stream-signature

Get the mimetype of a stream based on its contents.

Data for this script was generated from:
http://en.wikipedia.org/wiki/List_of_file_signatures and by looking at file headers with a Hex editor

This is a fork of buffer-signature
by @iarna.

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

Example use:

``js

const fs = require('fs')
const streamSignature = require('stream-signature')
const signature = new streamSignature()

signature.on('signature', signature => {
console.log(JSON.stringify(signature, null, 2))
})

fs.createReadStream('path/to/file.png')
.pipe(signature)
.pipe(…whatever else you want to do with the data…)

// outputs:
// {
// "mimetype": "image/png",
// "description": "Image encoded in the Portable Network Graphics format",
// "extensions": [
// "png"
// ]
// }
`

#### Changes from buffer-signature

* Converted to a PassThrough stream
* No Dependancies
* Emits 'signature' event as soon file signature is detected
* this event will also be emmited after no signature can be determined with the default application/octet-stream as the mimetype with an aditonal property unknown set to true`
* Added more missing filetypes such as:
* MP4
* MOV