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103 lines
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3.2 KiB
Text
103 lines
No EOL
3.2 KiB
Text
GStreamer Editing Services
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TODO
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FUNDAMENTAL GOALS:
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1) API must be easy to use for simple use-cases. Use and abuse
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convenience methods.
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2) API must allow as many use-cases as possible, not just the simple
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ones.
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* Project file load/save support (GESFormatter)
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Problems:
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Timelines can be stored in many different formats, we need to
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ensure it is as easy/trivial as possible for users to load/save
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those timelines.
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Some timeline formats might have format-specific
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sources/objects/effects which need to be handled in certain ways
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and therefore provide their own classes.
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The object that can save/load GESTimeline are Formatters.
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Formatters can offer support for load-only/save-only formats.
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There must be a list of well-known GES classes that all formatters
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must be able to cope with. If a subclass of one of those classes is
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present in a timeline, the formatter will do its best to store a
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compatible information.
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A Formatter can ask a pre-render of classes that it doesn't
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understand (See Proxy section).
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Formatters can provide subclasses of well-known GES classes when
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filling in the timeline to offer format-specific features.
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* Grouping/Linking of Multiple TrackObjects
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Problems:
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In order to make the usage of timelines at the Layer level as easy
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as possible, we must be able to group any TrackObject together as
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one TimelineObject.
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** Selection support
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* Effects support
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* in the Layers
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* as TrackObjects
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* Source Material object
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Problems:
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Several TimelineSource for a same uri actually share a lot
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in common. That information will mostly come from GstDiscoverer,
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but could also contain extra information provided by 3rd party
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modules.
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Definition:
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Material: n, The substance or substances out of which a thing is or
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can be made.
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In order to avoid duplicating that information in every single
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TimelineSource, a 'Material' object needs to be made available.
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A Material object contains all the information which is independent
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of the usage of that material in a timeline.
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A Material object can specify the TimelineSource class to use in a
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Layer.
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* Proxy support
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Problems:
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A certain content might be impossible to edit on a certain setup
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due to many reasons (too complex to decode in realtime, not in
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digital format, not available locally, ...).
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In order to be able to store/export timelines to some formats, one
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might need to have to create a pre-render of some items of the
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timeline, while retaining as much information as possible.
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Content here is not limited to single materials, it could very well
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be a complex combination of materials/effects like a timeline or a
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collection of images.
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To solve this problem, we need a notion of ProxyMaterial.
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It is a subclass of Material and as such provides all the same
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features as Material.
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It should be made easy to create one from an existing TimelineSource
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(and it's associated Material(s)), with specifiable rendering
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settings and output location.
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The user should have the possibility to switch from Proxy materials
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to original (in order to use the lower
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resolution/quality/... version for the editing phase and the
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original material for final rendering phase).
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