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Automatic Preview Image for Mediacast Videos

1 Initial Problem

Mediacasts support preview images for video objects.

However it is cumbersome to set a preview image.

• Either you have to generate it in advance. Then you can upload the preview image explicitly while uploading the video.
• Or you have to edit the video after uploading it. Then you can click on the button "extract preview image".

There is no simple way to extract a preview image automatically and by default.

2 Conceptual Summary

When uploading a video, a preview image will be extracted by default.

The user can override this, if he specifies a custom image.

3 User Interface Modifications

3.1 List of Affected Views

Mediacast > Content > Manage > Add

3.2 User Interface Details

In the dialog for adding new content in mediacasts (see screenshot above), we will introduce a radio group for the "preview image" option as follows:

Preview Image

• (x) Extract from Video
  • Second [1]
• ( ) Upload Custom Image
  • [Select File]
• ( ) None

The user can select, if the preview image is to be extracted automatically (default: extract automatically at second 1). Alternatively the user can select to upload a preview image manually, which is the current behaviour. If the user selects "Upload Custom Image", the file selector field becomes mandatory. If the user doesn't want any preview image to be extracted or uploaded, he can explicitly select the option "None".

3.2.1 Clarification, 12 Nov 2020

Due to the feature https://docu.ilias.de/goto_docu_wiki_wpage_6198_1357.html the creation screens will be simplified. There won't be an "Extract Preview Image" function in the creation screen. ILIAS will automatically extract a picture at second 1. Afterwards the editing screen will be presented and the user can choose a different second or preview file.

3.3 New User Interface Concepts

-

4 Technical Information

No technical issues.

5 Privacy Information

No privacy implications.

6 Security Implications

No security implications.

7 Contact

• Author of the Request: Kiegel, Colin [kiegel]
• Maintainer: Killing, Alexander [alex]
• Implementation of the feature is done by: {The maintainer must add the name of the implementing developer.}

8 Funding

If you are interest in funding this feature, please add your name and institution to this list.

• …

9 Discussion

JourFixe, ILIAS [jourfixe], 30 MAR 2020 : Suggestion is highly appreciate and scheduled for ILIAS 7.

Schmid, Fabian [fschmid], 30 MAR 2020: as mentioned in the JF, this can be deposited as a PreProcessor with the upload service, such as counting PDF pages:
Modules/File/classes/PreProcessors/class.ilCountPDFPagesPreProcessors.php
ans it's usage:
Modules/File/classes/class.ilObjFile.php:283

if ($upload->hasBeenProcessed() !== true) {
  if (PATH_TO_GHOSTSCRIPT !== "") {
    $upload->register(new ilCountPDFPagesPreProcessors());
  }
  $upload->process();
}

Hilbert, Mirco [mirco.hilbert], 24 NOV 2020: Currently, the preview image feature only supports videos which were uploaded directly in ILIAS, not video streams which are referenced by an URL, although FFmpeg supports operating on streams as well. But maybe this will be an other feature request?

10 Implementation

Test Cases

Test cases completed at 12 Nov 2020 by Killing, Alexander [alex]

• 42479 : mp4-Video hochladen

Approval

Approved at 2020-10-28 by Kiegel, Colin [kiegel].