probe-image-size/lib/parse_stream/psd.js

Get image size without full download (JPG, GIF, PNG, WebP, BMP, TIFF, PSD)

'use strict'


var ParserStream = require('../common').ParserStream
var str2arr = require('../common').str2arr
var sliceEq = require('../common').sliceEq


var SIG_8BPS = str2arr('8BPS\x00\x01')


module.exports = function () {
  var parser = new ParserStream()

  parser._bytes(6, function (data) {
    // signature + version
    if (!sliceEq(data, 0, SIG_8BPS)) {
      parser._skipBytes(Infinity)
      parser.push(null)
      return
    }

    parser._bytes(16, function (data) {
      parser._skipBytes(Infinity)

      parser.push({
        width: data.readUInt32BE(12),
        height: data.readUInt32BE(8),
        type: 'psd',
        mime: 'image/vnd.adobe.photoshop',
        wUnits: 'px',
        hUnits: 'px'
      })

      parser.push(null)
    })
  })

  return parser
}