You can specify the gstreamer pipeline used to play the particular media by either passing it on the command line to gstreamer-backend with the -p option or by passing it to the actions. The pipeline can be passed in as:

“pipeline:[your pipeline]”

This pipeline can be similar to the one used with the gst-launch application with a few minor modifications. In order to allow the changing of the media file the first part of the pipeline must contain a named filesrc element as follows:

“pipeline:filesrc location=video.mov name=media-src”

Doing this will allow the code to find the named element and replace the location with a new video file.