Compression Standards

JPEG: A commonly used video compression scheme, also known as MJPEG. JPEG has the least impact on the camera's processor, but it requires the most bandwidth.

H264: A new version of MPEG-4 compression used in high-definition video players such as Blu-ray™and HD-DVD. H.264 is the most processor-intensive, but it requires the least amount of bandwidth.

AVAILABLE CAMERA RESOLUTION

Refer to the following table for the resolution capabilities of your camera model

Table B. Available Camera Resolution

1920 x 1080	640 x 480

1600 x 1200	640 x 352

1280 x 1024	480 x 368

1280 x 960	480 x 272

1280 x 720	320 x 256

800 x 600	320 x 240

640 x 512	320 x 176

IMAGE RATE

The image rate is the number of images per second (ips) available for the video stream configuration. Available image rates are 30, 25, 24, 15, 12.5, 12, 10, 8, 7.5, 6, 5, 4, 3, 2.5, 2, and 1.

NOTE: The maximum image rate setting might not be obtainable due to the programmed compression standard and the resolution of the stream.

Refer to the following section for more information:

•Specifications on page 62

BIT RATE

The bit rate is the quality of the video stream (rendered in kilobits per second). The higher the value, the higher the video quality and bandwidth required.

NOTE: When you change any of the video stream configuration settings, the camera automatically adjusts the bit rate. If you manually reduce the bit rate lower than the camera's automatic setting, the image quality might be reduced and the stream selection options might be limited.

I-FRAME INTERVAL

The I-frame interval configures the number of partial frames that occur between full frames in the video stream. For example, in a scene where a door opens and a person walks through, only the movements of the door and the person are stored by the video encoder. The stationary background that occurs in the previous partial frames is not encoded, because no changes occurred in that part of the scene. The stationary background is only encoded in the full frames. Partial frames improve video compression rates by reducing the size of the video. As the I-frame interval increases, the number of partial frames increases between full frames. Higher values are only recommended on networks with high reliability. This setting is only available with H.264.

QUALITY OF SERVICE FOR DIFFERENTIATED SERVICES CODE POINT

Quality of Service (QoS) for Differentiated Services Code Point (DSCP) is a code that allows the network to prioritize the transmission of different types of data. This setting is only available with H.264.

NOTES:

•If you are not familiar with DSCP, contact your network administrator before changing this setting.

•Your network must be configured to use QoS. If you are unsure if your network is QoS-aware, contact your network administrator.

46	C2953M-B (10/09)