The new emerging NLE for GNU/Linux
State Parked
Date 2008-10-31
Proposed by Ichthyostega

Use Case analysis

The only way to defeat "featuritis" is to build upon a coherent design — 
which in turn relies upon a more or less explicit understanding what the application should be like, and the way the prospective user is thought to work with the program. Today, a generally accepted method for building up such an understanding is to do a use case analysis. Such a formal analysis would require to identify all usage scenarios with the involved actors and parts of the system, and then to refine them in detail and break them down into distinct use cases. Here, I’ll try a rather informal variant of such an analysis. I’ll restrain myself to describing the most important usage situations.

please participate in the discussion. It well may be that everything detailed here is self-evident, but I doubt so. At least the grouping and the omissions kind-of reflect a certain focus of the project

Describing basic Lumiera usage situations

The fundamental assumption is that the user works on a project, which is reflected in the fact that the user is working on a single session over an extended period of time (several hours to several years). External media will be imported and incorporated into this session, additional media will be created within this session, and finally there is at least one render or export procedure to harvest the results of this work.

Scenario (1) : Exploring Media

Various external media files are opened. You play, cue and examine the media. Tagging, labeling and adding notes. Marking of interesting points and ranges. Possibly breaking down into clips, or at least extract some ranges as clips. Draft arranging the clips, applying some effects to check the result and thus to find out about the viability of the footage. Playback of several media at the same time (several videos, but also video and music). Grouping of assets (media, clips, effects, markers) into folders.

Scenario (2) : Simple assembly

You build up a simple linear cut sequence. Either by

  • using a single source media, trimming it and cutting away (a small number of) unwanted parts

  • playing source media and spilling over (insert, overwrite) some parts into the final assembly

  • dragging over the pre-organised clips from clip folders to build up the assembly.

Sound is either used immediately as-is (the soundtrack attached to the media), or there is a similarly simple, linear music bed. Some people prefer to switch sound off entirely for this kind of work. In any case, the link is either automatic, or rather vague and soft (as music being vaguely correlated)

Scenario (3) : Augmenting an assembly

Without the intention to rework it from scratch, an already existing simple assembly is augmented, beautified and polished, maybe to conform with professional standards. This includes the “rescue” of a somewhat questionable assembly by repairing localized technical problems, but also shortening and re-arranging, and in extreme cases even changing the narrative structure. A distinctive property of this usage scenario is that work happens rather in the context of tasks (passes) — not so much isolated operations:

  • the task may be to get the rhythm or overall tempo right, and thus you go over the sequence and do trim, roll, shuffle or slide edits.

  • you may want to “fold-out” parts of the sound, thus interweaving o-sound and music

  • there may be a sound overdubbing and replacing pass

  • you may want to walk certain automation curves and adjust levels (sound volume or tone, fade, brightness/contrast/colour)

  • general polishing may include adding title overlays, fading in and out, adding (typically a single type of) transition(s) in a coherent manner

Scenario (4) : Compositional work

Here I define compositional work as a situation where you deal with multiple more or less independent sequences going on in parallel, similar to a musical score. Frequently, we encounter compositional parts embedded in a otherwise linear work, and often those parts evolve when Scenario (3) is driven to the extreme.

  • the most common situation is that o-sound, sound design and music work together with the temporal structure created in the image edits.

  • a movie with a complex narrative structure may induce compositional work on a very large scale (and existing applications frequently fall short on supporting such)

  • compositing often leads to compositional work. Special FX, masked objects being arranged, artificial elements to be integrated.

  • similarly any collage-like or heavily layered arrangements lead themselves to requiring compositional work.

The common distinctive property of all those situations is: objects are embedded into a primary context and have to obey the rules of this context, and at the same time have a close correlation to other objects which are embedded in a completely different (“orthogonal”) context. (To give a catchy example: assume, a CG monster has to be integrated. Besides the masked monster object, you have several colouring and blurring layers at completely different levels in the layering order, and at the same time you have correlated sound objects, which need to be integrated into the general sound-scape. And now your primary job is to get the movement and timings of the monster right in relation to the primary timing grid established by the existing edit)

The working style and thus the tool support necessary for compositional work is completely different to Scenario (3). After an initial build-up (which often is very systematic), the working profile can be characterized by tweaks to various parameters to be done in-sync at widely separated sites within the session, together with repeated cycles of “do it”, “assess the result”, “undo all and do some small detail differently”. Typically there is the need for much navigation (contrast this to Scenario (3) where you work in tasks or passes)

Scenario (5) : Working with Sound

The degree of integrating sound work is worth discussing. Often, due to limitations in existing tools, sound work is done in separate applications to a large extent. Which in turn forces the whole production into a sequential organisation scheme. First the edit has to be roughly final, and then the sound people can step in. (Of course this is an simplification). To list the common operations:

  • cleaning and preparing original sound

  • fitting sound library elements or separately produced sound

  • overdubbing

  • playing or building music to match the rhythm of the edit or the original footage

  • montage of dialogue and/or noise correlated to the primary content of the sequence

  • sound design, shaping the pace and the feel of a sequence

  • final balance mix

While clearly some of those tasks are always better done within a dedicated application, the ability to carry out this work partially within the main session and even while the basic edit is still in flux — may open new artistic possibilities.

Scenario (6) : Large Projects

At first sight, the operations and the work to be done in large projects is the same as in small ones. But large projects tend to create sort of an additional “layer” on top of the usage scenarios described thus far, which will “kick in” at various places.

  • work may be divided upon several editors, working on separate parts (sequences) which then need to be re-integrated

  • there may be a global asset organisation (naming scheme), which will be extended locally, resulting in nested naming scopes.

  • some quite basic stuff needs to be done in a coherent fashion, e.g. titles, a certain transition (template), the way fade-outs are done, a certain colour profile. Possibly, this stuff needs to be adjusted all over the project.

  • there will be a general (large scale) timing grid with distinct “check points” and probably there is the need to navigate to the different parts of the whole project.

  • there may be the necessity to build several versions of the same project in parallel (e.g. a short version and a extended director’s cut)

  • you may have to care for such nasty and tedious things as keeping sub-titles in-sync while the edit is still in flux

  • you may want to do integration builds, where you add placeholders just for the purpose to get an impression of the work as a whole.

Scenario (7) : Teamwork

Several people work on a project.

  • A longer sequence might be split up into parts, each one edited by another person. The parts will be collected and assembled by the chief editor. Edits to the parts will still be possible, but a system of permissions allows to lock down access to parts of the edit, so to prevent unexpected interferences.

  • Arrangements based on the same resources can be branched, tagged and merged.

  • Edits are logged with usernames

  • Markers can be shown/hidden on a per creator base.

  • Team members need ways to share and store notes and suggestion for each other work. Annotations can be added to clips, markers or arrangements

  • A pen tool could allow to scribble on top of frames or arrangements. An expressive and fast way to leave suggestions about deletions, movements and all other kinds of edits.

Scenario (8) : Script driven

The application is started “headless” (without GUI) and controlled via an API. Either an existing session is loaded, or a new session is created and populated. Then, some operations have to be done in a systematic manner, requiring a way to address parts of the session both unambiguously and in a way easy to access and control from a programming environment (you can’t just “see” the right clip, it needs to be tagged). Finally, there might be an export or render step. A variation of this scenario is the automatic extraction of some informations from an existing project.


  • describing such scenarios, even if hypothetical, create an anchor or point of referral for feature/GUI design work to be done in detail

  • relating features to working situations helps to see what is really important and what is rather of technical merit

  • compiling and discussing this list helps shaping the character of the application as a whole

  • the above compilation relates individual features to a general production process.

  • the goal of this compilation is to be fairly complete

  • any of those descriptions is artificial

  • sometimes it is better to develop an application technology driven, especially when it is technologically challenging to get it to work properly.

  • having such a large-scale vision may freak away people which otherwise might jump in and implement some crazy but valuable new feature

  • the listed usage scenarios intend to be fairly complete, which can be a limitation or even self-deception. Better have an open ended list.

  • the above compilation seems quite conventional and explicitly leaves out some scenarios

    • networked, distributed scenarios, compound applications

    • television, life video, VeeJay-ing

    • cartoons, animations, game design

  • avoiding a general plan, just sharing a vague general vision

  • just start out with one scenario directly at hand (e.g. the simple assembly) and not worrying about the rest

  • rather then defining those scenarios (which are necessarily hypothetical), rather stick to the operation level. E.g. a use case would be rather on the level of “triming a clip”

  • doing a complete state-of-the art UML use case analysis.

  • after having created the foundation, rather stick to an XP approach, i.e. implement, integrate and release small “usage stories”


Well, after having considered, compiled and written such an concept, altogether avoiding a big picture view of the application is not longer an option. To the other extreme, we neither have the resources, nor the circumstances for doing a rigid and formal analysis. Finally, the XP approach really sounds promising, and it should be clear that it is in no way ruled out. Nothing hinders us to have a detailed vision, but then to implement small usage stories which fit into this vision.

Besides, another consideration. The above compilation builds upon the notion, that there is a common denominator of film making craft, a core editing art, which has been shaped in the first 100 years of cinema, and which won’t go away within the next generation, even if the technological and practical circumstances of production change quite dramatically.


Template e.g. for regular TV series

Constraints to fit all contents within fixed timeline, cover topic, select collage of iconic scenes from archived and collected footage. Update intro and credit roll for each episode. Add in stopmotion, and 3D model animations with vocal commentaries. Gather together separate items from "outworkers".


2008-12-27 08:36:36


We have to revisit this, possibly someone (or a group) who wants to work on the workflow. For now its parked until revisited.

Do 14 Apr 2011 03:06:42 CEST Christian Thaeter