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

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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

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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
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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
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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
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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
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The major applications of a kiosk

• The overall interface design is done in
  Macromedia Flash movie

MS SQL
Adobe Illustrator
Adobe Photoshop
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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

• The End of the Presentation
• Any questions or comments?