-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

Creating Digital Creating Digital Video DemoVideo Demo Pinnacle Studio 8Pinnacle Studio 8

Hardware + SoftwareHardware + Software Microsoft MovieMakerMicrosoft MovieMaker

Software onlySoftware only Windows XP onlyWindows XP only