What you described is a possible use case for EMS Server-Side Playlists. This is a playlist file stored in the media folder of the EMS. It is just a regular text file with an extension of ".lst". It can be played like a normal stream except a playlist file name is used instead of a stream name in the URI. It contains a list of streams and/or media files to be played in sequence. For each entry, 2 playback settings are available: sourceOffset and duration. The first setting determines the starting time for playback, conditional selection of a live stream or a media file, and/or conditional skipping to the next entry in the playlist. The second setting determines the playback duration which could be the number of seconds, the full length of the media, or a single-frame.
Please refer to the EMS User Guide for details:
https://evostream.com/support/documenta … abilities/