Nudgis media are usually accompanied by slides extracted from the speaker's presentation or lecture. You can learn how to manage them from the player in the article "The Nudgis Dynamic Rich Media Player". But it is possible to go even further using the Edit mode of your content, and completely modify the slides associated with the media.

 

TABLE OF CONTENT

1/ OVERVIEW

2/ SLIDE DETECTION

3/ DELETE, ADD AND EDIT SLIDES

 

OVERVIEW

To access your media slide management, click on the "Edit" button in the top right-hand corner :

Then go to the "Slides" tab, where you can act on all the images extracted from your presentation and associated with your media :

You can navigate through the slides using the numbered bottom bar, or the "Previous/Next Slide" arrows. You can also delete the current image, or all slides.

Deleting an image will remove it from the list of slides in the player's sidebar, but will not delete it from your presentation's video stream.

These navigation and deletion functions can also be accessed via keyboard shortcuts, a list of which can be found in the same tab :

Other immediate information includes the number of slides, the origin of the video if it is a trimming, the position of the slide in the chronological order, and its time code :

It is also possible to modify the presentation of your elements, by choosing "List display". This simplified view does not involve viewing the image in any other way than the preview, but it does make it easier to take in the whole picture when you have got a lot of slides to manage :

As we will see later, the functionalities remain the same in each display mode, with the exception of "Sort slides", which does not exist in the "Slide display" view. This button is used when you change the time code of one or more slides. Activating this function will be necessary for chronological reorganisation to take place on the display once the new time codes have been assigned.

Now that we have got the basics down, we can turn to slide management.

 

SLIDE DETECTION

In the "Slides" tab, you have total control over your elements, starting with the elimination of unwanted images (errors in presentation, false positives leading to duplicates, etc...). Generally, when a media is created on Nudgis, a slide detection task is launched by default. As indicated in the article "How to add media to Nudgis", this option can be deactivated when the video is uploaded, however, most media deposited in Nudgis keep this option active. Thus, you will find a number of slides automatically extracted from your presentation in your Nudgis content.

Automatic slide detection is a process based on the detection of pixel changes on the screen. In addition, if these changes occur too quickly, the system will consider it as a video, and stop capturing slides (to avoid a large number of duplicates). This means that if several slides are chained together quickly in the presentation, they will not be captured. The results of automatic detection will therefore sometimes fall short of your expectations, but you can correct part or all of the slides detected : as we saw in the Overview, you can delete your elements individually or massively, and insert images individually as well. But it is also possible to restart the entire detection task, by clicking on "Launch a slides detection" :

This will open a window giving you full control over the detection settings :

You can choose the detection zone, symbolized by the red frame, in several ways :

• On the fly, by drawing the frame with your mouse
• By adjusting the X and Y position parameters
• By selecting an area from the drop-down menu. You will be able to choose between streams, and the selected one will be automatically cropped.

Further down the page, you can display the player controls, so you can navigate through the video, and check that your selection area applies correctly to the whole presentation.

The video controls display cannot coexist with the detection zone, so you must switch from one to the other for your checks

The final settings for the new detection are :

• Slide detection threshold sensitivity adjustment. Increase this value to reduce the number of slides detected (to avoid false positives due to digital noise in the video, or screen changes to be ignored, such as mouse movements). Reduce this value to detect smaller changes (which will increase the number of slides detected). The value represents the proportion of modified pixels (modified pixels per 1000 pixels) and must be between 0.001 and 100
• Deletion of existing slides, to avoid duplication
• Selection of the language to be used by the OCR (Optical Character Recognition) task in the analysed stream, to extract keywords

Once you have made your settings, click on "Start slides detection task". The task will be launched, and you will be able to follow its progress on the bar that appears at the top of the "Slides" tab :

By clicking on the task's information icon, you can view its precise details, cancel/restart it, or delete it completely :

Once the task has been completed, a pop-up window will let you refresh the page to view the results :

The images resulting from the new detection are then available in the media's "Slides" tab.

You can restart as many detections as you like, but bear in mind that depending on the number of tasks running on the server, the priority of your operation, and the length of the video, the detection may take some time to complete.

Note that the slide detection task can also enable you to automatically chapter your video : by adding the checkerboard icon shown below to one of your slides, the detection system will treat it as a chapter, and mark the item as such in the media timeline and navigation. If several chapters are created in this way, they will be indented in the order of detection.

 

DELETE, ADD AND EDIT SLIDES

Once you are satisfied with the overall detection results, you can refine your selection by adding and deleting individual slides.

To delete a slide, simply select it in the numbered navigation bar, then click on "Delete" :

The number of the slide to be deleted now turns red, as does the "Delete" icon. The latter changes its function to "Restore" the image if needed. You can also delete slides further down the page, by ticking the "Delete after validation" box corresponding to the item to be removed. The selected slides are only effectively deleted from the list once the changes have been saved.

To add a new item, simply click on "Add slide" :

A blank slide will be added :

Here you can choose the position of the image in the media by adjusting the timecode, add keywords corresponding to the new element, and of course choose the slide to insert from your workstation. Once these elements have been completed, save the changes, and the new slide is made available in the player. Note that it will not be visible in the video stream, but only in the slides in the sidebar.

Supported formats : .png, .gif, .jpg, .jpeg, .svg

You can do the same for existing slides, replacing the current image with the one selected on your workstation.

Once you have made your changes, if you have not filled in your keywords manually, you can launch an OCR analysis so that the keywords are searched for in the slides, and automatically filled in. The procedure is pretty much the same as for slide detection :

The more legible the text to be analyzed, the more accurate the results of keyword extraction by character recognition. Be sure to use a well-defined font and a plain background for your presentations

Once you have made all your settings, don't forget to "Save changes" to apply them to the media.

 

We have now covered all the possibilities for managing slides in Nudgis content, and this easy-to-use, adaptive editing feature will make it easier to enrich your videos and simplify your work around the key images in your presentations. Make sure to have a look at the Nudgis section of our Help Center for more articles on editing your media. We hope you will enjoy using our solutions !

To continue : "Subtitles in Nudgis"