Key frame
MPEG4 compression is based on
the key frame concept. The key frame is basically a reference video
frame captured directly from the video source, without reference to
previous frames just like JPEG and Wavelet video frames. The rest of
video frames are calculated based on motion and other video
parameters. The more frequent the key frame is captured, the larger
the video bandwidth requirements. The Video Catcher Elite and High
Speed Series now
has a control that lets you specify how often you want it to record
a key frame.
Bit Rate Control
As mentioned earlier, MPEG4
allows the compression algorithm to adapt to different bandwidth
environments to achieve the best results. The Bit Rate can adjusted via settings in the
Video Catcher software allowing the
user to experiment with the setting to achieve the best results.
Since the bandwidth can vary depending on the time of day such as
those offered by ADSL and cable modems, this level of control is
essential to get the best results.
