-multimedia basics- digital video integrating technology into the curriculum © jim lockard 2004
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-Multimedia -Multimedia
Basics-Basics- Digital VideoDigital Video
Integrating TechnologyIntegrating Technologyinto the Curriculuminto the Curriculum
© Jim Lockard© Jim Lockard20042004
MultimediaMultimediaThree “technologies“Three “technologies“
Graphics (images)Graphics (images) AudioAudio VideoVideo
Multimedia File Multimedia File SizeSize How much does it matter? How much does it matter?
Impact of delivery methodImpact of delivery method “ “Local” files Local” files
No concern No concern ifif on hard drive on hard drive•Quickest load timeQuickest load time
Other storage variesOther storage varies•CD, Zip, flash drive, networkCD, Zip, flash drive, network
Non-local filesNon-local files Moving among computersMoving among computers Download time from webDownload time from web
Graphics FilesGraphics Files Size depends onSize depends on
Image size (pixels)Image size (pixels) Color depth (1-16M colors)Color depth (1-16M colors) File format used (jpg, etc)File format used (jpg, etc)
““full screen” x “full color”full screen” x “full color” 640*480*(24/8) =640*480*(24/8) = 921,600 bytes (nominal)921,600 bytes (nominal)
Graphics Size Graphics Size ExampleExample Impact of file typeImpact of file type for 640x480 image for 640x480 image
Calculated =Calculated = 921,600 bytes 921,600 bytes
BMP = 901KBMP = 901K GIF = 219KGIF = 219K
256 color max256 color max JPG = 67KJPG = 67K Which format is “best?”Which format is “best?”
Digital AudioDigital Audio Quality Standard = CDQuality Standard = CD CD = 44,100kHz, 16-bit, stereoCD = 44,100kHz, 16-bit, stereo
1 min = ca. 10MB!1 min = ca. 10MB! 172kb/sec172kb/sec
FM Radio = 22,050kHz, 8-bit, monoFM Radio = 22,050kHz, 8-bit, mono 1 min = ca. 1.25MB1 min = ca. 1.25MB 22kb/sec22kb/sec
Telephone = 11.025kHz, 8-bit, monoTelephone = 11.025kHz, 8-bit, mono 1 min = ca. 625K1 min = ca. 625K
File Size & Download File Size & Download TimeTime
(Optimum Conditions)(Optimum Conditions) K/sec 100K 1MB
28.8K 3 33 sec 6 min
56K 6 17 sec 3 min
T1 150 0.7 sec 7 sec
Typical song would take nearly Typical song would take nearly 250 sec to download with T1 before playback can begin.
Digital Digital VideoVideo
What is it?What is it? Analog video — Analog video — digitizeddigitized
Most commonMost common Original digital videoOriginal digital video
Newer technologyNewer technology Catching on very rapidlyCatching on very rapidly
Digital Video Digital Video BenefitsBenefitsDigital Video Digital Video BenefitsBenefits
Inexpensive computer hardwareInexpensive computer hardware to create to create
Non-linear editing w/softwareNon-linear editing w/software Just another (large) file = Just another (large) file =
transmission potential (sort of) transmission potential (sort of) FTPFTP emailemail web pagesweb pages
More flexible (hyper) useMore flexible (hyper) use
To Create Digital To Create Digital VideoVideo
HardwareHardware AnalogAnalog Digitizing GearDigitizing Gear
$50 - $1000+$50 - $1000+ Digital camcorder + IEEE 1394 Digital camcorder + IEEE 1394
Firewire™ or iLink™Firewire™ or iLink™ Mavica & other digitalMavica & other digital ‘still’ cameras ‘still’ cameras
PC / web cameras (“golf balls”)PC / web cameras (“golf balls”)
To Create Digital To Create Digital VideoVideo
SoftwareSoftware Comes with hardware & XPComes with hardware & XP Capture first, then editCapture first, then edit
Not always same softwareNot always same software Varies a lot (learning curve)Varies a lot (learning curve)
Match to need, time & skillMatch to need, time & skill
Digital Video Digital Video IssuesIssuesDigital Video Digital Video IssuesIssues
Image quality (e.g., jagged lines)Image quality (e.g., jagged lines)
Limited resizing (pixels, jerky)Limited resizing (pixels, jerky)
Differing formats / architecturesDiffering formats / architectures Proprietary compression schemesProprietary compression schemes
Broadway AVI, M-JPEGBroadway AVI, M-JPEG
Storage requirements /Storage requirements /
download time download time
Digital Video Digital Video FilesFiles Video = “frames”Video = “frames”
How many / sec?How many / sec? Cf individual graphic Cf individual graphic
image image file size file size
Video = ++MBVideo = ++MB
Digital Video Image Digital Video Image SizeSize
Digital Video Image Digital Video Image SizeSize
Size (on screen)Size (on screen) Pixel dimensionsPixel dimensions
Common SizesCommon Sizes 160 x 120 (1/16)160 x 120 (1/16) 320 x 240 (1/4)320 x 240 (1/4) 640 x 480 (‘full’ screen)640 x 480 (‘full’ screen) 720 x 480 (“DVD” wide screen)720 x 480 (“DVD” wide screen)
What the viewer What the viewer reallyreally sees? sees? Depends on screen resolutionDepends on screen resolution
Digital Video Digital Video FormatsFormats QuickTime (mov)QuickTime (mov)
Compatibility issuesCompatibility issues Video for Windows (avi)Video for Windows (avi)
No further developmentNo further development MPEG (mpg, mpeg, mp#)MPEG (mpg, mpeg, mp#)
MPG1 = general use, Video CDMPG1 = general use, Video CD MPG2 = DVDMPG2 = DVD
StreamingStreaming Real vs MS vs QTReal vs MS vs QT Initial or convertInitial or convert
DV File SizeDV File Size FactorsFactorsDV File SizeDV File Size FactorsFactors
Image pixel dimensions (size)Image pixel dimensions (size) FPS – how to choose, if possible?FPS – how to choose, if possible? File format (more later)File format (more later)
AVI to streaming AVI to streaming (per software)(per software) Compression scheme (codec)Compression scheme (codec)
Within AVI & QT, streamingWithin AVI & QT, streaming Audio sampling (quality)Audio sampling (quality)
Impact of File SizeImpact of File Size
K/sec 100K 1MB
28.8K 3 33 sec 6 min
56K 6 17 sec 3 min
Cable / DSL
Varies, ~50-100 typical
2 sec 15-20 sec
T1 150 max 0.7 sec 7 sec
1 min video could take minutes to download
Digital MediaDigital Media How to avoid “downloading”?How to avoid “downloading”?
Can’t truly – files not localCan’t truly – files not local Can avoid Can avoid completecomplete download download
Streaming MediaStreaming Media Playback begins quicklyPlayback begins quickly Download to bufferDownload to buffer FIFOFIFO Competing FormatsCompeting Formats
Original vs Real (low Original vs Real (low action)action)22 sec.22 sec.
AVI (IR32)1.04MB5 fps
Real (28K)56K
Real (56K)93K
MPEG1Larger size3.17MB
Original vs Real (average)Original vs Real (average)40 sec40 sec
AVI (Cinepak)24.6MB
Real 28.8105K
Real 56K176K
Real LAN778K
MPEG16.18MB
Much detail atMuch detail at www.niu.edu/facdev/media/mmwww.niu.edu/facdev/media/mm
c.htmc.htm
Click on Web MediaClick on Web Media
www3.niu.edu/facdev/media/prwww3.niu.edu/facdev/media/presentations.htmesentations.htm
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