Video at the GSD

This is a quick reference guide for background info, common procedures and policies for creating and delivering digital and analog video at GSD. Our equipment is for members of the GSD community only. For more detailed information about specific applications and concepts, read the application-specific documentation available in hard and soft copy and use the web- there are all sorts of resources, FAQs, and tutorials out there for beginners and experts alike.

In addition, we have a video TA. While the TA's first role at the GSD is a student, (s)he may be available by appointment: video@gsd.harvard.edu

Video Editing Equipment
Storage Policies and Procedures
Cables and Adaptors, or lack there of
Grabbing Stills from Video - The Easiest Way
DV and Firewire
Digital Audio
What's up with Data Rates?
Video over the Web

Video Editing Equipment

Two OSX Mac G5s with iMovie 4, Final Cut Pro HD 4.5, Apple Quick Time Player 6+ located in L 41.

Software includes: After Effects, Media Cleaner Pro, Photoshop, Illustrator, iMovie, FinalCut Pro,Quick Time Player, Debabelizer, etc.

We also have various VHS, DV playback/recording decks, monitor, speakers, and digital video cameras.

Storage Policies and Procedures

Digital video takes up an enormous amount of disc space. Disc space is by its nature finite. As such, we need a mechanism to keep track of and manage this space. Formal policies and procedures are listed here. Failure to comply with these procedures will result in your files being deleted.

Any disk or partition called Scratch is always to be left empty when you are done working. It is to be used as temporary render space and an area to which you can move remote files from the network or jazz drive. Any file left in here can be deleted at any time by anyone.

Any file you create need to live in a folder that is called "yourusername". (Ex. "jsmith"). In addition, this folder should have a plain text file in there called "README", which details how to get in touch with you, how much disk space you need, for how long (not to exceed 2 weeks), and for what school project.

Please, please, please note: failure to comply to this procedure will definitely result in your work being deleted, and don't be rude and reserve 4 gigs for the whole year. Schedule your project so you use as little time and storage as possible, as the machines are shared by lots of people.

Cables and Adaptors, or lack thereof

There is a recording/playing deck in L41, and it requires that you to patch them together with various cables and adaptors. Because of the widespread and rampant theft of these cables and adaptors, you are responsible for your own, just as you are responsible for providing your own dv tapes, jazz drives, blank cds etc. Firewire, SVideo, BNC, RCA adaptors, cables, converters can all be purchased at a store like Radio Shack or Tweeter in Harvard Square.

Grabbing Stills from Video - The Easiest Way

There are always many ways to skin a cat, but here are my top 2 for this particular cat:

You can create a still image by saving a single frame of your movie. You can save the images in these formats:

JPEG, a standard format for compressing still pictures. The JPEG formats yields small files, but some data is lost in the compression. For this reason, JPEG is called a" lossy" format. It is the format to use if you intend to send an image through email or post it on a web page.

PICT, a picture file format that doesn't compress an image. Since it does not lose information through compression, it is called a "lossless" format. It mzintains the same level of quality from copy to copy. Use the PICT file format when you export a still image from a clip to reuse in your iMovie.

Select the clip that contains the image you want and position the playhead so the image appears in the iMovie monitor.
Choose File> Save Frame As, then type a name for the file.
Choose wherer you want to save the image ( desktop).
Choose the file format for your picture. Use PICT if you want to use the still image in an iMovie. Use JPEG if you want to email the image or post it on the Internet
Click Save.

DV and Firewire

If you have a DV camera, or have borrowed one of the GSD's, and you want to get video or stills from your footage, the absolute easiest way is to use a program called iMovie, found on many public Macintosh computers and the two Mac G5s and G4 in L41. All run a firewire cable from your DV Camera to the computer, turn the camera's power on, run the program called iMovie and you're basically done - actually, you may want to work through the iMovie Tutorial under the Help Menu, but as far as digital video goes, it doesn't get any easier.

NOTE: NTSC video is not hi-res stuff.... the most you can get out of a still is about 640x480 72dpi, so don't expect to enlarge or print high res images from video.

For more sophisticated users, we have a program called Final Cut Pro on MAC G5s in room L41... same hardware deal - patch your firewire cable from the camera to the box and run the program - Manuals for Final Cut Pro are in the Library on Reserve and in PDF format on Apple's Website.

Digital Audio

There are three programs that can be used to edit or create digital audio. They are GarageBand, iMovie, and Final Cut Pro. GarageBand is on the Macs located on the 4th tray cluster. iMovie and Final Cut Pro is on the G5s located in L 41, in the basement. There is a tutorial for each program to help users with the program. Don't leave files on public machines.

What's up with Data Rates?

Digital Video is really simple. Only 3 variables are involved.

1. Resolution, (or "geometry", or "screen size"). Most video geometry has a 4:3 ratio, such as 640 pixels wide, and 480 pixels high (640x480), (this is what you see on your TV at home), (320x240- this produces a file that is one quarter, not one half, the file size of 640x480 resolution), 240x180, 160x120, etc...

2. Frames Per Second (fps)- how many frames, or "still images", are displayed on the screen per second to give the illusion of fluid motion - related to choppiness vs. smoothness of video performance. The standard is 30fps. The bare minimum is around 8fps- anything less doesn't really work. Most folks use 15 or 30 fps for most digital applications.

3. Compression- this is where the magic happens- Nobody's computer is going to paint 30 high resolution tiff files, for example, on the screen every second- Try opening just one in Photoshop and watch how long it takes- 30 of them every second isn't going to happen. To get around this, a bunch of different people have come up with a bunch of different ways to compress and decompress (codec) these images so that they can be displayed 30 per second.

The key to good looking, smooth video is data rate- how much data can be piped onto your screen per second- Sometimes the bottleneck is your internet connection, sometimes your hard drive speed, sometimes your video card, sometimes your cpu... By adjusting different combinations of the above three variables, you can dramatically influence data rate, and thus, the quality of your video. Many applications allow you to specify a target data rate in the compression settings dialog box area. Make use of this.

Video over the Web

Video over the internet really can happen, but you need a fast connection and a good computer. We have a fast network at the GSD, and you can get pretty good performance depending on how much data you are trying to push over the wire, but the best solution still is to play the video files locally off of a hard drive for maximum image and sound quality, or better yet, off of a video tape using a VCR. If you are interested in using one of our streaming servers to distribute your video over the internet, contact the webmaster at GSD.

For more information about streaming low bandwidth video over the inter/intra net:

Apple Quicktime: Most of our digital editing systems are 100% Quicktime Compatible.
RealNetworks.com: Free software/docs on the leading a/v streaming technology on the net.
Adobe.com: Adobe has some excellent resources and tutorials and 'the basics of video' documents on their site.