Development [LWN.net]

Cinelerra 4 arrives

By Forrest Cook
September 3, 2008

Cinelerra is a compositing video and audio editor that is being developed by Heroine Virtual LTD's Adam Williams when he isn't playing with autonomous miniature helicopters. Cinelerra is derived from the now-discontinued Broadcast 2000 project. The project is described:

Unleash the 50,000 watt flamethrower of content creation in your UNIX box. Cinelerra does primarily 3 things: capturing, compositing, and editing audio and video with sample level accuracy. It's a movie studio in a box. If you want the same kind of editing suite that the big boys use, on an efficient UNIX operating system, it's time for Cinelerra. Cinelerra is not community approved and there is no support from the developer. Donations to community websites do not fund Cinelerra development.

The Wikipedia entry for Cinelerra summarizes the project's window set:

The user is presented with four screens: 1. The timeline, which gives the user a time-based view of all video and audio tracks in the project, as well as keyframe data for e.g. camera movement, effects, or opacity; 2. the viewer, which gives the user a method of "scrubbing" through footage; 3. the resource window, which presents the user with a view of all audio and video resources in the project, as well as available audio and video effects and transitions; and 4. the compositor, which presents the user with a view of the final project as it would look when rendered. The compositor is interactive in that it allows the user to adjust the positions of video objects; it also updates in response to user input.

The main Cinelerra page lists the software's many features. Version 4.0 of Cinelerra was released on August 8, 2008, the change log details the most recent feature additions. Older project history is available in the news document. One big change for this release is the availability of pre-compiled binaries for 32 and 64 bit versions of Ubuntu 8.04. This can be a real time saver due to the complexity of the build process, and will give access to a wider variety of users.

Cinelerra works best with specific hardware configurations. An NVidia graphic card is recommended: "Cinelerra supports OpenGL shaders on NVidia graphics cards. The video crunching power that was once exclusively the domain of SGI minicomputers is now yours. NVidia users can run many effects in realtime instead of rendering them. OpenGL also opens up new video resolutions, up to 4096x4096 on high end cards." And a 64 bit Linux platform is a good idea: "Since it's Linux, it's been 64 bit compliant for years. In fact, Cinelerra is only recommended for 64 bit mode. The reason is the large amount of virtual memory required for page flipping and floating point images often exceeds the limit of 32 bits. "

Your author has used Cinelerra in the past for audio editing, see this article for details. Cinelerra has one capability that is hard to find in other Linux audio editing software, the ability to split (render) a huge .wav file into a group of smaller .wav files across multiple position labels, all in one operation. This feature is useful for processing long audio recordings such as digitized vinyl album sides and copies of digital audio (DAT) tapes. This was the first operation that Cinelerra 4 was tried on. After some initial crashing difficulties, a startup warning message about an insufficient shmmax value was heeded. Changing shmmax is simply a matter of running echo 0x7fffffff > /proc/sys/kernel/shmmax as root before starting Cinelerra. After doing that, your author was unable to make the software crash while processing audio.

Lacking a high resolution video camera, your author was able to use his Nikon Coolpix S10 VR digital camera to produce low resolution .mov format movies with mono audio tracks. Cinelerra was able to display videos from this camera, specifically movies of thunderstorms. Individual frames containing lightning strikes were located by single stepping through interesting sections of the movie, the still frames were grabbed from the screen using an external application (xv). The single-step capability allowed the life cycle of a lightning bolt to be observed. This is a much less expensive way to procure photographs of lightning compared to using lots of 35mm film and specialized hardware.

Attempts to do actual video editing were somewhat less successful than simple playback. Creating a fade-in at the beginning of a short video clip worked, but several attempts to add a second video track crashed Cinelerra, as did saving a modified track. This may be related to the camera's data, which has confused other video players (mplayer) in the past or the lack of a professional quality video device. The computer was running a (not recommended) 32-bit version of Ubuntu and an older Radeon video card. As with high-end audio processing, it is probably best to put together a system with the specific hardware and operating system that is recommended for the application.

While Cinelerra is more of a professional video tool than a generic desktop application, it nonetheless has some very useful capabilities outside of its primary application space. It is the most full-featured video playback application that your author has experimented with, and it functions nicely as an audio processing tool.

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