[Libexif-devel] listing headers

[Torsten C. <tc...@va...>]

Hey folks,

Need some help with the API. Goal is to add/modify the GPS bit in the
exif information. But for now I just wanted to see what exif headers
are set. So I am iterating:

    unsigned int i;
    unsigned int t;
    const char *name;
    char value[128];
    const char *v;

    for (i = 0; i < EXIF_IFD_COUNT; i++) {
        ExifContent *ifd = ed->ifd[i];

        const char *ifd_name = exif_ifd_get_name(i);

        if (!ifd_name) {
            continue;
        }

        NSLog(@"idf: %s", ifd_name);

        for (t = 0; t < 0xffff; t++) {
            name = exif_tag_get_title(t);
            if (!name) {
                continue;
            }

            ExifEntry *entry = exif_content_get_entry(ifd, t);
            if (!entry) {
                continue;
            }

            v = exif_entry_get_value(entry, value, sizeof(value));

            if (!v) {
                continue;
            }

            NSLog(@"%s = %s", name, value);
        }
    }

But it seems like I am not getting all information

    idf: GPS
    GPS tag version = 0x02, 0x02, 0x00, 0x00
    InteroperabilityIndex = N
    InteroperabilityVersion = 30.00, 13.00, 53.58
    East or West Longitude = W
    Longitude = 89.00, 40.00, 11.16

For one the Longitude format is awkward. But more importantly - the
Latitude is missing. Using exiv2 on the file I get

 0x0000 GPSInfo      GPSVersionID                Byte        4  2 2 0 0
 0x0001 GPSInfo      GPSLatitudeRef              Ascii       2  N
 0x0002 GPSInfo      GPSLatitude                 Rational    3  30/1
13/1 133941/2500
 0x0003 GPSInfo      GPSLongitudeRef             Ascii       2  W
 0x0004 GPSInfo      GPSLongitude                Rational    3  89/1
40/1 6978/625

What am I doing wrong?

Oh btw: I came across this as well

  Unknown tag 0x882a (entry 9 in '0'). Please report this tag to
<lib...@li...>.

cheers
--
Torsten