Video compositing with Natron

Although traditional video editing programs allow you to trim footage and arrange everything into a pleasing whole, compositing applications such as Natron can help you create effects in postproduction on clips. Multiple effects can easily be connected and selected in a series through the user interface.

With a compositing application, using green-screen or news casting effects is little more than a few clicks away.

Considerable Control

Development of the free and open source Natron program began in mid-2013 at the French institute for scientific research (INRIA), which provided the necessary start-up funding [2]. In December, the project director, Alexandre Gauthier, won the INRIA "Boost Your Code" competition, which allowed him to work on Natron full time for 12 months.

Since June 2014, the development team has periodically released beta versions, which offer an amazing range of functions and by and large ran stably during tests (see the "Crash Risk" box). At the time of writing, the most current version was 1.0.0 – Release Candidate 2, which is the foundation for the fully stable version.

Natron is not intended for amateur filmmakers who want to quickly produce showy results. This fact is made clear through its unusual interface, which is heavily modeled after the professional program Nuke [3]. Instead of having a timeline, the videos and effects are presented in small boxes that the user interconnects. This concept takes some getting used to but makes building more difficult scenes easier than using conventional video editing programs.

Like the Pros

Because of Natron's desire to appeal professional filmmakers, the application implements a wide variety of features. Natron stores colors internally as 32-bit floating-point numbers, which enables precise color correction and color manipulation. Color management is handled by the OpenColorIO library.

OpenImageIO and FFmpeg import image and video files in various formats. Natron also is equipped with multiple effects. Besides the obligatory color correction and green-screen effects, a simple rotoscoping tool [4] is also included. Further video effects can be incorporated via the plugin interface OpenFX. Natron supports not only open source but also commercial OpenFX plugins, such as Furnace from The Foundry [5].

Users can see the result of changed settings without delay in the preview. This feature is made possible through particularly efficient processing carried out under the hood in which the program uses all of the available processor cores. At the same time,

Natron requires very few hardware resources: According to the developer, not more than 3GB of memory is required and the graphics card only needs to be supported by Standard OpenGL 1.5 with some extensions (i.e., GL_ARB_texture_non_power_of_two , GL_ARB_shader_objects , GL_ARB_vertex_buffer_object , and GL_ARB_pixel_buffer_object ).

Commercial programs in contrast are much more resource hungry. The rendering of produced scenes can also be run through a command-line program, which can be launched on a dedicated server or server farm.