Re: 1280x720 opens as 960x720 in Quicktime Player?

If the exported file is a deliverable, then it should be using square pixels. The file you are looking at has a PAR (pixel aspect ratio). Often referred to as anamorphic. There are several PAR's and the 960x720 is (I believe) the DVCPROHD 720 1.33 PAR.

The reason that some players know and others don't is a simple process of recognizing the PAR in the metadata of a file and applying it appropriately.

If you look at movie inspector in Quicktime 7, you'll notice that the encoded dimensions are 960x720...but "current size" is 1280x720. This is because QT is recognizing the PAR, and multiplying 960x1.33

PAR's should only be used when working in editable formats...by content producers. Once this stuff gets out into non-industry type people...it should always be square pixels.

Hope that helps...

-Jason