Fix up last exif read and write

postprocess.c

@@ -210,12 +210,6 @@ create_exif(struct Imagedata data)
     entry = init_tag(exif, EXIF_IFD_EXIF, EXIF_TAG_FNUMBER);
     exif_set_rational(entry->data, EXIF_BYTE_ORDER_INTEL, rational);
 
-    // aperture
-    rational.numerator = (long) ((double) data.aperture * denominator);
-    rational.denominator = denominator;
-    entry = init_tag(exif, EXIF_IFD_EXIF, EXIF_TAG_APERTURE_VALUE);
-    exif_set_rational(entry->data, EXIF_BYTE_ORDER_INTEL, rational);
-
     // focal length
     rational.numerator = (long) ((double) data.focal_length * denominator);
     rational.denominator = denominator;
@@ -223,13 +217,11 @@ create_exif(struct Imagedata data)
     exif_set_rational(entry->data, EXIF_BYTE_ORDER_INTEL, rational);
 
     // focal length, 35mm equiv
-    rational.numerator = (long) ((double) data.focal_length_35mm * denominator);
-    rational.denominator = denominator;
     entry = init_tag(exif, EXIF_IFD_EXIF, EXIF_TAG_FOCAL_LENGTH_IN_35MM_FILM);
-    exif_set_rational(entry->data, EXIF_BYTE_ORDER_INTEL, rational);
+    exif_set_short(entry->data, EXIF_BYTE_ORDER_INTEL, data.focal_length_35mm);
 
     // ISO
-    entry = init_tag(exif, EXIF_IFD_EXIF, EXIF_TAG_ISO_SPEED);
+    entry = init_tag(exif, EXIF_IFD_EXIF, EXIF_TAG_ISO_SPEED_RATINGS);
     exif_set_long(entry->data, EXIF_BYTE_ORDER_INTEL, data.isospeed);
 
     // Flash
@@ -245,6 +237,8 @@ read_exif(char *filename)
     uint16_t subifd_count;
     uint32_t *subifd_offsets;
     uint32_t exif_offset;
+    uint32_t value_count;
+    uint16_t *short_array;
     char *temp;
 
     TIFF *im = TIFFOpen(filename, "r");
@@ -311,18 +305,15 @@ read_exif(char *filename)
         err("failed to read EXIFTAG_EXPOSURETIME");
     }
 
-    if (TIFFGetField(im, EXIFTAG_ISOSPEED, &imagedata.isospeed) != 1) {
-        err("failed to read EXIFTAG_ISOSPEED");
+    if (TIFFGetField(im, EXIFTAG_PHOTOGRAPHICSENSITIVITY, &value_count, &short_array) != 1) {
+        err("failed to read EXIFTAG_PHOTOGRAPHICSENSITIVITY");
     }
+    imagedata.isospeed = short_array[0];
 
     if (TIFFGetField(im, EXIFTAG_FNUMBER, &imagedata.fnumber) != 1) {
         err("failed to read EXIFTAG_FNUMBER");
     }
 
-    if (TIFFGetField(im, EXIFTAG_APERTUREVALUE, &imagedata.aperture) != 1) {
-        err("failed to read EXIFTAG_APERTUREVALUE");
-    }
-
     if (TIFFGetField(im, EXIFTAG_FOCALLENGTH, &imagedata.focal_length) != 1) {
         err("failed to read EXIFTAG_FOCALLENGTH");
     }

postprocess.h

@@ -19,12 +19,11 @@ struct Imagedata {
         char *datetime;
         uint16_t exposure_program;
         float exposure_time;
-        float aperture;
-        int isospeed;
+        uint16_t isospeed;
         int flash;
         float fnumber;
         float focal_length;
-        float focal_length_35mm;
+        uint16_t focal_length_35mm;
 };
 
 void