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Introduction |
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Preparing audio and video
for the web is not a difficult process. However, it does require
specialized computer equipment, software, and several sequential
processes. Different software packages are available for
many of the steps, but the software chosen at each step impacts
both the quality of the final product and the software that can be
used for subsequent steps.
The most widely used file
types (formats) for audio and video on the web are:
| .mp3 |
MPEG3, audio only
cross-platform |
| .wav |
PC only, audio only
played by MS Windows integral sound system |
| .mov |
QuickTime
audio or video
cross-platform |
| .rp, .rm |
RealPlayer
audio or video
cross-platform |
| .wmp |
Windows Media
Player, claims to be cross-platform but in some cases, PC
only
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The four basic steps in
preparing media for the web are listed below. In addition to these
four steps, completed media files will need to be posted to a web or
media server that is compatible with the file type (format) created.
Web pages will also need to be written that will allow access to the
media files on the server.
| 1. |
Digitizing
and editing the media |
| 2. |
Self-containing
the media to make it independent of the software that created
it |
| 3. |
Compressing
the file to make it a usable size for web transmission |
| 4. |
Adding
the 'hint' track |
File
format will dictate which software will be used in the
final three steps, but the first step is independent of the file
format. The first step (digitizing and editing the media)
requires specialized equipment. To digitize audio, you will
need an audio suite
(source such as a cassette deck and amplifier or a boom box that
combines the tape player and amplifier in one unit) and a computer
with a sound input jack. The machine should have at
least 128 Mb of RAM. To digitize
analog video, a vcr
and a media converter box (such
as Dazzle or the Sony DVMC-DA2) and a specialized computer is
needed. The converter box actually changes the signal from
analog to digital (DV) format that the computer can process and
store. Not all computers can handle
DV, but most Macintoshes and some high-end PCs can.
Any computer destined to process and edit digital video should have
a minimum of 256 Mb of RAM.
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Considerations
When Choosing File Formats |
As mentioned above, file
format (.wav, .rm/.rp, .wmp or .mov) will dictate which software
must be purchased for the processes and server. The
table below lists some of the pros and cons for each format
| .wav |
pro |
can
be played as background to web page |
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con |
limited
to PC users |
| .mov |
pro |
plug-in
is free, server software is inexpensive, no licensing
required, works well on both platforms |
|
con |
not
as popular as RealPlayer or Windows Media |
| .mp3 |
pro |
very
popular with students, excellent compression ratio &
quality sound |
|
con |
audio
only |
| .rm/.rp |
pro |
very
popular with students, first 50 streams are free |
|
con |
Expensive:
Licensing fees for >50 streams from server( an
aggregate for all files, not per media clip) |
| .wmp |
pro |
very
popular with students, easy to use |
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con |
Not
truly cross-platform |
To learn more about these
media types, visit the Retiarius
Enterprises website.
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Repurposing
Video for the Web |
Web pages are quickly
becoming the 21st century equivalent of photocopying. They
require little storage space on a server, transfer quickly, and
give immediate access to everyone. But, more often than not,
the information is distributed widely without clear cut purpose.
Conversely, video
and audio files for the web require more storage space, can
require long downloads and larger files are difficult for users
with slow modems. This creates an opportunity for stringent
content analysis. If media files should be as small as possible
(and right now that means short), then any video clips must be
succinct and to the point. I recommend a three-minute rule
for video--if the clip is longer than three minutes, it is going
to be too large for most users. (With the great audio compressions
available, I use a 5 minute rule --because after 5 minutes, who is
still listening?)
To supplement the three
minute clip, the web page should become a complex media
experience. The page can offer text and activities
supporting the media so that the user has something to do during
the download. In language learning contexts, the page
can provide vocabulary/idiom support or provide background
information on the cultural aspects of the video. Thus,
video on the web becomes a more enriching experience than a
photocopied handout.
A terrific example of
just such an enriching experience can be seen at SUNY Cortland, on
a web site developed by French professor,
Marie Ponteiro in a lesson
on Europe for her French Civilization course. My apologies if you
don't read French.
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Getting
Started |
You will need a
specialized computer and software. I use and recommend
Macintosh computers. They are designed to process media and
there are many software programs already available for this
platform. The following recommendations are for Macintosh platform
only. Faculty, staff and students have access to these programs in
the Instructional Technology Center (ITC- 217 Chafee) and the Fine
Arts lab (Fine Arts - F102).
Audio:
Macromedia SoundEdit 16
(if you can find it) or Bias
Peak. Peak reduces the
number of steps in the process by self-containing the file when
saving to QuickTime format. (One less step is good.) I use Cleaner
for Compression--using either the Qualcomm Pure Voice codec or
.mp3. Lyrical or slurred voices (such as Russian or
Portuguese) sound better using teh .mp3 codec. English and
other languages I have tried work well with Qualcomm. Cleaner
can hint the tracks automatically
(this saving another step).
Video:
I use Final Cut Pro
to log and capture video. Apple's iMovie
would work just as well if you
have minimal editing needs. You can also trim the
beginning and end with QuickTime
Pro, but this is like using a
saber instead of a scalpel. I self-contain the files in QuickTime
Pro and then compress them in Cleaner.
The codec varies depending on high/low motion and desired file
size. Again, let Cleaner
hint your tracks for you.
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Storage
Issues
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Media just devours drive
space. Anyone working with media needs an external firewire drive
with lots of empty space. If you can't afford an external
drive, I recommend partitioning your hard drive. Once you
start capturing video, you'll need to defrag the drive on a
recurring basis. You won't have to reinstall programs, if
you have a separate media storage space that can be defragged
independently from the system and programs drive.
Why defrag? Because
video clips should be stored (even on the scratch[capture] disk)
without dropping frames. If the drive is clean, the media
file can be written in one continuous loop, without skips, jumps
or breaks. If the drive is fairly full, the computer will
have to write the file in sections, 8 MB here, 8 MB there, oops
dropped a frame... You get the picture. Norton
Utilities can defrag your media drive while you sleep.
Another reason to have an
external portable firewire drive is just that, portability.
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Getting
It on the Web
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I haven't mentioned
authoring web pages yet (that could be a treatise by itself), but
if you intend to embed
audio or video directly into the web page, I
RECOMMEND YOU DON'T USE MS FRONTPAGE. Take my advice
and write the code yourself or invest in DreamWeaver, it is just
too difficult to get the code right in FrontPage.
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