diegomura / jay-peg Goto Github PK

When I use react-pdf, I'm trying to insert a JPG image but for some reason the image reader fail when he try to decode EXIF metadata.
So i tried to reproduce the minimal code to get the error:

const JPEG = require('jay-peg').default;
const fs = require('fs');
const notWorkingImage = fs.readFileSync('/Users/me/Downloads/not-working.jpg');
JPEG.decode(notWorkingImage);

Leads to:

ReferenceError: IFDHandler is not defined
    at $0b53e5b7c7fe341c$var$IDFEntries.decode (/Users/me/Downloads/jpg-test/node_modules/jay-peg/dist/index.cjs:347:36)
    at $aa8b66bae6abe658$export$eabc71f011df675a._parseFields (/Users/me/Downloads/jpg-test/node_modules/restructure/dist/main.cjs:750:29)
    at $aa8b66bae6abe658$export$eabc71f011df675a.decode (/Users/me/Downloads/jpg-test/node_modules/restructure/dist/main.cjs:721:14)
    at $0b53e5b7c7fe341c$var$TIFFHeader.decode (/Users/me/Downloads/jpg-test/node_modules/jay-peg/dist/index.cjs:368:63)
    at $fcb208a95f6d048b$export$95a8b60f4da7dec8._parseFields (/Users/me/Downloads/jpg-test/node_modules/restructure/dist/main.cjs:750:29)
    at $fcb208a95f6d048b$export$95a8b60f4da7dec8.decode (/Users/me/Downloads/jpg-test/node_modules/restructure/dist/main.cjs:817:14)
    at $8ea28a08eae2a116$export$c4be6576ca6fe4aa.decode (/Users/me/Downloads/jpg-test/node_modules/restructure/dist/main.cjs:382:58)
    at $8ea28a08eae2a116$export$c4be6576ca6fe4aa.fromBuffer (/Users/me/Downloads/jpg-test/node_modules/restructure/dist/main.cjs:208:21)
    at Object.$4fa36e821943b400$var$decode [as decode] (/Users/me/Downloads/jpg-test/node_modules/jay-peg/dist/index.cjs:489:48)
    at Object.<anonymous> (/Users/me/Downloads/jpg-test/index.js:7:22)

The line of code who throw the error is:

entries.gpsInfo = IFDHandler(subuffer, $0b53e5b7c7fe341c$var$tags.gps, gps);

And in fact I don't understand what is this IFDHandler. Cause when I read the sources, the corresponding line of code is:

entries.gpsInfo = this._decodeIDFEntries(buffer, tags.gps, gps, true);

and there is no mention of an IFDHandler.

Seems like some JPEG encoders stuff extra data after EOI marker (see e.g. https://exiftool.org/forum/index.php?topic=4374.0). We bumped into this in real world usage (with react-pdf).

Would it be possible to end decoding at EOI marker and ignore rest of the data?

Looks like npm run build (or whatever you're using to compile) may not have been ran before npm publish for 1.0.2..

For example, the dist/index.cjs still shows on line 347

entries.gpsInfo = IFDHandler(subuffer, $0b53e5b7c7fe341c$var$tags.gps, gps);

rather than

entries.gpsInfo = this._decodeIDFEntries(buffer, $0b53e5b7c7fe341c$var$tags.gps, gps);

but line 271 is the src/marjers/exif.js in the bundle is as expected:

entries.gpsInfo = this._decodeIDFEntries(buffer, tags.gps, gps, true);

Result being i need to run npm i && npm run build in the node_modules/jay-peg after npm i to ensure the issue related to this change is resolved

in exif marker src/markers/exif.js IFDHandler is undefined. so printing an image with geolocation in @react-pdf/renderer will throw an error.

@diegomura tell me if I can help. thanks in advance!

Some JPEGs have a non-standard APP0 segment. It is non-standard but it breaks parsing because jay-peg assumes fixed size APP0.

I can't give the original image but here's the hex for the broken segment: (includes APP0 marker, two-byte size, and the whole marker data)

0xFF,0xE0,0x00,0x14,0x4A,0x46,0x49,0x46,0x00,0x01,0x01,0x01,0x01,0x2C,0x01,0x2C,0x00,0x00,0x41,0x4D,0x50,0x46

The last four bytes spell out AMPF in ascii, which according to a random googling is somehow related to some Apple extension. See also https://github.com/exiftool/exiftool/blob/master/lib/Image/ExifTool.pm#L2226