Re: DRAFT: eXIF 2017-03-05

On Mon, Mar 6, 2017 at 9:26 PM, Cosmin Truta <[email protected]> wrote:
> On 6 March 2017 at 20:48, Phil Harvey wrote:
>> 2. There is absolutely no need to say that any gap is filled.  It is only required that the IFD pointers point to the start of the IFD.  It doesn't matter what comes before it.  Some EXIF/TIFF writers will put the values first, and others will put the IFD first.   I have also see unreferenced data come first.  Any of these is fine.
>
> I don't see a disagreement between Glenn and Phil here. My
> interpretation of "padding bytes of unspecified content" is that Glenn
> is saying the same thing as Phil: that there may be unreferenced data
> of unspecified content before any IFD.
>
> Maybe if Glenn avoids using "filled" and "padding", would that make it
> less confusing? How about:
>
> "There may be unreferenced data segments of unspecified content,
> before or after any IFD."

Such unreferenced data segments must be of exactly the right
length to make the IFD pointer to the subsequent data valid.  That
is "filling" or  "padding" for eXIf chunk purposes, but not for Exif
spec purposes.

Glenn

------------------------------------------------------------------------------
Announcing the Oxford Dictionaries API! The API offers world-renowned
dictionary content that is easy and intuitive to access. Sign up for an
account today to start using our lexical data to power your apps and
projects. Get started today and enter our developer competition.
http://sdm.link/oxford