Common
Video Formats :
| Format |
Common
Applications |
Common
Codecs |
Requirements |
| Quicktime |
CD/Multimedia,
Internet, Non-Linear Editing |
Cinepak,
Indeo, Sorenson |
Downloadable
Player (Pre-Installed on most Macs) |
| AVI |
CD/Multimedia,
Internet, Non-Linear Editing |
Cinepak,
Indeo, Microsoft Video |
Windows
95/98/NT or Downloadable player for Windows 3.x & Macintosh |
| DirectShow |
CD/Multimedia,
Internet, DVD |
--- |
Downloadable
Player + Windows |
| MPEG-1 |
CD/Multimedia, Kiosks, Internet |
--- |
Hardware
Decoder or Software Decoder + High End Machine |
| MPEG-2 |
Broadcast,
DVD |
--- |
Hardware
Decoder,
DVD Player |
| Streaming
Video |
Internet |
RealVideo,
MPEG-4, TrueMotion, VDOnet |
Downloadable
Player |
|
|
Each
codec uses a unique algorithm to calculate how to optimally decrease a movie's
data rate (the amount of data transferred per second). Video played through
a CD-ROM requires a data rate of 200-300 KB/Sec, while video over the internet
requires even less (about equal to the target modem speed). Considering
full-frame, uncompressed, 30 fps video has a data rate of about 30 MB/Sec,
there is an enormous amount of data that needs to be omitted. Each codec
is different in how it chooses to "drop" information, whether
it be by decreasing the frame rate, lowering image detail, sampling fewer
colors, etc.
Compression quality also depends
on the movie content and movement occurring in the movie.
Currently, the newest codecs, Indeo 5 and Sorenson, provide the highest
quality video with extremely low data rates. Their only setback is that
most users do not have these new codecs installed on their machines. Consequently,
if you choose to distribute video compressed with these codecs, you must
provide users with the appropriate codec installation software, both of
which are available as free downloads from their respecive sites.
|