+Line 1:
+ - required to make strings used in the effect translatable
+Line 2:
+ - tag: MLT ("mlt_service") name of the effect
+ - id: internal kdenlive id, can be anything, but must be unique for each effect
+ - type: (default = "video") whether effect modifies video or audio (use "audio" then)
+ - unique: (default = "0") this effect cannot be attached multiple times to one clip (speed, fades, ...)
+ - version: (optional) minimum version of the effect required to be available (works only if the MLT filter provides the necessary metadata)
+Line 3:
+ - name of the effect that will appear to the user
+Line 4:
+ - Short description of the effect to be shown in the effect list
+ - Additionally a <full> part can be added inside. It's content will be available in the effect stack (see frei0r_lightgraffiti.xml for an example):
+ - supports HTML formatting (requires the use of CDATA)
+Line 5:
+ - name of the author(s) of the filter (not of the XML file ;))
+The rest:
+ - list of effect parameters:
+ - tag "name": visible name of the parameter (depending on the GUI this parameter uses)
+ - tag "comment": (optional) description of the parameter (support HTML formatting) (not yet supported by all widgets)
+ - attribute "name": MLT filter parameter name
+ - attribute "paramprefix": a string to be prepended to the parameter value before passing it to MLT
+ - attribute "default": initial value, format depends on parameter type
+ - attribute "type": widget (GUI) to use
+ - "fixed":
+ - sets a (MLT filter) parameter, but does not expose it to the user (no GUI)
+ - "constant":
+ - number
+ - represented by a slider
+ - additional parameter attributes:
+ - "factor": (optional) values coming from MLT will be multiplied with factor
+ - "offset": (optional) will be added to values coming from MLT after "factor" is applied
+ - "min": smallest value possible (after multiplying with "factor")
+ - "max": largest value possible (after multiplying with "factor")
+ - "suffix": (optional) displayed unit of the values
+ - "double":
+ - synonym for "constant"
+ - "bool":
+ - true/false
+ - represented by a checkbox
+ - "list":
+ - multiple choice
+ - represented by a drop-down menu
+ - additional parameter attribute:
+ - "paramlist": list of possible values separated by semicolon (no whitespaces!)
+ - addtional tag:
+ - "paramlistdisplay": (optional) list of names to use for the values separated by comma
+ - "position":
+ - time stored as frame number
+ - represented by a slider
+ - "color":
+ - color value, similar to representation HTML ("#rrggbb"/"#aarrggbb" or "0xrrggbbaa")
+ - represented by a button opening the KDE color dialog + a color picker button
+ - additional attributes:
+ - "alpha": (default = "0") use to enable alpha support
+ - "keyframe":
+ - keyframable number
+ - keyframes are opt-in (only one keyframe by default -> should be prefered over "constant" whenever possible)
+ - works with MLT filters that utilize start/end values
+ - same attributes as "constant"
+ - additional attributes:
+ - "intimeline": (default = "0") parameter to preselect for editing in the timeline (only one parameter can have "1")
+ - "widget": (optional) GUI based on the standard keyframe GUI (possible values: "corners")
+ - "simplekeyframe":
+ - works with MLT filters that use mlt_geometry for keyframe support (includes all frei0r filters)
+ - same attributes as "keyframe"
+ - "geometry":
+ - a rectangle: postion + dimension + additional value
+ - works with MLT filters using mlt_geometry
+ - the rect can be edited on the project monitor
+ - additional attributes:
+ - "fixed": (default = "0") use to disable keyframe support
+ - "showrotation": (default = "0") use to enable support to 3 axis rotation
+ - "opacity": (default = "true") use to disable support of the opacity setting
+ - "url":
+ - url/path
+ - represented by button to open "file open" dialog
+ - "wipe":
+ - special GUI for the wipe transition makes it possible to select a direction of a slide
+ - "addedgeometry":
+ - parameter linked to a "geometry" parameter
+ - "curve":
+ - cubic curve editor for the frei0r color curves filter (old version)
+ - "bezier_spline":
+ - cubic Bézier spline editor for the frei0r color curves filter (new version, might be reused for other filters)
+ - "roto-spline":
+ - GUI for the rotoscoping filter (spline on the monitor)
+ - "keywords":
+ - Text entry with a selection of possible keywords to be inserted in the text.
+ - additional tags:
+ - "keywords": list of possible keyword values separated by semicolon
+ - "keywordsdisplay": list of names to use for the values separated by semicolon
+ - "fontfamily":
+ - Font typeface entry
+==========