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exiftool-wrapper

JavaScript wrapper for ExifTool by Phil Harvey.

Installation

The usual way:

npm install exiftool-wrapper

Requirements

You need to have the ExifTool by Phil Harvey installed or be able to call it from your bash/console.

Usage

You can use callbacks or promises.

var exiftool = require('exiftool-wrapper');

exiftool.metadata({source, tags, maxBufferSize, useBufferLimit, callback});

Or if you need it to be sync:

exiftool.metadataSync({source, tags, maxBufferSize, useBufferLimit});

Depending on what you passed as source, you will either get single object or an array of objects containing the metadata. See below for a more detailed example.

Parameters

  • source: file, files or buffer. Examples:
    • String: source: 'path/to/my/image.jpg'
    • Array: source: ['path/to/my/image1.jpg', 'path/to/my/image2.jpg', 'path/to/my/video.mp4']
    • Buffer: source: <Buffer>, e.g. via fs.readFile()
  • tags: List of tags that should be included or excluded. If omitted, the function will return all metadata that is available in source. Add a single dash - in front of the tag to exclude it. Not case sensitive. Examples:
    • tags: ['imagewidth', 'imageheight'] will only return the width and height of an image/video.
    • tags: ['-imagewidth', '-imageheight'] will exclude width and height in the returned metadata.
  • useBufferLimit: If set to false the whole Buffer will be piped into ExifTool otherwise maxBufferSize will be used to cap the Buffer. (default: true)
  • maxBufferSize: Maximum length of Buffer, that will be piped into ExifTool. (default: 10000)
  • callback: Usual function (error, metadata) format. If omitted, metadata() will return a Promise

Example

Get filtered metadata (only imagewidth and imageheight) for a list of files under ./sampleimages/.

Also see: exiftool-wrapper/examples

var exiftool = require('exiftool-wrapper');
var fs = require('fs');
var path = require('path');


var samplepath = './sampleimages/'
fs.readdir(samplepath, function(err, files) {
  files = files.map(function(f) {
    return path.join(samplepath, f);
  })
  // As callback
  exiftool.metadata({source: files, tags: ['imagewidth', 'imageheight'], callback: function (err, metadata) {
    if(err) {
      return console.log(err);
    }
    console.log(metadata);
  }});
  // As Promise:
  exiftool.metadata({source: files, tags: ['imagewidth', 'imageheight']})
    .then(function(metadata) {
      console.log(metadata);
    })
    .catch(function(err) {
      console.log(err);
    });
});

Output:

[
  {
    "SourceFile": "sampleimages/Example.jpg",
    "ImageWidth": 275,
    "ImageHeight": 297
  },
  {
    "SourceFile": "sampleimages/NodeJS.png",
    "ImageWidth": 234,
    "ImageHeight": 73
  },
  {
    "SourceFile": "sampleimages/Stationary_wavelet_transform_lena.png",
    "ImageWidth": 1280,
    "ImageHeight": 1278
  }
]

Notes

  • It is not the fastest way to get your metadata.
  • Some tags will be missing, if maxBufferSize is too small. 10000 worked fine for basic data like imageheight and imagewidth.
  • .webm-files appear to be problematic when using useBufferLimit: false. This is an issue with ExifTool itself. It has problems with piped in webm-files.
  • Feedback would be great, since this is my first module.

Todo

Real tests.