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photostructure / exiftool-vendored.js

Fast, cross-platform Node.js access to ExifTool
https://photostructure.github.io/exiftool-vendored.js/
MIT License
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Regression on timezone extraction from an iPhone photo #160

Closed Offirmo closed 11 months ago

Offirmo commented 11 months ago

First thanks again for this useful lib. I realized that we're both writing a tool to sort our photos. Maybe we should compare notes 😅

Describe the bug A few month ago, the timezone on the attached picture was properly recognized as Australia/Sydney and passed as such in ExifDateTime (the picture was indeed taken in Sydney)

However, restarting dev today with the latest version of exiftool-vendored, the timezone is now reported as UTC+10

To Reproduce Here is the picture (HEIC) IMG_7477.heic.zip

From XnView "EXIF" view we can see

Expected behavior The timezone should be Australia/Sydney

Environment (please complete the following information):

Thanks!

mceachen commented 11 months ago

Thanks for reporting. What is the tag name for the date with the wrong time zone?

(Also, you may need to use your own instance with custom options if you don’t want backfilled timezones)

Offirmo commented 11 months ago

My app is trying a list of dates and trying to pick the most promising one. I need to dig a little bit to give you this info.

I'm very happy with backfilled timezones, the regression is going from Australia/Sydney (correct) to UTC+10 (inferior)

mceachen commented 11 months ago

I took a look at the attached file. UTC+10 is Australian Eastern Standard Time (AEST), which is the correct offset for July for Australia/Sydney.

Out of an abundance of caution, I'm purposefully not back-filling ExifDateTime instances that already have a zone specified in their raw form. In this instance, they match, but the offset is actually more reliable than the zone, as the zone requires a context time to determine the final offset. The prior brute-override was arguably a bug.

If you need the prior behavior, feel free to add a layer on top of your call to .read which does this sort of forced rewriting of the zone--there's example code in the read task: https://github.com/photostructure/exiftool-vendored.js/blob/df569e630791df3655cb13c559e1dd7569b22b1a/src/ReadTask.ts#L292