Video thumbnail generator generating WebVTT spec file
Thumbnails generator module. Uses [WebVTT](http://dev.w3.org/html5/webvtt/) as thumbnails descriptor. Can pack thumbnails into spritesheet using [node-sprit]() module.
## Installation
npm install thumbnails-webvtt --save
## Requirements
*[ffmpeg](https://www.ffmpeg.org/) used by `fluent-ffmpeg`
*[ImageMagick](http://www.imagemagick.org/) as used by `node-sprite`
Create thumbnails (and optionally pack them into spritesheet) and create WebVTT file for file(s). Options are described below
## Options
***output** defaults to `"SOURCE_DIR/SOURCE_BASENAME.vtt"`
* WebVTT filename
***assetsDirectory** defaults to `"SOURCE_BASENAME"`
* Name of folder which keeps thumbnails or spritesheet.
***size** defaults to `null`
* Size of generated thumbnails. If not specified original video stream `width` and `height` will be used. If only `width` or `height` is specified other will be computed according to source video ratio.
***size.width** defaults to `SOURCE_WIDTH`
* Read above
***size.height** defaults to `SOURCE_HEIGHT`
* Read above
***timemarks** defaults to `null`
* Array with timemarks in seconds. E.g. ['123.123', '345.345']
***numThumbnails** defaults to `null`
* Number of thumbnails to generate. Used in opposite to `timemarks`. Each thumbnail moment is calculated as `source_duration * 0.9 / numThumbnails`.
***spritesheet** defaults to `false`
* Generate spritesheet or not.
***spriteSheetName** defaults to `"thumbnails"`
* Spritesheet file name
***spriteSheetOptions** default to `null`
* Spritesheet options passed to [node-sprite](https://github.com/naltatis/node-sprite#options) `.sprite()` function.