-Multimedia Basics- Digital Video - PowerPoint PPT Presentation

-Multimedia Basics-Digital Video

Integrating Technology

into the Curriculum

© Jim Lockard

2004

• Three “technologies“
• Graphics (images)
• Audio
• Video

• How much does it matter?
• Impact of delivery method
• “Local” files
• No concern if on hard drive
• Quickest load time
• Other storage varies
• CD, Zip, flash drive, network
• Non-local files
• Moving among computers
• Download time from web

• Size depends on
• Image size (pixels)
• Color depth (1-16M colors)
• File format used (jpg, etc)
• “full screen” x “full color”
• 640*480*(24/8) =

921,600 bytes (nominal)

• Impact of file type for 640x480 image
• Calculated = 921,600 bytes
• BMP = 901K
• GIF = 219K
• 256 color max
• JPG = 67K
• Which format is “best?”

• Quality Standard = CD
• CD = 44,100kHz, 16-bit, stereo
• 1 min = ca. 10MB!
• 172kb/sec
• FM Radio = 22,050kHz, 8-bit, mono
• 1 min = ca. 1.25MB
• 22kb/sec
• Telephone = 11.025kHz, 8-bit, mono
• 1 min = ca. 625K

Broadband

Modem

Typical song would take nearly 250 sec to download with T1 before playback can begin.

• What is it?
• Analog video — digitized
• Most common
• Original digital video
• Newer technology
• Catching on very rapidly

• Inexpensive computer hardware to create
• Non-linear editing w/software
• Just another (large) file = transmission potential (sort of)
• FTP
• email
• web pages
• More flexible (hyper) use

• Hardware
• AnalogDigitizing Gear
• $50 - $1000+
• Digital camcorder + IEEE 1394
• Firewire™ or iLink™
• Mavica & other digital ‘still’ cameras
• PC / web cameras (“golf balls”)

• Software
• Comes with hardware & XP
• Capture first, then edit
• Not always same software
• Varies a lot (learning curve)
• Match to need, time & skill

• Image quality (e.g., jagged lines)
• Limited resizing (pixels, jerky)
• Differing formats / architectures
• Proprietary compression schemes
• Broadway AVI, M-JPEG
• Storage requirements / download time

• Video = “frames”
• How many / sec?
• Cf individual graphic image file size
• Video = ++MB

• Size (on screen)
• Pixel dimensions
• Common Sizes
• 160 x 120 (1/16)
• 320 x 240 (1/4)
• 640 x 480 (‘full’ screen)
• 720 x 480 (“DVD” wide screen)
• What the viewer really sees?
• Depends on screen resolution

• QuickTime (mov)
• Compatibility issues
• Video for Windows (avi)
• No further development
• MPEG (mpg, mpeg, mp#)
• MPG1 = general use, Video CD
• MPG2 = DVD
• Streaming
• Real vs MS vs QT
• Initial or convert

• Image pixel dimensions (size)
• FPS – how to choose, if possible?
• File format (more later)
• AVI to streaming (per software)
• Compression scheme (codec)
• Within AVI & QT, streaming
• Audio sampling (quality)

Modem

Broadband

1 min video could take minutes to download

• How to avoid “downloading”?
• Can’t truly – files not local
• Can avoid complete download
• Streaming Media
• Playback begins quickly
• Download to buffer
• FIFO
• Competing Formats

Real (28K)

56K

AVI (IR32)

1.04MB

5 fps

MPEG1

Larger size

3.17MB

Real (56K)

93K

Real 28.8

105K

Real 56K

176K

AVI (Cinepak)

24.6MB

MPEG1

6.18MB

Real LAN

778K

• www.niu.edu/facdev/media/mmc.htm
• Click on Web Media
• www3.niu.edu/facdev/media/presentations.htm

• Pinnacle Studio 8
• Hardware + Software
• Microsoft MovieMaker
• Software only
• Windows XP only