Axis Communications 230 MPEG-2 user manual Advanced Settings

AXIS 230 Operating the AXIS 230 19

•Max Digital Zoom - To prevent distortion of the video stream when zooming, set a maximum value for the digital zoom. This ensures that you always get video of a certain minimum defined quality.

•Focus Near Limit - This setting is useful when the camera is mounted e.g. behind glass in an outdoor enclosure. In certain circumstances, e.g. when rain or snow falls on the glass, the auto-focus function may attempt to refocus on this new element in the image. To prevent this phenomenon, set the focus near limit to a value greater than the distance at which distur- bances are likely to occur.

•Mirror - To flip the image horizontally 180 degrees, set this to On.

•IR Illumination - If the camera is placed in a very dark location without lighting or is used at night, the autofocus function will not find anything to focus on and will repeatedly attempt to focus the camera, thus causing unnecessary wear on the focusing motor. Under normal cir- cumstances, this is prevented by the built-in autofocus protection, but if using infrared (IR) illumination in a dark location, then the camera should behave as if the scene was lit normally, and the autofocus protection will not be necessary. Set the parameter to the correct setting for your application. Note that the AXIS 230 is intended for use in day and night situations, and will thus function well in very dark conditions, even when not using IR illumination.

Advanced Settings

The advanced settings allow the structure of the MPEG-2 video stream to be modified. The GOP (Group of Pictures) can take 3 forms - IBBP, IBP and IP. These forms describe the type of pictures included in the stream and also their internal order. An I-picture is a complete image, a P-image is the predicted difference between this image and a preceding I or P-picture, and a B-picture is a comparison with both earlier and later pictures.

Please note that changing this setting is likely to affect the amount of bandwidth required by the video stream, as well as the perceived latency. These settings should only be changed by experienced users.