https://github.com/mwunsch/overscan

A live coding environment for live streaming video
https://github.com/mwunsch/overscan

broadcasting gobject-introspection gstreamer racket

Last synced: 2 months ago
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A live coding environment for live streaming video

• Host: GitHub
• URL: https://github.com/mwunsch/overscan
• Owner: mwunsch
• License: lgpl-3.0
• Created: 2017-02-13T21:08:42.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2018-09-21T19:19:49.000Z (about 6 years ago)
• Last Synced: 2024-06-18T20:10:12.932Z (4 months ago)
• Topics: broadcasting, gobject-introspection, gstreamer, racket
• Language: Racket
• Homepage: https://www.overscan.tv/
• Size: 28.8 MB
• Stars: 35
• Watchers: 3
• Forks: 2
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-racket-and-scheme - overscan

README

        
# Overscan

A study in live video broadcasting with

the [Racket](http://racket-lang.org) programming language.

The goal of this project is to learn Racket and to better understand

the problems involved in:

+ The Real-Time Messaging Protocol

  ([RTMP](https://en.wikipedia.org/wiki/Real-Time_Messaging_Protocol))

  and constructing and streaming unbounded audio and video feeds.

+ The [Twitch](https://dev.twitch.tv)

  and

  [Facebook Live](https://developers.facebook.com/docs/videos/live-video) API's,

  for authentication, broadcasting live video streams, and gathering

  audience data.

+ Video compositing in software.

Originally, the end-goal was to build a toolkit like that found

in [StreamPro](https://streampro.io)

or [Streamlabs](https://streamlabs.com) (née _TwitchAlerts_) but using

a Racket DSL for on-the-fly compositing and graphics.

Now, this project's ambition is to provide a comprehensive live-coding

environment for video compositing and broadcasting. This project is

inspired by other live-coding environments

like

[Impromptu](http://impromptu.moso.com.au)/[Extempore](https://github.com/digego/extempore) and

[Overtone](http://overtone.github.io).

It is split into three parts:

1. The `ffi/unsafe/introspection` module. This module provides dynamic

   Racket bindings to [GObject Introspection][gobject-introspection],

   allowing interaction with C GObject libraries using common Racket

   idioms (i.e. providing [`racket/class`][racket/class] forms such as

   `send` and `get-field` for GObjects).

2. The `gstreamer` collection. Using the aforementioned Introspection

   module, this collection provides Racket bindings for

   [GStreamer](https://gstreamer.freedesktop.org), the open source

   multimedia framework.

3. The `overscan` collection and language. This provides a DSL for

   building a GStreamer pipeline for capturing common video sources

   (cameras and screens), compositing multiple sources, including

   generated graphics, and then encoding them and pushing them along

   to an RTMP server (like Twitch). All of this is designed to happen

   within a Racket REPL session, allowing the broadcaster full control

   over the stream by evaluating S-expressions. That's the idea, at

   least.

You can follow the development along

at . Read archives of previous weekly

devlogs at .

[gobject-introspection]: https://wiki.gnome.org/Projects/GObjectIntrospection

[racket/class]: https://docs.racket-lang.org/reference/mzlib_class.html

## Installation

Overscan has been tested on macOS Sierra with Racket v6.12 and

GStreamer v1.14.0. With a working Racket installation you can install

with `raco`:

    raco pkg install overscan

For Overscan to do anything meaningful, you also need to install

GStreamer and necessary plugins. Using homebrew:

    brew install gstreamer

This will install `gstreamer` along with dependencies `glib` and

`gobject-introspection`, all of which are required.

You also need to install GStreamer plugins:

    brew install gst-plugins-base --with-pango

    brew install gst-plugins-good

    brew install gst-plugins-bad --with-rtmpdump --with-fdk-aac

    brew install gst-plugins-ugly --with-x264

Copyright © 2017 - 2018 Mark Wunsch

This package is distributed under the GNU Lesser General Public

License (LGPL).  This means that you can link overscan into proprietary

applications, provided you follow the rules stated in the LGPL.  You

can also modify this package; if you distribute a modified version,

you must distribute it under the terms of the LGPL, which in

particular means that you must release the source code for the

modified software.  See http://www.gnu.org/copyleft/lesser.html

for more information.