Tue April 20 notes - Digital Video
- review March 30 notes : television and film
- wikipedia/Digital_video is a good place to start reading.
- Many digital video file formats.
- Each has
- a bandwidth (bits/sec)
- compression method (MPEG-2, MPEG-4, ...)
- typical media (CD, DVD, miniDV tape, ...)
- typical resolution (720x480 x 4:1:1 , ...)
- container file types ( .avi, .mov, , .vob, ...)
- Here's a summary.
- miniDV - used in most modern digital videocameras
4:1:1 color sampling, 25 Mbps, DCT compression (which jpegs also use)
can be interlaced or "progressive scan" (entire image in each 1/30 sec for NTSC)
1 hour of video on a tape; 20 min on DVD (!)
- MPEG-1 : VCD is low quality, not much video on a CD.
- MPEG-2 is what you find on a DVD; better quality.
- MPEG-4 is a compressed MPEG-2 : DivX, a movie fits on a CD. (3-15 Mbps)
- HDTV (high definition TV, broadcast or cable ) can go as high as 15-30Mbps ...
- various others - check out the table.
- What's really on a DVD (to pick one) ?
- Raw bit rate is something like
(720x480 pixels ) x 30 frames/sec x ( 8 greyscale bits + 4 color bits)
= 118 Mbits/sec (ouch!)
- compressed to at most 9 Mbps via spacial (jpeg DCT) and
time (record only differences) encoding; see
wikipedia/MPEG-2
and Tudor's detailed tutorial.
- Several security systems - CSS (Content Scrambling System), Region Codes, Macrovision
- So pop one into the laptop and take a look...
- Streaming vs file sharing : discuss ?
- What kinds of software applications might you need?
- capture : transfer video camera to computer
- edit : layering, cut'n'paste, effects, ...
- players : disks, files, streams
- sharing : peer 2 peer networks
- ripping : pulling it off a DVD
- burning : putting it on a DVD or CD
- conversion : lots of options
- streaming server : how to be a television station
- other ?
- Software - search on Google; this is a moving target
- Final Cut Pro - in media lab (Apple Mac, commercial)
- other popular commercial ?
- open source Mac video : http://www.apple.com/downloads/macosx/video/
(also various other Mac OS software)
- iStopMotion - animation, eh?
- DivXRay 3.0 (DVD -> MPEG4 conversion with cd writer)
- QuickMix 1.2 - editing?
- 3ivx D4 (DivX, Xvid quicktime/mp4)
http://www.3ivx.com/download/macos.html
- DivX (decoder only as quicktime codec; encoder not on Mac OS yet)
http://www.divx.com/divx/mac
- VLC (streaming)
http://www.videolan.og/vlc/download-macosx.html
- Motion - apple commercial text/graphics/video "behaviours"
$300, due for summer 2004 release
- Cleaner5 - Mac (video encoding)
http://www.discreet.com/products/cleaner/cleaner6/
- ffmpegX (open source video/audio encoder for Mac OS X)
http://homepage.mac.com/major4/
- MPlayer (opensource, multiplatform 3ivx, DivX, ... player)
- Xiph.org (http://www.xiph.org/) - Ogg Vorbis and Ogg Theoro
(open source audio and video formats)
- Ripping: afterdawn.com lists lots of applications
- DVDx (dvd->divX converter, freeware (?) , windows)
http://www.labdv.com/dvdx/
- DVDBackup (decode), DVD2oneX (compress), Toast (DVD burning)
- MacTheRipper (open source dvd ripper for Mac),
front end for dvdbackup,
http://www.wormintheapple.gr/macdvd/mtr.html
"Any copyright infringing activity you choose to perpetrate
using this application is illegal, wrong, and beyond our control."
- ImTOO DVD Ripper v2.0.9 www.imtoo.net/dvd-ripper.html
(windows, $35, "download now for free" - demo, I guess)
- Gordian Knot Rip Pack (open source, windows)
http://gordianknot.sourceforge.net/
- many others ...
- in class show and tell with a Mac: DVD Player, MPlayer,
Apple's "Disk Utility", MacTheRipper, and ffmpegX
- discuss projects and Friday's schedule
- in the news on Monday's NPR MarketPlace
- College Downloader Beware
"Schools are swamped with another kind of paperwork:
cease and desist orders."
- DVD Protection - No Easy Task
"Every time the movie industry creates a digital lock
on its products, a digital lock-picker figures out how to
break in."
- Pirated "Passion" copies swamp Peru