Re: [Openexr-devel] OpenEXR 2.0 backwards compatibility

[Piotr Stanczyk]

Hi Ben, 

I think that behaviour was present in the 1.7.x release. Which version were you 
building against previously?

Piotr

________________________________________
From: Ben Woodhall address@hidden
Sent: 15 May 2013 08:36
To: address@hidden
Subject: OpenEXR 2.0 backwards compatibility

Hello,

We found an issue when upgrading our EXR libraries to 2.0.  The new libraries 
automatically use "long names" for the channels if channels are added with 
names longer than 31 characters.  They set a bit of the version integer in the 
file header to switch to 255 character channel names.  In earlier EXR libraries 
these channel names were automatically truncated to 31 characters.  This is 
perfectly sensible but it means that saving single part images with channel 
names of more than 31 characters produces EXR 2.0 only images (as previous 
versions don't support "long names").

We can fix the compatibility by truncating channel names when writing single 
part files, however we're concerned that there may be other compatibility issue 
that we should be aware of.  Could you let me know if there are any other 
compatibility issues?  Is truncating names the right thing to do for backwards 
compatibility is there a better way to deal with this?

Any help appreciated.

Many thanks,  Ben