iPhone GPSTimeStamp variations

[clyde]

I found a bug in the GPSTimeStamp setting for images from iPhone 3GS. The seconds column has a value up to four digits long, which was apparently supposed to be hundredth-seconds. ExifTool (v8.84) treats these as full seconds. In the printable output it carries the extra seconds over to the minutes column to get a valid timestamp. That is sensible, but in this case it can skew the timestamp up to a couple hours. In other words a raw timestamp like this:

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GPSTimeStamp = 19 35 4135 (19/1 35/1 4135/1)
should have been:

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GPSTimeStamp = 19 35 4135 (19/1 35/1 4135/100)

Images before about 2011/05/15 have timestamps with a decimal point in the right place. Apparently the bug was introduced to iPhone around that time. I put together a script to fix these images for anyone who is interested. It will update GPSTimeStamp, replacing the integer seconds with a real/floating-point value.

[Phil Harvey]

Nice script.  Thanks for sharing.  I wasn't aware of this bug in the iPhone GPS.

- Phil