On this tab, you can request and watch videos for the past period (playbacks) from the unit cameras and save the required excerpts as files.

Requesting a playback

To request a playback, follow the steps below.

1. In the Action section, select the Request and view playback option.
2. Enter or select the name of the unit from which you want to request the playback. The list shows units for which cameras are configured. If the device type does not support the function of watching playbacks, the unit is not available for selection and the icon   is displayed next to its name. The units that are offline are not available for selection either and are marked with the icon . 
3. Select one or more cameras from which you want to receive the playback. Use the Select all option to select or cancel the selection of all cameras at the same time.
4. Specify the period for which you want to request the playback. You can select the period in the calendar or enter it in the field manually. When specifying the period, consider the following:
   
   • The duration of the period cannot go beyond 24 hours.
   • You can specify a present or a past date. By default, the 24-hour period of the previous date is selected.
   • The end time should not be earlier than the start time.
   • If a present date is specified, and the end time has not come yet, the playback is requested up to now.
5. Click Request.

When switching from the Video tab to another one before the playback is loaded, the system notifies you by means of a pop-up message as soon as it is loaded.

Watching a playback

The requested playback is displayed in the right part of the window. To watch it, click on the play icon or move the slider on the timeline. 

The timeline can consist of white and grey segments. A white segment means that there is no data for this period, and a grey one means that the playback is available at least for one of the selected cameras.

When watching playbacks, the following functions are available:

Saving a playback to files

You can save the required playback excerpt as a file which is later available on the Files tab, in messages, and in reports. There are two ways to do this:

1. Using the icon  in the mode of watching the playback;
2. Using the Save requested file to Files option in the Action section.

To save a playback excerpt in the first way, request a playback using the instructions above and follow these steps:

1. Move the slider to the required place on the timeline.
   
2. Click on the icon .
3. In the left part of the window, specify the duration before and after the event in seconds. The minimum allowed value is 1, and the maximum value is 30. The duration of the file you want to save is equal to the sum of the specified values and is displayed above the timeline as a red segment. 
   
   
4. If necessary, clear the selection of the cameras that shouldn't be included in the file. If a camera doesn't have any data for the whole interval you want to save, its name becomes grey and this camera is not included in the file.
5. In the drop-down list, select the tag corresponding to the event from the excerpt. The default tag is None.
6. Click on the Save to files button. The button is inactive if there is no data from any camera for all the interval you want to save.
7. If you want to save one or several excerpts of the same playback, move the slider and repeat steps 3 – 5. To exit the file saving mode, click on the cross.

To save a playback excerpt in the second way, follow these steps:

1. Select the Save requested file to Files in the Action section.

2. Enter or select the name of the unit for which you want to save a playback excerpt. The list shows units for which cameras are configured. If the device type does not support the function of saving video files, the unit is not available for selection and the icon   is displayed next to its name. The units that are offline are not available for selection either and are marked with the icon . 
3. Select one or more cameras from which you want to save the video file. Use the Select all option to select or cancel the selection of all cameras at the same time.
4. In the Event time field, enter the date and time of the event from the excerpt you want to save. You can do this manually or using the calendar. The event time is accurate to seconds.

5. Specify the duration before and after the event in seconds. The minimum allowed value is 1, and the maximum value is 30. The duration of the file you want to save is equal to the sum of the specified values.

6. Click Request.

The requested excerpt is saved only if the playback for the specified period is available on at least one of the selected cameras.

If the excerpt you are saving contains intervals with no data from all the cameras, the number and duration of the saved files is equal to the number and duration of intervals with available data.

In addition to the manual saving, you can configure the automatic saving of files in Wialon. To do this, create a notification with the Save a video as a file action.