Axis Communications 221 - Manual (Page 11)

11 AXIS 221 - Video Streams
Video Streams
The AXIS 221 provides several different image and video formats. The type to use depends
on your requirements and on the properties of your network.
The Live View page in the AXIS 221 provides access to Motion JPEG and MPEG-4 video
streams, as well as to single JPEG images. Other applications and clients can also access
these video streams/images directly, without going via the Live View page.
Video Stream Types
Motion JPEG
This format uses standard JPEG still images in the video stream. These images are then
displayed and updated at a rate sufficient to create a stream that shows constantly updated
motion.
The Motion JPEG stream uses considerable amounts of bandwidth, but also provides
excellent image quality and access to each and every individual image contained in the
stream.
Note also that multiple clients accessing Motion JPEG streams can use different image
settings.
MPEG-4
This is a video compression standard that makes good use of bandwidth, and which can
provide high-quality video streams at less than 1 Mbit/s.
The MPEG-4 standard provides scope for a large range of different coding tools for use by
various applications in different situations, and the AXIS 221 provides certain subsets of
these tools. These are represented as Video object types, which are selected for use with
different viewing clients. The supported video object types are:
• Simple - sets the coding type to H.263, as used by e.g. QuickTime™.
• Advanced Simple - sets the coding type to MPEG-4 Part 2, as used by AMC (AXIS
Media Control)
When using MPEG-4 it is also possible to control the bit rate, which in turn allows the
amount of bandwidth usage to be controlled. CBR (constant bit rate) is used to achieve a
specific bit rate by varying the quality of the MPEG-4 stream. When using VBR (variable
bit rate), the quality of the video stream is kept as constant as possible, at the cost of a
varying bit rate.
Notes: •MPEG-4 is licensed technology. The AXIS 221includes one viewing client license. Installing addi-
tional unlicensed copies of the viewing client is prohibited. To purchase additional licenses, con-
tact your Axis reseller.
•All clients viewing the MPEG-4 stream must use the same set of coding tools.