exiftool-wrapper

JavaScript wrapper for ExifTool by Phil Harvey.

Installation

------
The usual way:

``npm install exiftool-wrapper`

$3

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.

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

exiftool.metadata({source, tags, maxBufferSize, useBufferLimit, callback});
`
Or if you need it to be sync:
`javascript
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.




$3

* 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: , 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
`javascript
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:
`JSON
[
{
"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.