Video
in its raw form takes up huge amounts of space. For
example, one second of uncompressed NTSC video
takes about
27 Megabytes of
disk space. That is a lot of space if you only have
100 megabytes of space for your Web site. In order
to
make desktop video feasible, video compression algorithms
were created. So,
when you're done editing your clips, which includes
arranging them in the desired sequence, cropping them,
adjusting
the
audio,
and
adding transitions, titles, special effects and
sound effects as needed, you're ready to convert
your video project into a movie that can be played
on a Web site. At this point you
will need to compress your video for export.
There
are several questions that need to be addressed
here. These
are questions you will need to answer before deciding
how you would like to compress your video.
Which is
the correct size? What kind of picture quality do
you want?
Are you willing to be satisfied will a little lower
quality of the picture, to ensure the video will
download quickly and will take up a smaller amount
of space in your site? One important point to bring
up here is if you plan on streaming your video, you
may not want to compress at all. See Progressive
and Streaming Download. If you are planning
to stream your video to your viewers check out Streaming
Media, by Tim Dereg, for some great inf9ormation
on compression formats for stream video..
Video File Size
There
many things that affect the file size of video.To
learn more about what affects the file size of your videos, click
here.
Video
Compression
During
the process of compression, redundant
audio and video data is removed the file size
is lowered. Unfortunately, often times the
overall quality of video for your audienceis also
lowered. The more the video is compressed, the
more image and/or sound degradation will likely
occur.
Compression
Formats
There
are various types of video compression format choices for
each video capturing and editing software program.
This
quite
helpful. Each has it own benefits
and negative attributes.
Video
Compression Technology - Video Compression Tutorial
FOURCC
for video compression: An exhaustive list of character
codes to indentify video data stream formats.
A
Comparison of Internet audio compression formats
Example:
Although there are many video editing programs with a whole
array of compression choices, here is an example of a 30
second movie file that was edited in iMovie and needs to
be compressed.
Note
the different formats and the different attributes of each
compression method.
This chart will provide the you with helpful
information for deciding the format for compressing your
movie to the
final size (screen dimensions and file size) and quality
you want. Before
you make up your mind be sure to read the next section
on downloading video.
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