Axis Q7414 User Manual page 15

Audio
Enable Audio
Check the Enable audio box option to enable the audio functionality.
Note: Audio support must be also enabled under System Options > Security
The settings defined under Audio Settings are displayed under Current Audio Settings.
H.264
GOV Settings
The GOV structure describes the composition of the H.264 video stream which consists of 2 image forms, I-images and
P-images. An I-image is a complete image, whereas a P-image is only the differences in the image as compared with the
previous image.
The GOV length determines how many P-images are sent before the next complete I-image is sent.
Setting the GOV-length to a higher value saves considerably on bandwidth but if there is congestion on the network, there
may be noticeable decay in the video quality. Setting the GOV-length to a lower value increases the video quality, in this case.
Note:
GOV length should not be higher than the set frame rate when using a pre-trigger buffer, Pre-trigger and Post-trigger
buffers, on page 30.
Bit Rate Control
The bit rate type can be set as Variable Bit Rate (VBR) or Constant Bit Rate (CBR).
VBR adjusts the bit rate according to the image complexity, using more bandwidth for increased activity in the image, and less
for lower activity in the monitored area.
CBR allows you to set a fixed Target bit rate that consumes a predictable amount of bandwidth. As the bit rate would usually
need to increase for increased image activity, but in this case cannot, the frame rate and image quality are affected
negatively. To partly compensate for this, it is possible to prioritize either the frame rate or the image quality whenever the bit
rate needs to be increased. Not setting a priority means the frame rate and image quality are equally affected.
Note:
To determine a reasonable bit rate, go to Setup > Video & Audio > Video Stream > Image, check the Include checkbox
and enter the code #b in the Include text: field. The current bit rate will display as a text overlay on the Live View page.
To view the image stream while configuring the GOV settings and Bit rate control, select Open... under Preview.
MJPEG
Sometimes the image size is large due to low light or complex scenery. Adjusting the maximum frame size helps to control the
bandwidth and storage used by the Motion JPEG video stream in these situations. Defining the frame size as Default provides
consistently good image quality at the expense of increased bandwidth and storage usage during 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 maximum frame size should be set to an optimal value.
AXIS Q7414 - Video & Audio
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