MobileRead Forums - View Single Post - KindleUnpack (MobiUnpack): Extracts text, images and metadata from Kindle/Mobi files

NiLuJe · 07-17-2013, 12:44 AM

Hello again!

I'm still using a stripped down KindleUnpack in the Kindle ScreenSavers hack, and one user just ran into a weird thing: a JPEG file with no EXIF or JFIF header, used as the cover.

imghdr doesn't handle those, so it gets discarded as an unknown resource. FWIW, GIMP chokes on it too, but ImageMagick handles it fine. Since I'm using IM, I amended the imghdr check with another one, right after:

Code:

                # imghdr only checks for JFIF or Exif JPEG files. Apparently, there are some with only the magic JPEG bytes out there... ImageMagick handle those, so, do it too.
                if imgtype is None and data[0:2] == chr(0xFF) + chr(0xD8):
                    imgtype = "jpeg"

Has anyone ever encountered JPEG files like that before?

07-17-2013, 12:44 AM	#553
NiLuJe BLAM! Posts: 13,477 Karma: 26012492 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	Hello again! I'm still using a stripped down KindleUnpack in the Kindle ScreenSavers hack, and one user just ran into a weird thing: a JPEG file with no EXIF or JFIF header, used as the cover. imghdr doesn't handle those, so it gets discarded as an unknown resource. FWIW, GIMP chokes on it too, but ImageMagick handles it fine. Since I'm using IM, I amended the imghdr check with another one, right after: Code: # imghdr only checks for JFIF or Exif JPEG files. Apparently, there are some with only the magic JPEG bytes out there... ImageMagick handle those, so, do it too. if imgtype is None and data[0:2] == chr(0xFF) + chr(0xD8): imgtype = "jpeg" Has anyone ever encountered JPEG files like that before? Last edited by NiLuJe; 07-17-2013 at 12:49 AM.