Improved conversion accuracy of exif geotag data

Changed degrees and minutes of geotag data into double to avoid
data loss during cast.

Also improved error handling if geotag data can't be parsed.

bug:3381761
Change-Id: I864843c7fc699fe81e6acba801fe46d10a01925b

diff --git a/media/java/android/media/ExifInterface.java b/media/java/android/media/ExifInterface.java
index 11e27a9..925f965 100644 (file)
--- a/media/java/android/media/ExifInterface.java
+++ b/media/java/android/media/ExifInterface.java
@@ -299,12 +299,16 @@ public class ExifInterface {
         String lngRef = mAttributes.get(ExifInterface.TAG_GPS_LONGITUDE_REF);
 
         if (latValue != null && latRef != null && lngValue != null && lngRef != null) {
-            output[0] = convertRationalLatLonToFloat(latValue, latRef);
-            output[1] = convertRationalLatLonToFloat(lngValue, lngRef);
-            return true;
-        } else {
-            return false;
+            try {
+                output[0] = convertRationalLatLonToFloat(latValue, latRef);
+                output[1] = convertRationalLatLonToFloat(lngValue, lngRef);
+                return true;
+            } catch (IllegalArgumentException e) {
+                // if values are not parseable
+            }
         }
+
+        return false;
     }
 
     /**
@@ -373,12 +377,12 @@ public class ExifInterface {
 
             String [] pair;
             pair = parts[0].split("/");
-            int degrees = (int) (Float.parseFloat(pair[0].trim())
-                    / Float.parseFloat(pair[1].trim()));
+            double degrees = Double.parseDouble(pair[0].trim())
+                    / Double.parseDouble(pair[1].trim());
 
             pair = parts[1].split("/");
-            int minutes = (int) ((Float.parseFloat(pair[0].trim())
-                    / Float.parseFloat(pair[1].trim())));
+            double minutes = Double.parseDouble(pair[0].trim())
+                    / Double.parseDouble(pair[1].trim());
 
             pair = parts[2].split("/");
             double seconds = Double.parseDouble(pair[0].trim())
@@ -389,10 +393,12 @@ public class ExifInterface {
                 return (float) -result;
             }
             return (float) result;
-        } catch (RuntimeException ex) {
-            // if for whatever reason we can't parse the lat long then return
-            // null
-            return 0f;
+        } catch (NumberFormatException e) {
+            // Some of the nubmers are not valid
+            throw new IllegalArgumentException();
+        } catch (ArrayIndexOutOfBoundsException e) {
+            // Some of the rational does not follow the correct format
+            throw new IllegalArgumentException();
         }
     }