OpenImageIO/oiio — pull request #834 by mjmvisser (2014-03-31 21:06:45+00:00)
Title: force pixel aspect ratio to 1.0 if denominator <= 0 to avoid PAR of NaN

We received a bunch of dpx plates with pixel aspect ratio specified in the header as 0:0... which oiio dutifully turns into NaN. This patch checks for a non-zero denominator before dividing and defaults the PAR to 1.0 otherwise.