User Guide

AXIS 241QA/AXIS 241SA - Video and audio streams

Video and audio streams

The AXIS 241QA/AXIS 241SA provides several different video and audio stream formats.

The type to use depends on your requirements and on the properties of your network.

The Live View page in the AXIS 241QA/AXIS 241SA

provides access to Motion JPEG and

MPEG-4 video and audio streams, as well as to single JPEG images. Other applications and

clients can also access these video and audio streams/images directly, without going via

the Live View page.

Video stream types

Motion JPEG

This format uses standard JPEG still images in the vi

deo 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 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 241QA/AXIS 241SA 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

• Ad

vanced Simple - in Axis products, this sets the coding type to MPEG-4 Part 2

AMC (AXIS Media Control) supports both object types, while

QuickTime™ requires the

Simple object type. 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 241QA/AXIS 241SA includes one license for the

decoder required for viewing in AMC. Installing additional unlicensed copies of this decoder

is prohibited. To purchase more decoder licenses, contact your Axis reseller.

• All clients viewing the MPEG-4 stream must use the same image settings.