The Current State of Linux Video Production Software and its Developer Community Richard Spindler Schönau 75 6323, Bad Häring, Austria [email protected] Abstract At the time it was started, there were two potential applications available that could have According to Linux and Open Source/Free been used instead of starting a new project. Those Software thought leaders, the current situation in 1 2 Linux video editing and production software still two options were Cinelerra and Kino which were leaves a lot to be desired. Here we give an accurate already quite mature and widely used at that time. overview of the software that is already being However for the needs of the author, Kino was too developed for Linux video editing, or that is simple to support the kind of workflow that he currently being worked on. We will introduce the anticipated, and Cinelerra was too complex to developers or/and the development communities teach quickly to his collaborators. They were not that are behind these projects, and how the only choices, as new editing applications collaboration between projects works. We will emerged, likely because other Free Software mention interesting events and places where Linux enthusiasts were finding themselves in a similar video developers meet, and what groups might be dilemma. Those however, were also very much at interested in our work, or ought to be involved into a starting point of development, and far from being specific aspects of our work. We will outline mature enough for general use. where projects are still lacking to support specific use cases, and why they matter. Furthermore, we Over those years, the situation improved quite will discuss open problems, as well as rapidly, with different projects and communities opportunities for participation and collaboration, working on applications to fill a wide variety of and I will make some predictions about the future, user preferences. Also with the continued progress, based on the work that was already done, and that the awareness in the broader Free Software is currently being tackled. community for the need of user friendly video editing software was rising tremendously, giving Keywords those projects and communities the exposure they Linux, Video, Community, Developers. need to flourish. For example the lead of the Ubuntu Linux distribution Mark Shuttleworth 1 Introduction mentioned the lack of Linux video tools, and it is also an entry in the Free Software Foundations The author of this paper has been working on a Priority List3. Linux/Open Source/Free Software video editing application called ªOpen Movie Editorº for the last Actually for video processing software in Linux few years. Originally the project was started, and Open Source there are quite active and very because the author felt that the software available successful projects, but those are mainly concerned for working creatively with video under Linux was with encoding, processing and playback issues, lacking some aspects that he considered important and the authoring and creative work associated for his work, and the kind of work that he wanted to support. 1http://heroinewarrior.com/cinelerra.php 2http://www.kinodv.org/ 3http://www.fsf.org/campaigns/priority.html with non-linear video editing is far beyond their advent of the MPlayer7 project, and its associated agendas. However, the availability of software communities, and also animation where Blender is libraries, like ffmpeg4, gstreamer5, libquicktime6 likely the most widely known example. But there and many many more are a great and vital starting are also forays into territory that is more exotic, point, for creating a non-linear video editing citing FreeFrame8 as an example for an Open application, and all of the available efforts are Source video effect plugin standard, that is based on those projects, and ultimately those enjoying great enthusiasm and adoption in the foundational libraries enable the high-level VJing community. There is EffectTV, which projects to make the great progress that they are provides wacky realtime video effects that cover a doing. wide range of creative applications, and there are modular approaches that aim to provide a standard And very much like the diversity of the infrastructure and a platform for the development available support libraries, the active projects that of video based applications as well as a possibility are pushing the agenda of bringing video editing to to easily add video to any kind of application that the Linux using masses, are quite diverse. The could make good use of it. projects, while similar in their goals, are using quite different means to achieve their objectives. The author has been following most of those While this may appear as unnecessary foundational projects and their communities as fragmentation of efforts, for which projects are close as he could afford, because he is convinced occasionally criticized in public forums, it is that code reuse will be the key to getting Linux necessary and positive. This of course is a personal video editing to artists and users as fast as opinion of the author, which is very much based possible. on his experiences working on a video editor over One of the key projects in the area of the last few years. Writing a video editor is not that foundational libraries became ffmpeg over the last difficult, and the low communication overhead that years. Currently it is likely one of the most a very small team or individual developer has, can valuable toolboxes for the aspiring video achieve much higher efficiency and development developer. The project aims to develop the most speed. Especially for young projects, where the complete set of video compression decoders and roles of team members and developers are still encoders, and promotes being self contained to unclear and the optimal division of labor is not yet achieve the most efficient means of internal code worked out. reuse. While there always were specific However, even when working on projects that development libraries that focused on a specific appear to be competing, it can be quite beneficial encoding or decoding technology, or a family of to share knowledge and experiences between codecs, during the development of ffmpeg it project members, and this is what the author occurred, that many video codecs that appear to started to work on in the last year, and this is also use different technologies are actually quite similar what he is planning to continue and intensify in the internally, and source code and routines for basic future. operations and inner loops could be reused over a wide range of codecs. And this fact remaned pretty 2 Foundations much a mantra for the development of ffmpeg. In the Open Source and Free Software Even if a user is not aware that he is using community, there has always been quite a vivid ffmpeg, it is likely that if he has any kind of video interest in a lot of problems that are closely related related Open Source software installed, it is based to issues that are also relevant in video editing. on ffmpeg. Video players, media frameworks, Starting with the Gimp, and ImageMagick for tools and applications, there is simple nothing that image processing, and video compression can do without. Even the more high-level technology that became widely interesting with the frameworks for creating video applications, like Gstreamer, Gmerlin and MLT wrap ffmpeg. 4http://ffmpeg.mplayerhq.hu/ 5http://www.gstreamer.net/ 7http://www.mplayerhq.hu/ 6http://libquicktime.sourceforge.net/ 8http://freeframe.sourceforge.net/ The selection of a high-level video framework is style, and not so much in functionality, even actually one of the distinguishing features that though sometimes the focus is quite different, with characterizes the different non-linear video editing Gmerlin being more and more pushed towards its applications. PiTiVi9 for example choose to use use for video production applications. Gstreamer, a framework that is built upon the Gobject system in C, and was originally intended 3 Applications to become an universal open media framework Cinelerra, the oldest and most complete with pluggable modules, similar to what is application that comes close to the ideal of an available on non-free software platforms. While universal non-linear editing software, is still under the framework was never exercised to the level active development today. And while it requires that PiTiVi needs, it is currently being extended some effort to get started with, due to its and fixed for the sometimes more difficult complexity, it is actually known for leaving little interactions that are required for non-linear editing. to be desired, its productive feature set is Before, Gstreamer was used in the realm of media impressive, and very complete. Its developer, or playback and streaming, and accurate cuts and development team however favors more of a ªlone compositions were never needed. With the wolfº style of working, so there is little public introduction of PiTiVi, that has changed, and as a discussion about the direction and vision of it, matter of fact, this work also benefits the much to the dismay of interested users and framework itself. potential contributing developers. However, there Quite the opposite is the case with MLT, which is a community around Cinelerra, that consist of is the foundation of Kdenlive10 a video editor that active users, and several developers, that keep their is developed within the KDE framework. MLT own branch of Cinelerra, with patches, bugfixes, itself originated from an open source project that releases and repositories. Also Cinelerra-CV11 as was commissioned by a broadcast enterprise from this third party community calls itself provides India, where it powered playout servers for TV support and documentation around the Software. programs. MLT already supported complex time- Additionally, rising from the Cinelerra community, lines and composites, before it was adopted for a project was formed, that is relatively new, which Kdenlive, so it was quite a good match.