> Is there any reason why you don't want to do it yourself, simply loading the > first KBs of the file ? I haven't been writing JPEG decoders for a loooong > time, but I'm pretty sure the EXIF (APPn) marker must be written before the > image data (the SOS marker(s)), so it is at the beginning of the file.
I had thought of that , too. The reason is that I have no experience whatsoever with the JPEG file format. Nor with the EXIF file format. Also, I need to be able to parse at least JPEG, PNG, TIF, GIF, and I'd like to add HEIC. Best regards, Gabriel > You could simply parse the first markers of the file (0xFF, 0x??) and look > for the EXIF one. The JPEG file format (JFIF) is pretty simple to decode (I > can help). > > Regards, > > Raphaël > > > On Sun, Jan 8, 2023 at 3:30 PM Chris Ridd via Cocoa-dev > <cocoa-dev@lists.apple.com> wrote: > > > > On 7 Jan 2023, at 23:31, Gabriel Zachmann via Cocoa-dev > > <cocoa-dev@lists.apple.com> wrote: > > > >> > >> I wonder if there is a method to load the EXIF data out of the files > >> without opening them completely. That would seem like the ideal approach. > > > > That's the approach I am looking for, but I haven't found any API to do > > that. > > I’m sure you’ve tried the following, but in case you haven’t: > > * investigate mmapping each file into memory and use a version of the API > that takes NSData/CFData instead of a file/URL to get the EXIF information. > > * if the files are indexed by Spotlight, can you get the EXIF information > from a NSMetadataQuery search? > > Chris > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/cocoa-dev/lemoine.raphael%40gmail.com > > This email sent to lemoine.raph...@gmail.com
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