media-thumb-store

Media files key-value store with on the fly thumbnail generation. Support pluggable thumbnail generators for different media types. Support pluggable storage back-ends for storing file-path and file-meta-data. Include a built in thumbnail generator based on GraphicMagic. Automatically search for media files in media directory.

Included plug-ins:

mem-backend: a storage back-end for storing data in a memory dictionary.
mongoose-backend: a storage back-end for storing data in MongoDB.

gm-thumbnailer: a thumbnailer plug-in for creating image thumbnails.
    This plug-in require GraphicMagic to be installed and on the system path.
ffmpeg-thumbnailer: a thumbnailer plug-in for creating video thumbnails.
    This plug-in require ffmpeg to be installed and on the system path.

Install

use npm:

npm install media-thumb-store

Generating thumbnails with gm-thumbnailer and ffmpeg plugins

This gm plugin require GraphicMagic to be installed, download and install GraphicsMagick or use your package manager.

sudo apt-get install graphicsmagick

This ffmpeg plugin require ffmpeg to be installed, download and install ffmpeg or use your package manager.

sudo apt-get install ffmpeg

Basic Usage

var mediaThumbStore = require('media-thumb-store');
 
/**
 * Create a new thumbnail generator for images
 * Use the included GraphicMagic thumbnailer.
 *
 * Thumbnail images will be cached in './' folder under
 * Two sub-folders 'normal' and 'large'
 * This two sub-folders must exist before first thumbnail is cached.
 *
 *   thumb-folder|normal|thumb1.jpg
 *               |      |...
 *               |
 *               |large|thumb1.jpg
 *                     | ...
 *
 */
var imageThumbnailer = new mediaThumbStore.gmThumbnailer({
  // Set the root path for the thumbnail folders
  thumbDir: __dirname
});
 
/** 
 * Test our thumbnailer function
 * If the __dirname + '/normal' folder exsits a new thumbnail will
 * be created inside it.
 * @param {requestCallback} next Call next functions.
 */
function testThumbnailer(next) {
  imageThumbnailer(__dirname + '/img/happy-cat.jpg', 'normal', function(err, path) {
    if (err) {
      console.log('  Thumbnail not created');
    } else {
      console.log('  Thumbnail (size: normal) created at:' + path);
    }
    
    next();
  });
}
 
/**
 * Create a new media storage
 */
var myMedia = new mediaThumbStore({
  // Set the full path of the image sent if thumbnail creation fails
  defaultIcon: __dirname + '/normal/default.jpg',
  // Set the function to use for the creation of thumbnails for
  // files with 'image' mime type.
  imageThumbnailer: imageThumbnailer
});
 
/** 
 * Test our media storage object
 * Scan a media folder and insert all meta-data about the files 
 * to our storage object.
 * @param {requestCallback} next Call next functions.
 */
function testStorage(next) {
  myMedia.updateFromDir(__dirname + '/img', function() {
    // Print first 100 files found, order by name
    // See find method options below.
    myMedia.find({skip: 0, limit: 100, sortBy: 'name'}, function(err, results) {
      console.log(results);
 
      next();
    });
  });
}
 
/** 
 * Test our media storage thumbnailer
 * Find the happy-cat image in the storage meta-data 
 * and make a thumbnail for it.
 * @param {requestCallback} next Call next functions.
 */
function testFindThumb(next) {
  // Create thumbnail for the first image file named 'happy-cat'
  myMedia.find({where: ['mime~=^image', 'name==happy-cat']}, function(err, results) {
    // take the id of the first file found
    var id = results[0]._id;
 
    myMedia.findThumbById(id, 'normal', function(err, path) {
      console.log('Created thumbnail (size: normal): ' + path);
      
      next();
    });
  });
}

Options

mediaThumbStore

Options

mimeList {Array.<String>}
    An array of supported mime types.
    Defaults: ['image/jpeg',
        'image/png',
        'video/webm',
        'video/mp4',
        'audio/mpeg']
        
imageThumbnailer {function(mediaPath, size, callback(Error, thumbPath)}
    A function that get a path to a media file and callback with
    a path to a generated/cached thumbnail image
    Used for files with image mime type.
    Media and Thumbnail paths are absolute.
    Defaults: null, use default icon image
    
audioThumbnailer {function(mediaPath, size, callback(Error, thumbPath)}
    A function that get a path to a media file and callback with
    a path to a generated/cached thumbnail image
    Used for files with audio mime type.
    Defaults: null, use default icon image
    
videoThumbnailer {function(mediaPath, size, callback(Error, thumbPath)}
    A function that get a path to a media file and callback with
    a path to a generated/cached thumbnail image
    Used for files with video mime type.
    Defaults: null, use default icon image
    
store
    A back-end store module for data storage.
    The store module should implement:
        find(options, callback(err, results))
        findById(key, callback(err, result))
        create(object, callback(err))
    Defaults: null, ( fall back to memStore )
    
defaultIcon {String}
    Path a default image file, used when thumbnailer fails

Implements:

find([options], callback(err, results))
    Get media items from the data storage.
    Options are passed to the storae backend, 
    Backend should implement:
        skip {Number}
        limit {Number}
        sortBy {String}
        where {String[]} ( * See format of where string )
    
findById(key, callback(err, result))
    Get one media item from the data storage.

findThumbById(key, size, callback(err, result))
    Get a path to cached/generated thumbnail image of a media item.

create(filePath, callback(err))
    Append a media item to the data storage.

updateFromDir(root, callback(err))
    Recurcivly append/update all media items in a root folder.

Format of where string: '{field}{operator}{value}'

implemented Operators:
    ~= Regular exprsion
    == Equal to
    <  Less then
    >  greater then

For example:
    'name~=yosi' filter results where name
    match the regular exprsion /yosi/
    
    'name==yosi' filter results where name
    is exactly 'yosi'

gmThumbnailer

Options

keyGenerator {function({String})}
    Key generator is a function that generates a unique key for the
    object path field {String}.
    Default is md5 of the objects path field.
    
thumbDir {String}
    Path to the thumbnail directory
    
thumbSizes {Object}
    The default sizes of the generated thumbnails
    Defaults to {normal: 128, large: 256}
    
thumbQuality {Number}
    The generated thumbnail quality (1 bad .. 100 best)
    Defaults to 50

ffmpegThumbnailer

Options

keyGenerator {function({String})}
    Key generator is a function that generates a unique key for the
    object path field {String}.
    Default is md5 of the objects path field.
    
thumbDir {String}
    Path to the thumbnail directory
    
thumbSizes {Object}
    The default sizes of the generated thumbnails
     Defaults to {normal: 128, large: 256}
    
thumbQuality {Number}
    The generated thumbnail quality (1 bad .. 100 best)
    Defaults to 50

memStore

Options

keyGenerator {function({String})}
    Key generator is a function that generates a unique key for the
    object path field {String}.
    Default is md5 of the objects path field.

Implements

find(options, callback(err, results))
findById(key, callback(err, result))
create(object, callback(err))
update(key, object, callback(err))
remove(key, callback(err))
removeAll(callback(err))

mongooseStore

Options

url {String}
    MongoDB database url.
    Default to 'mongodb://localhost/mediafiles'

Implements

find(options, callback(err, results))
findById(key, callback(err, result))
create(object, callback(err))
update(key, object, callback(err))
remove(key, callback(err))
removeAll(callback(err))

User plugins

Thumbnailers plugins

The thumbnailer is a function that gets a path to a media file, and A callback function(err, thumbnailPath). If successful it will call the callback function with a path to Generated thumbnail. On fail it will set the thumbnailPath To null.

Example:

/** 
 * An example thumbnailer function that always return the same thumb
 * Not very useful...
 *
 * @param {String} path The path to a media file
 * @param {String} size The size of the thumbnail ('normal', 'large')
 * @param {function({Error} err, {String} path)} callback The 
 *    callback function that will receive the thumb image file path
 */
var thumbnailer = function(path, size, callback) {
  // do nothing with image in path
  // ...
  // set err to null, and send back a static image path
  callback(err, 'my-thumb.jpg');
};

( An example thumbnail module is in lib/thumbnailers/ )

Backend storage plug-ins

A plug-in store module for data storage

The store module should implement:
    find(options, callback(err, results))
    findById(key, callback(err, result))
    create(object, callback(err))

The find function options:
    limt {Nuber} max number of results
    
    skip {Number} start at result
    
    sortBy {String} field name to sort by:
        'name' will sort result by the 'name' field
        '-name' will sort by 'name' backwords
        
    where {String[]} a list of where strings

( An example store module is in lib/backends/ )