kantinfo: a simple infoscreen system

kantinfo.py shows slides in rotation on a screen. It was originally developed for the student-driven canteen at DIKU, but is now also used elsewhere.

See https://github.com/kantinen/infoscreen for the most prominent infoscreen using the kantinfo system.

Content

Supported file types and their corresponding actions:

• .html, .gif: Shown in a browser.
• .jpg, .png: Shown in an image viewer.
• .url: The URL in the file is either opened in a browser, or in a video player, depending on the form of the URL.
• .sh: Is executed.
• .eval: The executable is run, and its output is expected to be either a single line with a file path something.<ext>, which is then displayed according to these rules, or zero lines, which means that nothing is shown.
• .terminal: The program is run in a graphical terminal on the screen.

Configuration of slides

Each slide can have a YAML file configuring it. If a slide is called something.ext, then the corresponding configuration file is located in something.ext.yaml (not something.yaml, since there can be both a something.ext1 and a something.ext2). If no configuration file exists, then defaults are used.

The following fields are supported:

• duration: Specifies how long to display the slide, in seconds. The default value is 20 seconds. If the duration is -1, the system will not terminate the slide automatically, but rather wait for the slide to terminate itself.

• show_when: Specifies when to display the slide. Should contain a Python expression. Can use the variables now of type datetime.datetime, and now_timestamp of type int. Example: This will only show the slide on Tuesdays: show_when: now.isoweekday() == 2

• start_at and end_at (both have to be specified, or neither): Describes when to display the slide, in a 24 hour clock format. Incompatible with show_when (performs a subset of the functionality of that field).

• probability: Specifies the probability that a slide will be shown. Must be in the range 0 to 1. The default value is 1, meaning that the slides is always shown.

• intervals: For video slides only. Specifies segments from the video, one of which will play when the slide is shown. Supports either timestamps or whole seconds.

• start_pos and end_pos: For video slides only. Specifies what part of the video to play when the slide is shown. Supports either timestamps or whole seconds.

Example of a configuration that specifies, that the slide is only shown for 10 seconds:

duration: 10

Example of a configuration that specifies, that the slide is only shown between 13 and 14:

start_at: 13:00
end_at: 14:00

Example of a configuation that specifies segments of a video to play:

intervals: [['0:00' , '0:23'] , ['1:04', '1:30'] , [0, 500]]

Example of a configuation that specifies what part of a video to play:

start_pos: 0:10
end_pos: 1:40

or

start_pos: 41
end_pos: 100

Command interface

You can control a running instance of kantinfo.py, by running kantinfo-order.py, and giving it commands on standard in. kantinfo.py understands the following commands:

• goto_next: Stop the current slide and go to the next one.
• goto <slide>: Stop the current slide and go to <slide>.

Dependencies

kantinfo depends on the following software:

• python3
• pyyaml: YAML library for Python
• surf: Simple browser -- consider using https://github.com/Jobindex/surf for nicer transitions between slides.
• youtube-dl: video fetcher
• feh: Simple image viewer
• lxterminal: Simple graphical terminal

Copying

Copyright © 2014-2019 The Infoscreen Group

This work is free. You can redistribute it and/or modify it under the terms of the Do What The Fuck You Want To Public License, Version 2, as published by Sam Hocevar. See the COPYING file for more details.

The Infoscreen Group

Mostly coded by Troels and Niels.