2025-09-05 14:59:21 +08:00

786 lines
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JavaScript
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const decoder = new TextDecoder();
const toUTF8String = (input, start = 0, end = input.length) => decoder.decode(input.slice(start, end));
const toHexString = (input, start = 0, end = input.length) => input.slice(start, end).reduce((memo, i) => memo + ("0" + i.toString(16)).slice(-2), "");
const readInt16LE = (input, offset = 0) => {
const val = input[offset] + input[offset + 1] * 2 ** 8;
return val | (val & 2 ** 15) * 131070;
};
const readUInt16BE = (input, offset = 0) => input[offset] * 2 ** 8 + input[offset + 1];
const readUInt16LE = (input, offset = 0) => input[offset] + input[offset + 1] * 2 ** 8;
const readUInt24LE = (input, offset = 0) => input[offset] + input[offset + 1] * 2 ** 8 + input[offset + 2] * 2 ** 16;
const readInt32LE = (input, offset = 0) => input[offset] + input[offset + 1] * 2 ** 8 + input[offset + 2] * 2 ** 16 + (input[offset + 3] << 24);
const readUInt32BE = (input, offset = 0) => input[offset] * 2 ** 24 + input[offset + 1] * 2 ** 16 + input[offset + 2] * 2 ** 8 + input[offset + 3];
const readUInt32LE = (input, offset = 0) => input[offset] + input[offset + 1] * 2 ** 8 + input[offset + 2] * 2 ** 16 + input[offset + 3] * 2 ** 24;
const methods = {
readUInt16BE,
readUInt16LE,
readUInt32BE,
readUInt32LE
};
function readUInt(input, bits, offset, isBigEndian) {
offset = offset || 0;
const endian = isBigEndian ? "BE" : "LE";
const methodName = "readUInt" + bits + endian;
return methods[methodName](input, offset);
}
const BMP = {
validate: (input) => toUTF8String(input, 0, 2) === "BM",
calculate: (input) => ({
height: Math.abs(readInt32LE(input, 22)),
width: readUInt32LE(input, 18)
})
};
const TYPE_ICON = 1;
const SIZE_HEADER$1 = 2 + 2 + 2;
const SIZE_IMAGE_ENTRY = 1 + 1 + 1 + 1 + 2 + 2 + 4 + 4;
function getSizeFromOffset(input, offset) {
const value = input[offset];
return value === 0 ? 256 : value;
}
function getImageSize$1(input, imageIndex) {
const offset = SIZE_HEADER$1 + imageIndex * SIZE_IMAGE_ENTRY;
return {
height: getSizeFromOffset(input, offset + 1),
width: getSizeFromOffset(input, offset)
};
}
const ICO = {
validate(input) {
const reserved = readUInt16LE(input, 0);
const imageCount = readUInt16LE(input, 4);
if (reserved !== 0 || imageCount === 0) {
return false;
}
const imageType = readUInt16LE(input, 2);
return imageType === TYPE_ICON;
},
calculate(input) {
const nbImages = readUInt16LE(input, 4);
const imageSize = getImageSize$1(input, 0);
if (nbImages === 1) {
return imageSize;
}
const imgs = [imageSize];
for (let imageIndex = 1; imageIndex < nbImages; imageIndex += 1) {
imgs.push(getImageSize$1(input, imageIndex));
}
return {
height: imageSize.height,
images: imgs,
width: imageSize.width
};
}
};
const TYPE_CURSOR = 2;
const CUR = {
validate(input) {
const reserved = readUInt16LE(input, 0);
const imageCount = readUInt16LE(input, 4);
if (reserved !== 0 || imageCount === 0) {
return false;
}
const imageType = readUInt16LE(input, 2);
return imageType === TYPE_CURSOR;
},
calculate: (input) => ICO.calculate(input)
};
const DDS = {
validate: (input) => readUInt32LE(input, 0) === 542327876,
calculate: (input) => ({
height: readUInt32LE(input, 12),
width: readUInt32LE(input, 16)
})
};
const gifRegexp = /^GIF8[79]a/;
const GIF = {
validate: (input) => gifRegexp.test(toUTF8String(input, 0, 6)),
calculate: (input) => ({
height: readUInt16LE(input, 8),
width: readUInt16LE(input, 6)
})
};
const SIZE_HEADER = 4 + 4;
const FILE_LENGTH_OFFSET = 4;
const ENTRY_LENGTH_OFFSET = 4;
const ICON_TYPE_SIZE = {
ICON: 32,
"ICN#": 32,
// m => 16 x 16
"icm#": 16,
icm4: 16,
icm8: 16,
// s => 16 x 16
"ics#": 16,
ics4: 16,
ics8: 16,
is32: 16,
s8mk: 16,
icp4: 16,
// l => 32 x 32
icl4: 32,
icl8: 32,
il32: 32,
l8mk: 32,
icp5: 32,
ic11: 32,
// h => 48 x 48
ich4: 48,
ich8: 48,
ih32: 48,
h8mk: 48,
// . => 64 x 64
icp6: 64,
ic12: 32,
// t => 128 x 128
it32: 128,
t8mk: 128,
ic07: 128,
// . => 256 x 256
ic08: 256,
ic13: 256,
// . => 512 x 512
ic09: 512,
ic14: 512,
// . => 1024 x 1024
ic10: 1024
};
function readImageHeader(input, imageOffset) {
const imageLengthOffset = imageOffset + ENTRY_LENGTH_OFFSET;
return [
toUTF8String(input, imageOffset, imageLengthOffset),
readUInt32BE(input, imageLengthOffset)
];
}
function getImageSize(type) {
const size = ICON_TYPE_SIZE[type];
return { width: size, height: size, type };
}
const ICNS = {
validate: (input) => toUTF8String(input, 0, 4) === "icns",
calculate(input) {
const inputLength = input.length;
const fileLength = readUInt32BE(input, FILE_LENGTH_OFFSET);
let imageOffset = SIZE_HEADER;
let imageHeader = readImageHeader(input, imageOffset);
let imageSize = getImageSize(imageHeader[0]);
imageOffset += imageHeader[1];
if (imageOffset === fileLength) {
return imageSize;
}
const result = {
height: imageSize.height,
images: [imageSize],
width: imageSize.width
};
while (imageOffset < fileLength && imageOffset < inputLength) {
imageHeader = readImageHeader(input, imageOffset);
imageSize = getImageSize(imageHeader[0]);
imageOffset += imageHeader[1];
result.images.push(imageSize);
}
return result;
}
};
const J2C = {
// TODO: this doesn't seem right. SIZ marker doesn't have to be right after the SOC
validate: (input) => toHexString(input, 0, 4) === "ff4fff51",
calculate: (input) => ({
height: readUInt32BE(input, 12),
width: readUInt32BE(input, 8)
})
};
const BoxTypes = {
ftyp: "66747970",
ihdr: "69686472",
jp2h: "6a703268",
jp__: "6a502020",
rreq: "72726571",
xml_: "786d6c20"
};
const calculateRREQLength = (box) => {
const unit = box[0];
let offset = 1 + 2 * unit;
const numStdFlags = readUInt16BE(box, offset);
const flagsLength = numStdFlags * (2 + unit);
offset = offset + 2 + flagsLength;
const numVendorFeatures = readUInt16BE(box, offset);
const featuresLength = numVendorFeatures * (16 + unit);
return offset + 2 + featuresLength;
};
const parseIHDR = (box) => {
return {
height: readUInt32BE(box, 4),
width: readUInt32BE(box, 8)
};
};
const JP2 = {
validate(input) {
const signature = toHexString(input, 4, 8);
const signatureLength = readUInt32BE(input, 0);
if (signature !== BoxTypes.jp__ || signatureLength < 1) {
return false;
}
const ftypeBoxStart = signatureLength + 4;
const ftypBoxLength = readUInt32BE(input, signatureLength);
const ftypBox = input.slice(ftypeBoxStart, ftypeBoxStart + ftypBoxLength);
return toHexString(ftypBox, 0, 4) === BoxTypes.ftyp;
},
calculate(input) {
const signatureLength = readUInt32BE(input, 0);
const ftypBoxLength = readUInt16BE(input, signatureLength + 2);
let offset = signatureLength + 4 + ftypBoxLength;
const nextBoxType = toHexString(input, offset, offset + 4);
switch (nextBoxType) {
case BoxTypes.rreq: {
const MAGIC = 4;
offset = offset + 4 + MAGIC + calculateRREQLength(input.slice(offset + 4));
return parseIHDR(input.slice(offset + 8, offset + 24));
}
case BoxTypes.jp2h: {
return parseIHDR(input.slice(offset + 8, offset + 24));
}
default: {
throw new TypeError(
"Unsupported header found: " + toUTF8String(input, offset, offset + 4)
);
}
}
}
};
const EXIF_MARKER = "45786966";
const APP1_DATA_SIZE_BYTES = 2;
const EXIF_HEADER_BYTES = 6;
const TIFF_BYTE_ALIGN_BYTES = 2;
const BIG_ENDIAN_BYTE_ALIGN = "4d4d";
const LITTLE_ENDIAN_BYTE_ALIGN = "4949";
const IDF_ENTRY_BYTES = 12;
const NUM_DIRECTORY_ENTRIES_BYTES = 2;
function isEXIF(input) {
return toHexString(input, 2, 6) === EXIF_MARKER;
}
function extractSize(input, index) {
return {
height: readUInt16BE(input, index),
width: readUInt16BE(input, index + 2)
};
}
function extractOrientation(exifBlock, isBigEndian) {
const idfOffset = 8;
const offset = EXIF_HEADER_BYTES + idfOffset;
const idfDirectoryEntries = readUInt(exifBlock, 16, offset, isBigEndian);
for (let directoryEntryNumber = 0; directoryEntryNumber < idfDirectoryEntries; directoryEntryNumber++) {
const start = offset + NUM_DIRECTORY_ENTRIES_BYTES + directoryEntryNumber * IDF_ENTRY_BYTES;
const end = start + IDF_ENTRY_BYTES;
if (start > exifBlock.length) {
return;
}
const block = exifBlock.slice(start, end);
const tagNumber = readUInt(block, 16, 0, isBigEndian);
if (tagNumber === 274) {
const dataFormat = readUInt(block, 16, 2, isBigEndian);
if (dataFormat !== 3) {
return;
}
const numberOfComponents = readUInt(block, 32, 4, isBigEndian);
if (numberOfComponents !== 1) {
return;
}
return readUInt(block, 16, 8, isBigEndian);
}
}
}
function validateExifBlock(input, index) {
const exifBlock = input.slice(APP1_DATA_SIZE_BYTES, index);
const byteAlign = toHexString(
exifBlock,
EXIF_HEADER_BYTES,
EXIF_HEADER_BYTES + TIFF_BYTE_ALIGN_BYTES
);
const isBigEndian = byteAlign === BIG_ENDIAN_BYTE_ALIGN;
const isLittleEndian = byteAlign === LITTLE_ENDIAN_BYTE_ALIGN;
if (isBigEndian || isLittleEndian) {
return extractOrientation(exifBlock, isBigEndian);
}
}
function validateInput(input, index) {
if (index > input.length) {
throw new TypeError("Corrupt JPG, exceeded buffer limits");
}
if (input[index] !== 255) {
throw new TypeError("Invalid JPG, marker table corrupted");
}
}
const JPG = {
validate: (input) => toHexString(input, 0, 2) === "ffd8",
calculate(input) {
input = input.slice(4);
let orientation;
let next;
while (input.length > 0) {
const i = readUInt16BE(input, 0);
if (isEXIF(input)) {
orientation = validateExifBlock(input, i);
}
validateInput(input, i);
next = input[i + 1];
if (next === 192 || next === 193 || next === 194) {
const size = extractSize(input, i + 5);
if (!orientation) {
return size;
}
return {
height: size.height,
orientation,
width: size.width
};
}
input = input.slice(i + 2);
}
throw new TypeError("Invalid JPG, no size found");
}
};
const KTX = {
validate: (input) => toUTF8String(input, 1, 7) === "KTX 11",
calculate: (input) => ({
height: readUInt32LE(input, 40),
width: readUInt32LE(input, 36)
})
};
const pngSignature = "PNG\r\n\n";
const pngImageHeaderChunkName = "IHDR";
const pngFriedChunkName = "CgBI";
const PNG = {
validate(input) {
if (pngSignature === toUTF8String(input, 1, 8)) {
let chunkName = toUTF8String(input, 12, 16);
if (chunkName === pngFriedChunkName) {
chunkName = toUTF8String(input, 28, 32);
}
if (chunkName !== pngImageHeaderChunkName) {
throw new TypeError("Invalid PNG");
}
return true;
}
return false;
},
calculate(input) {
if (toUTF8String(input, 12, 16) === pngFriedChunkName) {
return {
height: readUInt32BE(input, 36),
width: readUInt32BE(input, 32)
};
}
return {
height: readUInt32BE(input, 20),
width: readUInt32BE(input, 16)
};
}
};
const PNMTypes = {
P1: "pbm/ascii",
P2: "pgm/ascii",
P3: "ppm/ascii",
P4: "pbm",
P5: "pgm",
P6: "ppm",
P7: "pam",
PF: "pfm"
};
const handlers = {
default: (lines) => {
let dimensions = [];
while (lines.length > 0) {
const line = lines.shift();
if (line[0] === "#") {
continue;
}
dimensions = line.split(" ");
break;
}
if (dimensions.length === 2) {
return {
height: Number.parseInt(dimensions[1], 10),
width: Number.parseInt(dimensions[0], 10)
};
} else {
throw new TypeError("Invalid PNM");
}
},
pam: (lines) => {
const size = {};
while (lines.length > 0) {
const line = lines.shift();
if (line.length > 16 || (line.codePointAt(0) || 0) > 128) {
continue;
}
const [key, value] = line.split(" ");
if (key && value) {
size[key.toLowerCase()] = Number.parseInt(value, 10);
}
if (size.height && size.width) {
break;
}
}
if (size.height && size.width) {
return {
height: size.height,
width: size.width
};
} else {
throw new TypeError("Invalid PAM");
}
}
};
const PNM = {
validate: (input) => toUTF8String(input, 0, 2) in PNMTypes,
calculate(input) {
const signature = toUTF8String(input, 0, 2);
const type = PNMTypes[signature];
const lines = toUTF8String(input, 3).split(/[\n\r]+/);
const handler = handlers[type] || handlers.default;
return handler(lines);
}
};
const PSD = {
validate: (input) => toUTF8String(input, 0, 4) === "8BPS",
calculate: (input) => ({
height: readUInt32BE(input, 14),
width: readUInt32BE(input, 18)
})
};
const svgReg = /<svg\s([^"'>]|"[^"]*"|'[^']*')*>/;
const extractorRegExps = {
height: /\sheight=(["'])([^%]+?)\1/,
root: svgReg,
viewbox: /\sviewbox=(["'])(.+?)\1/i,
width: /\swidth=(["'])([^%]+?)\1/
};
const INCH_CM = 2.54;
const units = {
in: 96,
cm: 96 / INCH_CM,
em: 16,
ex: 8,
m: 96 / INCH_CM * 100,
mm: 96 / INCH_CM / 10,
pc: 96 / 72 / 12,
pt: 96 / 72,
px: 1
};
const unitsReg = new RegExp(
`^([0-9.]+(?:e\\d+)?)(${Object.keys(units).join("|")})?$`
);
function parseLength(len) {
const m = unitsReg.exec(len);
if (!m) {
return void 0;
}
return Math.round(Number(m[1]) * (units[m[2]] || 1));
}
function parseViewbox(viewbox) {
const bounds = viewbox.split(" ");
return {
height: parseLength(bounds[3]),
width: parseLength(bounds[2])
};
}
function parseAttributes(root) {
const width = root.match(extractorRegExps.width);
const height = root.match(extractorRegExps.height);
const viewbox = root.match(extractorRegExps.viewbox);
return {
height: height && parseLength(height[2]),
viewbox: viewbox && parseViewbox(viewbox[2]),
width: width && parseLength(width[2])
};
}
function calculateByDimensions(attrs) {
return {
height: attrs.height,
width: attrs.width
};
}
function calculateByViewbox(attrs, viewbox) {
const ratio = viewbox.width / viewbox.height;
if (attrs.width) {
return {
height: Math.floor(attrs.width / ratio),
width: attrs.width
};
}
if (attrs.height) {
return {
height: attrs.height,
width: Math.floor(attrs.height * ratio)
};
}
return {
height: viewbox.height,
width: viewbox.width
};
}
const SVG = {
// Scan only the first kilo-byte to speed up the check on larger files
validate: (input) => svgReg.test(toUTF8String(input, 0, 1e3)),
calculate(input) {
const root = toUTF8String(input).match(extractorRegExps.root);
if (root) {
const attrs = parseAttributes(root[0]);
if (attrs.width && attrs.height) {
return calculateByDimensions(attrs);
}
if (attrs.viewbox) {
return calculateByViewbox(attrs, attrs.viewbox);
}
}
throw new TypeError("Invalid SVG");
}
};
const TGA = {
validate(input) {
return readUInt16LE(input, 0) === 0 && readUInt16LE(input, 4) === 0;
},
calculate(input) {
return {
height: readUInt16LE(input, 14),
width: readUInt16LE(input, 12)
};
}
};
function readIFD(buffer, isBigEndian) {
const ifdOffset = readUInt(buffer, 32, 4, isBigEndian);
let bufferSize = 1024;
const fileSize = buffer.length;
if (ifdOffset + bufferSize > fileSize) {
bufferSize = fileSize - ifdOffset - 10;
}
return buffer.slice(ifdOffset + 2, ifdOffset + 2 + bufferSize);
}
function readValue(buffer, isBigEndian) {
const low = readUInt(buffer, 16, 8, isBigEndian);
const high = readUInt(buffer, 16, 10, isBigEndian);
return (high << 16) + low;
}
function nextTag(buffer) {
if (buffer.length > 24) {
return buffer.slice(12);
}
}
function extractTags(buffer, isBigEndian) {
const tags = {};
let temp = buffer;
while (temp && temp.length > 0) {
const code = readUInt(temp, 16, 0, isBigEndian);
const type = readUInt(temp, 16, 2, isBigEndian);
const length = readUInt(temp, 32, 4, isBigEndian);
if (code === 0) {
break;
} else {
if (length === 1 && (type === 3 || type === 4)) {
tags[code] = readValue(temp, isBigEndian);
}
temp = nextTag(temp);
}
}
return tags;
}
function determineEndianness(input) {
const signature = toUTF8String(input, 0, 2);
if (signature === "II") {
return "LE";
} else if (signature === "MM") {
return "BE";
}
}
const signatures = /* @__PURE__ */ new Set([
// '492049', // currently not supported
"49492a00",
// Little endian
"4d4d002a"
// Big Endian
// '4d4d002a', // BigTIFF > 4GB. currently not supported
]);
const TIFF = {
validate: (input) => signatures.has(toHexString(input, 0, 4)),
calculate(input) {
const isBigEndian = determineEndianness(input) === "BE";
const ifdBuffer = readIFD(input, isBigEndian);
const tags = extractTags(ifdBuffer, isBigEndian);
const width = tags[256];
const height = tags[257];
if (!width || !height) {
throw new TypeError("Invalid Tiff. Missing tags");
}
return { height, width };
}
};
function calculateExtended(input) {
return {
height: 1 + readUInt24LE(input, 7),
width: 1 + readUInt24LE(input, 4)
};
}
function calculateLossless(input) {
return {
height: 1 + ((input[4] & 15) << 10 | input[3] << 2 | (input[2] & 192) >> 6),
width: 1 + ((input[2] & 63) << 8 | input[1])
};
}
function calculateLossy(input) {
return {
height: readInt16LE(input, 8) & 16383,
width: readInt16LE(input, 6) & 16383
};
}
const WEBP = {
validate(input) {
const riffHeader = toUTF8String(input, 0, 4) === "RIFF";
const webpHeader = toUTF8String(input, 8, 12) === "WEBP";
const vp8Header = toUTF8String(input, 12, 15) === "VP8";
return riffHeader && webpHeader && vp8Header;
},
calculate(input) {
const chunkHeader = toUTF8String(input, 12, 16);
input = input.slice(20, 30);
if (chunkHeader === "VP8X") {
const extendedHeader = input[0];
const validStart = (extendedHeader & 192) === 0;
const validEnd = (extendedHeader & 1) === 0;
if (validStart && validEnd) {
return calculateExtended(input);
} else {
throw new TypeError("Invalid WebP");
}
}
if (chunkHeader === "VP8 " && input[0] !== 47) {
return calculateLossy(input);
}
const signature = toHexString(input, 3, 6);
if (chunkHeader === "VP8L" && signature !== "9d012a") {
return calculateLossless(input);
}
throw new TypeError("Invalid WebP");
}
};
const AVIF = {
validate: (input) => toUTF8String(input, 8, 12) === "avif",
calculate: (input) => {
const metaBox = findBox(input, "meta");
const iprpBox = findBox(
input,
"iprp",
metaBox.offset + 12,
metaBox.offset + metaBox.size
);
const ipcoBox = findBox(
input,
"ipco",
iprpBox.offset + 8,
iprpBox.offset + iprpBox.size
);
const ispeBox = findBox(
input,
"ispe",
ipcoBox.offset + 8,
ipcoBox.offset + ipcoBox.size
);
const width = readUInt32BE(input, ispeBox.offset + 12);
const height = readUInt32BE(input, ispeBox.offset + 16);
return { width, height };
}
};
function findBox(input, type, startOffset = 0, endOffset = input.length) {
for (let offset = startOffset; offset < endOffset; ) {
const size = readUInt32BE(input, offset);
const boxType = toUTF8String(input, offset + 4, offset + 8);
if (boxType === type) {
return { offset, size };
}
if (size <= 0 || offset + size > endOffset) {
break;
}
offset += size;
}
throw new Error(`${type} box not found`);
}
const typeHandlers = {
bmp: BMP,
cur: CUR,
dds: DDS,
gif: GIF,
icns: ICNS,
ico: ICO,
j2c: J2C,
jp2: JP2,
jpg: JPG,
ktx: KTX,
png: PNG,
pnm: PNM,
psd: PSD,
svg: SVG,
tga: TGA,
tiff: TIFF,
webp: WEBP,
avif: AVIF
};
const keys = Object.keys(typeHandlers);
const firstBytes = {
56: "psd",
66: "bmp",
68: "dds",
71: "gif",
73: "tiff",
77: "tiff",
82: "webp",
105: "icns",
137: "png",
255: "jpg"
};
function detector(input) {
const byte = input[0];
if (byte in firstBytes) {
const type = firstBytes[byte];
if (type && typeHandlers[type].validate(input)) {
return type;
}
}
return keys.find((key) => typeHandlers[key].validate(input));
}
function imageMeta(input) {
if (!(input instanceof Uint8Array)) {
throw new TypeError("Input should be a Uint8Array");
}
const type = detector(input);
if (type !== void 0 && type in typeHandlers) {
const size = typeHandlers[type].calculate(input);
if (size !== void 0) {
size.type = type;
return size;
}
}
throw new TypeError(`Unsupported file type: ${type}`);
}
export { imageMeta };