Page History: Camcorder Element
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Page Revision: 2015/01/01 20:57
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Camcorder
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| Info |
| Category: |
Monitoring |
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AddIn: |
Base Elements |
| Creator: |
OkazoLab Team |
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Scope: |
Global |
| Owns Snippets: |
no |
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Usage: |
Background |
Element actions aligned with different epochs of the parent event
| Epoch | Actions |
|---|
| Initialized | The element starts capturing video/audio |
| Rendered |
| Activating |
| Activated |
| Running | The captured video is streamed into a file |
| Deactivated |
| Deinitialized | The element stops capturing video/audio |
Properties
Generic Properties
| Name | Description | Constraints | Value Type | Upon Change |
|---|
| Settings |
| Video Device | Defines a video device for capturing. A drop-down selection list shows all devices available in the system. | | String |
| Device Settings | Opens a window with OS settings of the selected video device. | |
| Audio Device | Defines an audio device for capturing. A drop-down selection list shows all devices available in the system. | | String |
| Output Folder | Opens the dialog for selecting a local folder that will hold all recorded videos. If no or relative path is defined, the videos will be saved relative to the location of the experiment file. | |
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| Custom Settings |
| Use Custom Settings | Define whether custom frame size and framerate are used for video capturing. The custom settings are only applied, if the resolution and framerate values are supported by the selected video device. Otherwise, the device's default settings are used. | | Boolean |
| Resolution | Define the resolution of a captured video. The video frames can be scaled to any size in rendering, but choosing a larger resolution improves rendering quality with a cost in performance. | | clSize |
| Frame Rate | Define the custom framerate of video capturing, in frames per second | | Int32 |
| Runtime Status |
| Save Marker Now | Runtime snippet action that that adds a sync text marker into the recorded video. Use the action in the code snippets, e.g. 'SaveMarkerNow=\"Trial Onset\";'. In order to end the marker, save an empty string: 'SaveMarkerNow=\"\";' | | String |
| Actual Settings | Returns the actual resolution and framerate of the current video capture. The property is updated at the start of every experiment run. | | String |
+=== Properties inherited from clElement ===
Inherited properties of clElement
| Name | Description | Constraints | Value Type | Upon Change |
|---|
| Control |
| Is Enabled | If set to false the element is completely omitted when the experiment is run. | | Boolean |
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| Title | Title of the element. | | String |
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Camcorder element allows synchronized video recording using any computer video device, e.g. web-camera, at the background of experiment.
Description
The camcorder element streams a video into a file (one per experiment run) together with custom text markers that can denote experiment events or carry other information. Use Windows Media Player for playback of recorded videos to unsure visibility of the markers.
Practical Use
- Add new Camcorder element to any event in your experiment
- Click on the Camcorder element and select video and audio devices for capturing.
- Select a local folder for storing the captured videos via the 'Output Folder' property of the Camcorder element
- If you want to add custom text markers in a captured video at runtime, add a proxy variable to the 'Save Marker Now' property of the Camcorder element
- Captured video will be streamed in a new file each time as you run your experiment. The file name is composed of the run time and title of the experiment, e.g. "2014-04-11 01_52-camcorder.wmv"
- In order to record a marker into the video file, assign a custom text value to the 'Save Marker Now' proxy at the selected moment in your experiment (see the code example below).
//
SaveMarkerNow="Fixation Event | Trial"+TrialNumber;
Notes
- We recommend to use Windows Media Player for viewing recorded video files because other video players may not be able to show the embedded text markers.