This section lists the settings found in the Camera Video tab,
in the Video task.
The Video tab allows you to define multiple video quality (resolution, frame rate,
and so on) configurations for each video stream generated by your video
encoder. For each stream, you can also specify its usage (or function) and specific network
settings.
Video quality
In the Video quality section, you can configure settings that affect the quality of
the video (image resolution, bit rate, frame rate, and so on). Multiple video quality
configurations can be defined for the same stream on different schedules.
Video quality settings might vary from one manufacturer to another. No manufacturer
supports them all.
NOTE: For any setting not covered in the list below, refer to
the manufacturer’s documentation.
Resolution:
Data format and image resolution. The available choices depend on the type of video
unit you have.
NOTE: On certain models of video units that support a large
number of video feeds (4 to 12), some high resolution formats might be disabled if
you enable all the video streams, because the unit cannot handle all the streams at
high resolutions.
Quality:
Video quality depends on a combination of settings. Config
Tool proposes a list of predefined
configurations for you to choose from. To adjust each of them individually, select
Custom from the Quality drop-down
list.
Bit rate:
Sets the maximum bandwidth (kbps) allowed for this encoder.
Bit rate mode:
Certain types of video units (such as Axis) allow you to set the maximum bit rate at
the unit level. In this case, the
Bit rate mode drop-down list is
available for your bit rate settings.
Variable:
Variable bit rate (VBR) adjusts the bit rate according to the complexity of
the images in the video. This uses a lot of bandwidth when there is a lot of
activity in the image and less bandwidth when the monitored area is quiet.
Constant:
Constant bit rate (CBR) allows you to set a fixed target bit rate that will
consume a predictable amount of bandwidth, which will not change, whatever
happens in the image. This requires you to set another parameter, the Bit
rate priority.
Bit rate priority:
If you choose to maintain a constant bit rate, the encoder might not be able to keep
both the frame rate and the image quality at their set values when the activity in the
image increases. The
Bit rate priority lets you configure which aspect of video
quality you wish to favor when you are forced to make a compromise.
Frame rate:
Maintains the frame rate at the expense of the image quality.
Image quality:
Maintains the image quality at the expense of the frame rate.
None:
Lowers both the frame rate and the image quality to maintain the bit rate.
Frame rate:
Sets the number of frames per second (fps). A high frame rate (10 fps
or more) produces fluid video and is essential for accurate motion
detection. However, increasing the frame rate also sends more information
over the network, and therefore, requires more bandwidth.
Image quality:
Sets the image quality (the higher the value, the better the quality). Higher image
quality requires more bandwidth, which might compromise the frame rate.
When
bandwidth is limited, you should consider the following:
- To retain very good image quality, restrict the number of images per second
(lower frame rate).
- To transmit more images per second at a high frame rate, lower the image
quality.
The encoder tries to maintain each quality setting. However, if bandwidth is
limited, the encoder might reduce the frame rate in favor of the image
quality.
Automatic settings:
Certain models of encoders (such as Bosch) let you select this option instead of
setting your own value for image quality. To set the image quality manually, you have
to select Custom in the Quality drop-down
list.
Key frame interval:
A key frame is a frame that contains a complete image by itself as
opposed to a usual frame that only holds information that changed compared to the
previous frame. If your network is less reliable, you require a higher key frame rate
to recover more quickly from cumulative errors in the video. Frequent key frames
require a higher bandwidth. You can specify the key frame interval in seconds (1 to
20) or by frames (based on the frame rate).
Recording frame rate:
Record the video at a lower frame rate than the rate used for viewing video. This
setting save storage space, but it does not reduce bandwidth usage. Setting the
Recording frame rate to anything other than All frames locks the
Key frame interval.
Profile and level:
Used only for MPEG-4 streams, the profile determines the tools
available when generating the stream (for example, interlace, or B frames), and the
level limits the resource usage (for example, max bit rate).
Video object type:
The Video Object Type (VOT) to use for MPEG-4 streams. The available choices are
governed by the choice of Profile and Level.
GOP structure:
Stands for
Group Of Picture structure. It is possible to configure up to four
types of GOP structures:
I:
Stands for Intra frame structure. Meaning only Intra (key frame) frames
are sent. This is primarily for using an external multiplexer.
IP:
Stands for Intra and Predicted frame structure. This setting results in
the lowest possible video delay.
IPB:
Stands for Intra and Predicted and Bidirectional frame structure. This
setting enables the user to have a higher quality and a higher delay.
IPBB:
Stands for Intra and Predicted and Bidirectional and Bidirectional
frame structure. This setting enables the highest quality and a highest
delay.
GOP length:
Stands for Group Of Picture length. With this value, it is possible to change
the distance (number of frames) between the intra-frames in the
MPEG-2 video stream.
Streaming type:
Select between VES (video elementary stream), which sends only video information, or
PRG (program stream), which sends both video and audio information.
Input filter mode:
Lets you select a noise filter to apply to the video signal before it is encoded. It
has four settings:
None,
Low,
Medium, and
High.
NOTE: Removing noise from the video signal also reduces the sharpness of the
image. If the video signal is relatively clean, do not apply any filter
(None). The higher the filter level, the more blurry the video image becomes.
Keeping a sharp image creates more pixels to encode, which uses more bandwidth. This
is why on some video units the default is set to Medium.
Bit rate control:
Lets the encoder automatically lower the bit rate when one of the
decoders is reporting transmission errors (dropped packets). This usually happens when
there is a lot of motion on the camera. The encoder drops the bit rate as low as
necessary to let all decoders receive an error free transmission. When the motion
subsides, the encoder gradually increases the bit rate until it reaches the configured
maximum limit.
The trade-off between low bit rate and transmission errors is that with a low bit
rate, the image stays crisp but the video might appear choppy, while with transmission
errors, the image contains noises, but the video stays fluid.
Compression mode:
Select between SM4, Verint's proprietary version of MPEG-4 compression, or ISO, the
standard MPEG-4 compression.
Stream usage
The
Stream usage options are only available for encoders capable of generating
multiple video streams. It allows you to specify the usage (or function) of each stream.
Live:
Default stream used for viewing live video in Security
Desk.
Recording:
Stream recorded by the Archiver for future investigation.
Remote:
Stream used for viewing video when the bandwidth is limited.
Low resolution:
Stream used instead of the Live stream when the tile used to view the stream
in Security
Desk is small.
High resolution:
Stream used instead of the Live stream when the tile used to view the stream
in Security
Desk is large.
Network settings
The
Network settings options allow you to configure the desired connection type used
by the video encoder.
UDP port:
Port number used when the connection type is unicast UDP. If the
encoder supports multiple video streams, this parameter is different for each
stream.
Connection type:
Defines how communication is established between the Archiver and the camera for
sending or receiving video streams.
Best available:
Lets the Archiver select the best available connection type for the stream.
The best available types rank in this order, according to availability:
Multicast, UDP, TCP, RTSP over HTTP, and RTSP
over TCP.
Unicast UDP:
Forces the stream to be sent in UDP to the Archiver. The stream must be
formatted using the RTP protocol.
Unicast TCP:
Forces the stream to be sent in TCP to the Archiver. Here, TCP is
taken in the broad sense. For some types of cameras, the Archiver establishes a
TCP connection to the unit and receives the stream in a proprietary protocol.
For others, the stream is sent over HTTP. Typically, the stream is not formatted
according to the RTP protocol by the unit. The Archiver has to convert the
stream to the RTP protocol to be archived or retransmitted to the system.
RTSP stream over HTTP:
This is a special case of TCP connection. The Archiver uses the RTSP protocol
to request the stream through an HTTP tunnel. The stream is sent back through
this tunnel using the RTP protocol. This connection type is used to minimize the
number of ports needed to communicate with a unit. It is usually the best way to
request the stream when the unit is behind a NAT or firewall, because requests
sent to HTTP ports are easily redirected through them.
RTSP stream over TCP:
This is another special case of TCP connection. The Archiver uses the RTSP
protocol to request the stream in TCP. The request is sent to the RTSP port of
the unit.
Same as unit:
Special case for Panasonic units. The connection type is the same for all
streams of the unit. When present, it is the only connection type supported. The
real connection type must be set in the specific configuration page of the
unit.
Multicast address:
The multicast address and port number are assigned automatically
by the system when the video unit is discovered. Each video encoder is assigned a
different multicast address with a fixed port number. If the encoder is capable of
generating multiple video streams, then a multicast address should be assigned to each
stream. This is the most efficient configuration.
Boost quality on manual recording
Temporarily boost video quality when the recording is started manually by a Security
Desk user when they click the Record
() button or the Add bookmark () button. This option is only available for the
recording stream.
Boost quality on event recording
Temporarily boost video quality when the recording is triggered by a system
event (the Start recording action
was executed, an alarm was triggered, or because of a motion event). Boost
quality on event recording settings have priority over the Boost quality on manual
recording settings. The length of the video quality boost depends on the event type,
and the camera’s recording settings.