VfxApply Presets Documentation
==============================


## Preset keys

**Common keys**

| Key               | Type           | Description
|------.------------|----------------|-------------------------------------------
| `preset/name`     | *String*       | A description string for this preset
| `preset/group`    | *String|Null*  | Logical grouping
| `preset/plugin`   | *String*       | The id of the plugin this preset is for
| `preset/props`    | *Array*        | Properties used by the plugin
| `preset/params`   | *Array|Null*   | Parameters for tweaking

## Properties

**ffmpeg**

| Property          | Type           | Description
|-------------------|----------------|-------------------------------------------
| `filter`          | *String*       | The filter string, with optional param placeholders
| `extra`           | *String|Null*  | Extra options to pass on the ffmpeg command line
| `type`            | *Enum|Null*    | ffmpeg filter type; One of `complex` (default), `audio` or `video`


**natron**

| Property          | Type               | Description
|------.------------|--------------------|-------------------------------------------
| `project`         | *String*           | Natron project file name
| `input`           | *String|Int|Null*  | Extra options to pass on the ffmpeg command line
| `output`          | *String|Int|Null*  | ffmpeg filter type; One of `complex`, `audio` or `video`
| `framescale`      | *Float*            | Ratio of output frames to input files, 2.0=twice as many out as in=half speed

**executor**

| Property          | Type               | Description
|------.------------|--------------------|-------------------------------------------
| `set`             | *Array*            | Define variables
| `script`          | *Array*            | Define commands
| `set/%/value`     | *String*           | Set variable % to value.
| `set/%/escape`    | *Bool*             | If true, the resulting vriable will be escaped
| `script/%/info`   | *String*           | Info about what this step is doing
| `script/%/exec`   | *String*           | Command to execute
| `script/%/parse`  | *Map*              | Parse output from command, see docs for plugin


## Parameters

All parameters must specify `label` and `type`. The remaining keys are depending on the
type of parameter.

**float**

Float parameters need to specify `min`, `max`, `default` and optionally `step`.


## Examples

### ffmpeg

    preset:
        name:   Normalize audio level
        group:  ffmpeg/audio
        plugin: ffmpeg
        props:
            filter: "dynaudnorm=m={maxgain}:s={compress}"
            extra: "-c:v copy"
            type: complex
        params:
            compress:   { label:"Compression factor", type:float, min:0.0, max:30.0, default:0.0 }
            maxgain:    { label:"Max gain factor", type:float, min:0.0, max:100.0, default:10.0 }

### natron

    preset:
        name:   Apply a CCTV look to the video
        group:  natron
        plugin: natron
        props:
            project: natron-cctv.ntp
            reader: Reader1
            writer: Writer1

### executor

    preset:
        name: Stabilize video clip (two-pass)
        group: video
        plugin: executor
        props:
            set:
                inputtrf: { value:"{%uinput}.trf", escape:true }
            script:
                analyze:
                    info: Getting stabilization vectors
                    exec: "transcode -i {%input} -J stabilize"
                    parse:
                        from: 'stderr'
                        regex: '/encoding frames \[0-([0-9]+?)\],\s+([0-9\.]+?) fps/'
                        frame:1
                        eta:2
                stabilize:
                    info: Stabilizing video
                    exec: "transcode -i {%input} -o {%output} -J transform -y xvid"
                    parse:
                        from: 'stderr'
                        regex: '/encoding frames \[0-([0-9]+?)\],\s+([0-9\.]+?) fps/'
                        frame:1
                        eta:2
                cleanup:
                    exec: "rm {%inputtrf}"