded into Avid Xpress.
  • ? Once there is a good highlight, it is edited
    and exported into the Windows Media Cleaner.
  • ? In the Cleaner, encode it as a Windows
    Media file
  • ? Save it as a Windows Media file and Windows
    object file.
  • ? Transfer the wvx and wmv files into the two
    different server machines.

43
Video Server- Storage
  • RAID level 5 RAID 5 allows three or more drives
    to stripe the data across drives. Even two
    drives can function well.
  • Video Naming in the Web and Video Servers
  • ? Video name team name / show name purpose
    number in order
  • For example, the first Flyers history video is
    named as flyhis01.wvx in database and
    flyhis01.wmv in the video server.
  • ? There are subvideos. These are smaller video
    files than video files. It is used when somebody
    comments on a particular game or play that
    happened. It is played with the main video clip.
    The processes of uploading and retrieving a
    subvideo file are same as the video ones.

44
Video Server- Storage
Video
Subvideo
VideoID (PK) Date Description Team EventID History
Highlights Profile Community Filename PlayerID
SubVideoID (PK) VideoID (FK) Description Filename
ltVideo and Subvideo tables at the database in
the web servergt
45
Video Server- Storage
ltVideogt
VideoID
Date
Description
Team

Filename

1005
5/19/1974
1st Stanley Cup
Flyers

flyhis05

ltSubvideogt
SubVideoID
VideoID
Description
Filename
2004
1005
Clarke
flyper04
2005
1005
MacLeish
flyper05
2006
1005
Parent
flyper06
ltAn example of Video and Subvideo tables at the
database in the web servergt
46
Video Server- Digital Archive
  • Tape backup is done every night
  • At the end of the season, most of the used videos
    are removed

47
Video Retrieval
  • Process of retrieving a video clip from the
    Windows Media Server
  • ? A user clicks on the video icon

A video is selected by a user.
48
Video Retrieval
? Request the metafile with video id
Action script Flash at kiosk
Video (Subvideo) table in the Web Server
ASP as Middleware
? Get the requested metafile
Embedded Media Player
? Reference the video using its metafile
Video Server
? Play the video by streaming
ltProcess of retrieving a videogt
49
Video Retrieval
  • Metafile Windows Media Protocol Windows Media
    Server video folder media file.
  • A single file retrieval
  • ltASX version 3.0gt
  • ltEntrygtltref href mms//ctc_wms/video/sixgre03.
    wmv /gt lt/Entrygt
  • lt/ASXgt
  • Multiple file retrieval
  • ltASX version 3.0gt
  • ltEntrygt ltref href mms//ctc_wms/video/fly
    his05.wmv /gt lt/Entrygt
  • ltEntrygt ltref href mms//ctc_wms/video/flyper04
    .wmv /gt lt/Entrygt
  • ltEntrygt ltref href mms//ctc_wms/video/flyper05
    .wmv /gt lt/Entrygt
  • ltEntrygt ltref href mms//ctc_wms/video/flyper06
    .wmv /gt lt/Entrygt
  • lt/ASXgt

50
Video Retrieval
The metafile has been sent to Windows Media
Server. It opens and references the actual media
file in the video server.
As soon as the enough data is arriving, the
embedded Windows Media Player decompresses the
digital file, transforms it into analog format,
and plays it by streaming.
51
Video Retrieval
  • If there are multiple requests from multiple
    clients, the server do multi-streaming
  • The server usually can multi-stream
  • videos more than 200 streams,
  • considering the total of around 150
  • kiosks.
  • No Intelligent streaming
  • a. It provides a poor quality video
  • b. Streaming uses the dedicated
  • network between two buildings. So,
  • the bandwidth can be considered
  • as a constant.

ltVideo Servergt
kiosk
flyhis05.wmv
flyper04.wmv
flyper05.wmv
kiosk
flyper06.wmv
kiosk
sixgre03.wmv
Multiple Streaming
52
How-to streaming video
  • Recommended web site
  • For doing simple media streaming over the
    Internet, check out the web site,
    http//catalyst.washington.edu/catalyst/how-to/dig
    italvideo
  • There are specific instructions depending on
    which application you are using. RealMedia,
    QuickTime, and Media Cleaner Pro.
  • For Windows Media Encoder, check out msdn library.

53
Network Architecture for video
54
Network Architecture for video
  • RTSP (Real Time Streaming Protocol)
  • RTSP is an application-level protocol for
    control over the real-time data delivery. It is
    associated with the port 554. Sources of data can
    be audio, video, or live data feeds. This
    protocol is designed to cope with
    bandwidth-demanding and real-time streams.

Video Server
Kiosk Client
Media file RTSP
Windows Media Player
Frame Relay Gateway
TCP
TCP
IP
IP
IP
Ethernet
Ethernet
Physical
ltRTSPs Video Delivery Methodgt
55
References
56
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