20 Nov 2017

[Blog] Scheduled Playout

Hello everyone, Erik here with a quick post about a new feature we're currently working on: simulating a live stream based on one or multiple VoD assets scheduled to play out continuously.

This 'simulated live' type of stream is usable in various scenarios, ranging from a small broadcaster or hobby user who wants to set up a continuous stream consisting of a limited amount of pre-recorded footage, to a large station wanting to maintain full control of what programs to broadcast at which time.

We decided that this would be a nice feature to include in our software, and after our — nearly finished — 2.13 release, we will be working at full speed to incorporate our new style of internal metadata storage in memory, giving way to allowing multiple inputs to contribute to a single stream. This feature will not only allow the development of our scheduled playout system, but will also create the possibilities from merging multiple separate source files into a single multi-bitrate stream, or having multiple different versions of encryption active at the same time.

Playlist creation

The first scenario we will support is single file playout loopback. This will allow for a single file to be looped continuously, while for the viewers it will look like a single live stream. Though not useful for many cases, it will provide an easy setup if you don't change your programming, keeping the stream active at all times.

With some more advanced configuration, we will be supporting m3u files. This file format is what most people know from the HLS format, while at the same time providing a straightforward way to handle a simple list of filenames without providing extra information. Any extended headers available in the file will be ignored, and both .m3u and .m3u8 extensions will be supported.

Using this playlist setup will not only allow you to schedule multiple files in a loop, it will also allow you to edit the playlist while it is running. For every entry in the playlist, after playing out the entry, the playlist will be reloaded before determining what the next file in the playlist is. This allows you to amend your playlist as it runs, replacing one program with another, or even continuously updating your playlist file so it will never loop, but acting as an actual live broadcast channel.

That's it for this small update, if you have any requests or questions about this upcoming feature, please let us know.

Our next post will be by Jaron, with an explanation about how MistServer works internally.