image-size - npm Package Compare versions

Comparing version 0.1.17 to 0.1.20

Contributors.md

		@@ -6,1 +6,2 @@ ##### Contributors
		* [Rudy Krol](https://github.com/rkrol)
		* [Linus Unnebäck](https://github.com/LinusU)

lib/patches.js

		@@ -8,3 +8,47 @@ // Abstract reading multi-byte unsigned integers
		}
		Buffer.prototype.readUInt = readUInt;

		module.exports = Buffer.prototype.readUInt = readUInt;
		function readBits (bits, offset) {
		offset = offset \|\| 0;

		var value = 0, byte, start, bitsToRead;
		while (bits > 0 && this.length) {
		value = value << (bits > 8 ? 8 : bits);
		start = Math.floor(offset / 8);
		byte = this[start];
		bitsToRead = (start + 1) * 8 - offset;
		value \|= byte & (Math.pow(2, bitsToRead) - 1);
		offset += bitsToRead;
		bits -= bitsToRead;
		}

		return value;

		// var byteCount = Math.ceil(bits / 8);
		// var byteOffset = Math.floor(offset / 8);

		// var source = [].slice.call(this,
		// byteOffset, byteOffset + byteCount);

		// var start = ((byteOffset + 1) * 8) - offset;
		// console.log(source, start);
		// var value = 0, read = 0;
		// for (var i = 0; i < bits;) {
		// if ((bits - i) >= 8 && ((offset & 7) === 0)) {
		// value \|= (bytes[offset >> 3] << i);
		// read = 8;
		// } else {
		// value \|= ((this[offset >> 3] >> (offset & 7) & 0x1) << i);
		// read = 1;
		// }

		// offset += read;
		// i += read;
		// }

		// return value >>> 0;
		}
		Buffer.prototype.readBits = readBits;


		module.exports = {};

lib/types.js

		@@ -7,4 +7,4 @@ module.exports = [
		'jpg',
		'tiff'
		// 'webp'
		];
		'tiff',
		'webp'
		];

lib/types/webp.js

		@@ -7,3 +7,2 @@ // based on https://developers.google.com/speed/webp/docs/riff_container
		var vp8Header = 'VP8' === buffer.toString('ascii', 12, 15);
		// console.log(buffer.readUInt32LE(4));
		return (riffHeader && webpHeader && vp8Header);
		@@ -13,25 +12,37 @@ }
		function calculate (buffer) {

		var chunkHeader = buffer.toString('ascii', 12, 16);
		var lossless = ('L' === chunkHeader[3]);
		if (lossless) {
		// var chunkSize = buffer.readUInt32LE(16);
		var signature = buffer.toString('hex', 20, 21);
		if (signature === '2f') {
		// read 14 bits of width & 14 bits of height
		var bits = buffer.slice(21, 25).toJSON();
		bits = bits.map(function (dec) {
		// console.log(dec.toString(2));
		return dec.toString(2);
		}).join('');
		// console.log(bits);
		// var width = (bits[0] << 6) + (bits[1] >> 2);
		// var height = bits[]
		// console.log(bits, width, (bits[0] << 6), (bits[1] >> 2));
		}
		} else {
		// TODO: implementation for lossy webp
		buffer = buffer.slice(20, 30);

		// Lossless webp stream signature
		if (chunkHeader === 'VP8 ' && buffer[0] !== 0x2f) {
		return calculateLossy(buffer);
		}

		// Lossy webp stream signature
		var signature = buffer.toString('hex', 3, 6);
		if (chunkHeader === 'VP8L' && signature !== '9d012a') {
		return calculateLossless(buffer);
		}

		return false;
		}

		function calculateLossless (buffer) {
		return {
		'width': 1 + (((buffer[2] & 0x3F) << 8) \| buffer[1]),
		'height': 1 + (((buffer[4] & 0xF) << 10) \| (buffer[3] << 2) \|
		((buffer[2] & 0xC0) >> 6))
		};
		}

		function calculateLossy (buffer) {
		// `& 0x3fff` returns the last 14 bits
		// TODO: include webp scaling in the calculations
		return {
		'width': buffer.readInt16LE(6) & 0x3fff,
		'height': buffer.readInt16LE(8) & 0x3fff
		};
		}

		module.exports = {
		@@ -38,0 +49,0 @@ 'detect': isWebP,

package.json

		{
		"name": "image-size",
		"version": "0.1.17",
		"version": "0.1.20",
		"description": "get dimensions of any image file",
		@@ -5,0 +5,0 @@ "main": "lib/index.js",

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