Knowledge Base

Procedure for Domain

1. Press the Windows key + R.
2. Type lusrmgr.msc and press OK.
3. Open the Users folder and double-click Guest.
4. Deselect Account is disabled and click OK and close the lusrmgr window.
5. Press the Windows key + R.
6. Type gpedit.msc and press OK.
7. Open Computer Configuration\Windows Settings\Security Settings\Local Policies\User Rights Assignment and double-click Deny access to this computer from the network.
8. Click Guest and then choose Remove > OK.
9. Close the Local Group Policy Editor window.

Map the Shared Folder with MediaRecorder Video Files

Carry out this procedure on both computers.

1. Open File Explorer and then This PC.
2. Click Computer and then click the Map network drive icon.
3. Choose a name for the drive and browse to the shared folder.

   Important: Make sure you select the same drive on both computers.

4. Click Finish.

Note: When you now start the computer with The Observer XT, you need to enter the login details for the computer with MediaRecorder.

MediaRecorder with The Observer XT

Install N-Linx Agent

Aim: To install and set up the tool that starts MediaRecorder when you start an observation in The Observer XT.

Important: Install N-Linx Agent on the computer with MediaRecorder.

Prerequisite: You installed N-Linx Server on a computer in the network.

Procedure

1. From my.noldus.com, download N-Linx Agent Setup.exe.
2. In the N-Linx Agent Setup window, select MediaRecorder control in the Drivers and Tools field and click Next.
3. Accept the terms in the End-User License Agreement and click Install.

Connect N-Linx Agent to N-Linx Server

1. Click the arrow in the bottom-right corner of your window to open the system tray. Then double-click the N-Linx Agent icon.
2. In the N-Linx Server Address field, enter the computer name of the computer with N-Linx Server. See To find the computer name.

   You can also enter the IP address, but then the IP address of the computer with N-Linx Server must be fixed. Ask your system administrator for assistance.

   If MediaRecorder runs on the same computer as N-Linx Server, leave the entry localhost in the N-Linx address field. N-Linx Agent then automatically connects with N-Linx Server.

   Note: See To change the port if the default port 5672 is already in use.

3. If the connection with N-Linx Server is established, the text Connected appears in the lower-left corner of the N-Linx Agent window.

To Find the Computer Name

To find the name of the computer with N-Linx Server, open the Control Panel on that computer and choose System.

To Change the Port

N-Linx Agent by default uses port 5672 to communicate with N-Linx Server. If this port is in use, type the new port after a colon in the N-Linx Server Address field.

Important: Select the same port in all components that communicate with N-Linx Server. Also, disable Windows Firewall for this port.

Notes:

• N-Linx Agent is installed in the folder C:\Program Files\Noldus\N-Linx Agent 1.
• If you did not install N-Linx Server yet, it will not be possible to establish a connection.
• The Status of MediaRecorder in the N-Linx Agent window is Online when MediaRecorder is open and connected to N-Linx Server.

Create MediaRecorder Settings

Aim: To connect MediaRecorder to N-Linx Server and select the video file folder.

Prerequisites:

• If MediaRecorder, The Observer XT, and N-Linx Server are not all installed on the same computer, you created exceptions for the N-Linx port in Windows Firewall. See Create exceptions for N-Linx port in Windows Firewall.
• You installed N-Linx Server on a computer in the network.
• N-Linx Agent is installed on the computer with MediaRecorder and connected to N-Linx Server. See Install N-Linx Agent.

Procedure

1. In MediaRecorder, choose File > Preferences > N-Linx settings.
2. Select Allow communication with N-Linx Server.
3. In the N-Linx Server address field, leave the default value Localhost if MediaRecorder runs on the same computer as N-Linx Server. If the programs run on different computers, enter the name of the computer with N-Linx Server. See also To find the computer name.
4. In the N-Linx Server port field, leave the default port 5672. Ask your system administrator for assistance if this port is used by another program.
5. When the connection with N-Linx Server is established the Status will be Connected. Click OK.
6. If MediaRecorder and The Observer XT run on different computers, select the mapped drive as location to store the video files and not the original folder. The original folder is locally on the computer with MediaRecorder and cannot be accessed by The Observer XT.

   Example: You mapped the default folder C:\Users\Public Documents\Noldus\MediaRecorder\Video files as X:\. Set the default video file location where MediaRecorder stores its video files to X:\ and not to the original folder.

Create The Observer XT Settings

Aim: To enable communication between The Observer XT and N-Linx Server.

Prerequisites:

• You installed N-Linx Server on a computer in the network.
• If MediaRecorder and The Observer XT, or N-Linx Server run on different computers, you created exceptions for the port that N-Linx uses in Windows Firewall. See Create exceptions for N-Linx port in Windows Firewall.
• N-Linx Agent is installed on the computer with MediaRecorder and connected to N-Linx Server. See Install N-Linx Agent.
• MediaRecorder is open.

Procedure

1. In The Observer XT, choose File > Preferences > N-Linx Settings.
2. Select Use N-Linx server to connect with other applications.
3. In the N-Linx Server address field, enter the computer name of the computer with N-Linx Server. If The Observer XT is installed on the same computer as N-Linx Server, leave the default entry Localhost.
4. In the N-Linx Server port field, leave the default port 5672. Ask your system administrator for assistance if this port is used by another program.
5. Click Test connection. If a connection with N-Linx Server is found, the Status will change to Connected.
6. Click OK.
7. Choose Setup > Project Setup.
8. Under Observation source, select Live Observation. The Devices window now opens. If not, click the Devices button.
9. Select MediaRecorder [Version number][Computer name] and click Edit Settings. MediaRecorder now opens if it is not already open.
10. Click Edit Settings again. A window with the available configurations now opens. Select the configuration file you want to use and click OK. If you do not select a configuration, Current Settings.mrs will be used. Optionally enter a unique name in the Identify device as field. This way you can control multiple instances of MediaRecorder with one instance of The Observer XT.
11. Repeat steps 9 and 10 for each MediaRecorder instance.

Note: When you close MediaRecorder, the MediaRecorder line in the Devices window (step 9) will be grayed out and the status will change to Disabled. MediaRecorder will start when you create an observation.

Carry Out an Observation in The Observer XT

Procedure

1. In The Observer XT, choose Observe > Observation > New to create an observation.
2. See Carry out your observation in The Observer XT Help.
3. Press the Start observation button and score the data. See Start the observation and Score data in The Observer XT Help.
4. Press the Stop observation button. See Stop the observation in The Observer XT Help.

Important: Allow enough time between the actions. If you start an observation before MediaRecorder is completely open, video recording will not start.

Troubleshooting: MediaRecorder Control with The Observer XT

When MediaRecorder control with The Observer XT does not function properly, check the following:

• On the computer with MediaRecorder, check that N-Linx Agent is running. See step 1 in Connect N-Linx Agent to N-Linx Server. If there is no N-Linx Agent icon in the system tray, the program is not running. Then double-click the file NLinxAgent.exe in the folder C:\Program Files\Noldus\N-Linx Agent 1.
• On the computer with MediaRecorder, check that the status of N-Linx Agent is Connected. If not, follow steps 2 and 3 in Connect N-Linx Agent to N-Linx Server.
• In MediaRecorder, check that the checkbox Allow communication with N-Linx Server is selected (see step 2 in Create MediaRecorder Settings).
• In The Observer XT, check that Use N-Linx server to connect with other applications is selected (see step 2 in Create The Observer XT settings) and that the Status in the window is Connected (see step 5 in Create The Observer XT settings).
• In The Observer XT, check that MediaRecorder is selected (see step 9 in Create The Observer XT settings).
• On all computers with MediaRecorder, The Observer XT, and N-Linx Server, check that an exception is made in Windows Firewall for all inbound and outbound traffic through port 5672 (see Create exceptions for N-Linx port in Windows Firewall).
• Check that N-Linx Server is running. To do so, press Ctrl + Shift + Esc and open the Services tab. Locate the line RabbitMQ and check that the Status is Running. If not, right-click the line and select Start.

Synchronize Videos with Events

Aim: To synchronize the MediaRecorder videos with the event log of The Observer XT.

When is Manual Synchronization Not Needed?

Videos created by MediaRecorder are automatically synchronized with the events in The Observer XT when you followed the procedure in MediaRecorder with The Observer XT. An automatic offset is applied to the videos. See View the automatic offset of videos imported into The Observer XT to see which offset was applied.

When is Manual Synchronization Needed?

You need to synchronize videos and events manually in the following situations:

• You start video recording manually and import the videos into The Observer XT.
• You have an older version of The Observer XT that does not support N-Linx data transfer.

See Synchronize manually for the procedure.

View the Automatic Offset of Videos Imported into The Observer XT

The procedure depends on what you did:

• You controlled video recording with The Observer XT.
• You manually started video recording within 10 seconds after starting the observation in The Observer XT.

You Controlled Video Recording with The Observer XT

Right-click the video in The Observer XT and choose Properties. The field Recording details shows the offset.

You Manually Started Video Recording Within 10 Seconds After Starting the Observation in The Observer XT

When you import the videos into The Observer XT, an offset is automatically set. A message with the calculated offset is shown. If you right-click the video in The Observer XT, the offset is also shown next to Recording details in the Video Properties window that opens.

However, there can still be up to 1 second asynchronism between the observation and the video files. If that is a problem for the accuracy of your experiments, Synchronize manually to fine-tune the synchronization.

Synchronize Manually

Aim: To synchronize imported MediaRecorder videos with events in The Observer XT.

Prerequisites: One of the following situations is true:

• You have The Observer XT 11 or lower.
• You have The Observer XT 12.5 or lower and The Observer XT and MediaRecorder run on different computers.
• You manually started video recording more than 10 seconds after starting an observation in The Observer XT and imported those videos manually into The Observer XT.

You must carry out the following steps:

1. Determine the time difference between video and events.
2. Apply offset to correct for the time difference.

Determine the Time Difference Between Video and Events

1. Make sure an event is recognizable in the videos and the event log. For example, create a dummy behavior with a key code in the coding scheme.
2. Carry out an observation and simultaneously record a video or the keyboard.
3. In The Observer XT, press the key of the dummy behavior. The event is recorded in the Event log and is visible in the video.
4. Import the video into The Observer XT.
5. Open the observation and scroll to the recognizable event in the video. Note the time difference of the event in the video and the event log.

Apply Offset to Correct for the Time Difference

1. In The Observer XT, open the observation and click the Offset button on the toolbar.
2. Select Numerical Offset to open the File Synchronization window.
3. Set the time difference in the Offset cell. For example, if the video started 0.2 seconds before the observation, enter 0.20 seconds in the Offset field of the video.

Note: You can also use the SyncBox to assess the delay. See the Technical Note - The SyncBox - The Observer XT for more information.

MediaRecorder with EthoVision XT

How to Record Videos for EthoVision XT

You can create videos for use in EthoVision XT in two ways:

• First create videos in MediaRecorder and then track from video file in EthoVision XT.
• Control video recording by MediaRecorder with EthoVision XT when you track live.

In both cases, if you work with analog cameras, you must adjust the aspect ratio in EthoVision XT. If you work with digital cameras, this is not necessary. See Adjust the video aspect ratio (analog cameras only).

Prevent Black Frames at the Start of Your Videos

To make sure that MediaRecorder waits for an I-frame before it starts recording you can edit the VsSettings file that comes with MediaRecorder. If you do not edit this file, your video may start with black frames and EthoVision will not be able to track the video from the start.

The VsSettings file is installed together with MediaRecorder. You can find the file in C:\ProgramData\Noldus\MediaRecorder\6.

By default the ProgramData folder is a hidden folder. In Windows Explorer on the View tab select Hidden items in the Show/hide section to view the folder.

1. Right-click VsSettings.xml and select Copy. Right-click and select Paste to make a copy of the file. Keep this copy in case you want to go back to the original settings.
2. Open the VsSettings.xml file in Notepad or a similar text editor.
3. From the Edit menu select Find and type Wait in the search field.
4. To make sure that MediaRecorder waits for an I-frame before it starts recording, edit the file and change 0 to 1.
5. Save the file.

First Create Videos in MediaRecorder and Then Track from Video File in EthoVision XT

Aim: To create videos that can be used for tracking in EthoVision XT.

Prerequisite: You have cameras that are supported for tracking in EthoVision XT.

Procedure

1. Create videos in MediaRecorder.
2. In EthoVision XT, select Track from video file and select the video. See the EthoVision XT Help for details.

Notes:

• Important: In theory you can create video files from many different digital cameras with MediaRecorder. However, the quality of the digital camera is essential for accurate tracking. If you use other hardware or cameras than the supported ones, you need to check whether the time information in the video files is correct. See Test an unsupported setup in Specifications.
• When you use analog cameras, you must adjust the aspect ratio. For digital cameras that are not supported this may also be necessary. See Adjust the video aspect ratio (analog cameras only).
• Choose EthoVision as the Output Quality if you record from four cameras simultaneously. With the default settings two cameras are recorded on CPU and two on the video card (GPU). This results in differences in file size. By selecting EthoVision as the output quality, all four cameras will be recorded using CPU power. For more information see Output settings.
• Choose DanioVision as the Output Quality if you film DanioVision larvae. With this setting the compression of the video files is optimized for DanioVision tracking.

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Source: Media Recorder 6.5 Reference Manual