buffer-signature

Get the mimetype of a buffer based on its contents.

Data for this script was generated from: http://en.wikipedia.org/wiki/List_of_file_signatures

Additional support for mp4 and mov formats from @cmd430

This is a fork of file-signature by @leahcimic.

To match against any file format, you'll need a minimum of 22 bytes from the start of the file.

Example use:

var identifyBuffer = require('buffer-signature').identify;
console.log(identifyBuffer(fs.readFileSync('path/to/file.jpg')));

var identifyStream = require('buffer-signature').identifyStream;
fs.createReadStream('path/to/file.jpg').pipe(identifyStream(info => {
  console.log(info)
}).pipe(…whatever else you want to do with the data…)

// outputs:
// {
//   description: 'A commonly used method of lossy compression for digital photography (image).',
//   mimeType: 'image/jpg'
//   extensions: ['jpg', 'jpeg']
// }

Changes form file-signature

• Made identify take a buffer instead of a filename
• Added identifyStream
• Refreshed magic number list from Wikipedia and fixed signature matcher to support offsets
• Added a bunch of missing mimetypes
• Ditched bespoke buffer equality function for Buffer.equals