Video capture card resources

By default, the resources of the video capture card used to process and digitize video signals are uniformly distributed between cameras. The frame rate of the digitized video signal is limited by the ADC resources for video signal processing and digitization.

Axxon PSIM software package components that are used for configuring video capture cards can give additional ADC resources to one or more cameras, and thus increase the frame rate of video signals from these cameras. At the same time the frame rate of the video signal from other cameras decreases.

The joint use of Axxon PSIM and video capture cards provides the following options for reallocating video capture card resources between cameras:

Option 1. Reallocation of cameras between ADCs of a video capture card.

ADC resources are generally characterized by the maximum total frame rate of video signals. By default, ADC resources are uniformly distributed between cameras, which are processed and digitized by this ADC. Thus, the more video signals from cameras are digitized and processed by the ADC, the lower the frame rate of each digitized video signal.

Reallocation of cameras between ADCs allows increasing the frame rate for some cameras by means of decreasing it for others.

If all allowable cameras are connected to a video capture card, then only uniform distribution on ADC is possible. In this case, every ADC of a video capture card digitizes and processes video signals from an equal number of cameras. Thus, the maximum allowable frame rate is the same for all video signals (except for video signals of different formats and different frame resolutions).

If the number of cameras connected to a video capture card is less than their maximum number, then you can reallocate them between ADCs of a video capture card. For this, those cameras whose frame rate you want to increase are allocated separately to one ADC or allocated in a number that is less than the maximum allowable one. Cameras allocated to a given ADC that aren't subject to strict frame rate requirements are reallocated to other ADCs.

An example of allocating cameras to ADCs is shown in the figure.

A. Uniform camera allocation between ADCs

B. reallocating the cameras between ADCs to allocate extra resources to Camera1

Option 2. Reallocation of resources of one ADC between cameras, video signals of which are processed and digitized by one ADC.

By default, the ADC resources are uniformly distributed between cameras, video signals of which are digitized and processed by this ADC. 

Reallocation of cameras between ADCs allows increasing the frame rate for some cameras by means of decreasing it for others. Reallocation of resources of one ADC to the cameras is much less effective than reallocation of cameras between the ADC. Therefore, you must do this only if camera reallocation to the ADC is impossible or if it doesn't help. 

To reallocate resources of one ADC between cameras, give one of the cameras extra ADC resources for its video signal processing and digitization. You can give extra ADC resources by removing them from other cameras video signals of which are processed by the ADC.

Thus, within one ADC, you can increase the frame rate of video signal from one camera only when you decrease the frame rate of video signal from other cameras.

To do this, place the selected camera in the priority process queue.

An example of reallocation of resources of one ADC between cameras is shown in the figure below.

A. Uniform camera allocation between ADCs

B. reallocating the cameras between ADCs to allocate extra resources to Camera1

Operation modes of the video capture cards’ ADC

ADC operation mode is defined by the number of processed and digitized video signals. There are two modes:

1. Live video.
2. Multiplexing.

In the Live video mode, all resources of an ADC are used to process only one video signal. The mode provides digital video stream with a maximum frame rate of 25 FPS in PAL format and 30 FPS in NTSC format.

If the ADC processes two or more video signals, its resources are used in the multiplexing mode. Then the ADC resources are uniformly allocated between the cameras, and in addition to video signal processing, part of its resources support the multiplexing process. Thus, in the multiplex mode, the total frame rate of video signals digitized by a single ADC is much lower than in the Live video mode.

The maximum allowable total frame rate in the multiplexing mode depends on the frame resolution of video signals.

For ADC that digitizes all video signals with standard (352 x 288 pixels in PAL format, 352 x 240 pixels in NTSC format) and/or high (704 x 288 pixels in PAL format, 640 x 240 pixels in NTSC format) frame resolution, the total frame rate is 16 FPS in PAL format and 20 FPS in NTSC format.

If ADC digitizes at least one of the video signals with full resolution (704 x 576 pixels in PAL format, 640 x 480 pixels in NTSC format), the maximum allowable total frame rate reduces to 12 FPS in PAL format and 15 FPS in NTSC format.

Frame rate setup procedure

With default settings, you can receive digitized video signals with frame rates that are 2 FPS in PAL format and 2.5 FPS in NTSC format.

During setup, you can increase and reduce the frame rate.

To set up the frame rate, do the following:

1. Switch off the Camera objects that correspond to the idle video channels. This allows allocating the resources between working cameras only, thus increasing the frame rate of their video signals. 
2. Change frame grooming.
3. Reallocate cameras on ADC of the video capture card.
4. Reallocate resources of one ADC between cameras (priority process queues).

In most cases, 1 and 2 setting steps are sufficient to set the frame rate. 3 and 4 setting steps are necessary only with high frame rate requirements to one or more cameras.

Configuring video subsystem with disabled video channels

By default, resources of video capture cards’ ADC are allocated uniformly between all video channels, whether there is any signal passing through it or not. Thus, even if a video channel has no signal, the resources of ADC are allocated to each video channel.

To prevent allocation of ADC resources for digitization and processing of idle video channels, you must disable the Camera objects that correspond to these channels in Axxon PSIM.

Disable several Camera objects in turn.

To disable the Camera objects that correspond to the idle video channels in Axxon PSIM, do the following:

1. Define the numbers of the idle video capture channels (taking into account BNC plug numbering).
2. Go to the Hardware tab in the System settings window.
3. In the object tree on the Hardware tab, select the Camera object, created before, with the same channel number as the BNC plug (idle channel). The settings panel for the selected object is displayed on the right of the Hardware tab.
4. Make sure that video signal isn't displayed in the video field (1).
   
   The display of the video signal in the video field indicates that the Camera object matches another video channel.
5. The video channel number is specified in the Channel number drop-down list in the Basic settings tab (2). Match the Camera object with the channel number, which corresponds to the BNC plug number and the Camera object number, or scan for a Camera object, matched with the desired channel number.
6. Set the Disable checkbox (3).
7. Click the Apply button.

The disabled Camera object is indicated with a cross mark.

Configuration of video subsystem with disabled video channels is complete.

Actual frame rate

We recommend defining the actual frame rate of video signal digitization and then setting up the frame rate for video signals from video surveillance system cameras. 

You must perform frame rate setup if frame rates of video signals from one or more cameras don't meet the requirements.

Actual frame rates are defined for each camera individually.

To define the actual frame rate for a selected camera, do the following:

1. Configure the Video surveillance monitor (see Configuring video display on Video Surveillance Monitor);
2. Enable the Debug mode in Axxon PSIM using the tweaki.exe utility (see Tweaki.exe utility for advanced setup of the Axxon PSIM software system, The Settings panel of the Axxon PSIM section).

As a result, the current frame rates of the digitized video signals are displayed directly in the Video surveillance monitor. To get information about the frame rate of the video signal from the selected camera, display the Surveillance window corresponding to the selected camera in the Video surveillance monitor and activate this window by clicking it with the left mouse button. A window with video signal information is displayed in the upper right corner:

• video stream frame rate (FPS);
• size of the displayed frame in bytes ( you can use this parameter, for example, to understand whether the displayed frame is a reference frame or to calculate the average bitrate);
• video stream resolution in pixels.

Note that this information window displays initial data about the video stream from the camera or from the archive transmitted to the Video surveillance monitor. The actual displayed frame rate of the video stream can be different, see Displaying information about a video stream on top of a video.

Changing frame decimation

By default Axxon PSIM digitizes video signals with the frame rate lower than maximum allowed one. This is caused by the following:

1. Video signal processing and digitization with a high frame rate is a resource-intensive process. When the video signal frame rate increases, configuration requirements increase for the computer used as a server.
2. Video signal is transmitted to the Remote Workplaces with the same frame rate as it is digitized. Thus, network capacity requirements increase together with the frame rate increase.

By default, the total frame rate of video signals, which are digitized and processed by the same ADC, is two times lower than the maximum allowed one. This ratio is supported by frame decimation, which provides every second frame for further processing by the functional modules of the Axxon PSIM.

You can reduce (total frame rate increases) or increase (total frame rate decreases) the decimation.

Frame decimation is changed separately and independently for every ADC.

To change decimation of ADC video signals, do the following:

1. Go to the Hardware tab in the System settings window (1).
2. Select the Video capture device object that was created before and corresponds to the configured ADC of the video capture card on the Hardware tab in the objects tree (2). The settings panel for the selected object is displayed in the right part of the Hardware tab.
   
3. If it is necessary to increase the total frame rate up to the maximum allowed value, move the Rate slider to the max position (3).
4. If it is necessary to reduce the total frame rate to the minimum allowed value, move the Rate slider to the min position. The minimum total frame rate of video signals, digitized and processed by a selected ADC, is three times lower than the maximum allowed one.
5. If it is necessary to return the default decimation settings, move the Rate slider to the middle position. The default total frame rate is two times lower than the maximum allowed one.
6. Click the Apply button (4).
7. Close the System settings window and restart Axxon PSIM.

Allocation of video capture card’s resources

By default all cameras are uniformly allocated to ADC of video capture card. Thus, ADC resources are uniformly distributed between cameras, connected to the video capture card, and all cameras have the same frame rate of the digitized video signal. 

If the number of cameras connected to a video capture card is less than their maximum allowed number, it is possible to reallocate them between different ADCs of the video capture card. This allows increasing the frame rate for some cameras by means of decreasing the same frame rate value for other cameras. 

Before reassigning the cameras to ADCs of the video capture card, disable the Camera objects corresponding to disabled cameras (see Configuring video subsystem with disabled video channels section).

To increase the frame rate of the video signal from one or more cameras, do the following:

1. Go to the Hardware tab in the System settings window.
2. Select the Camera object, created before, corresponding to the camera whose frame rate you want to increase, in the objects tree on the Hardware tab. The settings panel for the selected object is displayed on the right of the Hardware tab.
3. In case, if you want to increase the frame rate of a camera up to the Real time rate (25 FPS in PAL format and 30 FPS in NTSC format), reallocate other cameras, the video signals of which are digitized by the same ADC as for this camera, to other ADCs.

For this, move the Camera objects to the parent branches of other Video capture device objects. You can set the parent Video capture device object for the Camera object by selecting the number of the parent object in the Video capture device list of the Camera object settings panel. As a result, the Camera object moves to the child branch of the set Video capture device object in the objects tree.

Example 1. Configuring video signal digitization with the Real time frame rate.

Task. Video signal on Camera 2 must be digitized with the Real time frame rate.

Initial data. The card has four ADCs. They are matched to four Video capture device objects in the objects tree. The video capture card may have up to 16 cameras connected to it. Eight cameras are actually connected to the video capture card. The objects matched to the remaining eight cameras are disabled. Each of two ADCs, matched to the Video capture device 1 and Video capture device 2 objects, is configured to digitize the signals from four cameras. The ADCs matched to the Video capture device 3 and Video capture device 4 objects aren't configured to digitize signals from any cameras. An example of the objects tree is given in figure A:

A. Initial data                                            B. Result

Solution. Do the following:

1. Select the Camera 1 object in the objects tree. The settings panel for the selected object is displayed.
2. Select Video capture device 3 in the Video capture device list.
3. Click the Apply button.
4. The Camera 1 object moves to the child branch of the Video capture device 3 object (see B).
5. Repeat 1-4 steps for the Camera 3 and Camera 4 objects.
6. Select the Video capture device 1 object in the objects tree.
7. Make sure that the Speed slider is in the max position.
   If the Speed slider is in the max position, then setup is completed.
   If the Speed slider is in another position, move it to the max position and do 8-10 steps.
8. Click the Apply button.
9. Close the System settings window and restart Axxon PSIM.
10. The frame rate of the selected camera increases up to the Real time rate (for information on testing the frame rate change, see Actual frame rate).
11. If the number of connected cameras doesn't allow setting up digitization of video signal from one of the cameras with the real time rate (for example, when 15 out of 16 allowed cameras are connected) or if it is necessary to increase the frame rate of several cameras simultaneously to the rate lower than the real time one, the allocation of cameras between ADCs is performed as follows: the cameras for which it is necessary to increase the frame rate, are allocated between ADCs in the number less than the maximum allowable one. The frame rate is increased by as many times as the number of cameras on ADC is reduced.

Allocation of video capture card’s resources is complete.

Example 2. Configuring video signal digitization from two cameras with increased frame rate

Task. Video signal on Camera 1 and Camera 5 must be digitized with increased frame rate.

Initial data. The card has four ADCs. They are matched to four Video capture devices objects in the objects tree. The video capture card may have up to 16 cameras connected to it. 12 cameras are actually connected to the video capture card. The objects matched to the remaining four cameras are disabled. Each of three ADCs, matched to the Video capture device 1, Video capture device 2 and Video capture device 4 objects, is configured to digitize the signals from four cameras. The ADC, matched to the Video capture device 3 object, isn't configured to digitize the signals from any camera. An example of the objects tree is given in figure A.

A. Initial data                                            B. Result

Solution. Do the following:

1. Select the Camera 1 object in the objects tree. The settings panel for the selected object is displayed.
2. Select the Video capture device 3 value from the Video capture device list.
3. Click the Apply button.
4. The Camera 1 object moves to the child branch of the Video capture device 3 object (B).
5. Repeat 1-4 steps for the Camera 5 object.
6. The frame rate on Camera 1 and Camera 5 increases twofold (for information on testing the frame rate change see the Actual frame rate section).
7. Click the Apply button.

Allocation of video capture card’s resources is complete.

Video signal processing priorities

By default, the ADC resources are uniformly distributed between cameras, video signals of which are digitized and processed by this ADC.

Reallocation of cameras between ADCs allows increasing the frame rate for some cameras by means of decreasing it for others. Reallocation of resources of one ADC to the cameras is much less effective than reallocation of cameras between the ADC. Therefore, you must do this only if camera reallocation to the ADC is impossible or if it doesn't help. 

To reallocate resources of one ADC between cameras, give one of the cameras extra ADC resources for its video signal processing and digitization. You can give extra ADC resources by removing them from other cameras video signals of which are processed by the ADC.

To give a camera extra ADC resources, place it in the video signal processing queue, which has the higher priority than the other cameras.

Axxon PSIM provides 1/2 and 1/3 process queues.

When a camera has a 1/2 process queue, its video signal is processed in every second frame. Thus, the digitization frame rate on this camera is the half of total frame rate of the considered ADC.

When a camera has a 1/3 process queue, its video signal is processed in every third frame. Thus, the digitization frame rate on this camera is one third of total frame rate of the considered ADC.

Example 1. The ADC is configured to digitize video signal from four cameras.

If all the cameras have a common queue, the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 3, Camera 4, Camera 1, Camera 2, Camera 3…

Let us suppose that Camera 1 has 1/2 queue, and the rest of the cameras are in the common queue. Then the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 1, Camera 3, Camera 1, Camera 4, Camera 1…

Thus, the frame rate on Camera 1 is increased by two times and becomes the half of total frame rate of the considered ADC. The frame rate of each of the remaining cameras becomes 1.5 times less and makes up 1/6 of total frame rate of the considered ADC.

Example 2. The ADC is configured to digitize the video signal from three cameras.

If all the cameras have a common queue, the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 3, Camera 1, Camera 2, Camera 3…

Let us suppose that Camera 1 has a 1/2 queue, and the rest of the cameras are in the common queue. Then the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 1, Camera 3, Camera 1, Camera 2…

Thus, the frame rate of Camera 1 is increased by 1.5 times and becomes the half of total frame rate of the considered ADC. The frame rate of each of the remaining cameras becomes 1.33 times less and makes up 1/4 of total frame rate of the considered ADC.

Example 3. The ADC is configured to digitize video signal from four cameras.

If all the cameras have a common queue, the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 3, Camera 4, Camera 1, Camera 2, Camera 3…

Let us suppose that Camera 1 has 1/3 queue, and the rest of the cameras are in the common queue. Then the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 3, Camera 1, Camera 4, Camera 2, Camera 1…

Thus, the frame rate of Camera 1 is increased by 1.33 times and becomes one third of total frame rate of the considered ADC. The frame rate of each of the remaining cameras becomes 1.125 times less and makes up 2/9 of total frame rate of the considered ADC.

Example 4. The ADC is configured to digitize video signal from four cameras.

If all the cameras have a common queue, the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 3, Camera 4, Camera 1, Camera 2, Camera 3…

Let us suppose that Camera 1 and Camera 2 have 1/2 queue, and the rest of the cameras are in the common queue. Then the ADC digitizes video signals in the following sequence:

Camera 1, Camera 2, Camera 3, Camera 1, Camera 2, Camera 4, Camera 1…

Thus, the frame rate of Camera 1 is increased by 1.33 times and becomes equal one third of total frame rate of the considered ADC. The frame rate of Camera 2 is also increased in 1.33 times and becomes equal one third of total frame rate of the considered ADC. The frame rate of each of the remaining cameras becomes 1.5 times less and makes up 1/6 of total frame rate of the considered ADC.

Reallocation of resources of one ADC between the cameras is possible in two modes:

1. In the processing mode, that is, with video signal digitization and processing prior to its display on the screen.
2. In the recording mode, that is, with video signal digitization and processing prior to its recording into the server archive. When cameras are switched to the recording mode, video signals are displayed with the rate, corresponding to the given ADC resource allocation.

Setting video processing priority

In video digitizing and processing mode before displaying it on the screen, ADC resources are reallocated between the cameras by queueing one of the cameras with 1/2 or 1/3 priority.

This setting is relevant only for the following video capture cards: FS5, FS6, FS8 and FS16.

To change the order of processing video from the selected camera, do the following:

1. Go to the Hardware tab in the System settings window.
2. Select the Camera object created before corresponding to the camera, the ADC video processing queue of which you want to change on the Hardware tab in the objects tree. 
3. Go to the Advanced settings tab on the settings panel of the Camera object.
   
4. Set the processing slider in the Priority group to the position:
   
   1. 1/2 to queue the camera with 1/2 priority for ADC video processing.
      
   2. 1/3 to queue the camera with 1/3 priority for ADC video processing.
   3. Normal (default), if it is necessary to return the camera into the normal queue for ADC video processing.
5. Click the Apply button.

Setting video processing priority is complete.

Setting video recording priority

In video digitizing and processing mode before recording it to the video server archive, ADC resources are reallocated between the cameras by queueing one of the cameras with 1/2, 1/3 or the Real time priority.

If the camera with Real time priority switches into the recording mode, it is allocated all ADC resources for its video processing and digitizing. Thus, the frame rate on this camera becomes equal to the total frame rate of the video signals that are processed and digitized by this ADC. Video signals from other cameras, allocated to a given ADC, aren't processed, displayed, and recorded to the disk. 

To change the processing queue of the video from the selected camera in the recording mode, do the following:

1. Go to the Hardware tab in the System settings window.
2. Select the Camera object created before corresponding to the camera, the ADC video processing queue of which you want to change in recording mode on the Hardware tab in the objects tree. 
3. Go to the Advanced settings tab on the settings panel of the Camera object.
4. Set the recording slider in the Priority group to the position:
   1. 1/2 to queue the camera with 1/2 priority for ADC video processing.
   2. 1/3 to queue the camera with 1/3 priority for ADC video processing.
   3. Real time to queue the camera with the Real time priority for ADC video processing in the recording mode.
      
   4. Normal (default), if it is necessary to return the camera into the normal queue for ADC video processing in the recording mode.
5. Click the Apply button.

Setting video recording priority is complete.