Server Side Clipping and Trimming

by Roni Cohen

Kaltura server now supports the new abilities to clip or trim an entry. The trimming or clipping is done physically on the file system using conversion engines such as FFMPEG.

Clipping vs Trimming:

  1. Clipping- Create a new entry from an existing entry. Allows you to specify the start and end time for the new entry – the clip, this can be used to create a 2 minutes intro video to a long lecture or to take parts from one, such as homework assignments. You can also clip a long lecture to several shorter clips divided by subjects. The new entry will point to it’s source entry which it was clipped from, so you can always know what was the source entry for the clip – this can be found on the KaltruraBaseEntry->rootEntryId property.

    You can find all the clips that were created from a given entry, for example entry ID ‘0_ad523s’, by this simple API call:

    In order to chain several clips from a single video, create a dynamic playlist with this filter:

  2. Trimming – No new entry is created. Sometimes, you may want to trim the start and/or end of a video, removing redundant parts. Trimming is performed on the source flavor of the entry, modifying that video permanently.

 

In order to trim an entry using Kaltura’s API just follow these steps:
*written in PHP and uses our PHP client library.

*Code was taken from our new clipping application

So trim away!

  • Pingback: It’s Time For Time Based Data – Part 1 | Kaltura Community Blog

  • http://www.automaticsync.com Art Morgan

    When you clip or trim, will caption assets associated with the entry be copied/updated accordingly?

  • http://ran.yefet.net Ran Yefet

    No. Clipping/Trimming does not affect related caption assets.

  • http://www.automaticsync.com Art Morgan

    Ok. That would be a nice feature for Falcon :-) In the meantime it will be a lot of manual work for people to re-create captions for edited videos if they’ve already captioned. At least putting in APIs for clipping/trimming caption assets would allow developers to build in changes to caption assets that correspond to the clip or trim actions.

    Also, in the KMC you could give people a warning if they try to edit a video that is already captioned. A lot of education users of Kaltura are very serious about captioning, and they also like the clip features but if clips don’t bring the captions they won’t be able to use it.