ExifTool Forum

ExifTool => The "exiftool" Application => Topic started by: herb on July 13, 2013, 02:28:28 PM

Title: 9.33 - question to support for EXIF UTF-16 Unicode text
Post by: herb on July 13, 2013, 02:28:28 PM
Hello Phil,

In your latest release notes you wrote: Added support for EXIF UTF-16 Unicode text (previously treated as UCS-2)
Please give some more details, what this really means.

Thanks in advance
Herb
Title: Re: 9.33 - question to support for EXIF UTF-16 Unicode text
Post by: Phil Harvey on July 13, 2013, 05:09:28 PM
Hi Herb,

In practice, there is no difference, because I have never seen anyone use a UTF-16 surrogate pair in EXIF Unicode text.  But in theory, if you did use the UTF-16 surrogate pair mechanism, then ExifTool now handles these extended characters in EXIF Unicode.  Other than the extended surrogate pairs possible with UTF-16, I think it is the same as UCS-2.  My guess is that just about every application out there treats EXIF text as UCS-2.  The EXIF specification is not specific about what flavour of Unicode, and I think it may even pre-date common usage of UTF-16, so it is likely that it meant UCS-2.  However, the (more recent) MWG recommendation states that UTF-16 should be used, so I have changed this.  As I said, I don't expect this to affect anyone.  Anything that worked before should continue to work because UTF-16 is a superset of UCS-2.

- Phil
Title: Re: 9.33 - question to support for EXIF UTF-16 Unicode text
Post by: herb on July 14, 2013, 11:26:57 AM
Hello Phil,

thank you for the detailed explanations.

Best regards
Herb