User manual

AXIS Q7424–R

Video and Audio

Setting the compression level affects the image quality and bandwidth; the lower the compressio n, the higher the image quality

with higher bandw idth requirements.

To avoid bandwidth problems on the network, you can limit the frame rate allowed to each viewer. The maxim um fra m e rate ca n be

set to Unlimited, or you can limit the frame rate to a value.

An image or text can be superimposed over the image as overlay. See

Overlay, on pag e 18

Save your setting s before they can take effect.

H.264

H.264, also known as M PEG-4 Part 10/AVC, is a video compression standard that provides high quality video streams at low bit r ates.

An H.264 video stream consists of different types of frames such as I-frames and P-frames. An I-frame is a complete image whereas

P-frames only contain the differences from previous frames.

The GOV length is the number of frames between two consecutive I-frames. Increasing the GOV length may save considerably on

bandwidth requirements in some cases, but may also have an adverse affect on image q uality.

ThebitratecanbesetasVariable Bit Rate (VBR) or Constant Bit Rate (C BR ). VB R adjusts the bit rate according to the image

complexity, using up more bandwidth for increased activity in the image, and less for lower image activity. CBR allows you to set a

ﬁxed Target bit rate that consumes a predictable amount of band width. As the bit rate would usually need to increas e for increased

image activity, but in this case cannot, frame rate and image qualityareaffectednegatively. Topartly compensate for this, it is

possible to prioritize either fra m e rate or im age quality. Not setting a priority me ans that frame r ate and image quality are equally

affected. You mu st sa ve you r settin g s bef ore they can take effec t .

The current bit rate can be set to a ppear as text overlay. To do this, select the Include text check box option under Overlay

Settings and enter the modiﬁer#b in the ﬁeld.

MJPEG

Sometimes the image size is large due to low light or complex scenery. Adjusting the maxi

mum frame size helps to control the

bandwidth and storage used by the Motion JPEG video stream i n these situations. Setting the frame size to the Default setting

provides consistently good image quality at the expense of increased bandwidth and storage usage in low light. Limiting the frame

size optimizes bandwidth and storage usage, but may give poor image quality. To

prevent increased bandwidth and storage usage,

the ma ximum fram e size should be set to an optimal value.

Quad stream

A Quad view displays images from all four channe ls on a single scre e n; where the ima ge s from each came ra take up a quarter of

the display area. It is possible to deﬁne settings for the video stream in quad view.

Stream Proﬁles

There are four pre-programmed stream proﬁle s available for quick set up. The settings for these can be adjusted. New customized

proﬁles can also be created. Each proﬁle has a descriptive name, indicating its purpose.

•Thestreamproﬁles can be accessed from the Stream proﬁle dro p-dow n list in the Live View page.

• To add, copy, modify, and remove stream proﬁles go to Video & Audio > Stream Proﬁles.

• To select the def ault stream proﬁle go to Live View Conﬁg > Stream Proﬁle and choose the proﬁle from the drop-down list.

For more information see the online help

on this page.

Camera Settings

The Video & Audio > Camera Settings page provides access to advanced image settings for the Axis product.