When video is captured in AVI
or RAW format, the captured uncompressed file
will be very large (approximately 100MB per minute). It is necessary to compress it into a smaller file. The easiest way is to
convert it into MPEG-1 (Moving Picture Experts Group) format. This will save you
a lot of file space since the compression ratio is about 10 to 1 (100MB will
be compressed into 10 MB), without losing picture quality.
By compressing AVI or RAW video
files into MPEG-1 format you can also create a Video CD or create files that can
be viewed on the internet. Some people like to convert their home videos tapes
into a Video CD, since its quality does not
degrade like tapes do. You can view it on your TV but you'll need either a Video
CD player, or DVD player that also support MPEG decoding. Most DVD players today
support Video CD's.
Video CD, or VCD, is a digital movie format. It's basically a primitive
version of DVD. Video CD was introduced by Philips and Sony in 1993. It never caught on in
North America, but it became hugely popular in Asia, where most households
didn't already have VCRs. In Asia, Video CD players are roughly as common as
VCRs in North America: China alone manufactures 2 million VCD players a year.
A Video CD is the same as a music CD or a CD-ROM,
except that instead of music or software, it holds movies, using compressed
MPEG-1 video. Its resolution is 352x240 (NTSC) or 352x288 (PAL), which is
roughly comparable to VHS.
A single VCD disc can only hold about 70 minutes of video. You can play VCDs back on a Video CD player connected
to a TV, or on a fast PC with a CD-ROM drive. Some DVD players can also play
VCDs.
First introduced in 1997, DVD,
when compared to Video CD, provides much higher resolution 720x480 (NTSC),
720x576 (PAL). DVD movies use MPEG-2 compression, rather than the MPEG-1
compression used by Video CDs.
