Lumiera
The new emerging NLE for GNU/Linux
Note Draft, please help rephrase/review and shorten explanations!
Assets View

The session contains various things that can be edited, worked on and connected. These things are collectively known as the assets. The assets view is a “bookkeeping view” for displaying and managing the assets of the current session. It provides a list of all ingested footage, a list of all clips, effects, transitions, available timelines and sub-sequences, automation data, time grids, tags, labels and similar internal artefacts.

Builder

This is a kind of compiler that creates low-level, or processing, graphs by traversing and evaluating the relevant parts of the high-level-model and using the Rules System.

Busses

A list of global Pipes representing the possible outputs (master busses) similar to audio mixing desk. A bus defines the properties of the rendered output (Framerate, Resolution, Colorformat and so on). Busses are part of a Timeline.

Config System/Preferences

TODO: agree on one term here Provides defaults for all kinds of application configurations. These include machine specific configurations for performance characteristics, File and Plugins Paths and configuration data and so on. Note that this only provides defaults for data that has not already been set. Many settings will then be stored within the project which override Config/Preferences.

Controller Gui

This can be either a full Software implementation for a Transport control (Widgets for Start/Stop/Rev/Ffw etc) or some Gui managing an Input Device. They share some feature to attach them to controllable gui-entities (Viewers, Timeline Views)

Cursor

Playback- or edit position

Focus

TBD

High Level Model

All the session content to be edited and manipulated by the user through the GUI. The high-level-model will be translated by the Builder into the Low Level Model for rendering.

Input Device

Some hardware controler, like an extra keyboard, midi mixer, Jog, .. TODO: we still need to decide on whether we can treat the main keyboard as special global state or whether we can handle the keyboard as a generic input devide.

Low Level Model

The generated Processing Graph, to be “performed” within the engine to yield rendered output

MediaStream

Media data is supposed to appear structured as stream(s) over time. While there may be an inherent internal structuring, at a given perspective any stream is a unit and homogeneous. In the context of digital media data processing, streams are always quantized, which means they appear as a temporal sequence of data chunks called frames.

OutputDesignation

A specification denoting where to connect the output of a pipe. It might either be given absoulutely, i.e as a Pipe-ID, or by a relative or an indirect specification

OutputManager

Manages all external outputs of the application and provides output slots targetting these.

OutputMapping

Diverts one output designation into another designation, e.g. when hooking up a sequence as a virtual clip within another sequence.

OutputSlot

Opaque descriptor for an output facility, ready to dispose frames of data to be output.

Pipe

Conceptual building block of the high-level model. It can be thought of as simple linear processing chain. A stream can be sent to a pipe, in which case it will be mixed in at the input, and you can plug the output of a pipe to another destination. Furthermore, effects or processors can be attached to the pipe. In addition to global pipes (busses) in each Timeline, each clip automatically creates N pipes (one for each distinct content stream. Typically N=2, for video and audio)

Placement

A Placement represents a relation: it is always linked to a Subject (this being a Media Object) and has the meaning to place this Subject in some manner, either relatively to other Media Objects, by some Constraint or simply absolute at (time, output). Placements are used to stitch together the objects in the high-level-model. Placements thus are organised hierarchically and need to be resolved to obtain a specific value (time point, output routing, layering, fade,…)

PlayController

coordinating playback, cueing and rewinding of a playback position, visible as Playhead cursor in the GUI. When in play state, a PlayController requests and directs a render process to deliver the media data needed for playback.

Processing Graph

Rendering is expressed as a detailed network of nodes. The edges can be envisaged as data flow, while the nodes represent data processing.

Project

The top-level context in which all editing is done over an extended period of time. A Project can be saved and re-opened. It consists of various things a user is working on: user-information, assets, state and objects to be edited.

RenderTask

This is basically a PlayController, but directly collects output without moving a PlayheadCursor (could be a progress indicator) and not operating in a timed fashion, but freewheeling or in background mode

Rules System

Translating the Timeline to the underlying Processing Graphs involves some logic and knowledge about handling/converting data. This may be configued with this Rules System. Typically Lumiera will provide sane defaults for most purposes but may extended/refined for site specific things.

Sequence

A collection of Media Objects (clips, effects, transitions, labels, automation) placed onto a tree of tracks. By means of this placement, the objects could be anchored relative to each other, relative to external objects, absolute in time. A sequence can connect to global pipes when used as a top-level sequence within a timeline, or alternatively it can act as a virtual-media when used within a meta-clip (nested sequence). A Sequence by default contains just a single root track and directly sends to the master bus of the Timeline.

Session

the current in-memory representation of the Project when opened within an instance of Lumiera. This is an implementation-internal term. For the GUI and the users POV we should always prefer the term "Project" for the general concept.

StreamType

Classification of a media stream. StreamType is a descriptor record. While external media processing libraries usually do provide some kind of classification already, within lumiera we rely on an uniform yet abstract classification which is owned by the project and geared to fit the internal needs, especially for the wiring and connecting. A Lumiera stream type is comprised of the parts

  • media kind (Video, Image, Audio, MIDI, Text,… )

  • prototype (open ended collection of semantical kinds of media, examples being stereoscopic, periphonic, monaural, binaural, film quality, TV, youtube).

  • implementation type (e.g. 96kHz 24bit PCM, 2 channels muxed)

  • intention tag (Source, Raw, Intermediary and Target)

Time Axis

An entity defining the temporal properties of a timeline. A time axis defines the time base, kind of timecode and absolute anchor point. Besides, it manages a set of frame quantisation grids, corresponding to the outputs configured for this timeline (through the global busses). The GUI representation is a time ruler with configurable time ticks showed on top of the timeline view

Timeline

the top level element(s) within the Project. It is visible within a timeline view in the GUI and represents the effective (resulting) arrangement of media objects, resolved to a finite time axis, to be rendered for output or viewed in a Monitor (viewer window). Timeline(s) are top-level and may not be further combined. A timeline is comprised of:

  • Time axis, defining the time base

  • Play Controller (WIP: discussion if thats belongs to the timeline and if we want a 1:N relation here). Note by Ichthyo: yes, our current discussion showed us that a play controller rather gets allocated to a timeline, but isn’t contained therein.

  • global pipes, i.e. global busses like in a mixing desk

  • exactly one top level Sequence

Timeline Segment

A range in the timeline which yields in one Processing graph, commonly the range between cut points (which require a reconfiguration of the graph).

Timeline View

A view in the GUI featuring a given Timeline. There might be multiple views of the same timeline, all sharing the same PlayController. A proposed extension is the ability to focus a timeline view to a sub-Sequence contained within the top-level sequence of the underlying Timeline. (Intended for editing meta-clips)

Track-head/patchbay

the box in front of a track allowing to control properties of the elements contained within this track, unfold nested tracks and so on. To a large extent, it corresponds to the placement of this track and allows to manipulate this placement

  • TODO: better term for this

  • Note by Ichthyo: while I like the term "patchbay", my concern with this is that it has already a very specific meaning in audio applications; and while our track heads certainly can serve as a patchbay, that is not the main purpose and they can do things beyond that..

Viewer

The display destination showing video frame and possibly some effect overlays (masking etc.). When attached to a timeline, a viewer reflects the state of the timeline’s associated PlayController, and it attaches to the timeline’s global pipes (stream-type match or explicitly), showing video as a monitor image and sending audio to the system audio port. A number of supplimentary features are possible: the viewer could support the ability to attach to view points within the render network; the capability to display a second stream as an overlay (partially) which would enable user comparison or it might even be possible to allow the Viewer to be collapsed to a control, thus, allowing a video to be sent to a dedicated monitor, e.g., to a separate X/-display or to a firewire.