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Getting started

What is Live Compositor?​

LiveCompositor is a media server for real-time, low latency, programmable video and audio mixing.

LiveCompositor targets real-time use cases, with a significant focus on situations where latency is critical. It is a great fit for any video conferencing, live-streaming, or broadcasting solutions where you need to combine or modify video on the fly. However, you can also use it for non-real-time use cases, for example, apply some effect on a video from an MP4 file and write the output to file as MP4.

Where to start?​

To get started check out our Guides section that will walk you through common scenarios.

  • Quick start basic video composing and audio mixing setup.
  • Deliver input streams explains and shows examples of streaming multimedia to the LiveCompositor and use them for mixing/composition.
  • Receive output streams explains and shows examples of receiving streams with results of mixing/composition from the LiveCompositor
  • Basic Layouts describes how to achieve a few of the most basic layouts when composing video.
  • Transitions (View/Rescaler) shows a few basic examples of animated transitions on View/Rescaler components.

The main concept and basic abstractions that the LiveCompositor operates on are described in the Concepts section.

How to use it?​

Live Compositor can be used standalone or as a part of a Membrane Framework multimedia pipeline.

Standalone​

You can use LiveCompositor as a standalone multimedia server. The server can be started by:

Membrane Framework plugin​

Membrane Framework has its own way of handling multimedia, so to fit into that ecosystem some features do not translate one-to-one between standalone compositor and the plugin.

Notable differences:

  • Inputs/outputs in LiveCompositor can include both audio and video at the same time, but with the Membrane plugin you need to create separate inputs/outputs for each media type.
  • No support for MP4 files as input. It is more idiomatic to use Membrane plugins to read MP4 files instead.
  • To connect inputs/outputs to LiveCompositor you need to first register them before sending/receiving the stream, but with the Membrane plugin connecting pads covers both those steps.

Parts of this documentation were written with a standalone scenario in mind, so make sure to always consult the plugin documentation first. For example, to see how to send a scene update check out documentation on HexDocs, but if you want to know what options the View component supports, then consult the documentation here.